Computer Professionals and Carpal Tunnel Syndrome (CTS) A Longitudinal Study of Industrial and Clerical Workers: Incidence of Carpal Tunnel Syndrome and Assessment of Risk Factors Carpal tunnel syndrome with normal nerve conduction studies. Sonography versus nerve conduction studies in patients referred with a clinical diagnosis of carpal tunnel syndrome. The potential value of ultrasonography in the evaluation of carpal tunnel syndrome Multiperspective follow-up of untreated carpal tunnel syndrome A pilot study comparing two manual therapy interventions for carpal tunnel syndrome. Prolonged median sensory latency as a predictor of future carpal tunnel syndrome. A manual therapy intervention improves symptoms in patients with carpal tunnel syndrome: a pilot study Randomized controlled trial of nocturnal splinting for active workers with symptoms of carpal tunnel syndrome. Sensitivity and specificity of carpal tunnel syndrome signs. The value added by electrodiagnostic testing in the diagnosis of carpal tunnel syndrome. Prevalence of carpal tunnel syndrome in a general population. Practice parameter for electrodiagnostic studies in carpal tunnel syndrome: summary statement. Sonographic Wrist Measurements and Detection of Anatomical Features in Carpal Tunnel Syndrome Carpal tunnel syndrome: prevalence in the general population. Early versus delayed endoscopic surgery for carpal tunnel syndrome: prospective randomized study.
Carpal Tunnel Syndrome ( CTS ) is an important problem among computer professionals . Hence the prevalence of CTS among computer professionals and risk factors were studied . 648 subjects were selected from 4,276 computer professionals from 21 companies with a simple r and om sampling method . CTS was diagnosed based on clinical features . The prevalence of CTS was found to be 13.1 % ( 95 % CI 10.5–15.7 % ) . Subjects with over 8 years of computer work , over 12 hrs of work per day and system administrators were at a higher risk for CTS ( OR 3.3 , 4.9 and 2.5 respectively ) . Flexed or extended h and position had higher risk for CTS . Higher risk for CTS was found with higher exposure to computer work . Ergonomic considerations are important in facilitating proper positioning of h and while working with a computer . Further studies on CTS risk factors among computer professionals are essential for planning prevention This study followed workers over an extended period of time to identify factors which may influence the onset of  Carpal Tunnel Syndrome ( CTS ) . The purpose was to evaluate incidence of CTS and to create a predictive model of factors that play a role in the development of CTS . This prospect i ve study followed 432 industrial and clerical workers over 5.4 years . Incident cases were defined as workers who had no prior history of CTS at baseline testing and were diagnosed with CTS during the follow-up period or at the follow-up screening . On the basis of logistic regression , significant predictors for CTS include baseline median-ulnar peak latency difference , a history of wrist/h and /finger tendonitis , a history of numbness , tingling , burning , and /or pain in the h and , and work above the action level of the peak force and h and activity level threshold limit value . This longitudinal study supports findings from previous cross-sectional studies identifying both work related ergonomic stressors and physical factors as independent risk factors for CTS The utility of electrodiagnostic testing in the evaluation of carpal tunnel syndrome ( CTS ) has been question ed . We studied patients who met the clinical criteria for CTS and compared patients who had normal nerve conduction studies ( NCS ) with patients who had abnormal NCS . We found that 25 % of the CTS patients without confounding neurologic disorders had normal NCS with median palmar nerve stimulation .  Patients with abnormal NCS were older and heavier and had more clinical features of CTS . NCS results could not be predicted accurately from clinical features by use of logistic regression models . This was especially true in clinical ly borderline cases . NCS did not predict the outcome of conservative management . We concluded that NCS provide independent information in the evaluation of suspected CTS , especially when fewer clinical criteria are present , but that NCS are not helpful in predicting the outcome of nonsurgical management PURPOSE To compare the diagnostic value of high-resolution ultrasound ( US ) with nerve conduction studies ( NCS ) in patients with clinical ly defined carpal tunnel syndrome ( CTS ) . METHODS A prospect i ve study was conducted on 66 consecutive patients investigated for sensory h and symptoms . The gold st and ard was the clinical diagnosis of CTS . RESULTS NCS showed greater diagnostic sensitivity ( 82 % ) than US ( 62 % ) in supporting a diagnosis of CTS . With increasing neurophysiologic severity of median neuropathy , there was increasing convergence of the two test methods . Abnormal US as the only diagnostic supportive evidence of CTS was rare . However , the positive predictive value of US for CTS was 100 % . CONCLUSION NCS show better sensitivity than US in supporting a diagnosis of CTS . However , because of its high positive predictive value , one may consider using US as a screening test , eliminating the need for NCS in the majority of clinical suspicion of CTS and reserving NCS for cases in which US is negative The authors compared ultrasonography with electrophysiology for the diagnosis of  carpal tunnel syndrome ( CTS ) on 110 clinical ly affected wrists . An increased cross sectional area in the proximal carpal tunnel larger than 0.11 cm2 in combination with compression signs on longitudinal scans proved to be highly predictive for CTS ( sensitivity , 89.1 % ; specificity , 98.0 % ) . Ultrasound was comparable to electrophysiology in the diagnosis of CTS , and in 35 % of cases changes in morphology suggested a specific therapeutic strategy Objective : To assess the course of untreated carpal tunnel syndrome ( CTS ) . Methods : The Italian CTS Study Group prospect ively followed up ( 10 to 15 months ) 196 untreated patients ( 274 h and s ) with idiopathic CTS with multiple measurements of CTS .  Baseline factors were used to predict the evolution of untreated CTS in multiple regression analysis . Results : Comparison of baseline and follow-up data showed a significant spontaneous improvement of patient-oriented and neurophysiologic measurements . A significant correlation between evolution and initial severity of CTS was observed .  CTS measurements improved in patients with more severe initial impairment whereas they worsened in patients with milder initial impairment . The main positive prognostic factor was short duration of symptoms . Similarly , spontaneous improvement was more frequently associated with young age . Conversely , baseline bilateral symptoms and positive Phalen predicted a poor prognosis . Conclusions : Some patients with CTS  improve spontaneously without surgical treatment OBJECTIVE The purpose of this study was to determine the clinical efficacy of manual therapy interventions for relieving the signs and symptoms of  carpal tunnel syndrome ( CTS ) by comparing 2 forms of manual therapy techniques : Graston Instrument-assisted soft tissue mobilization ( GISTM ) and STM administered with the clinician h and s. METHODS The study was a prospect i ve comparative research design in the setting of a research laboratory . Volunteers were recruited with symptoms suggestive of CTS based upon a phone interview and confirmed by electrodiagnostic study findings , symptom characteristics , and physical examination findings during an initial screening visit . Eligible patients with CTS were r and omly allocated to receive either GISTM or STM . Interventions were , on average , twice a week for 4 weeks and once a week for 2 additional weeks . Outcome measures included ( 1 ) sensory and motor nerve conduction evaluations of the median nerve ; ( 2 ) subjective pain evaluations of the h and using visual analog scales and Katz h and diagrams ; ( 3 ) self-reported ratings of symptom severity and functional status ; and ( 4 ) clinical assessment s of sensory and motor functions of the h and via physical examination procedures . Parametric and nonparametric statistics compared treated CTS h and and control h and and between the treatment interventions , across time ( baseline , immediate post , and at 3 months ' follow-up ) . RESULTS After both manual therapy interventions , there were improvements to nerve conduction latencies , wrist strength , and wrist motion . The improvements detected by our subjective evaluations of the signs and symptoms of CTS and patient satisfaction with the treatment outcomes provided additional evidence for the clinical efficacy of these 2 manual therapies for CTS . The improvements were maintained at 3 months for both treatment interventions . Data from the control h and did not change across measurement time points . CONCLUSIONS Although the clinical improvements were not different between the 2 manual therapy techniques , which were compared prospect ively , the data substantiated the clinical efficacy of conservative treatment options for mild to moderate CTS The purpose of the study was to determine whether abnormal median sensory nerve conduction among asymptomatic workers was predictive of future symptoms suggestive of carpal tunnel syndrome ( CTS ) . This was a prospect i ve study involving 77 workers who were identified as asymptomatic cases with electrodiagnostic findings of median mononeuropathy compared to an age- and sex-matched control group . Follow-up was completed an average of 70 months later , and subjects who reported pain , numbness , tingling , or burning in the distribution of the median nerve , based upon a h and diagram , were classified as having CTS symptoms . The follow-up participation rate was 70 % . Among subjects with abnormal median sensory latencies , 23 % went on to develop symptoms consistent with CTS within the follow-up period , compared with 6 % in the control group ( P= .010 ) . Age and h and repetition were also risk factors for CTS , but the majority of asymptomatic workers with a median mononeuropathy do not become symptomatic over an extended time In carpal tunnel syndrome ( CTS ) , manual therapy interventions ( MTI ) reduce tissue adhesion and increase wrist mobility . We evaluated the efficacy of a MTI in relieving CTS signs and symptoms . Twenty-two CTS patients ( pts ) ( 41 h and s ) were treated with a MTI , consisting in 6 treatments ( 2/week for 3 weeks ) of soft tissues of wrist and h and s and of carpal bones . Pts were assessed for h and sensitivity , paresthesia , h and strength , h and and forearm pain , night awakening ; Phalen test , thenar eminence hypotrophy and Boston Carpal Tunnel Question naire ( BCTQ ) Symptom Severity Scale ( SSS ) and Functional Status Scale ( FSS ) . Median nerve was studied by sensory nerve conduction velocity ( SNCV ) and distal motor latency ( DML ) . CTS was scored as minimal , mild , medium , severe and extreme . We considered as control group the same pts assessed before treatment : at baseline ( T0a ) and after 12 weeks ( T0b ) . Pts were evaluated at the end of treatment ( T1 ) and after 24-week ( T2 ) follow-up . At T0b , versus T0a , forearm pain and Phalen test positivity were increased and h and strength reduced ( p < 0.05 ) . BCTQ – SSS and BCTQ – FSS scores improved at T1 versus T0b ( p < 0.05 ) with the amelioration maintained at T2 . At T1 , the number of pts with paresthesia , night awakening , hypoesthesia , Phalen test , h and strength reduction and h and sensitivity was reduced with the lacking of symptoms maintained at T2 ( p < 0.05 ) . No changes in SNCV , DML and CTS scoring were shown . MTI improved CTS signs and symptoms , with benefits maintained at follow-up . Thus , it may be valid as a conservative therapy OBJECTIVES To determine whether nocturnal splinting of workers identified through active surveillance with symptoms consistent with carpal tunnel syndrome ( CTS ) would improve symptoms and median nerve function as well as impact medical care . DESIGN R and omized controlled trial . SETTING A Midwestern auto assembly plant . PARTICIPANTS Active workers with symptoms suggestive of CTS based on a h and diagram . INTERVENTION The treatment group received customized wrist splints , which were worn at night for 6 weeks ; the control group received ergonomic education alone . MAIN OUTCOME MEASURES Change in wrist , h and , and /or finger discomfort , carpal tunnel symptom severity index , median sensory nerve function , and the percentage of subjects who had carpal tunnel release surgery . RESULTS The splinted group , unlike the controls , had a significant reduction in wrist , h and , and /or finger discomfort and a similar trend in the Levine carpal tunnel symptom severity index , which was maintained at 12 months . A secondary analysis showed that more median nerve impairment at baseline was associated with less clinical improvement among controls but not among the splinted group . CONCLUSIONS Workers identified with CTS symptoms in an active symptom surveillance tended to benefit from a 6-week nocturnal splinting trial , and the benefits were still evident at the 1-year follow-up . The splinted group improved in terms of h and discomfort regardless of the degree of median nerve impairment , whereas the controls showed improvement only among subjects with normal median nerve function . Results suggest that a short course of nocturnal splinting may reduce wrist , h and , and /or finger discomfort among active workers with symptoms consistent with CTS The sensitivity and specificity of six carpal tunnel syndrome ( CTS ) signs were determined by evaluating 143 subjects ( 228 h and s ) with symptoms of CTS . Immediately after performing the six physical examination tests , st and ard nerve conduction studies were performed on all 228 h and s to determine the presence or absence of CTS . CTS was present in 142 h and s and absent in 86 h and s. The signs were not very sensitive ( 23 - 69 % ) , but were fairly specific ( 66 - 87 % ) for CTS . A square-shaped wrist and abductor pollicis brevis weakness were the most sensitive signs ( 69 and 66 % , respectively ) , and are recommended as part of the examination of CTS . Median nerve hypesthesia and the Phalen sign both have fair sensitivity ( 51 % ) but good specificity ( 85 and 76 % , respectively ) . The median nerve compression sign and the Hoffmann-Tinel sign both have poor sensitivity ( 28 and 23 % , respectively ) , and thus are less helpful in evaluating subjects with suspected CTS BACKGROUND There is no clear-cut consensus on the best diagnostic criteria for carpal tunnel syndrome . The objective of this study was to compare the probability of carpal tunnel syndrome being present following electrodiagnostic testing with the probability of it being present after the diagnosis was established on the basis of a clinical evaluation alone . METHODS The study sample included patients with any peripheral nerve diagnosis who had been referred to the electrodiagnostic laboratory of an academic health-care center . The probability of carpal tunnel syndrome before electrodiagnostic testing ( pretest probability ) was estimated with use of the CTS-6 , a vali date d clinical diagnostic aid that is used to estimate the probability of carpal tunnel syndrome on the basis of the presence or absence of six clinical findings recorded as part of the history or noted on physical examination . All patients then underwent a st and ard electrodiagnostic assessment of the median nerve by a neurologist blinded to the result of the CTS-6 evaluation . Sensory nerve conduction velocity was used to classify the result of the electrodiagnostic testing as either positive or negative for carpal tunnel syndrome with use of two different criteria ( one stringent and one lax ) derived from the literature . The main outcome measure was the difference between the pretest and posttest probabilities of carpal tunnel syndrome . RESULTS One hundred and forty-three patients were studied . The pretest probability of carpal tunnel syndrome ranged between 0.10 and 0.99 ( mean [ and st and ard deviation ] , 0.81 + /- 0.22 ) . Seventy-three percent of the patients had a pretest probability of at least 0.80 . The average change in probability for these patients was -0.02 when the stringent electrodiagnostic criterion was used and -0.06 when the lax criterion was used . With either electrodiagnostic criterion , the majority of the large changes in probability were for patients for whom the pretest probability was < or = 0.50 . The probability of carpal tunnel syndrome was lowered after the electrodiagnostic testing in most of these cases . CONCLUSIONS For the majority of patients who are considered to have carpal tunnel syndrome on the basis of their history and physical examination alone , electrodiagnostic tests do not change the probability of diagnosing this condition to an extent that is clinical ly relevant CONTEXT Carpal tunnel syndrome ( CTS ) is a cause of pain , numbness , and tingling in the h and s and is an important cause of work disability . Although high prevalence rates of CTS in certain occupations have been reported , little is known about its prevalence in the general population . OBJECTIVE To estimate the prevalence of CTS in a general population . DESIGN General health mail survey sent in February 1997 , inquiring about symptoms of pain , numbness , and tingling in any part of the body , followed 2 months later by clinical examination and nerve conduction testing of responders reporting symptoms in the median nerve distribution in the h and s , as well as of a sample of those not reporting these symptoms ( controls ) . SETTING A region in southern Sweden with a population of 170000 . PARTICIPANTS A sex- and age-stratified sample of 3000 subjects ( age range , 25 - 74 years ) was r and omly selected from the general population register and sent the survey , with a response rate of 83 % ( n = 2466 ; 46 % men ) . Of the symptomatic responders , 81 % underwent clinical examination . MAIN OUTCOME MEASURES Population prevalence rates , calculated as the number of symptomatic responders diagnosed on examination as having clinical ly certain CTS and /or electrophysiological median neuropathy divided by the total number of responders . RESULTS Of the 2466 responders , 354 reported pain , numbness , and /or tingling in the median nerve distribution in the h and s ( prevalence , 14.4 % ; 95 % confidence interval [ CI ] , 13.0%-15.8 % ) . On clinical examination , 94 symptomatic subjects were diagnosed as having clinical ly certain CTS ( prevalence , 3.8 % ; 95 % CI , 3.1%-4.6 % ) . Nerve conduction testing showed median neuropathy at the carpal tunnel in 120 symptomatic subjects ( prevalence , 4.9 % ; 95 % CI , 4.1%-5.8 % ) . Sixty-six symptomatic subjects had clinical ly and electrophysiologically confirmed CTS ( prevalence , 2.7 % ; 95 % CI , 2.1%-3.4 % ) . Of 125 control subjects clinical ly examined , electrophysiological median neuropathy was found in 23 ( 18.4 % ; 95 % CI , 12.0%-26.3 % ) . CONCLUSION Symptoms of pain , numbness , and tingling in the h and s are common in the general population . Based on our data , 1 in 5 symptomatic subjects would be expected to have CTS based on clinical examination and  electrophysiologic testing Orthodromic SNAPs were recorded over the median nerve using needle electrodes at the wrist and elbow after stimulation of the thumb and middle fingers . CMAPs were recorded with concentric needle electrodes placed in the endplate zone of the APB after stimulation at the wrist and elbow . NCVs were determined for 28 male and 20 female normal subjects aged 16 to 62 years . There was no significant difference in NCV between male and female subjects . There was a decrease in NCV with increasing age . No CTS patients were studied . 186 . Occupational Disease Surveillance . Carpal tunnel syndrome . MMWR Morb Mortal Wkly Rep 1989;38:485 - 489 . Background Reference Source : Baker , 1990 . 187 . * Osborn JB , Newell KJ , Rudney JD , Stoltenberg JL . Carpal tunnel syndrome among Minnesota dental hygienists . J Dent Hyg 1990;64(2):79 - 85 . Criteria Met ( 2/6 : 1,2 ) Source : Medline Search . 188 . Padua L , Lo Monaco M , Valente EM , Tonali PA . A useful electrophysiologic parameter for diagnosis of carpal tunnel syndrome . Muscle Nerve 1996;19:48 - 53 . Criteria Met ( 6/6 : 1,2,3,4,5,6 ) . Source : Medline Search . Abstract : In 43 patients ( 50 h and s ) with clinical manifestations of mild-moderate CTS and 36 healthy volunteers ( 40 h and s ) , orthodromic sensory nerve conduction velocity ( SNCV ) was measured with surface electrodes in the median nerve between the third digit and palm and between the palm and wrist . These figures were used to calculate the ratio of distal to proximal conduction ( distoproximal ratio ) . All 90 h and s were also subjected to other nerve conduction studies used for diagnosis of CTS . All control h and s presented distoproximal ratios less than 1.0 reflecting higher conduction rates in the proximal segment . In contrast , 49 of 50 CTS h and s ( 98 % ) presented reversed ratios ( > 1.0 ) indicating compromised proximal conduction . The sensitivity of this test was significantly greater than that of other methods evaluated , including comparative studies and segmental study of the palm-wrist portion of the median nerve . Segmental study of median SNCV with calculation of the distoproximal ratio is a sensitive technique for diagnosis of CTS in patients with normal findings in st and ard nerve conduction studies . Note : The author indicated by correspondence that the mean ± SD for the Control DML in Table 1 should read 3.2 ± 0.4 and not 3.2 ± 0.8 as published . 189 . Padua L , LoMonaco M , Gregori B , Valente EM , Padua R , Tonali P. Neurophysiological classification and sensitivity in 500 carpal tunnel syndrome h and s. Acta Neurol Sc and 1997;96:211 - 217 . Criteria Med ( 6/6 : 1,2,3,4,5,6 ) Source : Medline Search . Abstract : Prospect i ve study of 500 h and s ( 379 patients ) with clinical diagnosis of CTS symptoms . Normal values from the same laboratory previously published ( Padua , 1996 ) . In the 500 CTS patients , DML was prolonged ( 55 % ) , median orthodromic sensory latency was prolonged ( D2 , 74 % ; D3 , 67 % ) . Of the remaining 117 patients with normal DML and median orthodromic sensory studies over 14 cm , the median sensory palmwrist NCV over 8 cm was abnormal in 21 % and the distoproximo ratio of the median palm and digit segments was abnormal in 87 % . 190 . Palliyath SK , Holden L. Refractory studies in early detection of carpal tunnel syndrome . Electromyogr Clin Neurophysiol 1990;30:307 - 309 . Criteria Met ( 5/6 : 1,3,4,5,6 ) Source : Medline Search . Abstract : Using paired stimuli and varying the inter-stimulus interval , the absolute refractory period ( ARP ) and relative refractory period ( RRP ) , were determined in 10 patients with mild electrophysiologic changes suggestive of CTS . They found that the sensory RRP was sensitive in diagnosing early CTS . 191 . * Pavesi G , Olivieri MF , Misk A , Mancia D. Clinical electrophysiological correlations in the carpal tunnel syndrome . Ital J Neurol Sci 1986;7:93 - 96 . Criteria Met ( 3/6 : 2,3,5 ) Source : Medline Search . 192 . Pease WS , Cannell CD , Johnson EW . Median to radial latency difference test in mild carpal tunnel syndrome . Muscle Nerve 1989;12:905 - 909 . Criteria Met ( 4/6 : 1,3,5,6 ) Source : Medline Search . Abstract : The following techniques were studied : ( a ) antidromic DSL median radial differences to the thumb , ( b ) antidromic DSL after stimulation at the wrist and recording from the third digit , ( c ) median mid-palmar DSL compared as a ratio of the wrist to middle finger DSL , ( d ) median ulnar DSL latency difference between the ulnar Practice Parameter : Carpal Tunnel Syndrome Muscle & Nerve Supplement X 2002 S971 SNAP recorded from the little finger after stimulation at the wrist and the median DSL after stimulation at the wrist and recording from the middle finger , and ( e ) median motor DML after recording from the APB after stimulation at the wrist .  Three hundred thirty-three symptomatic h and s in 262 patients were initially evaluated with subgroups of patients with CTS evaluated with different tests . The median radial DSL difference and median ulnar DSL difference were most likely to be abnormal followed by median DSL then the palmto-wrist DSL latency ratio and lastly the DML . 193 . Pease WS , Cunningham ML , Walsh WE , Johnson EW . Determining neurapraxia in carpal tunnel syndrome . Am J Phys Med Rehabil 1988;67:117 - 119 . Criteria Met ( 5/6 : 1,3,4,5,6 ) Source : Medline Search . Abstract : With needle stimulation at the wrist and midpalm , CMAPs were recorded over the APB in 25 CTS patients and 23 healthy asymptomatic persons . They found a significant difference in the amplitude of the CMAP in the CTS group when compared to the control group . They propose that this is evidence for conduction block ( neurapraxia ) in CTS . 194 . Pease WS , Lee HH , Johnson EW . Forearm median nerve conduction velocity in carpal tunnel syndrome . Electromyogr Clin Neurophysiol 1990;30:299 - 302 . Criteria Met ( 4/6 : 1,3,4,5 ) Source : Medline Search . Abstract : The NCV of the median nerve in the forearm was determined by 2 methods : ( a ) stimulation in the forearm and recording the nerve action potential at the wrist , and ( b ) stimulation at the wrist and elbow with recording over the APB , in 21 CTS patients and 16 control subjects . They found that the forearm NCV was slowed in the CTS group using either technique . The authors have proposed that this suggest that there is proximal nerve dysfunction as a result of median nerve compression in the carpal tunnel . 195 . * Peterson GW , Will AD . Newer electrodiagnostic techniques in peripheral nerve injuries . Orthop Clin North Am 1988;19:13 - 25 . Criteria Met ( 0/6 ) Source : Narkis , 1990 . 196 . * Phalen GS . The carpal tunnel syndrome : clinical evaluation of 598 h and s. Clin Orthop 1972;83:29 - 40 . Background Reference . Source : Katz 1990 ( J Rheumatology ) . 197 . * Phalen GS . The carpal tunnel syndrome : seventeen years ’ experience in diagnosis and treatment of 654 h and s. J Bone Joint Surg 1966;48:211 - 228 . Criteria Met ( 1/6 : 2 ) Source : Meyers , 1989 . 198 . Phalen GS , Gardner WJ , LaLonde AA . Neuropathy of the median nerve due to compression beneath the transverse carpal ligament . J Bone Joint Surg 1950;32-A:109 - 112 . Background Reference . Source : Braun , 1989 . 199 . Plaja J. Comparative value of different electrodiagnostic methods in carpal tunnel syndrome . Scan J Rehabil Med 1971;3:101 - 108 . Criteria Met ( 4/6 : 1,3,5,6 ) Source : Joynt , 1989 . Abstract : The following techniques were studied : ( a ) CMAP potentials were recorded after stimulation at the wrist and recording with coaxial needle electrodes , ( b ) orthodromic SNAPs with stimulation over the index finger and recording with surface electrodes at the wrist , ( c ) needle EMG using a coaxial needle  , ( d ) strength/ duration curves and chronaxy .  Fifty-six cases of CTS and 20 normal subjects were evaluated .  Sensory latencies were more likely to be abnormal than the other techniques measured . 200 . Preston DC , Logigian EL . Lumbrical and interossei recording in carpal tunnel syndrome [ see comments ] . Muscle Nerve 1992 ; 15 : 1253 - 1257 . Criteria Met ( 5/6 : 1,3,4,5,6 ) Source : Medline Search . Abstract : Median motor studies are commonly “ normal ” in mild carpal tunnel syndrome ( CTS ) . This reflects either the sparing of motor compared to sensory fibers , or the inability of conventional studies to detect an abnormality . A novel approach to demonstrate early motor fiber involvement in CTS is the placement of the same active electrode lateral to the third metacarpal , allowing recording from the second lumbrical or the deeper interossei , when stimulating the median or ulnar nerves at the wrist , respectively . We compared the difference between these latencies in 51 normal control h and s to 107 consecutive patient h and s referred with symptoms and signs suggestive of CTS , who were subsequently proven to have electrophysiologic CTS by st and ard nerve conduction criteria . A prolonged lumbrical-interossei latency difference ( > 0.4 ms ) was found to be a sensitive indicator of CTS in all patient groups . It was also helpful in patients with coexistent polyneuropathy , where localization of median nerve pathology at the wrist was otherwise difficult . 201 . * Preston DC , Ross MH , Kothari MJ , Plotkin GM , Venkatesh S , Logigian EL . The median-ulnar latency difference studies are comparable in mild carpal tunnel syndrome . Muscle Nerve 1994 ; 17 : 1469 - 1471 . Criteria Met ( 2/6 : 1,3 ) . Source : Medline Search . Abstract : Compares sensitivity 159 patients of orthodromic palm-wrist mixed palmar median-ulnar peak latency difference with normal < 0.4 ms , antidromic wrist-D4 sensory median-ulnar onset latency difference with normal < 0.5 ms , and the second lumbrical/interossei motor with normal < 0.5 ms . See discussion of benefits of techniques and diagrams of electrode placements and line drawings of electrode and stimulator placement . 202 . Preswick G. The effect of stimulus intensity in motor latency in carpal tunnel syndrome . J Neurol Neurosurg Psychiatry 1963;26:398 - 401 . Criteria Met ( 4/6 : 1,3,5,6 ) Source : Loong , 1971 . Abstract : With stimulation at the wrist and coaxial needle electrode recording from the APB , DMLs were recorded at super-maximal stimulation and threshold stimulation in 29 CTS h and s Introduction . This study compares anatomical findings at wrist level in patients with known carpal tunnel syndrome ( CTS ) and controls by ultrasonography ( US ) . Material and Methods . Wrist-US investigations of 28 consecutive patients with 38 diagnosed , idiopathic CTS were compared to 49 healthy volunteers without history of CTS . Internal wrists dimensions , the presence of flexor muscle bellies in the carpal tunnel , and cross-sectional area of the median nerve were analyzed . The findings were correlated to gender , age , and BMI . Results . US demonstrated a square internal carpal tunnel configuration in CTS patients compared to controls ( P < 0.001 ) . Patients with CTS showed a trend towards the presence of flexor muscles bellies in the carpal tunnel ( odds ratio 1.77 , 95 % CI 0.337–8.33 ) . CTS was present in women with  higher BMI  ( P = 0.015 ) . Conclusion . US allowed detection of specific anatomical features at wrist level in CTS patients . This observation may enable — following confirmation in larger prospect i ve studies —risk evaluation for CTS development To study the prevalence of  carpal tunnel syndrome ( CTS ) in the general population and the value of brachialgia paraesthetica nocturna ( BPN ) in diagnosing CTS , an age and sex stratified r and om sample of 715 subjects was taken from the population register of Maastricht ( The Netherl and s ) and surrounding villages , between September 1983 and July 1985 . The response rate was 70 % . Of these , 12 CTS cases had already been diagnosed . Of the remaining subjects , 64 ( 13 men , 51 women ) woke up because of BPN . Among these subjects 1 man and 23 women were found to have CTS . The prevalence rate of undetected CTS was 5.8 % [ 95 % confidence interval ( CI ) : 3.5 - 8.1 % ] in adult women ; 3.4 percent ( 95 % CI : 1.5 - 5.3 % ) had already been diagnosed as CTS . The overall prevalence rate for men was 0.6 % ( 95 % CI 0.02 - 3.4 % ) . These figures have to be regarded as minimal estimates . The overall diagnostic value of BPN for CTS was 38 % , while for women only this was 45 % ( 95 % CI : 31 - 60 % ) OBJECTIVE To compare the effects of early versus delayed endoscopic surgery in patients with moderately severe carpal tunnel syndrome ( CTS ) . METHODS The study included 100 patients with CTS . Investigations performed before surgery excluded secondary causes . Patients with moderately severe CTS ( grade 3 - 4 ) were r and omly assigned . Bl and 's neurophysiologic grading scale for CTS was used to assess the patients . Patients underwent an endoscopic carpal tunnel release using an indigenously design ed instrument . RESULTS Following a course of conservative treatment , surgical treatment was offered in two groups : early surgery ( n = 51 ; < 1 week after diagnosis ) and delayed surgery as per the usual waiting list ( n = 49 ; > 6 months after diagnosis ) . Improvement in both groups was significant ( P < 0.001 ) . When both groups were compared , improvement was better for the early surgery group ( P < 0.001 ; confidence interval 6.35 - 9.12 ) . CONCLUSIONS On the basis of this study , early endoscopic surgery is proposed in patients with moderately severe CTS
Conclusion There is insufficient epidemiological evidence that computer work causes CTS
Background This review examines evidence for an association between  computer work and carpal tunnel syndrome ( CTS ) .