Exercise-induced compartment syndrome is an exercise-induced condition of the leg. It is characterized by reversible ischemia of the muscles of a muscle compartment. Diagnosis is made by measuring compartment pressures at rest, during exercise and after exercise (answer 2 correct). Treatment usually consists of fasciotomies of the affected compartments. Although MRI is not very useful in establishing the diagnosis, it can help in the differential diagnosis.

Exercise-induced compartment syndrome is an exercise-induced condition of the leg. It is characterized by reversible ischemia of the muscles of a muscle compartment. Diagnosis is made by measuring compartment pressures at rest, during exercise and after exercise ([HIDDEN]). Treatment usually consists of fasciotomies of the affected compartments. Although MRI is not very useful in establishing the diagnosis, it can help in the differential diagnosis.

A 27-year-old male, a regular athlete, refers pain in the right leg after continuous running. He has visited a physiotherapist on several occasions and has been diagnosed with calf overload. Several months have passed, she has not improved and refers intense pain after physical activity that subsides with rest in the hours following exercise. What test can help in the diagnosis?

Positron emission tomography with 18 FDG.

Determination of posterior compartment pressure immediately after activity.

Doppler ultrasound to rule out a circulatory disorder of the lower extremity.

[MR-Imaging of lower leg muscle perfusion].

This article describes the potential of dynamic contrast- enhanced magnetic resonance tomography (DCE-MRT) for the visualization and quantification of blood flow of lower leg muscles at rest and after individually adjusted muscular exercise. Five cases were chosen to exemplify the qualitative and semi-quantitative blood flow evaluation in the lower leg muscles. The crural muscle state was determined with an isometric maximal strength measurement from a female patient with peripheral arterial occlusive disease (pAVK), a male patient with coronary heart disease (KHK) without clinical signs of a pAVK, a volunteer with sufficient physical activity in accordance with the Freiburg Questionnaire of Physical Activity and two professional athletes. After calibration of the plantarflexion ergometer MR-PEDALO (Figures 2a and 2b) for the execution of auxotonic muscle work a 1- minute alternating foot extension and flexion exercise on MRPEDALO was performed in the MR machine. Instead of the lower leg splint shown in Figures 2a and 2b the MR coil fits exactly in MR-PEDALO used for DCE-MRT. Mechanical work performed during the 1-minute exercise ranged from 52 watt seconds (Ws) to 244 Ws (0.65 W to 4.07 W), indicating similar interindividual work loads in relation to the individual maximum isometric strength. DCE-MRT was performed at rest and immediately after auxotonic exercise test (T1w 2DFLASH- GE sequence with TR/TE/alpha: 100 ms/6 ms/70 degrees; field of view: 400; matrix: 81 x 256; slice thickness: 10 mm; acquisitions: 73 at 8.3 s each; total examination time: 9.24 min; bolus application of Magnevist, Schering, 0.02 ml/kg kg, 20 ml bolus NaCl, flow 2 ml/s, 22G cannula in a cubital vein). Signal intensity (SI) curves were analyzed with DynaVision (MeVis gGmbH, Bremen, Germany). Measuring peripheral blood flow needs appropriate muscular stress tests. The SI-curves of the region of interest (ROI) representing the peroneus, tibialis anterior and gastrocnemius muscle run almost parallel at rest. Workloads between 52 Ws and 244 Ws (0.65 W and 4.07 W), similar in relation to the individual maximum isometric strength, induce distinctive changes of the upslope, wash-in, peak and washout of SI-curves preferably for the peroneus muscle and less predominant also for the tibialis anterior muscle and gastrocnemius muscle respectively. The first case, a 55-year-old female patient with peripheral arterial occlusive disease (pAVK) stage Fontaine IIb before (Figure 3a) and after (Figure 3b) percutaneous transluminal angioplasty (PTA) of a right femoral artery stenosis shows after interventional treatment a rapid post-exercise SI-increase in the peroneus muscle. The steeper SI-curve indicates a better contrast medium inflow due to an improved perfusion. The second case, a 65-year-old man suffering from coronary heart disease without clinical signs of pAVK (Figure 4) exercised with a workload of 92 Ws. After stress test the ROI for the peroneus muscle shows a clear intensity increase. After exercise the SI-curve for the tibialis anterior muscle shows a similar, but less predominant change while the shape of the SI-curve of the gastrocnemius muscle remains mainly identical. A 23-year-old male person with average physical activity (Figure 5) performed DCE-MRT of the left lower leg after stress test with 172 Ws demonstrating a rapid signal increase in the peroneus muscle while the synergistic tibialis anterior muscle and antagonistic gastrocnemius muscle show a comparatively slow contrast-medium wash-in. A 26-year-old male athlete (Figure 6) exercised with 196 Ws showing a rapid contrast medium inflow in the peroneus muscle and initially also in the synergistic tibialis anterior muscle. A contrast-medium wash-out appears in both muscles, while the shape of the gastrocnemius muscle SI-curve remains substantially unchanged. A 26-year-old female athlete (Figure 7) exercised with 244 Ws. Post exercise SI-curves show a distinctive and rapid increase of contrast medium wash-in with a sharp peak particularly in the peroneus muscle and similarly in the tibialis anterior and gastrocnemius muscle. After exercise all SI-curves show a wash-out phase. SI-curves show relative increase in correlation with Time-to-Peak (TTP) decrease and Mean-Intensity to Time Ratio (MITR) increase indicating blood flow reserve mobilization after exercise. Individual muscle state seems to be linked to muscle recruitment and muscle coordination reflected by post-exercise SI-curves. The gastrocnemius muscle shows comparatively low SI-curve changes after muscular load test. Further methodological standardization and optimization of the stress test is mandatory to assure intra- and interindividual comparisons. Due to direct visualization and quantitative evaluation of the peripheral microcirculation DCE-MRT has a diagnostic potential for monitoring therapeutic response in peripheral circulation disorders and sports medicine.

[Athletes with exercise-related pain at the medial side of the lower leg].

Two patients were diagnosed with exercise-related pain at the medial side of the lower leg. The first patient, an 18-year-old woman who had expanded her athletic activities extensively, had developed pain at the inner side of the distal third portion of the left lower leg. She showed over-pronation of the ankle during running. A 3-phase bone scintigram revealed diffuse uptake of the tracer covering a large portion of the medial tibia margin. Based on this evidence, a diagnosis of periostalgia was made. She recovered after a period of relative calf massages and used insoles. The second patient was a 28-year-old male endurance runner who developed pain at the medial shin after intensifying his training regimen. The periods without pain during running became increasingly shorter, and the medial side of the lower leg became sore and tense. Intracompartmental pressure measurements indicated exercise-related posterior deep compartment syndrome of the calf. The patient recovered after fasciotomy. In athletes, exercise-related symptoms of the medial side of the lower leg can be usually attributed to the tibial periosteum or tendons of the deep calfmusculature, tibial stress reaction or fracture, or a compartment syndrome of the deep calf. Surgery is indicated for chronic compartment syndrome, but conservative therapy provides favourable outcomes in the other types of disorders. The optimal conservative therapeutic approach is unknown, but it is advisable to temporary reduce symptom-provoking athletic activity and modify any risk factors present. Ankle over-pronation during running is considered a very relevant intrinsic risk factor.

High-energy phosphate metabolism during calf ergometry in patients with isolated aorto-iliac artery stenoses.

Patients with peripheral arterial disease (PAD) and aorto-iliac atherosclerotic lesions suffer from a broad range of complaints, such as pain at the hip, the thigh, and calf claudication. The purpose of this study was to investigate the high-energy metabolism in the calf muscle of patients with PAD with isolated aorto-iliac stenoses during incremental plantar flexion exercise. Using a 1.5 T whole-body magnetic resonance (MR) scanner, 12 patients with PAD with uni- or bilateral aorto-iliac atherosclerotic lesions and 10 healthy male controls underwent serial phosphor-31 MR spectroscopy during incremental exercise at 2, 3, 4, and 5 W. The phosphocreatine (PCr) time constants were calculated for each increment and recovery using a monoexponential model. In the patient group, the run-off resistance was determined on MR angiograms. In both the patients and the controls, the ankle brachial pressure index was measured. The diseased legs exhibited significantly increased PCr time constants during the second and the third workload increment at 3 and 4 W, but not during the first increment at 2 W and recovery compared with normal controls. Only 3 diseased legs succeeded the last increment at 5 W. We detected significant correlations between the ankle brachial pressure index scores and the PCr time constants when including both the diseased and the control legs. The diseased legs showed a significant correlation with the run-off resistance only during the first increment. Our study shows that the impairment of muscle metabolism, expressed by prolonged PCr time constants, occurs with greater work intensities in patients with aorto-iliac disease compared with patients with multisegmental PAD, as recently published, whereas our patients collective exhibited normal PCr recovery time constants. Our findings may help to understand variability of clinical symptoms in aorto-iliac PAD.

Unilateral Exertional Compartment Syndrome in a Pediatric Competitive Figure Skater.

Chronic exertional compartment syndrome (CECS) occurs when there is an increase in interstitial pressure within a non-compliant fascial compartment during exercise. The hallmark sign of CECS is a consistent onset of symptoms at a specific time, distance or intensity of activity followed by resolution of symptoms when the activity is stopped. Chronic exertional compartment syndrome commonly occurs in the lower legs, is bilateral 85% to 95% of the time and occurs most often in running athletes. The purpose of this case report is to describe the clinical presentation of unilateral chronic exertional compartment syndrome in a pediatric athlete that did not present with the hallmark signs for CECS and additionally participates in a sport where CECS is not common. The subject is a 13 year old female competitive figure skater who presented to physical therapy with right calf pain when figure skating and performing functional tasks. During the initial evaluation the patient had pain at rest as well as with objective testing of the right lower leg. The patient did not progress as expected in physical therapy and therefore the differential diagnosis was re-visited and additional measures were performed. The patient was re-diagnosed with unilateral chronic exertional compartment syndrome. The diagnosis was first clinical and later confirmed by intracompartmental testing. This case report illustrates a patient diagnosed with CECS by intra-compartmental pressure testing that did not present with the standard signs and symptoms; she did not participate in a sport where CECS is typically seen and her symptoms were unilateral. This report represents the importance of consistently including CECS in the differential diagnosis of lower leg pain in athletes regardless of the initial presentation and the sport in which they participate. Additionally, it highlights the importance of a detailed subjective history and the significance of aggravating and alleviating factors in relation to training.

Polymyalgia Rheumatica (PMR) with Normal Values of Both Erythrocyte Sedimentation Rate (ESR) and C-Reactive Protein (CRP) Concentration at the Time of Diagnosis in a Centenarian Man: A Case Report.

The possibility that polymyalgia rheumatica (PMR) can be diagnosed when both ESR and CRP are normal at the time of diagnosis and before therapy with glucocorticoids, has been often discussed in the literature. We present a case report of a 100-year-old Caucasian man referred to our outpatient clinic, complaining of chronic pain in the shoulder and hip girdle associated with normal values of both ESR (21 mm/1st hour) and CRP (4 mg/dL). In the previous four months, several anti-inflammatory drugs and painkillers associated with physiotherapy treatments gave no significant improvement in pain and self-care. After an ultrasound (US) and an 18-fluorodeoxyglucose positron emission tomography associated with total body computed tomography (18-FDG PET/CT) examination, PMR was diagnosed and he started therapy with 17.5 mg prednisone, obtaining a fast improvement in pain and self-care. After 10 months of tapering, he stopped prednisone without relapse. During a 3-year follow-up, no alternative diagnosis was done. When a patient complains of chronic bilateral shoulder and hip girdle pain associated with normal inflammatory indices, it is reasonable to think in the first instance that this person is not suffering from PMR. Moreover, the possibility that PMR may onset in a centenarian person, is exceptional. In our patient, when we piece the puzzle together, the diagnosis of PMR was the most possible one.

[Value of transcutaneous staged dynamic oximetry of stage II arteritis of the leg].

The clinical and prognostic value of transcutaneous oxygen pressure measurements at rest has been established in Leriche Stage III and IV occlusive peripheral arterial disease but is controversial in Stage II because there is an overlap of transcutaneous pO2 (Tc pO2) values with those of normal subjects. The authors report the results of Tc pO2 measurements during exercise testing in a group of patients with Stage II occlusive arterial disease of the lower limbs. Seventy-eight patients with an average age of 53 years (range 40 to 65 years) whose claudication perimeter and site of pain had been carefully assessed and who had also recently undergone Doppler arterial examination and arteriography and 35 control subjects with an average age of 54 years (range 45 to 70 years) were studied. The Tc pO2 was continuously measured with a multimodular Kontron Supermon at 4 different sites simultaneously: precordium (reference probe), thigh, calf and foot in the dorsal recumbent position after 30 minutes rest, during a standardised exercise stress test at 50 watts and during the recovery phase. The results were expressed as ratio of tissue oxygenation (RTO): thigh, calf or foot Tc pO2/precordial Tc pO2 X 100 in order to take into account the patients cardiorespiratory status and adaptation to exercise. The RTO in normal subjects remained at the upper limits of the resting value throughout exercise and then returned slowly to basal values during the recovery phase.(ABSTRACT TRUNCATED AT 250 WORDS)

Bilateral Exertional Compartment Syndrome With Endoscopic Fasciotomy Surgical Intervention in a High School Athlete.

A 17-year-old female presented to the physical therapy clinic with bilateral lower leg pain that worsened with activity. The patient experienced numbness, tingling, and cramping along the lateral and posterior portions of her legs during basketball practice, and her symptoms had gradually worsened over the past eight months. She obtained minimal relief with conservative treatments such as stretching and rest. X-rays and MRI of the lower limbs were obtained six months after symptoms began and were unremarkable. Further evaluation included compartment pressure testing taken before and after exercise. The patient demonstrated diagnostic pressures indicative of compartment syndrome in two compartments bilaterally. The patient was subsequently diagnosed with exertional compartment syndrome. Exertional compartment syndrome is a cause of muscle pain that occurs due to increased tissue pressure within the confinement of the closed fascial space during exercise. Patients are often misdiagnosed or there is a significant delay in the correct diagnosis. The gold standard for diagnosis is measurement of intracompartmental pressures with the Stryker catheter. Clinicians should consider exertional compartment syndrome in active patients who present with generalized muscle pain or sensation deficits that worsen with activity and are relieved with rest. Surgical intervention is a reasonable intervention and the only definitive option for an athlete with chronic exertional compartment syndrome who wants to continue high-level competition. Endoscopic fasciotomies are the new preferred techniques compared to more invasive open surgeries, which require a full incision. Endoscopic fasciotomy has a quicker healing time and has been shown to be as effective at relieving compartment syndrome symptoms as invasive open techniques. After surgical intervention, the patient reported a 90% reduction in symptoms and had returned to full sport participation within two months.

Exercise hyperemia for the study of peripheral circulation.

Blood flow in the calf was measured during postexercise hyperemia in normal subjects and in PAD patients by means of a foot ergometer that gives direct reading of the work performed. In normals, first and peak flow increased with the rise of work load up to 100 KGM. The duration of hyperemia increased with a work load of 30 to 200 KGM. In PAD patients, first flow did not coincide with peak flow. Peak flow was lower and delayed, and the duration of hyperemia was more prolonged than in normal subjects. In patients with intermittent claudication, first flow, peak flow, and work load were higher than in patients with rest pain or impending gangrene. Exercise hyperemia appears as a useful test for screening normal limbs from those with arterial obstruction. Since in PAD patients exercise is interrupted when muscular pain appears, it is evident that the earlier the arrest of work and the appearance of pain, the greater is the involvement in the arterial tree of the leg. Therefore the exercise hyperemia test can be used also as a means of evaluating the different stages of PAD.

Non-invasive neurosensory testing used to diagnose and confirm successful surgical management of lower extremity deep distal posterior compartment syndrome.

Chronic exertional compartment syndrome (CECS) is characterized by elevated pressures within a closed space of an extremity muscular compartment, causing pain and/or disability by impairing the neuromuscular function of the involved compartment. The diagnosis of CECS is primarily made on careful history and physical exam. The gold standard test to confirm the diagnosis of CECS is invasive intra-compartmental pressure measurements. Sensory nerve function is often diminished during symptomatic periods of CECS. Sensory nerve function can be documented with the use of non-painful, non-invasive neurosensory testing. Non-painful neurosensory testing of the myelinated large sensory nerve fibers of the lower extremity were obtained with the Pressure Specified Sensory Device in a 25 year old male with history and invasive compartment pressures consistent with CECS both before and after running on a tread mill. After the patient's first operation to release the deep distal posterior compartment, the patient failed to improve. Repeat sensory testing revealed continued change in his function with exercise. He was returned to the operating room where a repeat procedure revealed that the deep posterior compartment was not completely released due to an unusual anatomic variant, and therefore complete release was accomplished. The patient's symptoms numbness in the plantar foot and pain in the distal calf improved after this procedure and his repeat sensory testing performed before and after running on the treadmill documented this improvement. This case report illustrates the principal that non-invasive neurosensory testing can detect reversible changes in sensory nerve function after a provocative test and may be a helpful non-invasive technique to managing difficult cases of persistent lower extremity symptoms after failed decompressive fasciotomies for CECS. It can easily be performed before and after exercise and be repeated at multiple intervals without patient dissatisfaction. It is especially helpful when other traditional testing has failed.

High-energy phosphate metabolism during incremental calf exercise in patients with unilaterally symptomatic peripheral arterial disease measured by phosphor 31 magnetic resonance spectroscopy.

The treadmill exercise test is the most important examination of the functional ability of patients with intermittent claudication or leg pain during exercise, but it does not provide any metabolic information in the calf muscle. The purpose of this study was to investigate the high-energy metabolism in the calf muscle during incremental progressive plantar flexion exercise of a selected peripheral arterial disease (PAD) patient group. Using a 1.5-T whole-body magnetic resonance scanner, 17 male patients with PAD who had 1 symptomatic and 1 asymptomatic leg and 9 healthy male controls underwent serial phosphor 31 (31P) magnetic resonance spectroscopy during incremental exercise at 2, 3, 4, and 5 W. Furthermore, magnetic resonance angiography was performed, and the ankle-brachial pressure index was determined in the patient group. The runoff resistance (ROR) was separately assessed in each patient's leg. The symptomatic legs exhibited significantly increased phosphocreatine (PCr) time constants during the first three workload increments (2-4 W) and the recovery phase compared with the asymptomatic legs and the normal controls. Only two symptomatic legs reached the last increment at 5 W. Compared with the normal controls, the asymptomatic legs showed significantly increased PCr time constants only at 5 W. In the patient group, we detected significant correlations between the PCr time constants and the ROR, as well as the ankle-brachial pressure index. Moreover, the symptomatic legs presented significantly lower PCr levels and pH values at the end of exercise compared with the asymptomatic and control legs. Our study shows that muscle function in PAD patients can be objectively quantified with the help of 31P magnetic resonance spectroscopy and correlates significantly with hemodynamic parameters such as ROR and ankle-brachial pressure index. Consequently, 31P magnetic resonance spectroscopy seems to be a useful method to monitor the muscle function of PAD patients for evaluation of established therapies or new therapeutic strategies during research trials.

Effect of dry needling of gluteal muscles on straight leg raise: a randomised, placebo controlled, double blind trial.

To use a randomised, double blind, placebo controlled trial to establish the effect on straight leg raise, hip internal rotation, and muscle pain of dry needling treatment to the gluteal muscles in athletes with posterior thigh pain referred from gluteal trigger points. A randomised, double blind, placebo controlled trial of 59 male runners was performed during the 2002 Australian Rules football season. Subjects were thoroughly screened and had magnetic resonance imaging of their hamstring muscles to exclude local pathology. The inclusion criterion was reproduction of recognisable posterior thigh pain with the application of digital pressure to the gluteal trigger points. Subjects randomly received either therapeutic or placebo needle treatment on one occasion at their gluteal trigger points. Range of motion and visual analogue scale data were collected immediately before, immediately after, 24 hours after, and 72 hours after the intervention. Range of motion was measured with passive straight leg raise and hip internal rotation. Visual analogue scales were completed for hamstring and gluteal pain and tightness at rest and during a running task. Magnetic resonance imaging scans revealed normal hamstring musculature in most subjects. Straight leg raise and hip internal rotation remained unchanged in both groups at all times. Visual analogue scale assessment of hamstring pain and tightness and gluteal tightness after running showed improvements immediately after the intervention in both groups (p = 0.001), which were maintained at 24 and 72 hours. The magnitude of this improvement was the same for therapeutic and placebo interventions. Resting muscle pain and tightness were unaffected. Neither dry needling nor placebo needling of the gluteal muscles resulted in any change in straight leg raise or hip internal rotation. Both interventions resulted in subjective improvement in activity related muscle pain and tightness. Despite being commonly used clinical tests in this situation, straight leg raise and hip internal rotation are not likely to help the therapist assess response to treatment. Patient reports of response to such treatment are better indicators of its success. The mechanisms by which these responses occur and the reasons for the success of the placebo needling treatment are areas for further investigation.

[Regional blood flow and oxygen consumption in the leg muscles of normal subjects and in those with arterial insufficiency. Study of the distribution of C15O2 and of 15O2 using positron emission tomography].

We first studied the distribution of radioactivity during continuous inhalation of C15O2 and 15O2 in traverse tomograms of the greatest diameter of legs, at rest and immediately after exercise (ankle flexions). C15O2 and 15O2 were distributed homogeneously and symmetrically in both legs of normal subjects at rest. The activity accumulated in the anterolateral region after exercise. In patients, this pattern of distribution was similar but asymmetrical, depending on the arterial pathology. No systematic distribution of either C15O2 or 15O2 was observed. In a second step, we studied quantitatively blood flow (F), oxygen uptake (R) and oxygen extraction (E) in 11 subjects: 5 normals (23 +/- 1 years) and 6 patients (60 +/- 11 years) suffering from unilateral intermittent claudication. We used the bolus inhalation technique of C15O2 and 15O2. In the normal leg at rest, ranges were 2.5 to 8.0 ml/min.hg for F, 0.9 to 21.3 mumol/min.hg for R and 3.6 to 33.4% for E. In the pathological leg at rest, ranges were 3.7 to 11.3 ml/min.hg for F, 3.8 to 10.6 mumol/min.hg for R and 7.1 to 24.5% for E. After exercise, ranges were 6.4 to 62.8 ml/min.hg for F, 66.0 to 386.3 mumol/min.hg for R and 29.2 to 89.5% for E in both legs. There was no straight difference between normal and pathological legs soon after exercise. This study allows us to expect that the demonstration of such a difference implies a longer delay of data acquisition following the slow post-ischemia recovery.

Can pain influence the severity of findings of an (18)F-FDG PET/CT scan in loosening hip arthroplasty?

Pain is a common symptom after loosening and/or after infection of arthroplasty. The aim of the present case report is to indicate that fluorine-18-fluorodeoxy-glucose positron emission tomography/computerized tomography((18)F-FDG PET/CT) scan can be used for the evaluation of pain at the site of arthroplasty with a semi quantitative measurement. An 84 years old male patient, with a history of papillary thyroid cancer was referred to our Nuclear Medicine Department for an (18)F-FDG PET/CT scan for evaluation of his metastatic disease. He reported right hip prosthesis thirty years ago and now suffered from significant pain in the right hip joint which on a scale  from 1 to 10 could be rated as grade 8. White blood cell count, sedimentation rate and C-reactive protein were within normal limits. Four years ago he also had severe pain on the right leg that  could be rated as grade 8, and underwent an (18)F-FDG PET/CT scan that showed a maximum standardized uptake value (SUV(max)) of 9.8. A year later, at a follow up (18)F-FDG PET/CT scan  and under a similar severe pain, SUV(max) was 10. The patient had a hip prosthesis in the left leg 3 years ago, for which he reported pain that could be rated as grade 3 and  the SUV(max) was then 3.7. The degree of (18)F-FDG uptake is related to cellular metabolic rate and to the number of glucose transporters. In inflammation, the activated inflammatory cells demonstrate increased expression of glucose transporters and the affinity of glucose transporters for deoxyglucose is increased by various cytokines and growth factors.  Furthermore, when the mononuclear cells and the granulocytes are activated by certain infectious humoral stimuli, they use large amounts of glucose by the hexose monophosphate shunt and the rate of oxygen uptake is intensely increased, during the so called "respiratory burst". In the present case, it was interesting to note that the degree of (18)F-FDG uptake at the sites of loosening hip arthroplasty was related to the severity of pain. Signs of infection or inflammation although  not obvious in our case, could not be excluded because sensitivity, specificity and accuracy of PET for detecting infection associated with hip prostheses has been  reported to be, 90%, 89.3% and 89.5%, respectively and sensitivity and specificity for detecting periprosthetic inflammation 100% and 45.5%,respectively. In another study using as a criterion for periprosthetic infection the increased (18)F-FDG activity at the bone-prosthesis interface of the femoral component, sensitivity, specificity, positive and negative predictive values for the (18)F-FDG PET study  where 85%, 93%, 80% and 95%, respectively. Inflammation, often intense, may be present in aseptic loosening and characterized by increased periprosthetic (18)F-FDG uptake. In conclusion, in our case the degree of (18)F-FDG uptake in a loosening hip arthroplasty was related to the severity of pain although inflammation or infection could also play some role.  Further studies are required to prove this suggestion.

[Contribution of the maximal exercise test to diagnosis the vascular origin of leg pain in athletes].

Leg pain is a common debilitating symptom in athletes. Vascular disease is not often proposed as a possible cause. Maximal exercise with measure of the ankle-brachial index after exercise can be an interesting diagnostic test. We report an illustrative case where an athlete presented leg pain revealing arterial disease disclosed by exercise. Interestingly, sub-maximal exercise did not cause pain, causing a delay in diagnosis. The vascular origin of leg pain can be detected with a maximal exercise test that induces the symptomatic pain or at least clinical discomfort.

The diagnostic value of intracompartmental pressure measurement, magnetic resonance imaging, and near-infrared spectroscopy in chronic exertional compartment syndrome: a prospective study in 50 patients.

Patients with chronic exertional compartment syndrome have pain during exercise that usually subsides at rest. History and physical examination may raise suspicion of the syndrome; diagnosis is usually confirmed with intracompartmental pressure measurement after exercise. Studies have shown that magnetic resonance imaging and near-infrared spectroscopy have diagnostic ability in this syndrome. Magnetic resonance imaging and near-infrared spectroscopy can be used to diagnose chronic exertional compartment syndrome. Cohort study (diagnosis); Level of evidence, 2. Patients were enrolled if there was clinical suspicion of chronic exertional compartment syndrome, and a fasciotomy was performed based on this suspicion. Before fasciotomy, intracompartmental pressure, near-infrared spectroscopy, and magnetic resonance imaging data were collected during and after exercise on a treadmill. Near-infrared spectroscopy and intracompartmental pressure values were recorded in the same manner after fasciotomy. Retrospective proof that diagnosis of the syndrome had been correct was the absence of exertional complaints from the preoperative examination during exercise at postfasciotomy visit. Fifty patients (100 legs) participated in the prefasciotomy visit; 3 refused fasciotomy; 2 were lost to follow-up. Of 45 patients who completed the postfasciotomy visit, the diagnosis of chronic exertional compartment syndrome was retrospectively confirmed in 42 patients and discarded in 3 patients. The sensitivity for intracompartmental pressure (cutoff point, 35 mmHg) found in this study was 77% (67%-86%, exact 95% confidence interval), lower than estimates from the literature (93%). The sensitivity (previously defined cutoff) for near-infrared spectroscopy was 85% (76%-92%, exact 95% confidence interval), validating the estimate found in the literature (85%). Sensitivity of magnetic resonance imaging was comparable to that of intracompartmental pressure and near-infrared spectroscopy; associated specificity at a given sensitivity appeared to be lower with magnetic resonance imaging. This study validates the sensitivity of near-infrared spectroscopy and provides estimates for the sensitivity and specificity of magnetic resonance imaging in chronic exertional compartment syndrome in a large group of patients. The sensitivity of noninvasive near-infrared spectroscopy is clinically equivalent to that of invasive intracompartmental pressure measurements.

[Quantitative 201Tl-scintigraphy of the lower limb in arterial occlusive disease].

201Tl scintigraphy is useful in evaluating the hemodynamic consequences of arterial stenoses in arterial occlusive disease. The aim of the present study was to determine normal values for absolute Tl uptake in the lower leg, for the quotient between left and right lower leg uptake as well as for the redistribution pattern after bicycle exercise. We examined as reference 49 patients without clinical evidence of peripheral or coronary artery disease: absolute Tl uptake in the lower leg in anterior scintigraphy (acquisition time: 120 sec) was 5.02 +/- 1.70 counts/pixel (left) and 5.21 +/- 1.53 counts/pixel (right), the quotient between right and left lower leg was 0.85 +/- 0.09 and the redistribution pattern (quotient of the mean activity exercise/rest) 0.82 +/- 0.17 (left) and 0.83 +/- 0.15 (right). The arithmetic mean minus 2 standard deviations was regarded as the lower limit of normal. In 8 patients with mechanical compression of the left femoral artery before injection at least two scintigraphic parameters were abnormal, in 7 patients with angiographically proven peripheral artery disease at least one scintigraphic parameter was below normal. Quantification of Tl redistribution offers diagnostic advantages in bilateral peripheral artery disease.

Complex Regional Pain Syndrome Caused by Lumbar Herniated Intervertebral Disc Disease.

Most cases of complex regional pain syndrome (CRPS) occur after some inciting injury. There are a few cases of CRPS after an operation for disc disease. CRPS from a mild herniated intervertebral disc (HIVD) without surgical intervention is even rarer than CRPS after an operation for disc disease.A 22-year-old man was transferred to a pain clinic. He had continuously complained about back and right leg pain. He presented with a skin color change in the right lower leg, intermittent resting tremor, stiffness, and swelling in the right leg. He complained of a pulling sensation and numbness in his right buttock, posterior thigh, lateral calf, and ankle. This symptom was in accordance with L4/5 radiculopathy. Magnetic resonance imaging (MRI) also showed L4/5 HIVD that was central to the bilateral subarticular protrusion.He was diagnosed as having CRPS, which fits the revised International Association for the Study of Pain (IASP) criteria. He fulfilled 4 symptom categories (allodynia, temperature asymmetry and skin color change, sweating changes, decreased range of motion and motor dysfunction) and 3 of 4 sign categories (allodynia, temperature asymmetry and skin color changes, decreased range of motion and motor dysfunction). The bone scan and thermography also revealed CRPS.For the past 2 months, we have performed intensive treatments. But, he never became pain-free and walking for 5 minutes led to persistent leg pain. We decided to perform percutaneous nucleoplasty, which can directly decompress a HIVD. On the next day, he achieved dramatic symptom relief. The visual analog scale (VAS) score improved to 3, compared to the VAS score of 9 at the first visit. The skin color change, allodynia, and tremor in the right leg disappeared, and the temperature asymmetry normalized. Motor weakness of the right leg also recovered.We report an unusual case of CRPS that was caused by L4/5 HIVD without a history of trauma or surgery. It has a clear causal relationship between HIVD and CRPS and definitively fits in the newly revised IASP criteria. In conclusion, mild HIVD can cause CRPS without any trauma. And percutaneous nucleoplasty can be considered as a treatment option.

Effects of prior heavy-intensity exercise during single-leg knee extension on VO2 kinetics and limb blood flow.

The effects of prior heavy-intensity exercise on O(2) uptake (Vo(2)) kinetics of a second heavy exercise may be due to vasodilation (associated with metabolic acidosis) and improved muscle blood flow. This study examined the effect of prior heavy-intensity exercise on femoral artery blood flow (Qleg) and its relationship with Vo(2) kinetics. Five young subjects completed five to eight repeats of two 6-min bouts of heavy-intensity one-legged, knee-extension exercise separated by 6 min of loadless exercise. Vo(2) was measured breath by breath. Pulsed-wave Doppler ultrasound was used to measure Qleg. Vo(2) and blood flow velocity data were fit using a monoexponential model to identify phase II and phase III time periods and estimate the response amplitudes and time constants (tau). Phase II Vo(2) kinetics was speeded on the second heavy-intensity exercise [mean tau (SD), 29 (10) s to 24 (10) s, P < 0.05] with no change in the phase II (or phase III) amplitude. Qleg was elevated before the second exercise [1.55 (0.34) l/min to 1.90 (0.25) l/min, P < 0.05], but the amplitude and time course [tau, 25 (13) s to 35 (13) s] were not changed, such that throughout the transient the Qleg (and DeltaQleg/DeltaVo(2)) did not differ from the prior heavy exercise. Thus Vo(2) kinetics were accelerated on the second exercise, but the faster kinetics were not associated with changes in Qleg. Thus limb blood flow appears not to limit Vo(2) kinetics during single-leg heavy-intensity exercise nor to be the mechanism of the altered Vo(2) response after heavy-intensity prior exercise.

Utilization behavior

Diagnosis Quantitative methods of assessing utilization behavior are not available for use and because of this those who notice changes in behavior similar to that of the signs of UB should see a doctor. Many functional disorders can be mistaken for frontal dysfunction as several neurological causes can be attributed to frontal dysfunction. Proper criteria need to be in place for determining UB but because this disorder is in the elementary stage, researchers have not arrived at a full understanding of the disorder. Doctors can test the patient's response, communication and motor skills but the only way to fully diagnose this disorder is to do a scan of the brain to see if the frontal lobe has been damaged. This can be done with the following scan types: CT Scan (X-ray computed tomography) MRI (Magnetic resonance imaging) PET (Positron emission tomography) SPECT (Single-photon emission computed tomography)

Exercise testing criteria to diagnose lower extremity peripheral artery disease assessed by computed-tomography angiography.

The sensitivity and specificity of exercise testing have never been studied simultaneously against an objective quantification of arterial stenosis. Aims were to define the sensitivity and specificity of several exercise tests to detect peripheral artery disease (PAD), and to assess whether or not defined criteria defined in patients suspected of having a PAD show a difference dependent on the resting ABI. In this prospective study, consecutive patients with exertional limb pain referred to our vascular center were included. All patients had an ABI, a treadmill exercise-oximetry test, a second treadmill test (both 10% slope; 3.2km/h speed) with post-exercise pressures, and a computed-tomography-angiography (CTA). The receiver-operating-characteristic curve was used to define a cut-off point corresponding to the best area under the curve (AUC; [CI95%]) to detect arterial stenosis ≥50% as determined by the CTA. Sixty-three patients (61+/-11 years-old) were included. Similar AUCs from 0.72[0.63-0.79] to 0.83[0.75-0.89] were found for the different tests in the overall population. To detect arterial stenosis ≥50%, cut-off values of ABI, post-exercise ABI, post-exercise ABI decrease, post-exercise ankle pressure decrease, and distal delta from rest oxygen pressure (DROP) index were ≤0.91, ≤0.52, ≥43%, ≥20mmHg and ≤-15mmHg, respectively (p<0.01). In the subset of patients with an ABI >0.91, cut-off values of post-exercise ABI decrease (AUC = 0.67[0.53-0.78]), and DROP (AUC = 0.67[0.53-0.78]) were ≥18.5%, and ≤-15mmHg respectively (p<0.05). Resting ABI is as accurate as exercise testing in patients with exertional limb pain. Specific exercise testing cut-off values should be used in patients with normal ABI to diagnose PAD.

Accuracy of Palpation-Guided Catheter Placement for Muscle Pressure Measurements in Suspected Deep Posterior Chronic Exertional Compartment Syndrome of the Lower Leg: A Magnetic Resonance Imaging Study.

A diagnosis of lower leg deep posterior chronic exertional compartment syndrome (dp-CECS) is made by a dynamic pressure measurement. The insertion of a pressure catheter is guided by anatomic landmarks (freehand) or by ultrasound. The catheter tip is ideally positioned in the tibialis posterior muscle (TP). The accuracy of in vivo catheter placement using lower leg magnetic resonance imaging (MRI) in healthy patients suspected of having dp-CECS has never been studied. To analyze whether a freehand catheter insertion results in accurate positioning in the TP as confirmed by MRI in patients with suspected dp-CECS. Case series; Level of evidence, 4. Catheters were inserted into central portions of the TP using a standard puncturing technique guided by lower leg anatomic landmarks. After timed muscle pressure measurements during a standard provocative treadmill running test, lower leg MRI scans were obtained and evaluated by 2 skilled radiologists. Catheter tip placement was termed accurate (in the TP), suboptimal (in the deep posterior compartment but outside the TP), or inaccurate (outside the deep posterior compartment). Between March 2013 and September 2014, a total of 24 patients (8 male, 16 female; mean age, 30 years [range, 18-54 years]) underwent an intracompartmental pressure (ICP) measurement, followed by MRI. Cardinal symptoms were pain during exertion (20% very severe, 53% severe, and 20% moderate) and tightness (29% very severe, 43% severe). Symptoms were bilateral in 74% of patients. Nine of the 24 patients were diagnosed with dp-CECS based on elevated ICPs. Of the 24 patients, catheter tip placement was accurate in 10 (42%), whereas suboptimal placement was achieved in 9 (38%). Five procedures were inaccurate (transition zone between the deep and superficial compartments, n = 3; in the superficial lower leg compartment, n = 2). Signs of a hematoma were found in 38% of the patients, although there were no associated clinical symptoms. Palpation-guided placement of catheters for TP pressure measurements is suboptimal in more than half of the patients with suspected lower leg dp-CECS. Optimizing the pressure catheter tip positioning technique may improve diagnostic accuracy in dp-CECS.

The quantitation of blood flow/metabolism coupling at rest and after exercise in peripheral arterial insufficiency, using PET and 15-0 labeled tracers.

Regional blood flow and oxygen uptake of the lower limbs were studied in 11 patients with arterial insufficiency (10 with severe unilateral, 1 with bilateral intermittent claudication). Regional muscle blood flow (F), oxygen consumption rate (R), and oxygen extraction fraction (E) were evaluated by positron emission tomography (PET) and bolus inhalation of C15O2 and 15O2 by the patient. Tomograms were recorded at the greatest diameter of legs, at rest and ten minutes after a treadmill walk test leading to the development of ischemic pain in the affected leg. In 5 patients, F and E were correlated with the results of occlusive venous strain gauge plethysmography and with the measurements of blood gases in one brachial artery and in the femoral vein of the affected limb. Blood flow values measured at rest and after exercise by PET were poorly correlated with the plethysmographic findings. This may be because PET does not interfere with flow as venous occlusion plethysmography does in low peripheral pressure conditions. The results show that F, R, and E were not significantly different in normal and pathologic legs at rest. The values of F and R were significantly higher in pathologic than in normal lower limbs, ten minutes after exercise, whereas E was not significantly altered by exercise at any side. This suggests that, during the recovery from a walk test, the delayed increase in oxygen uptake is proportional to the delayed hyperemia in the ischemic muscles ("oxygen debt") and probably not linked to a luxury perfusion.

Medial collateral ligament bursitis in a 12-year-old girl.

A 12-year-old female athlete, training for an international career in pentathlon, was referred to our clinic because of 2 years of recurrent localized swelling and activity-related pain in the medial aspect of her right knee, since falling from a horse and hitting her knees on the ground. She had been examined by a number of doctors over this period and treated with physiotherapy without a proper diagnosis and with no improvement. She could run only very limited distances before excruciating pain and swelling, and she had to abandon participation in competitions. During rest, the swelling decreased but never disappeared entirely. Clinical examination revealed minor effusion and localized tenderness on palpation around the medial joint line. Magnetic resonance imaging showed fluid between the medial capsule and medial collateral ligament, but could not identify any connection to the joint. Arthroscopy revealed a cleavage in the posterior medial joint capsule, superior and close to the medial meniscus, that was connected to the medial collateral ligament bursa. The cleavage was simply expanded, which emptied the bursa, followed by compression bandage and ice for 2 weeks. An immediate positive effect was observed and she could run pain free without swelling within 3 weeks of surgery. Six months after surgery, there has been no recurrence. To our knowledge, this is the first time this injury has been described in a child.

99Tcm-sestamibi uptake in the leg muscles and in the myocardium in patients with intermittent claudication.

99Tcm-Sestamibi has now replaced 201Tl as a cardiac imaging agent. In addition to the myocardial uptake there is also a considerable uptake in the striated muscle, which may be used for analyzing the muscular perfusion. Sixteen patients with intermittent claudication were investigated with 99Tcm-Sestamibi-SPECT (single photon emission computerized tomography) in order to visualize coronary ischemic disease. After the registration of the myocardial perfusion they were also studied regarding their leg muscle perfusion. This was done at rest and during standardized stress test using a bicycle ergometer. In 10 of the patients there was an increase in the isotope uptake in the myocardium from work to rest > 10% reflecting pronounced myocardial ischemia, which, however, was symptomatic in only 4 of the patients. The muscular uptake in the myocardium of 99Tcm-Sestamibi in the thigh increased significantly from rest to exercise (P < 0.01), while it remained unchanged in the calf muscle. There were no significant correlations at rest between the ratio of the right and left systolic blood pressure in the ankles and the ratio between the right and left isotope uptake in the calves, but the increase in the isotope uptake from rest to work correlated with the blood pressure ratio at r = 0.79, P < 0.01 (anterior projection) and r = 0.71, P < 0.01 (posterior projection).

Sacral fatigue fracture in a young girl with no history of trauma or reported athletic activity: a case report.

Sacral fatigue fractures in the young population usually occur due to repetitious physical strain from vigorous athletic activity; they are extremely rare in those younger than 13 years without intense physical activity. We report a case of sacral fatigue fracture in a healthy elementary school girl without any history of trauma or excessive athletic activity. A healthy 11-year-old girl experienced sudden low back pain upon standing after a short break in a normal running exercise for physical education at school. At her first orthopaedic visit, she was unable to walk independently and was limping on her left leg. Neurological examination revealed that the left straight leg raising test was positive at 80 degrees with associated left buttock pain but without motor and sensory deterioration. Radiological examination showed no obvious fractures in the lumbar vertebrae or pelvis. Magnetic resonance imaging demonstrated high intensity signal changes on the short tau inversion recovery image of the left ala, and sacral fatigue fracture in the left ala was diagnosed. She was instructed to rest at home and allowed minimal walking with a crutch under endurable pain for 4 weeks. Within 3 weeks, her low back pain gradually reduced, and after 4 weeks, she could walk independently without gait pain. Sacral fatigue fractures should be considered in the diagnosis of young patients who present with unexplained low back pain.

Simultaneous isotope clearance from the muscles of the calf and thigh.

There has been no end to the attempts made to determine the site and severity of arterial lesions in claudicants by the use of non-invasive methods but, so far, their diagnostic value has been limited. A method whose diagnostic accuracy in determining the site and functional severity of the lesions approaches that of arteriography is discussed. The hyperaemic index, which is the ratio of the total excess of blood supply during post-exercise hyperaemia over the maximum hyperaemic flow, has been determined in the thigh and calf simultaneously, by measuring the 99Tcm muscle clearance in 30 limbs of 20 healthy volunteers and 139 limbs of 145 patients with claudication. Lumbar arteriography classified the lesions in all patients as 0-10 per cent, 10-40 per cent, 40-70 per cent and more than 70 per cent stenosis. A bivariate analysis of the hyperamic indices of the thigh and calf determined the site and whether single lesions consisted of a stenosis greater or less than 70 per cent. In limbs with combined aorto-iliac and superficial femoral lesions the values of the hyperaemic indices could determine which of the two lesions was the more severe in addition to whether lesions consisted of a stenosis greater or less than 70 per cent. These findings have been confirmed in a further blind prospective study of 47 limbs in which determination of the site and severity of lesions preceded aortography.

Case report: the role of multimodal imaging to optimize the timing of return to sports in an elite athlete with persistent COVID-19 myocardial inflammation.

COVID-19 has been associated with myocardial abnormalities on cardiac magnetic resonance imaging (CMR). We report a case of COVID-19 myocarditis in an elite athlete. A male, 21-year-old elite football player had tested positive for SARS-CoV-2 on a polymerase-chain-reaction test and was referred for cardiac evaluation after experiencing palpitations after returning to sports (RTS). Biochemical evaluation demonstrated elevated N-terminal pro b-type natriuretic peptide (NT-proBNP) and high-sensitive Troponin T. Echocardiography demonstrated left ventricular function within normal ranges for athletes but with diminished basal, posterolateral, and septal strain. Cardiac magnetic resonance imaging (CMR) showed increased T1 values and late gadolinium enhancement (LGE) in the basolateral and mid-ventricular posterior segments. Focal COVID-19 myocarditis was diagnosed and the patient remained restricted from sports, in line with the 2020 ESC sports cardiology guidelines. Two months later, his electrocardiogram (ECG) showed inferoposterolateral T-wave inversion (TWI). Serial imaging studies were performed to optimize RTS timing. Cardiac magnetic resonance imaging showed persistently increased T1/T2 values and persistent LGE at 5 and 7 months. At 9 months, 18 F-fluorodeoxyglucose (FDG)-positron emission tomography (PET)-computerized tomography (CT) demonstrated no pathologically increased cardiac FDG-uptake. Subsequent exercise ECG and Holters demonstrated no complex ventricular arrhythmias. The patient made a complete return to elite competitive sports, without any adverse events at 15 months of follow-up. Cardiac symptoms in athletes post-COVID-19 should prompt cardiac evaluation. As COVID-19 myocarditis inflammation can persist beyond the 3-6 months of recommended sports restriction, a more personalized approach to RTS timing can be warranted. In cases with myocardial oedema without other signs of inflammation, FDG-PET-CT can be of added value to assess active myocardial inflammation.

Calf muscle stimulation with the Veinoplus device results in a significant increase in lower limb inflow without generating limb ischemia or pain in patients with peripheral artery disease.

Increase in arterial inflow to the lower limbs is important to obtain functional improvement in peripheral artery disease (PAD) patients with claudication. The aim of this study was to assess the effect of electrical stimulation of calf muscles on arterial inflow and tissue oxygen content in PAD in the area of stimulation. Fifteen adult patients [mean (standard deviation) age, 62 (12 ) years; height, 165 (8)cm; weight, 76 (13) kg; lowest ankle-brachial index 0.66 (0.19)] with stable arterial claudication were recruited. All patients performed a treadmill test (3.2 km/h, 10% slope) associated with a transcutaneous oximetry test expressed as decrease from rest of oxygen pressure (DROP) index values (calf changes minus chest changes from rest) with a maximum walking distance (median [25th/75th percentiles]) of 295 [133-881] m. The DROP index on the symptomatic side was -25 [-18/-34] mm Hg. On another day the patients underwent electrical stimulation in the seated position on the leg that was the most symptomatic on the treadmill. After resting values were recorded, the gastrocnemius was stimulated for 20minutes at increasing contraction rates at 5-minute steps of 60, 75, 86, and 100bpm on the most symptomatic side. Arterial blood inflow with duplex Doppler ultrasound scanning of the femoral artery, DROP transcutaneous oxygen pressure value, and oxygen concentration (O2Hb) from the near-infrared spectroscopic signal of the calf were recorded on both sides. Patients were instructed to report eventual contraction-induced pain in the stimulated calf. Results are given as mean (standard deviation) or median [25th/75th percentiles] according to distribution, and the level of statistical significance was set at P < .05 on two-tailed tests. Lower limb inflow (mL/min) was 64 [48/86] vs 63 [57/81] (P> .05) before stimulation, 123 [75/156] vs 57 [44/92] (P < .01) at 60bpm, 127 [91/207] vs 49 [43/68] (P < .01) at 75bpm, 140 [84/200] vs 57 [45/71] (P < .01) at 86bpm, and 154 [86/185] vs 55 [46/94] (P < .01) at 100bpm on the stimulated vs nonstimulated limb, respectively. No apparent decrease or significant leg difference was observed in DROP index or O2Hb values. None of the patients reported contraction-induced pain in the leg. Electrical stimulation of calf muscle with the Veinoplus device results in a significant increase of arterial inflow without measurable muscle ischemia or pain. Potential use of this device as an adjuvant treatment to improve walking capacity in PAD patients remains to be evaluated.

Deep vein thrombosis in a young marathon athlete.

Resident's case problem. A 21-year-old athletic male college student presented to a direct-access physical therapy clinic with complaints of left calf pain 4 days in duration. After initial examination, a working diagnosis of calf strain was formulated. Three days following initial examination, the patient reported 80% improvement in symptoms and was performing activities of daily living pain free. Four weeks later, the patient returned with complaints of reoccurring calf pain. The patient's signs, symptoms, and history at subsequent follow-up no longer presented a consistent clinical picture of calf strain; therefore, a D-dimer assay was ordered to rule out a deep vein thrombosis (DVT). The D-dimer was elevated so the patient was admitted to the hospital and started on low-molecular-weight heparin. A compression ultrasound revealed an extensive left superficial femoral and popliteal DVT in this otherwise healthy athlete. Lower extremity DVT is a serious and potentially fatal disorder. Physical therapists need to be diagnostically vigilant for vascular pathology in all patients with extremity pain and swelling. Employing the best current evidenced-based screening tools to rule out vascular pathology, such as deep and superficial vein pathology, should be the goal of every clinician. The Wells score is one such screening tool that has proven to be beneficial in this area. This case report presents a dilemma in diagnosis and illustrates the importance of revisiting differential diagnoses with each patient encounter. Clinicians must consider the possibility of a DVT with every patient seen with posterior leg pain. Diagnosis, level 4. doi:10.2519/jospt.2011.3823.

Blood flow measurements in lower limb arteries using duplex ultrasound.

The increase in blood flow in exercise is to provide more oxygen to tissues. The kinetics of flow at the common femoral artery bifurcation were established in normal subjects together with its relationship with oxygen uptake. Furthermore, the changes in flow were evaluated in patients undergoing superficial femoral artery angioplasty. After a known anaerobic test (Wingate test), normal subjects underwent a preferential increase in profunda femoris artery flow (ninefold increase), compared with superficial femoral artery flow (fourfold increase), indicating predominantly thigh exercise. The relationship between oxygen uptake and lower limb blood flow was studied before, during and after moderate intensity exercise. Oxygen uptake was measured by mass spectrometry and assessed by breath-by-breath analysis. The rate of increase for limb blood flow, as indicated by the time constant, was faster (28.8 +/- 4.4 s; mean +/- sem) than oxygen uptake (41.5 +/- 7.2 s) at the onset of exercise. This implies that limb blood flow is in excess of the oxygen requirements of muscle and therefore not the critical determinant for oxygen uptake by muscle. Flow in the lower limb arteries was measured before and after superficial femoral artery angioplasty in 22 patients. In addition, collateral blood flow was estimated using a mathematical model. Follow-up was carried out to 1 year. At 1 month, a significant decrease in profunda femoris artery flow (from 224 +/- 84 to 98 +/- 43 ml min-1, P < 0.05, paired t test) and a marked diminution in collateral flow (from 186 +/- 34 to 18 +/- 8 ml min-1, P < 0.05) was noted with no change in total limb blood flow. As expected, a significant increase in superficial femoral artery blood flow was seen (148 +/- 79 to 312 +/- 94 ml min-1, P < 0.05). From the studies, it can be seen that non-invasive duplex ultrasound flow measurements can reliably be obtained in the lower limb, allowing the kinetics of flow after exercise and the changes in flow after surgical intervention to be evaluated. This work provides a foundation for the study of oxygen kinetics and limb blood flow in athletes, the elderly and patients with peripheral vascular disease.

Intractable sciatica due to intraneural nodular fasciitis detected by positron emission tomography.

Case report. To describe a patient with nodular fasciitis in the sciatic nerve, detected by positron emission tomography (PET). Severe sciatic pain is commonly caused by lumbar disc herniation, lumbar spinal stenosis, or neoplastic lesion. These lesions are usually diagnosed by plain radiograph, myelography, computed tomography, and magnetic resonance imaging.Nodular fasciitis is a benign connective tissue tumor usually presenting as a firm, rapidly-growing lesion, occasionally arising in the forearm. Only 5 cases of intraneural nodular fasciitis have been reported in the published data, and although some have demonstrated mild neuropathy, none have shown nodular fasciitis with intractable sciatica. A 37-year old woman experienced severe sciatica after hitting her left buttock hard on the edge of a bathtub. Physical examination demonstrated intense radiating pain from the left buttock to the lateral calf. There was weakness in the sciatic nerve innervated musculature. She was diagnosed with piriformis syndrome in a local hospital. However, the symptoms remained unchanged after surgery, releasing the piriformis. Conventional imaging of the sciatica including plain radiograph, computed tomography, and magnetic resonance imaging of the spine showed a return of abnormal findings. PET detected an abnormal lesion in the sciatic nerve in the posterior compartment of the patient's left thigh, indicating an intraneural tumor in the sciatic nerve. Subtotal resection was achieved and histologic evaluation of the specimen showed the typical features of nodular fasciitis. After surgery, the patient was relieved of all symptoms, with no evidence of recurrence at the recent 2-year follow-up. This is the first reported case of intraneural nodular fasciitis presenting with severe radiculopathy. Nodular fasciitis should be considered in the differential diagnosis of severe sciatica. PET may be a useful tool for diagnosing sciatica of unknown origin that cannot be identified using conventional imaging tools.

High-energy phosphate metabolism in the calf muscle during moderate isotonic exercise under different degrees of cuff compression: a phosphorus 31 magnetic resonance spectroscopy study.

The purpose of this study was to investigate phosphocreatine (PCr) and inorganic phosphate levels as well as pH changes in exercising muscle at a workload of 4.5 W under progressive cuff stenoses, whereby the flow reduction due to cuff compression was quantified by flow-sensitive magnetic resonance imaging. By using a whole-body 1.5-T magnetic resonance scanner and an exercise bench, serial phosphorus 31 (31P) magnetic resonance spectroscopy with a time resolution of 30 seconds was performed in 10 healthy men. Percentage changes in PCr, inorganic phosphate (Pi), and pH were statistically evaluated in comparison with baseline. The exercise protocol was characterized by a constant workload level of 4.5 W. Ischemic conditions were achieved by a cuff that was placed at the upper leg. Consecutively, increments of 0, 60, 90, 120, and 150 mm Hg were applied. Each increment lasted for 3 minutes. The following rest period was 10 minutes. Blood flow increased significantly immediately after the onset of muscle exercise. No significant changes in blood flow were detected as long as the air pressure of the pneumatic cuff was 60 to 90 mm Hg. Significant reductions in blood flow were observed immediately after inflation of the cuff to 120 and 150 mm Hg. PCr passed into a steady state during the first increment with 0 mm Hg and showed no substantial changes during the increment with 60, 90, and 120 mm Hg. PCr hydrolysis seemed progressive during the 150-mm Hg increment. Pi passed into a plateau level at the onset of exercise and increased significantly at the increment of 150 mm Hg. The pH turned into a steady state with no significant changes during the increments up to 120 mm Hg. At 150 mm Hg, pH decreased progressively. PCr levels at the end of the 150-mm Hg increment correlated significantly and moderately with the reduction in blood flow. Our study shows that the ischemic condition during constant muscle exercise is clearly characterized by PCr and Pi kinetics, as well as by pH changes. The correlation between the degree of blood flow reduction and PCr levels in the exercising muscle groups, which are supplied by the stenosed arteries, is the first essential of using 31P magnetic resonance spectroscopy in the assessment of the effect of arterial stenoses on muscle function in claudicants.