Disembodiment is a core feature of depersonalization disorder (DPD). Given the narratives of DPD patients about their disembodiment and emotional numbing and neurobiological findings of an inhibition of insular activity, DPD may be considered as a mental disorder with specific impairments of interoceptive awareness and body perception.We investigated cardioceptive accuracy (CA) of DPD patients (n = 24) as compared to healthy controls (n = 26) with two different heartbeat detection tasks (“Schandry heartbeat counting task” and “Whitehead heartbeat discrimination task”). Self-rated clearness of body perception was measured by questionnaire.Contrary to our hypothesis, DPD patients performed similarly to healthy controls on the two different heartbeat detection tasks, and they had equal scores regarding their self-rated clearness of body perception. There was no correlation of the severity of “anomalous body experiences” and depersonalization with measures of interoceptive accuracy. Only among healthy controls CA in the Schandry task was positively correlated with self-rated clearness of body perception. Depersonalization was unrelated to severity of depression or anxiety, while depression and anxiety were highly correlated. Anxiety and depression did not modify the associations of depersonalization with interoceptive accuracy.Our main findings highlight a striking discrepancy of normal interoception with overwhelming experiences of disembodiment in DPD. This may reflect difficulties of DPD patients to integrate their visceral and bodily perceptions into a sense of their selves. This problem may be considered an important target for psychotherapeutic treatment approaches. Depersonalization-derealization disorder  interoceptive accuracy in a sample of DPD patients using a healthy comparison group free from “anomalous body experiences”. We applied two different methods of heartbeat detection, the “Schandry heartbeat counting task” In this context, we hypothesized that patients with DPD differ from healthy volunteers in that they show poorer cardioceptive accuracy in heartbeat counting and discrimination, and impaired self-rated perception of the body. We further assumed that the severity of anxiety and depression modulates cardioceptive accuracy and subjective perception of the body.The study was approved by the Ethics Committee of the State Board of Physicians of Rhineland-Palatinate (Germany). All participants provided their written informed consent to participate in this study. The sample consisted of 24 DPD patients and 26 healthy volunteers  . The diaBody perception was assessed with a short German questionnaire, the “Kurzer Fragebogen zur Eigenwahrnehmung des Körpers (KEKS)” (English: short questionnaire for body perception) Severity of depersonalization was assessed with the Cambridge Depersonalization Scale CDS, . The CDSSeverity of depression was measured with the Beck Depression Inventory-II (BDI-II) Schandry heartbeat counting task SchandryCA = Modified heartbeat discrimination task based on Whitehead Whitehead = d′ = z hit rate - z false alarm rate.CAThe signal of the electrocardiogram (ECG) was monitored using three ECG Ag/AgCl electrodes (diameter: 45 mm), recorded with a Biopac MP150 amplifier system, high-pass filtered (0.5 Hz) and stored on a disk (sampling rate: 1 kHz) for offline analyses. R-waves were identified online by the software programs E-Prime 1.1 and AcqKnowledge 3.9.0 running on a DELL Latitude E 6500 computer.Before the experimental procedure, participants completed the trait questionnaires. Participants were seated in front of a LCD computer screen in a comfortable chair. Electrodes for ECG-measurement were placed according to a standard lead II configuration , approximated by placements on the torso Prior to the heartbeat detection tasks participants completed a training trial. They were instructed to relax, keep still and not to take their own pulse or try any other manipulations facilitating the detection of heartbeats. Thereafter, participants completed each of the two heartbeat detection paradigms  in permutated order across participants, interrupted by a break of 1 min. After the experiment the participants completed the state questionnaires.Data are presented as numbers (n) and percentages (%) or mean ± standard deviation. Normal distribution was tested with the Kolmogorov-Smirnov-Z Test . In the case of normal distribution t-Tests and Pearson's product-moment correlations were applied, and non-parametric methods if the variable was not normally distributed . Categorical data were compared by Chi-square test. Cohen's d was calculated to show the effect sizes of mean differences. The primary dependent variables were CA-Schandry and CA-Whitehead and self-rated precision of body perception (KEKS score). Differences in these scores between DPD patients and healthy controls (HC) were compared by t-test or Mann-Whitney U test. Further, we calculated correlation coefficients to determine associations between depersonalization and CA-Schandry, CA-Whitehead and self-rated body perception (KEKS) as well as depression, anxiety and possible moderating variables . Correlation analyses were calculated for the two groups separately, or for the whole sample if appropriate. For explorative analysis we compared DPD patients stratified by use of antidepressants, and by high versus low anxiety and depression respectively. The high and low anxiety and depression groups were determined by median split. Based on previous studies and our considerations, we tested for an interaction of depersonalization × anxiety in the DPD group. For this purpose we calculated an analysis of variance in the DPD group. A 2×2 ANOVA was calculated to test for changes of the performance in the Whitehead task between the training and experimental trial. For all tests a two-sided significance threshold of α = .05 was defined a priori.DPD patients did not differ from healthy controls (HC) with regards to age and sex. DPD patients had significantly fewer years of schooling than HC, and their BMI was significantly higher. DPD patients differed strongly regarding severity of depersonalization , anomalous body experiences , depression  and anxiety  . There w2 = 0.60, df = 1, p = 0.70). DPD patients reported significantly more illusory body perception, i.e. perception of “cerebellum” and “left heart valve”  provided incomplete data in the Whitehead paradigm and were thus excluded from further analyses regarding this variable. Neither were there any group differences in cardioceptive accuracy or heart beat discrimination nor in the perception of body parts as self-rated in the KEKS . In the Based on the prima facie impression of a diverging development of the scores in the Whitehead task from the training trial to the experimental trial see , we compAs shown in We explored potential effects of antidepressant medication in the DPD group by comparing DPD patients taking antidepressants with those free from antidepressants. Patients with antidepressants did not differ significantly with respect to the heart perception tasks , heart rate, subjective body perception (KEKS), BMI or any of the psychometric scores CDS, CDS-ABE, BDI-II and STAI see .In order to explore possible modifying effects of depression and anxiety, we divided the DPD group by the median in STAI (<63 versus ≥63) and BDI (<26 versus ≥26) and compared CA Schandry, CA Whitehead, heart rate and KEKS and depersonalization between these two respective subgroups. There were no significant differences between DPD patients with high anxiety see  or high Contrary to our hypothesis, DPD patients performed similarly well compared to healthy controls on two different heart beat detection tasks. In addition, they had equal scores regarding their self-rated clearness of body perception. There was no correlation of the severity of depersonalization and “anomalous body experiences” with measures of cardioceptive accuracy. Severity of anxiety or depression did not modify this relationship. Interestingly, performance in the Whitehead paradigm changed differentially between the two groups from the training to the experimental trial. Only among healthy controls cardioceptive accuracy in the Schandry task was positively correlated with self-rated precision of body perception. In line with previous studies, mean heart rate correlated negatively with cardioceptive accuracy in the Schandry task In summary, results from the present study suggest that DPD may be characterized by a remarkable discrepancy between pervasive narratives of disembodiment and normal interoceptive accuracy at both behavioral (heart beat perception tasks) and questionnaire-based levels (self-rated clearness of body perception). This finding may reflect a conflict between DPD patients' conceptual thinking or beliefs about themselves (i.e. meta-cognitions) and what they actually perceive. While they feel detached from their body and report emotional or physical numbing, actual subjective body perception is unimpaired, and heartbeat detection similar to normal, healthy volunteers. As recently proposed by Garfinkel and Critchley From a neurobiological perspective, it has been suggested that interoceptive awareness results from the interplay of both bottom-up  and top-down processes  Concerning the high comorbidity of the DPD patients, our sample was comparable with samples from other experimental or clinical studies The following limitations have to be kept in mind concerning our considerations: First, the sample size may have limited the power of the current study to detect small differences of interoceptive accuracy between DPD patients and healthy controls. Nevertheless, even if there might be small differences between DPD patients and health persons, this would still contrast strongly with the overwhelming experiences of disembodiment of DPD sufferers. It is unlikely that small differences in heart beat detection performance should result in such large differences in subjective experiences of disembodiment. Second, despite substantial correlations between accuracy in heartbeat perception and the detection of sensations originating from other organ systems In conclusion, our main findings highlight the discrepancy of normal interoceptive accuracy with overwhelming experiences of disembodiment in DPD. This striking discrepancy may reflect difficulties of DPD patients to integrate their actual visceral and bodily perceptions into a sense of their selves. This problem may be considered as an important target for DPD specific psychological treatment approaches. Further studies on the mechanisms of disembodiment and the measures to overcome this disembodiment are needed.Table S1Comparison of DPD patients taking antidepressants with those DPD patients free form antidepressants.(DOC)Click here for additional data file.Table S2Comparison of DPD patients with high versus low anxiety.(DOC)Click here for additional data file.Table S3Comparison of DPD patients with high versus low depression.(DOC)Click here for additional data file.


The purpose of this study was to explore a data set of patients with fibromyalgia (FM), rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) who completed the Revised Fibromyalgia Impact Questionnaire (FIQR) and its variant, the Symptom Impact Questionnaire (SIQR), for discriminating features that could be used to differentiate FM from RA and SLE in clinical surveys.The frequency and means of comparing FM, RA and SLE patients on all pain sites and SIQR variables were calculated. Multiple regression analysis was then conducted to identify the significant pain sites and SIQR predictors of group membership. Thereafter stepwise multiple regression analysis was performed to identify the order of variables in predicting their maximal statistical contribution to group membership. Partial correlations assessed their unique contribution, and, last, two-group discriminant analysis provided a classification table.The data set contained information on the SIQR and also pain locations in 202 FM, 31 RA and 20 SLE patients. As the SIQR and pain locations did not differ much between the RA and SLE patients, they were grouped together (RA/SLE) to provide a more robust analysis. The combination of eight SIQR items and seven pain sites correctly classified 99% of FM and 90% of RA/SLE patients in a two-group discriminant analysis. The largest reported SIQR differences (FM minus RA/SLE) were seen for the parameters "tenderness to touch," "difficulty cleaning floors" and "discomfort on sitting for 45 minutes." Combining the SIQR and pain locations in a stepwise multiple regression analysis revealed that the seven most important predictors of group membership were mid-lower back pain , tenderness to touch , neck pain , hand pain , arm pain , outer lower back pain  and sitting for 45 minutes .A combination of two SIQR questions ("tenderness to touch" and "difficulty sitting for 45 minutes") plus pain in the lower back, neck, hands and arms may be useful in the construction of clinical questionnaires designed for patients with musculoskeletal pain. This combination provided the correct diagnosis in 97% of patients, with only 7 of 253 patients misclassified. Rheumatoid arthritis (RA), systemic lupus erythematosus (SLE) and fibromyalgia (FM) are usually easily discriminated on clinical examination, but have several overlapping features that make their differentiation more problematic in epidemiological surveys. For instance, pain, fatigue and morning stiffness are commonly reported in all three disorders. The current study was stimulated by the increasing interest in developing questionnaires that can accurately predict the occurrence of FM in both epidemiological and clinical settings -5. Durinet al.  showed that FM patients, compared with RA/SLE patients, reported significantly more tenderness  and pain . An interaction  comparing the two patient groups shows that this approximates a four-point difference for tenderness relative to a two-point difference for pain. These differences may in part account for why tenderness but not pain was a stronger predictor in classifying patients in the discriminant analysis. Additionally, the FM group reported more tenderness than pain , while RA/SLE patients reported slightly more pain than tenderness . Thus "tenderness" was rated higher by FM patients, while pain was rated higher by RA/SLE patients .A repeated measures 2 × 2 analysis of variance  was performed on the means for FM and RA/SLE. A main effect [F1, 251) = 84.87; , 251 = 8P = 0.0002) and tenderness  were both independent predictors of total pain site scores . In the RA/SLE group, only pain  but not tenderness  predicted total pain sites . This demonstrates that while SIQR pain predicts pain sites in both groups, tenderness to touch predicts pain sites only in the FM group.A second analysis using standard multiple regression was conducted to determine how tenderness and pain, uniquely and together, predicted total pain site scores in the FM and RA/SLE groups separately. In FM patients, pain  among FM patients.This analysis of FIQR/SIQR items and 24 pain locations provides some potentially useful pointers to questions that could be used in the construction of epidemiological questionnaires in surveys of musculoskeletal pain. The questions in the SIQR reflect the domains  that the Outcome Measures in Rheumatology Clinical Trials (OMERACT)  has recoper se is not part of these criteria. Thus it was of interest to note that in this analysis, tenderness to touch in SLE patients was similarly rated in RA and SLE patients (2.9 vs. 3.4).While the classification criteria for RA, SLE and FM all require a physical examination, epidemiological surveys seldom provide for patient examination, thus the development of discriminatory questionnaires is problematical. The one physical examination criterion for FM, as per the 1990 American College of Rheumatology (ACR) classification criteria, is the finding of ≥11 of 18 designated tender points ,13. One Overall the combination of seven pain sites and eight SIQR items together produced a multiple R of 0.81 (65% variance), accounting for substantial variance in group membership, with a correct classification rate of 97%. From a conceptual perspective, it is interesting to note that the largest component of this variance (30%) was shared by pain sites and SIQR items, indicating that pain locations and SIQR dimensions are intimately connected in differentiating FM from RA/SLE. The additional unique contribution of pain sites (24%) and SIQR items (11%), particularly tenderness to touch, suggest that epidemiological surveys should consider both of these items to maximize their effectiveness. But neither pain sites nor SIQR variables alone seem sufficient to differentiate patient groups. The role of SIQR pain was different and also significant when examining within-group correlations rather than correlations across groups (pooled across groups) as described above. Both SIQR pain and SIQR tenderness to touch significantly predicted pain site scores in the FM group, while only SIQR pain predicted total pain site scores in the RA/SLE group. Furthermore, the means for SIQR tenderness to touch and SIQR pain were different, thus showing discriminant validity between FM and RA/SLE.A notable finding in this study was that the SIQR question on tenderness to touch, along with neck pain, arm pain and hand pain, were important symptoms to consider when developing questionnaires to distinguish FM from RA or SLE. In all analyses, tenderness contributed equally with other specific pain sites to the classification of FM and RA/SLE patients. The SIQR pain variable did not help to distinguish FM from RA or SLE patients, possibly because the pain site captures pain ratings, thus making the SIQR "pain" variable redundant. This notion is supported by the observation that tenderness was correlated with pain (0.55), but was more strongly associated with group diagnosis than pain (0.52 vs. 0.35).Nevertheless, while pain and tenderness uniquely predicted pain sites, they did not account for much variance in pain site. A more refined measure of pain locations, such as a pain VAS, one that specified the nature or quality of the pain in greater detail or one which included axial, distal and proximal subscale scores, might provide more useful information than a simple count of presence or absence of pain.We are not aware of other survey questionnaires that ask about "tenderness to touch." However, the recent preliminary diagnostic FM criteria paper did find that a widespread pain index and muscle tenderness were the most important variables in the classification of cases and noncases of FM, although tenderness was not used in the final formulation of the criteria . It seemet al. [Although FM patients had higher pain scores than RA/SLE patients 6.0 vs. 3.9), pain was not a useful between-group discriminator. We surmised that this was due to pain locations being a better discriminator. The SIQR only asks about pain in the general sense, and maybe more specific questions would be useful in epidemiological surveys. For instance, Perrot .9, pain There are several limitations of the present study. The number of RA/SLE patients was small compared to the FM population (51 vs. 202). The pain locations were designed to reflect a composite of widespread pain and peripheral pain. In this respect, it may have been useful to include the wrists and ankles, joints that are commonly involved in RA. The RA and SLE patients were specifically screened for not having concomitant FM, and thus this study does not provide any useful information on that common combination, which is now known to skew the results of questionnaires such as the DAS . The patWhile researching background information for this paper, it became apparent that very little information has been published regarding musculoskeletal pain in SLE patients. A typical description is, "Joint involvement in SLE is similar to that of rheumatoid arthritis, primarily affecting the small joint of the hands, wrists and knees ... patients' symptoms (pain and stiffness) are usually out of proportion to the degree of synovitis present on physical examination" . An incoThis study analyzed data derived from patients with FM, SLE or RA who had completed the FIQR and/or SIQR and identified sites of pain in 24 locations. A combination of two SIQR questions ("tenderness to touch" and "difficulty sitting for 45 minutes") plus pain in four locations  identified the correct diagnosis in 97% of patients. Overall, this report provides some pointers for distinguishing FM patients from patients with RA or SLE in clinical questionnaires and raises some potentially novel issues regarding musculoskeletal symptoms in SLE patients.ACR: American College of Rheumatology; ANOVA: analysis of variance; DAS: Disease Activity Score; FIQ: Fibromyalgia Impact Questionnaire; FIQR: Revised Fibromyalgia Impact Questionnaire; FM: fibromyalgia; MDD: major depressive disorder; RA: rheumatoid arthritis; SIQR: Symptom Impact Questionnaire; SLE: systemic lupus erythematosus.The authors declare that they have no competing interests.RF and RB contributed equally to the design of the study, the analysis of the data and the writing of the manuscript.


Chronic musculoskeletal pain is a common cause of chronic pain, which is associated with a total cost of $635 billion per year in the U.S. Emerging evidence suggests an anti-nociceptive action of botulinum toxin, independent of its muscle paralyzing action. This review provides a summary of data from both non-randomized and randomized clinical studies of botulinum toxin in back pain and various osteoarticular conditions, including osteoarthritis, tennis elbow, low back pain and hand pain. Three randomized controlled trials (RCTs) of small sizes provide evidence of short-term efficacy of a single intra-articular injection of 100 units of botulinum toxin A (BoNT/A) for the relief of pain and the improvement of both function and quality of life in patients with chronic joint pain due to arthritis. Three RCTs studied intramuscular BoNT/A for tennis elbow with one showing a significant improvement in pain relief compared with placebo, another one showing no difference from placebo, and the third finding that pain and function improvement with BoNT/A injection were similar to those obtained with surgical release. One RCT of intramuscular BoNT/A for low back pain found improvement in pain and function compared to placebo. Single RCTs using local injections of BoNT in patients with either temporomandibular joint (TMJ) pain or plantar fasciitis found superior efficacy compared to placebo. One RCT of intramuscular BoNT/B in patients with hand pain and carpal tunnel syndrome found improvement in pain in both BoNT/B and placebo groups, but no significant difference between groups. Most evidence is based on small studies, but the use of BoNT is supported by a single, and sometimes up to three, RCTs for several chronic musculoskeletal pain conditions. This indicates that botulinum toxin may be a promising potential new treatment for chronic refractory musculoskeletal pain. Well-designed large clinical trials are needed. This report highlighted that persistent pain affects 100 million Americans with a cost of $635 billion in direct costs and lost wages. Musculoskeletal pain is the most common cause of persistent pain and is most often due to arthritis, back pain and/or local musculoskeletal conditions , and (less commonly) injuries. In a European survey of pain prevalence in the general population, moderate to severe pain lasting 6-months or longer was reported by 19% respondents, of whom 40%  had joint pain2. Arthritis affects nearly 50 million adults in the U.S., and is projected to increase in prevalence to 67 million adults, or 25% of those aged 18 years and older, by the year 20303. Arthritis is the leading cause of disability in adults ≥18 years in the U.S.4, the third leading cause of work limitation in the U.S.5, is associated with 992,100 annual hospitalizations6 and 44 million annual outpatient visits7. In 2003, the total cost of arthritis was $128 billion in the U.S., including $81 billion in direct medical costs and $47 billion in indirect costs (lost earnings)8. Back pain is a leading cause of persistent pain and is the fifth-most-common reason for physician visits10. Back pain was responsible for 50% of all chronic pain problems in a European survey2. In a U.S. survey, each year 15% of American adults report frequent back pain or pain lasting more than two weeks11. The annual costs of lower back pain in the U.S. exceed $100 billion13. Treatment of chronic musculoskeletal pain secondary to joint pain and/or back pain constitutes a major challenge.Pain is a major public health problem. Pain was recognized as a major challenge by the Institute of Medicine (IOM) in their recent report17. In normal healthy individuals, these nociceptors have a high threshold for excitation in response to mechanical and thermal stimuli. Normal activities such as walking, stair climbing and sports  do not cross this threshold for nociceptor activation and therefore these activities are not associated with pain or unpleasant sensations. However, joint injury or inflammation is associated with decrease in the excitation threshold of these nociceptors. This leads to enhanced responses to both innocuous and noxious mechanical, chemical and thermal stimuli. This phenomenon is called peripheral sensitization18. Chronic joint inflammation is also associated with hyperexcitability of spinal nociceptive neurons i.e., central sensitization20. A variety of mediators can sensitize joint nerves and nociceptors to mechanical stimuli including bradykinin, serotonin, substance P, prostaglandin E2, prostaglandin I2 and neuropeptide Y17. Another contributor to joint pain and inflammation is neurogenic inflammation, which involves the release of neuropeptides from nerve terminals in response to inflammation, the release of neuropeptides from postganglionic sympathetic nerves due to sympathetic reflexes and the release of neuropeptides due to cytokine or neuropeptide-stimulation of local inflammatory cells21. It is likely that these processes underlie the clinical observed signs and symptoms of pain and mechanical hyperalgesia in inflamed joints. Recent reviews describe the processes of sensitization and neurogenic inflammation and summarize our current understating of joint pain and the various mechanisms contributing to it18. Activation of glial cells, other immune cells and cytokines also contribute to the generation of pain27. The role of pain pathways, pain receptors and various contributors to both inflammatory and neuropathic pain has been summarized in recent studies and reviews33.All joint structures except articular cartilage are innervated with articular nerves that contain A-delta, A-beta and C-fibers36. Common side effects include: peptic ulcer disease with its complications (bleeding and perforation), renal failure and liver toxicity in patients using NSAIDs; sedation, confusion, constipation and falls in those taking narcotics; and liver toxicity in patients taking acetaminophen. Both intra-articular therapies  as well as topical preparations such as capsaicin and lidocaine have limited efficacy in patients with osteoarthritis (OA) and/or joint pain41. Physical therapy is effective42, but feasibility remains an issue as some patients are unable to adhere to physical therapy regimens due to personal preference and/or comorbidities, the need for transportation for frequent visits and the inconvenience of frequent travel and the time commitment involved. Thus, at present, limited effective and safe therapeutic options are available for refractory musculoskeletal pain. Therefore, new therapeutic options for treatment of musculoskeletal pain are needed.Commonly used approaches to treat musculoskeletal pain include oral therapies, intra-articular therapies, topical treatments and physical therapy. The main challenges to the use of therapies for refractory musculoskeletal pain include their limited efficacy and the risk of toxicity. Use of common oral therapies such as non-steroidal anti-inflammatory drugs (NSAIDs), opioid medications (narcotics) and analgesics (acetaminophen etc.), which are effective for some patients with chronic musculoskeletal pain, is associated with a significant risk of side effects, especially in the elderly43. In an animal model, botulinum toxin A  injections into the rat paw reduced formalin-induced paw edema, tissue glutamate release and spinal cord electrical excitations44. BoNT/A inhibited stimulated substance P-release46 and CGRP-release48 in models of acute and chronic inflammation.In vitro studies showed that BoNT/A inhibited stimulated CGRP release from rat trigeminal ganglia49 and capsaicin-stimulated substance P-release from embryonic rat dorsal root ganglia neurons50. In particular, BoNTs have been shown to inhibit cytokines, neuropeptides and other inflammatory mediators that play an important role in the pathophysiology of both rheumatoid arthritis and rat adjuvant arthritis 54. Thus, there is pre-clinical evidence suggesting an anti-nociceptive mechanism of action of botulinum toxin. Various clinical studies support the anti-nociceptive action of botulinum toxin57, while some studies have found no such evidence60.Botulinum toxin (BoNT) is one of the most potent neurotoxins and consists of a 50 kDa light chain and a 100 kDa heavy chain linked with a disulfide bond. It exists in seven serotypes, A through G. Botulinum toxin has been shown to interfere with the expression of various neuropeptides such as substance P and calcitonin gene-related protein (CGRP), which are key mediators of neurogenic inflammationThe objective of this systematic review was to synthesize data from both randomized and non-randomized trials to assess the safety and efficacy of botulinum toxin in osteoarticular pain.61. Inclusion criteria included the use of botulinum toxin, randomized or non-randomized study that included adults with musculoskeletal pain and reported clinical outcomes. Studies of myofascial pain syndromes were not included in this review, since they have been the focus of previous reviews63. I summarized case reports only when they provided new evidence for a particular use of botulinum toxin. In the sections below, I summarize data that provides initial evidence for the anti-nociceptive action of botulinum toxin, followed by existing evidence related to the use of botulinum toxin in various musculoskeletal pain conditions including refractory arthritis.In this evidence-based literature review, I performed a focused systematic review of published non-randomized (prospective and retrospective cohort studies and case series) and randomized studies of botulinum toxin for arthritis and musculoskeletal pain by performing two PubMed searches: one using the terms "botulinum toxin" and "musculoskeletal pain" and another using the terms "botulinum toxin" and "arthritis". In addition to summarizing the key studies identified from this search, I also reviewed the bibliography of key reviews to identify any studies that may have been missed using the search strategy, including our recent review of the use of botulinum toxin in osteoarticular pain64, injectable treatments for knee osteoarthritis65 or use of neurotoxin for the treatment of painful disorders66, In this review, I provide a review of evidence regarding botulinum toxin for the treatment of musculoskeletal pain conditions.Recent reviews have summarized the injectable treatments for osteoarthritisIn this section, I summarize the data from non-randomized studies followed by data from randomized controlled trials (RCTs) for the efficacy of botulinum toxin’s efficacy in refractory shoulder joint pain (1 randomized study) and refractory knee joint pain (2 randomized studies) .69. In a retrospective study, Mahowaldet al. reported the results of intra-articular injections of botulinum toxin type A (IA-BoNT/A) in 15 shoulder and lower extremity joints in 11 patients experiencing refractory pain67. All patients were receiving analgesics/NSAIDs and none had experienced relief with intra-articular corticosteroids. Patients received 25–100 units of IA-BoNT/A. There were 9 men and 2 women with an age range of 42–82 years. Joint pain was measured on a 0–10 numeric rating scale (NRS). Pain relief began within 2 weeks in most patients. A single intra-articular injection of botulinum toxin was associated with a clinically and statistically significant decrease in pain severity and improvement in function compared to baseline: lower extremity and shoulder pain decreased from 7 to 2.7 and 8.2 to 2.4, respectively; shoulder flexion improved from 68 to 113 degrees and shoulder abduction improved from 50 to 74 degrees, respectively. Timed stand tests (the time taken to stand up ten times from a sitting position) improved from 36 to 23 seconds. The duration of relief/improvement lasted 3–10 months. None of the patients reported any adverse events and no motor-sensory deficits were found on lower extremity examination after the IA-BoNT/A injection.There are three non-randomized that provide evidence for the efficacy of BoNT in cases of refractory joint pain68. Nine of the ten re-injections were associated with pain reduction, as seen with the first injection. Pain severity decreased from 6.6  to 3.3  on a 0–10 NRS, which was statistically significant (p = 0.003). Pain relief lasted 3–17 months. None of the patients reported any local or systemic adverse events related to BoNT/A. One patient experienced increased joint swelling with no increase in joint pain 3 weeks after BoNT/A injection. Another patient experienced a continued increase in joint pain after BoNT/A injection, which was relieved with a subsequent BoNT/A injection.Another report described the long-term follow-up of these 11 patients with 15 treated joints, of which ten joints were re-injected with 30–150 units of BoNT/A intra-articularly  at the patient’s request, when pain returned69. This case series comprised 9 women and 2 men with a mean age of 48 years . Median pain scores decreased significantly after BoNT injections, with a median decrease of 3 on a 0–10 NRS pain scale . Three patients experienced no change in pain severity after botulinum toxin injections, while eight experienced a decrease. No patients reported any increase in pain severity after BoNT injection. Pain reduction began within 3–5 days. Five patients received repeat injections. There was no evidence of decreasing efficacy of pain relief with repeated BoNT injections; in fact, the duration of pain relief increased with each successive treatment for 4 of the 5 patients with multiple treatments. All patients that experienced pain reduction with BoNT injections also noted improved function in activities of daily life and the range of motion in their joints. The median duration of pain relief with BoNT injections was 1.6 months longer than that seen with previous corticosteroid injections. There were no adverse events reported by the patients.In another case series, 11 adults with refractory pain underwent injection of botulinum toxin type A  or type B  into the sacroiliac, cervical/lumbar facet or sternoclavicular joints, C-2 roots and lumbar discet al. performed a double-blind RCT of BoNT/A  into glenohumeral (shoulder) joints of patients with refractory, chronic shoulder joint pain due to osteoarthritis or rheumatoid arthritis of the shoulder joint, who had all failed conservative management70 , they were given the option to drop out of the randomized phase of the study, and request the second unblinded injection with 100 units of IA-BoNT/A, which led to the beginning of an open-label phase. The published paper reported the results from the 1-month double-blind portion of the study36 patients with 43 painful shoulder joints were randomized. Mean age was >70 years, 95% were men, >85% had OA as the underlying diagnosis, mean shoulder pain duration was 8–11 years, comorbidity index was high, at least 50% had been treated each with narcotics or non-steroidal anti-inflammatory drugs (NSAIDs), and all had failed previous IA-corticosteroid injections.72) at 1 month compared with 36% in the placebo group (p = 0.22).Reductions in shoulder pain severity were significantly greater in the IA BoNT/A group compared to the IA placebo group at 1 month . 61% of patients in the IA BoNT/A group experienced clinically meaningful pain relief  subscales at 1-month, namely bodily pain, role physical, energy/vitality, role emotional and mental health . Improvements in quality of life exceeded the clinically meaningful threshold of 10-points for all 5 SF-36 subscales in IA-BoNT/A group versus as opposed to only 1 subscale in the IA-placebo group. McGill affective pain dimension improved significantly more in BoNT/A compared to placebo at 1-month (p = 0.047). Other secondary measures showed a trend in improvements, but were not statistically significantly different between treatment groups. The Shoulder Pain and Disability Index (SPADI) showed a trend towards greater improvement in BoNT/A versus placebo group (p = 0.0826). Treatment-failure after 1 month, defined as a drop-out from the blinded phase due to inefficacy and request for an active treatment injection, was 2.5-times higher in the placebo vs. the BoNT/A group; 45% (10/22) vs. 19%  respectively. 61% in BoNT/A group experienced clinically meaningful pain relief at 1 month ) compared to 36% in the placebo group (p = 0.22).The change in pain severity was influenced by baseline SPADI disability. In those patients with a higher SPADI disability score (>61.3), the decrease in VAS pain ratings at 1 month was significantly greater in the BoNT/A group (a 3.6 reduction) compared with the placebo . On the other hand, in patients with lower SPADI disability score (≤61.3), no significant difference was observed in VAS pain severity reduction between BoNT/A (a 1.9 reduction) and placebo groups .Overall adverse events were similar in IA-BoNT/A and IA-placebo groups. No significant difference in serious adverse events was noted. Common adverse events such as dry mouth, flu-like symptoms, dizziness etc. were not statistically significantly different between treatment groups in this small study, powered for efficacy, but not safety outcomes.Comparison of IA-BoNT/A to IA-corticosteroid. Boonet al. compared IA-BoNT/A to IA-corticosteroids in patients with radiographic and clinical knee OA in an RCT73 , a clinically unstable medical or psychiatric condition or history of neuromuscular disease, aminoglycoside or curare-like agents use or severe peripheral neuropathy. RCT73 . In a siThe primary outcome was VAS (0–10) pain scores at 8-weeks post-injection (rated using a 10cm line). Secondary outcomes included lower extremity pain and function assessment using the Western Ontario McMaster Universities Arthritis Index (WOMAC), quality of life assessment using the SF-36, patient global assessment and time taken for a 40-meter self-paced walk (in seconds). The study was powered to detect a 2cm reduction in a VAS pain rating within each group compared to baseline scores. Non-responders were allowed to request a second injection at 8-weeks during face-to-face clinic visit after the blinded injection. Additional follow-up assessments were done at 12 and 26 weeks using mailed questionnaires.2, symptom duration ranging from 6–10 years and 50–65% were women. Patients had tried multiple modalities for knee pain relief in the past, including: 70–80% had tried IA-corticosteroid injections, 35–50% had tried IA-hyaluronic acid injections, 55–65% had tried acetaminophen, 75–90% had tried corticosteroids and 45–80% had tried physical therapy. All 60 patients (35 women and 25 men) completed the 8-week follow-up.Baseline characteristics were similar in the three groups. Patients had a mean age of 61–64 years, body mass index 28–31 kg/m72, was reported by 42% in the IA-corticosteroid group, 60% in 100-unit IA-BoNT/A group and 26% in the 200-unit IA-BoNT/A group . Secondary outcomes including WOMAC pain scores, function and stiffness and self-paced 40 meter walk time improved significantly within each of the three groups at 8-weeks, compared to baseline  in the IA-corticosteroid group. In the 100-unit IA-BoNT/A (low dose) group, pain severity decreased significantly from 6.6±1.9cm to 4.5±2.2cm ; and in the 200 units (high-dose) IA-BoNT/A group decreased from 6.6±1.4cm to 5.9±2.4cm . A 2cm reduction in VAS pain scores, which is considered a clinically meaningful reduction in painComparison of IA-BoNT/A to IA-placebo. In a recent review article, Mahowaldet al. summarized the results of an RCT comparing a single injection of 100 units of BoNT/A reconstituted in 1 ml of saline plus 1 ml of 2% lidocaine (treatment group) to a single injection of IA-saline plus 1 ml of 2% lidocaine (placebo group) in patients with refractory knee pain due to knee OA74  and IA-placebo groups . However, at 3 months the decrease in pain was significant only in the IA-BoNT/A , but not in the placebo group .Due to a differential treatment effect evident on scatter plots, patients were stratified by baseline NRS pain scale scores into moderate (4.5–6.9) or severe (7 or higher) pain for exploratory analyses. In the severe knee pain group, significant changes in McGill sensory, affective and total pain scores were noted in the IA-BoNT/A, but not in the placebo group .In summary, three RCTs and three non-randomized studies indicate that a single intra-articular injection of botulinum toxin is associated with a clinically meaningful reduction of pain and an improvement of function in patients with refractory joint pain due to osteoarthritis or other underlying arthritic-conditions. The non-randomized studies have the limitations of bias, lack of a placebo arm and over-amplification of the treatment effect. All three randomized studies had small samples, short follow-up, and tested a single dose of botulinum toxin. Hence, it is not known if the toxin is effective for long-term pain relief and what the most optimal dose is. Also, due to small sample size, these studies could not provide data with regards to who are the best candidates for this injection. Therefore, larger studies are needed to assess the most effective dose, the long-term safety of intra-articular injections and to define as to which patients might be the best candidates for this treatment option.76. Pain relief began by 2 weeks in 10 patients, 3 weeks in one and after 1 month in two patients.In an open-label case series of 14 patients with "treatment-resistant" tennis elbow, Moore and colleagues injected 20–40 units of BoNT/A into the extensor digitorum communis and found >50% pain relief in 9/14 and complete pain relief in 4/14 patients during the 6–8 month follow-upet al. studied 40 patients with refractory tennis elbow pain with a duration of over 6 months, who had experienced no pain relief from ≥1 corticosteroid injections and a full course of physiotherapy77  or saline placebo injections into soft tissue and muscle 1cm from the lateral epicondyle79 (In another study by Wongdyle79 . Patient80 (a priori designation of outcomes as primary versus secondary.Another randomized study compared 1 to 2 injections of 30–40 units of Botulinum toxin type A (Allergan Inc.) into the wrist extensor with the surgical release of the extensor origin of the extensor carpi radialis brevis tendon80 . Forty pet al. compared botulinum type A to corticosteroid injection for the treatment of acute and subacute tennis elbow of 16 patients with 19 affected elbows81. Compared to corticosteroid, botulinum type A injection was associated with less pain reduction (p = 0.02) but a greater decrease in grip strength (p = 0.01) at 4-weeks post-injection. With the progression of time since injection, the amount of pain reduction increased in the botulinum toxin group, but decreased in corticosteroid group, though this difference was not statistically significant. No significant differences between groups were noted in quality of life. Thus, corticosteroid was superior to botulinum toxin type A in relieving pain in tennis elbow at 4-weeks after injection.In a double-blinded RCT, Lin82. The site of injection was the painful origin of the forearm extensor muscles and patients were followed up to 18 weeks. Compared to placebo, patients in the botulinum toxin A group had a significant improvement in pain as early as the second week after injection (p = 0.003). Both subjective general assessment of response to injection as well as blinded physician assessments also showed improvement in botulinum toxin A group, compared with the placebo group, both at six weeks (p = 0.001) and at 18 weeks (p = 0.001). Both groups experienced a consistent increase in fist closure strength, but there was no significant difference between groups. The extension of the third finger was observed to be significantly weakened at two weeks in the botulinum toxin A group and not saline control group, but this complication had completely resolved at 18 weeks.A double-blinded RCT comparing a single injection of 60 units of botulinum toxin A (Dysport) compared to saline was performed in 132 patients with chronic tennis elbow in a multicenter studyIn summary, results from five RCTs of patients with tennis elbow indicate that botulinum toxin may be effective , in at least some patients with tennis elbow; however, given that 3 of the 5 trials had negative results, this needs further study. An important observation was that the studies with the largest sample sizes of 60 and 132 was positive, compared to the three negative studies that had smaller sample sizes . A smaller sample size may have made the study underpowered and led to negative results. A short follow up period is another limitation of these RCTs. The studies differed in patient population (patients with non-refractory vs. refractory disease), duration of disease (>3 months vs. >6 months vs. 10 months), site of injection  and the dosage of preparation used (60 units of Dysport vs. 50 units of Botox vs. 30–40 unit injections of Botox) in the three RCTs respectively.83. The patients in this study had not gained pain relief from conservative treatment after 3 to 12 months of symptom duration. In 29 cases, only one treatment was administered. The majority of the injections were administered intraorally. Patients were observed for up to 12 months. 80% of patients reported an improvement in pain. The mean pain severity decreased from 6.4 to 3.5 on the 0–10cm VAS scale. Thirteen patients experienced a "major improvement" as evident by the disappearance of pain. Relief lasted 3–12 months during the observation period for most individuals; only 7 patients requested re-injection. One patient experienced temporary speech impairment and swallowing difficulty post-injection, which had completely reversed after 2–5 weeks.In an open-label study of 41 patients with painful hyperactivity of the masticatory muscles, 200 units of BoNT/A (Dysport) was injected intramuscularly, with 8 conducted under electromyographic guidance)84. Patients were followed up to 8 weeks. The mean age was 41 years and 39 were women. Comparing pre-injection to 8-week post-injection assessments, a significant improvement was noted in the pain VAS from a median of 8 to 5, functional disability index scores dropped from 5.3 to 3.9mm, tenderness to palpation reduced from 15.5 to 6mm and jaw opening extent improved from 29.5 to 34.5 mm (p<0.05 for assessments). No subjects reported worsening of their condition or any side effects after the injection.In an open-label study, 46 patients who had experienced TMJ pain for a median duration of 96 months were injected with 50 units of botulinum toxin A in each masseter muscle and 25 units in each temporalis muscles under electromyographic guidance85. The mean age was 39 years and 13 were women with a mean symptom duration of 10 years. Compared to pre-injection, at 8 weeks post-injection, a significant improvement was noted in patients; mean pain VAS scores dropped from 7.3 to 4, functional disability index scores reduced from 5.5 to 3.1, tenderness to palpation scores improved from 17 to 7.6 and jaw opening extent increase from 27 to 34 mm (p<0.05 for assessments).In another study, 15 patients with temporomandibular disorder received 150 units of BoNT/A with 50 units in each masseter and 25 units in each temporalis muscle bilaterally86  of botulinum toxin A  or placebo (n=30) in both masticatory muscle86 . The patIn summary, the evidence for efficacy of intramuscular injections of botulinum toxin for TMJ pain are based on non-randomized studies and one single blind study where the nature of the blinding (patient- or physician-blinded) as well as the time-point for outcome measurement were not described. Botulinum toxin may induce short-term pain relief in cases of temporomandibular disease. The results of this study are also limited by the short follow-up duration. Thus, more RCTs of botulinum toxin in TMJ disorders are needed to support its efficacy.et al. reported the results of injection of 200–500 units of botulinum toxin A intramuscularly in up to 4–5 trigger points per each side of the back from L2 to S1 in 60 patients with chronic low back pain in an open-label prospective study87. The mean age was 47 years, mean disease duration was of 9 years, 18 were women and 62% had concurrent radicular pain. A positive response was defined by the occurrence of 2 out of the following 3 criteria: a ≥50% improvement in pain VAS scores, an improvement of 2 or more grades in the pain and functional subsets of the Oswestry Low Back Pain Questionnaire, and a ≥30% increase in the number of pain-free days from baseline. 58% of patients responded positively at 2 months and of these 17% still reported improvement at 4 months of follow-up. Most patients with improvements at 2 months reported that the beneficial effects weaned off by 4 months. 18 of the 19 patients that received re-injection reported beneficial response at a 2 month follow up. Two patients reported a mild, flu-like reaction lasting 3–5 days. None of the patients reported any muscle weakness.Neyet al. was in Chinese and as a translation was not available, therefore, I could not include a full assessment this review88. This 2-month study included 27 patients randomized to acupoint injection of botulinum toxin A into tender points at the third lumbar transverse process and an acupuncture group treated with acupuncture at the same points as in the acupoint-injection group.A randomized study by Liu89 (Foster and colleagues compared 200 units of Botulinum toxin A (Allergan) injected intramuscular paravertebrally from L1-5/L2-S1 (n=15) to placebo (n=16) in 31 patients with chronic back pain of ≥6 month duration89 . 40 unitet al. compared the efficacy of botulinum toxin A to control  in relieving myofascial pain in patients experiencing mechanical low back pain due to bilateral myofascial pain syndrome involving the iliopsoas and/or the quadratus lumborum muscles90. 27 patients who were enrolled in the study received a bilateral, fluoroscopically guided injection in the affected muscle(s) to randomly deliver botulinum toxin A to one side of the low back and a control drug in the opposite side. Botulinum toxin A injection did not significantly reduce pain more than saline or bupivacaine control in the contralateral side. No significant differences between groups were noted in improvement of patients’ daily life activities or psychologic status.DeAndreaset al. evaluated the efficacy of botulinum toxin A injections used in conjunction with physical therapy for the treatment of back pain due to piriformis syndrome in a 12-week study90. 67 patients received 72 injections  and were assigned to one of the three groups, botulinum toxin A, triamcinolone + lidocaine or saline placebo. All patients received therapy. Patients injected with botulinum toxin A experienced more pain relief than patients receiving lidocaine with corticosteroid (p = 0.04) or saline placebo (p = 0.001).A double-blinded randomized study by FishmanIn summary, intramuscular injections of botulinum toxin in patients with chronic back pain seemed to provide short-term benefits of pain reduction. This is based on one non-randomized study and two RCTs in patients with chronic low back pain. Both RCTs had a small sample size and included patients with chronic symptoms. Pain improvement was noted in both RCTs and function, measured in one study, also improved. The effects were not assessed at long-term follow-up, i.e., at 6-months or longer. In addition, in one study all groups received physical therapy, and therefore the effects in the intervention arm may be attributable to an interaction between therapy and botulinum toxin. More evidence is needed to examine the utility of botulinum toxin in the treatment of back pain.et al. reported a case series of 9 patients with chronic plantar fasciitis, who were injected with 200 units of botulinum toxin A (Dysport) in the plantar fascia91. Patients were followed up to one year after the injection. Statistically significant pain relief began two weeks after the injection  and persisted for the 52 weeks of follow up . Muscle weakness or systemic effects were not seen.Placzek92  who had experienced chronic refractory plantar fasciitis for 6 months or more, and who had failed to respond to conventional therapies except surgery or extracorporeal shock therapy92 . In thisIn summary, the evidence is based on one non-randomized study and one RCT. Pain and function both improved short-term in botulinum toxin compared to placebo at 3- and 8-week follow-up in RCT and pain improved up to 1-year follow-up in the non-randomized study. While the data seems promising, more RCTs are needed and evidence of efficacy at longer-term is needed to assess whether botulinum toxin can provide a longer-term relief in patients with plantar fasciitis.93  into the vastus lateralis muscle in 8 women with chronic anterior knee pain of more than 6 months duration who had failed to respond to conservative management, e.g. patello-femoral bracing or taping94 (One non-randomized study provides evidence for the use of botulinum toxin in cases of anterior knee pain. Singerping94 . The inj95. The mean age was 68 years (age range 41–82 years). The Harris Hip Score, a commonly used measure of hip function, increased significantly after 2, 4 and 12 weeks after the BoNT/A injection (p<0.0001). There was a significant decrease in pain 2, 4 and 12 weeks after the BoNT/A injection (p< 0.001).One non-randomized study provides evidence for the use of botulinum toxin in hip pain. A total of 400 units of Botulinum toxin type A (Dysport) were injected into the adductor longus and the adductor magnus muscles in 39 patients with hip osteoarthritis96. On the other hand, intra-articular injections may work primarily by their effect on the analgesic pathways97.This was a focused review of randomized and non-randomized studies, not a systematic review or a meta-analysis. Therefore findings must be interpreted with caution. In particular, the summary section for various musculoskeletal pain disorders highlights the limitation of studies included. In particular, evidence for the efficacy of botulinum toxin in anterior knee pain and hip pain was based on non-randomized study data only (one study for each), and is subject to bias. Also, the evidence presented here includes both intramuscular and intra-articular injections for a variety of musculoskeletal disorders. Even though presented together, their effects may differ. The intramuscular injections may have complex effects, including the analgesic effects, effects from blocking acetylcholine release from motor nerve endings, and the elimination of muscle myofascial trigger pointsIn this review, I have summarized studies of the use of botulinum toxin for musculoskeletal pain. Most studies used either an intra-articular or intramuscular route of administration in patients with refractory pain, who had not responded to multiple other treatment interventions. Pre-clinical laboratory evidence supports an independent anti-nociceptive mechanism of action of botulinum toxin. While there are several osteoarticular conditions for which botulinum toxin has been studied in an RCT compared to placebo, for several conditions such as low back pain, plantar fasciitis, temporomandibular disorder and carpal tunnel syndrome, the evidence is based on non-randomized data and only a single RCT. For other conditions, such as osteoarthritis of the knee/shoulder and tennis elbow data in support of its use from several RCTs and non-randomized studies was available. Most RCTs included in this review had several limitations. Most studies were single center, had a small sample size, short follow-up and in some cases, non-standardized injection techniques. The evidence for an anti-nociceptive action of botulinum toxin in osteoarticular pain is growing. Side effects seem to be mild, and in cases of muscle weakness, reversible; however, data from larger samples needs to be generated. Evidence from larger multicenter studies of longer duration that test various doses, regimens and routes of administration of botulinum toxin are needed to better define its role in management of osteoarticular pain. Musculoskeletal pain is a big problem for society. There is need of new and easy performed treatment alternatives. This very comprehensive review on the treatment with botulinum toxins for different musculoskeletal pain disorders is subsequently very welcome for all that treat patients with retractable pain in bone, muscles, and joints. I am happy to recommend a further study of this well written review.I have read this submission. I believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard. I am now satisfied with the revised paper.I have read this submission. I believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard. We thank Dr. Gerwin for his critique and recommendations. The manuscript is a decent, very detailed, and almost complete review. The title and abstract are appropriate for the content of the article and the conclusions are sensible and justified.Am J Phys Med RehabilLin YC (2010) ,JBJS AmPlaczek R (2007) .However, I do have two significant reservations. Unfortunately, for a complete review of the published data concerning the topic 'botulinum toxin and pain' we found two RCTs missing:Hameed F (2012),Cheng OT (2012),Sim WS (2011)), hence by reading this manuscript, little information may be new to the informed reader.Furthermore, there have been at least 3 review articles with the same topic in 2012  Am J Phys Med Rehabil,Placzek R (2007) JBJS Am.However, I do have two significant reservations. Unfortunately, for a complete review of the published data concerning the topic 'botulinum toxin and pain' we found two RCTs missing: We thank the reviewer for pointing us to the two missing studies, which have now been included in the review. Hameed F (2012),Cheng OT (2012),Sim WS (2011)), hence by reading this manuscript, little information may be new to the informed reader.Furthermore, there have been at least 3 review articles with the same topic in 2012  treatments only. Our review is more comprehensive in that it includes muscucloskeletal (MSK) pain, not just knee OA or OA. We thank the reviewer for pointing out these pertinent reviews. We refer to them in our paper and discuss how our review adds to what’s already been published. Both Hameed and Chenget al. provides a very brief overview of a few studies of botulinum toxin for any indication, without providing much detail about key studies. Thus, we believe our review adds to the already published reviews, and provides a complete perspective on the potential role of botulinum toxin in the treatment of MSK pain. Sim“Recent reviews have summarized the injectable treatments for osteoarthritis (64), injectable treatments for knee osteoarthritis (65) or use of neurotoxin for the treatment of painful disorders (66), In this review, we provide a review of evidence regarding Botulinum toxin for the treatment of musculoskeletal pain conditions.” This article reviews the use of botulimum toxin in the treatment of pain, rather than in the treatment of muscle contraction. This is a new area of potentially great interest and therefore the review is both timely and presents a new use of botulinum toxin to be considered. The drawback in the article is that it is a systematic review, not a metaanalysis and not a critical review. As such, it could be shortened by summarizing the studies with less detail. The greater detail in which the cases are described does not add a great detail, since they are simply recapitulations of the study, and do not tell tell us if the study is credible or not. I suggest that the author either be more concise in the summaries, or be more critical in assessing the studies. Moreover, the author includes both intra-articular injections and intramuscular injections. The intramuscular injections may have complex effects, including; analgesic effects, effects from blocking acetylcholine release from motor nerve endings, and the elimination of muscle myofascial trigger points. et al and of DeAndreset al.  However, the review is incomplete. For example, he  discusses low back pain with injections into the lumbar paraspinal musculature, but only gives Ney and Forster as two references. He could have included the work of GulThe title and abstract are appropriate.  My comments regarding the nature of his review are given above.  The conclusion is accurate and justified. There are no experimental data to discuss, since this is a review article. In summary, the topic is timely, the review summarizes the data from some but not all relevant studies and in that sense is not complete, and the summary does not address the credibility of the articles cited, and that is a weakness.I have read this submission. I believe that I have an appropriate level of expertise to confirm that it is of an acceptable scientific standard, however I have significant reservations, as outlined above. We thank the reviewers, who provided great insights. The revisions made in response to their comments have improved the quality and clarity of this paper. Here are our responses to the comments from reviewer #2.   Reviewer comments Response to reviewers Robert Gerwin, Pain & Rehabilitation Medicine, Bethesda, MD, USA Status and Report: 11 Mar 2013     This article reviews the use of botulimum toxin in the treatment of pain, rather than in the treatment of muscle contraction. This is a new area of potentially great interest and therefore the review is both timely and presents a new use of botulinum toxin to be considered. Thank you. The drawback in the article is that it is a systematic review, not a metaanalysis and not a critical review. As such, it could be shortened by summarizing the studies with less detail. The greater detail in which the cases are described does not add a great detail, since they are simply recapitulations of the study, and do not tell tell us if the study is credible or not. I suggest that the author either be more concise in the summaries, or be more critical in assessing the studies.  We agree and have listed this as a limitation of our review. We have added an overall limitation section for our review. We have also added a section of comments related to study strengths and weaknesses of each indication to provide a more critical assessment of each study.    Summary and Study limitations:plantar fasciitis In summary, the evidence is based on one non-randomized study and one RCT.  Pain and function both improved short-term in botulinum toxin compared to placebo at 3- and 8-week follow-up in RCT and pain improved up to 1-year follow-up in non-randomized study.  While the data seems promising, more RCTs are needed and evidence of efficacy at longer-term is needed to assess whether botulinum toxin can provide a longer-term relief in patients with plantar fasciitis.”    “Limitations of this review This was a focused review of randomized and non-randomized studies, not a systematic review or a meta-analysis.  Therefore findings must be interpreted with caution.  In particular, the summary section for various musculoskeletal pain disorders highlights the limitation of studies included.  In particular, evidence for the efficacy of botulinum toxin in anterior knee pain and hip pain was based on non-randomized study data only (one study for each), and is subject to bias. The intramuscular injections may have complex effects, including the analgesic effects, effects from blocking acetylcholine release from motor nerve endings, and the elimination of muscle myofascial trigger points.  On the other hand, intraarticular injections may work primarily by their effect on the analgesic pathways. “   “Moreover, the author includes both intra-articular injections and intramuscular injections. The intramuscular injections may have complex effects, including; analgesic effects, effects from blocking acetylcholine release from motor nerve endings, and the elimination of muscle myofascial trigger points.  We agree that intramuscular and intra-articular injections likely have different mechanisms of action.  Both types of injections are commonly used in the treatment of MSK pain, the focus of our paper. We mention the important point brought up by the reviewer in the discussion of results. However, the review is incomplete. For example, he discusses low back pain with injections into the lumbar paraspinal musculature, but only gives Ney and Forster as two references. He could have included the work of Gul et al and of DeAndres et al.   et al. and Lewet al. to our review. We are sorry but could not find Gulet al. We have now added DeAndresThe title and abstract are appropriate.  Thank you. My comments regarding the nature of his review are given above. The conclusion is accurate and justified. There are no experimental data to discuss, since this is a review article.  Thank you. In summary, the topic is timely, the review summarizes the data from some but not all relevant studies and in that sense is not complete, and the summary does not address the credibility of the articles cited, and that is a weakness. We have now included the additional studies pointed out by the reviewer. We have also added statements related to the credibility of each studies for each condition (please see responses to reviewer comments in the sections above and the changes in the revised article).


The effect of peripheral nerve blocks on postoperative delirium in older patients has not been studied. Peripheral nerve blocks may reduce the incidence of postoperative opioid use and its side effects such as delirium via opioid-sparing effect.A prospective cohort study was conducted in patients who underwent total knee replacement. Baseline cognitive function was assessed using the Telephone Interview for Cognitive Status. Postoperative delirium was measured using the Confusion Assessment Method postoperatively. Incidence of postoperative delirium was compared in two postoperative management groups: femoral nerve block ± patient-controlled analgesia and patient-controlled analgesia only. In addition, pain levels  and opioid use were compared in two groups.P = 0.002). However, there was no significant difference between the groups with respect to postoperative pain level or the amount of intravenous opioid use.85 patients were studied. The overall incidence of postoperative delirium either on postoperative day one or day two was 48.1%. Incidence of postoperative delirium in the femoral nerve block group was lower than patient controlled analgesia only group (25% vs. 61%, Femoral nerve block reduces the incidence of postoperative delirium. These results suggest that a larger randomized control trial is necessary to confirm these preliminary findings. Postoperative delirium is a common postoperative complication among older surgical patients, occurring in up to 60% of surgical patients after major surgery . PostopeAccordingly, we conducted a prospective nested cohort study in patients who underwent unilateral total knee replacement (TKR) to examine the effect of postoperative pain management on delirium. The aim of the present study was to compare the incidence of postoperative delirium between patients who had femoral nerve block for postoperative analgesia vs. those who did not. We chose this patient population because patients who undergo orthopedic joint replacement surgery are typically older and the incidence of postoperative delirium is high ,9. MoreoThe study was approved by the Institutional Review Board of the University of California, San Francisco, and was part of a larger study examining the pathophysiology of postoperative delirium conducted from 2001-2011 at the University of California, San Francisco Medical Center. A subset of patients in this study (n = 31) was included in a previous paper evaluating the use of patient-controlled analgesia (PCA) in patients with postoperative delirium .Before participating in the study, written informed consent was obtained from each patient. Inclusion criteria were patients who were ≥ 65 yrs of age who underwent unilateral TKR. Patients who were not able to speak English, not able to provide written informed consent, or those with moderate to severe dementia were excluded. We did not include patients who had an epidural catheter postoperatively, since most of our patients received anticoagulants for deep venous thrombosis prophylaxis, which have the potential to increase the occurrence of epidural hematoma. As a result, postoperative epidural analgesia has been rarely used in our institution in patients undergoing unilateral TKR.The anesthesia and postoperative pain management methods were not controlled by the study. Two different postoperative pain management groups were compared in the study. Group 1: continuous femoral nerve block ± patient controlled analgesia (PCA), Group 2: PCA analgesia only. The patients in Group 1 received either general anesthesia with inhalational agents or spinal anesthesia with single shot femoral nerve block with local anesthetic  followed by continuous local anesthetic infusion in the femoral nerve catheter. The anesthesia team performed sensory and motor testing of femoral nerve block right before surgery. Group 2 received general or regional block  followed by intravenous PCA analgesia. The epidural catheter was discontinued in the Post Anesthesia Care Unit (PACU) before patient was transferred to the floor.Continuous femoral nerve infusion and PCA were started in the PACU and both techniques were maintained typically for 1-2 days postoperatively. Local anesthetic  was used for femoral nerve infusion and titrated to keep the pain scores < 5 per our institutional practice.Hydromorphone was the standard opioid for postoperative pain management in our institution. If hydromorphone was not used, for example because of patient allergy or sensitivity, morphine sulfate or fentanyl was used. Morphine sulfate and fentanyl doses were converted to hydromorphone using the conversion formula: 5 mg of morphine sulfate = 1 mg of hydromorphone, 50 mcg of fentanyl = 1 mg of hydromorphone . The dosThe preoperative interview was conducted by a trained research assistant in the preoperative anesthesia clinic, typically less than 2 weeks prior to surgery. The preoperative interviewer collected health and demographic information associated with postoperative delirium, including age, gender, race, level of education, history of central nervous system (CNS) disorders, daily alcohol consumption, baseline cognitive status. The CNS disorders included delirium, dementia, depression, seizure and other CNS disorders. Information from the preoperative physical exam included American Society of Anesthesiologists (ASA) classification, and the use of preoperative opioids and benzodiazepine, and preoperative pain level were obtained.Baseline cognitive status was obtained in person or over the phone preoperatively using the Telephone Interview for Cognitive Status (TICS) . TICS isScreening of depression was performed using 15-question Geriatric Depression Scale (GDS)  preoperaIn addition, patients were asked to rate their baseline pain levels using the 11-point numeric rating scales (NRS) from "no pain" to "worst possible pain" .The same trained research assistant conducted the structured interviews, which occurred daily for 2 days postoperatively between approximately 9 a.m. and 12 p.m., in the patient's hospital room. Postoperative delirium was measured using the Confusion Assessment Method (CAM) . DiagnosPain levels at rest were measured in the same way as the preoperative evaluation, using the NRS. Information related to postoperative pain management (type of pain management and opioid usage) was obtained through the review of medical records.Other potential variables  for postoperative delirium were assessed. Altered sleep-wake cycle was defined as a change in the regular sleep pattern per subjective report by patient.P < 0.20, stepwise logistic regression was performed to determine the independent contribution of predictor variables on postoperative delirium. P-values < 0.05 were considered significant. All analyses were performed using SAS 9.2 .First, if a patient completed at least 75% of items of the TICS and GDS, we substituted each item with item-mean value. Chi-square tests (Fisher's exact test if the cell count was less than 5) were used for the categorical variables. Mantel-Haenszel chi-square tests were used for the ordinal variables. Two sample t-tests were conducted for the continuous variables except opioid dose. Wilcoxon non-parametric test were performed to examine the association between postoperative pain management techniques and use of opioids. With bivariate correlates of P = 0.06) with no differences in postoperative pain and opioid consumption. This preliminary result led to a further analysis and patients between 2007-2011 were added. The total number of patients who underwent non-cardiac surgery was 674, and 88 patients underwent TKR between 2001-2011. 2 patients who underwent bilateral TKR, 2 patients who had postoperative epidural infusion, and 1 patient who had femoral and sciatic nerve blocks were excluded. Thus, 85 patients met our criteria for this study; 31 patients had femoral nerve block ± PCA and 54 had PCA only. Patient characteristics and preoperative data are shown in Table P = 0.03). However, this significant difference in opioid use did not extend to the next postoperative day.Initially, we analyzed the group of patients who underwent TKR between 2001-2006 . We found that there was a trend of lower incidence of postoperative delirium in the femoral nerve block group . Stepwise logistic regression analysis was performed using the bivariate correlates with P-value < 0.20 for postoperative delirium on POD1 or POD2. These variables were preoperative TICS scores and pain management  (Table P = 0.002) and preoperative TICS score was also significant , P = 0.03).The overall incidence of delirium on either POD1 or POD2 was 48.1%. Table y) Table . Pain maWe also investigated the impact of missing data on our results. Overall, 14 patients had incomplete delirium assessment or preoperative TICS score due to patients' refusal or medical condition. There was no significant difference between patients with missing and without missing in all variables. No catheter related complications were noted.In this study, we found that the overall incidence of postoperative delirium to be 48.1%, which was consistent with that found in previous studies ,17,18. TAlthough postoperative delirium is prevalent and prognostically important, evidence-based preventive therapy is limited. Previous studies have investigated other prophylactic measures in preventing postoperative delirium using pharmacological  no opioid related side effects ; 2) the contralateral limb will not be affected; and 3) not associated with hypotension as may occur with an epidural.Our study results showed that pain management was a predictor of postoperative delirium and also showed femoral nerve block reduced the rate of delirium. The current findings did show that the use of femoral nerve block reduced the amount of intraoperative opioid dose, but the opioid sparing effect did not appear to extend to the postoperative opioid. The reduced intraoperative opioid use is likely related to the bolus of local anesthetic  administered for femoral nerve block during the catheter placement. A single shot femoral nerve block with local anesthetic often lasts up to 12-24 hours. The lack of difference in postoperative opioid usage and pain level may be secondary to the location of the femoral nerve catheter. Capdevila et al.  reportedWe assessed patients' cognitive status and other clinical outcomes for 2 days postoperatively. If a patient had experienced cognitive changes later, the incident may have been missed. However, because the incidence of postoperative delirium is higher and surgical pain is intense the first few days after surgery, we believe that we have captured the most important time period in this study.Pain assessment was conducted once daily during the patient interview. Because acute postoperative pain is dynamic and may fluctuate, we may not have evaluated the complex relationship between postoperative pain and delirium completely. However, from our experience, pain assessment once in the morning vs. twice a day assessments showed no significant difference in pain scores. In a separate pilot study of 20 patients evaluating the potential differences in pain scores between once a day vs. twice a day assessments, we found that only 2% of pain scores were significantly different between the two methods.The initial analysis on patients between 2001-2006 showed a trend of lower incidence of postoperative delirium in the femoral nerve block group. This result led to the further analysis including more patients, and it became statistically significant for lower incidence of postoperative delirium and reduced intraoperative opioid consumption, but not statistically significant for the postoperative pain levels and opioid use. Our results should still be considered as pilot since sample size calculation shows that 61 subjects per group  will be needed for a future trial, given a power of 80% and level of significance at 0.05. A prospective study that is adequately powered is indicated to confirm this preliminary finding.Lastly, our study design was a nested cohort, therefore there could be a potential bias with this type of study. It was not randomized, although the two groups of patients were matched with respect to preoperative demographics except for ASA physical status, additional covariates that may have been important may have been missed and need to be considered in future prospective randomized trial.In summary, our study showed that femoral nerve block was associated with a lower incidence of postoperative delirium compared to the PCA only treatment. These results suggest pain management strategy should be considered in future trials of postoperative delirium.The authors declare that they have no competing interests.SK participated in the design of the study. EL performed the statistical analysis. LPS participated in the designed of the study and performed the statistical analysis. KJB participated in coordination of the study and helped to draft the manuscript. JML designed and oversaw the study. All authors read and approved final manuscript.The pre-publication history for this paper can be accessed here:http://www.biomedcentral.com/1471-2253/12/4/prepub


Low back pain in pregnancy is common and research evidence on the response to chiropractic treatment is limited. The purposes of this study are 1) to report outcomes in pregnant patients receiving chiropractic treatment; 2) to compare outcomes from subgroups; 3) to assess predictors of outcome.Pregnant patients with low back or pelvic pain, no contraindications to manipulative therapy and no manual therapy in the prior 3 months were recruited.Baseline numerical rating scale (NRS) and Oswestry questionnaire data were collected. Duration of complaint, number of previous LBP episodes, LBP during a previous pregnancy, and category of pain location were recorded.The patient’s global impression of change (PGIC) (primary outcome), NRS, and Oswestry data (secondary outcomes) were collected at 1 week, 1 and 3 months after the first treatment. At 6 months and 1 year the PGIC and NRS scores were collected. PGIC responses of ‘better’ or ‘much better’ were categorized as ‘improved’.The proportion of patients ‘improved’ at each time point was calculated. Chi-squared test compared subgroups with ‘improvement’. Baseline and follow-up NRS and Oswestry scores were compared using the paired t-test. The unpaired t-test compared NRS and Oswestry scores in patients with and without a history of LBP and with and without LBP during a previous pregnancy. Anova compared baseline and follow-up NRS and Oswestry scores by pain location category and category of number of previous LBP episodes. Logistic regression analysis also was also performed.52% of 115 recruited patients ‘improved’ at 1 week, 70% at 1 month, 85% at 3 months, 90% at 6 months and 88% at 1 year. There were significant reductions in NRS and Oswestry scores (p < 0.0005). Category of previous LBP episodes number at one year (p = 0.02) was related to ,improvement’ when analyzed alone, but was not strongly predictive in logistic regression. Patients with more prior LBP episodes had higher 1 year NRS scores (p = 0.013).Most pregnant patients undergoing chiropractic treatment reported clinically relevant improvement at all time points. No single variable was strongly predictive of, improvement’ in the logistic regression model. Low back and pelvic pain in pregnant women is such a common phenomenon that it is often considered a normal part of the pregnancy-3. HowevPregnancy-related low back pain is most often divided into 3 categories based on location. These are: lumbar spine pain (LP), posterior pelvic pain (PPP), or a combination of these two,2,9, witAlthough the etiology of low back pain associated with pregnancy is not definitively known, the predominate theories include biomechanical changes due to the enlarging uterus resulting in an increasing lumbar lordosis and the influence of the hormone relaxin on stabilizing ligaments leading to hypermobility of joints-14.The treatment of pregnancy-related low back pain has often been a ‘watch and wait’ approach, as medication use in pregnancy is strongly discouraged in many cases and it iFinally a prospective randomized trial was published in 2013 which compared routine obstetrical care for pregnant patients suffering from low back pain with chiropractic treatment consisting of manual therapy, stabilization exercises and patient education. The chiAdditional research is therefore needed from a larger number of chiropractors to assess outcomes as would be obtained in routine chiropractic practice and to follow the patients for a longer time period. Furthermore, it is desirable to see if factors associated with improvement or failure to improve identified in previous studies will also be found in this current study. Thus, tThis is a prospective, cohort, outcomes study. Patients with baseline and 1 year data are included in the study. Cantonal ethics approval was obtained prior to the start of the study and all patients signed informed consent.Pregnant patients over the age of 18 with low back pain, pelvic pain, or both of any duration who have not undergone chiropractic or manual therapy in the prior 3 months were recruited from chiropractic practices in Switzerland. All chiropractors in the German and French speaking regions of the country were invited to submit patients but 2 multi-clinician practices in particular that receive a high number of referrals from gyaecologists were targeted specifically. These two practices were asked to recruit all consenting pregnant patients. Patients with specific pathologies of the lumbar spine that are contraindications to chiropractic manipulative treatment, such as tumors, infections, inflammatory spondylarthropathies, acute fractures, Paget’s disease and severe osteoporosis, were excluded.Chiropractic treatment was not standardized to any specific treatment methods or frequencies and was left to the discretion of the treating clinician. However, it is known from the Swiss job analysis study that the Diversified method of high velocity, low amplitude spinal manipulative therapy (SMT) is the most common SMT method used in this country.The numerical rating scale (NRS) for pain, where 0 = no pain and 10 = the worst pain imaginable, and the Oswestry questionnaire, which has been validated in German and French,20 were One week after the first consultation/treatment, data from the NRS, patient’s global impression of change (PGIC) scale, and the Oswestry questionnaire were collected from the patient via a short telephone interview. Similarly, these same data were collected at 1 month and 3 months after the start of chiropractic treatment via telephone interviews. At 6 months and 1 year after the first chiropractic treatment, the NRS and PGIC scores were collected, but not the Oswestry data. These telephone interviews were conducted by trained research assistants at the university, unknown to the patients or clinicians. The PGIC scale was a 7 point verbal scale, including the options ‘much worse’, ‘worse’, ‘slightly worse’, ‘no change’, ‘slightly better’, ‘better’, and ‘much better’. Patients responding ‘better’ or ‘much better’ were categorized as ‘improved’ and all other patients as ‘not improved’. This was considered the primary outcome measure. Additionally, one question was included on the 1 year follow-up data collection concerning the patient satisfaction with their treatment. The options included: ‘very happy’, ‘happy’, ‘neutral’, ‘unhappy’ and ‘very unhappy’.The time frame within which each data collection telephone interview was allowed was narrow. If a patient could not be reached within the window of time allowed, that data collection time point was missed but the patient remained in the study. However, if 3 consecutive data collection telephone interviews were missed, the patient was deleted from the study.Descriptive statistics were calculated. The proportion (%) of patients improved at each data collection time point was calculated. Subgroup analysis was carried out using ‘improved’ or ‘not improved’ as categorical variables. The chi-squared test was used to compare the presence/absence of LBP during a previous pregnancy, category of the number of previous episodes of LBP, and the category of the location of LBP with ‘improvement’. The scores on the baseline and follow-up NRS for pain and Oswestry questionnaire were compared using the paired t-test. The unpaired t-test was used to compare NRS and Oswestry scores in patients with and without a prior history of LBP and for patients with and without LBP during a previous pregnancy. Anova was used to assess for differences in baseline and follow-up NRS and Oswestry scores by location category of the LBP and category of the number of previous episodes of LBP. NRS and Oswestry change scores were also calculated for each follow-up time period compared to the baseline scores.Logistic regression analysis was also performed to determine statistically significant predictors of improvement using the 10 baseline variables  at 1 month, 3 months, 6 months and 1 year after start of treatment. The full model containing all predictors was also assessed for statistical significance and ability to distinguish between patients who improved or did not improve as well as the proportion of correctly classified cases.Baseline and 1 year data were available on 115 patients. In order to obtain 1 year outcomes data on these 115 patients, 143 were enrolled with baseline data. Seven of these 143 patients requested to drop out of the study prior to the 1 year data collection time point and 28 other patients were not able to be contacted for 3 consecutive telephone data collection time periods. Thus they were deleted from the study. The patients came from a total of 15 different chiropractors. One hundred of the 115 patients came from the 2 practices specifically targeted. One of these sites has 4 chiropractors and the other 3 and all referred pregnant patients to the study.rd trimester of pregnancy (Table The mean patient age was 32.96 (SD = 4.64) years and the mean gestational week was 26.21 (SD = 6.98). Table Over half of the patients reported clinically relevant ‘improvement’ at 1 week, with the vast majority ‘improved’ at all subsequent data collection time points Table . StatistAt 1 year, 85.2% of patients (n = 98) were ‘very happy’ or ‘happy’ with their chiropractic treatment and 6% (n = 7) were ‘unhappy’.X2  = 40.71, p < 0.009 at 1 month, indicating that the model could distinguish between patients ‘improved’ and ‘not improved’. Between 55.7% and 79.0% of the variability is explained by this set of variables at 1 month after start of treatment. However, no single independent variable made a unique statistically significant contribution to the model. Additionally, at 3 months, 6 months and 1 year the model was not statistically significant as the vast majority of patients were ‘improved’.Logistic regression analysis using the 10 independent variables  looking at chiropractic treatment for pregnant patients with low back or pelvic pain,17. The In the RCT by George et al. one treatment arm of the trial on pregnant women suffering from LB, PP or both included treatment by a chiropractor. The results clearly showed a statistically and clinically significant greater level of improvement for the patients who received the additional chiropractic treatment. HoweverComparing the outcomes from this study on Swiss patients with those from a very similarly designed outcomes study on patients in the United States (US), shows tAnother relevant, although perhaps not surprising finding from this current cohort study includes the fact that patients who reported a higher number of previous LBP episodes (≥ 5) were less likely to report clinically relevant improvement, particularly at 1 year after the first treatment. However, this factor was not predictive in the logistic regression model. This is consistent with other studies that show that back pain is commonly recurrent-23. HoweThe literature states that 94% of women who have LBP in a previous pregnancy have recurrent pain with subsequent pregnancies. HoweverNo serious adverse events were reported in this study and over 85% of the patients were happy or very happy with their chiropractic treatment. Adverse events from spinal manipulation to pregnant women or those in the early post-partum period are very rare with only 7 cases found in the literature. All seeSome of the limitations to this study have been alluded to above. Because this is a cohort study without a control group or other treatment group for comparison, the outcomes reported cannot be assumed to arise from the treatment. Additionally, the patients in this study were treated primarily at two practice sites but by different chiropractors and the details of the types of treatments and treatment dosage are not known. No attempt was made to compare outcomes by practitioner or style of treatment. This would be interesting for future studies. As previously stated, the use of the Oswestry questionnaire was not the best choice for this patient population, but was the best available that was translated and validated in both German and French. Additionally, the assessment of symphysis pubis pain in these pregnant patients was not specifically assessed as it was desired to use those same categories of low back pain in pregnancy that previous papers used in order to make direct comparisons.A large proportion of pregnant patients with LBP or pelvic pain undergoing chiropractic treatment report clinically relevant improvement in their symptoms at all time points up to 1 year. There is a relationship between the number of prior episodes of LBP and ‘improvement’ with patients reporting more episodes being less likely to improve. However, this was not a strong predictor of, improvement‘ when placed into a logistic regression model.LBP: Low back pain; LP: Lumbar spine pain; n: Number; NRS: Numeric rating scale for pain; PGIC: Patient’s global impression of change; PPP: Posterior pelvic pain; PTS: Patients; SD: Standard deviation; SMT: Spinal manipulative therapy.The authors declare that they have no competing interests.CP: Ethics approval submission, Literature search, data entry, analysis and interpretation of data, drafting and revising the manuscript, final approval of the manuscript. DM: Patient recruitment, baseline data collection, patient treatment, final approval of the manuscript. BKH: Concept and design of the study, manuscript preparation and final approval of the manuscript.