Consensus criteria for the classification of carpal tunnel syndrome in epidemiologic studies

Prevalence and work-relatedness of carpal tunnel syndrome in the working population, United States, 2010 National Health Interview Survey

BACKGROUND

Patterns of prevalence and work-relatedness of carpal tunnel syndrome (CTS) among workers offer clues about risk factors and targets for prevention.

METHODS

Data from an occupational health supplement to the 2010 National Health Interview Survey were used to estimate the prevalence of self-reported clinician-diagnosed CTS overall and by demographic characteristics. The proportion of these cases self-reported to have been attributed to work by clinicians was also examined overall and by demographic characteristics. In addition, the distribution of industry and occupation (I&O) categories to which work-related cases of CTS were attributed was compared to the distribution of I&O categories of employment among current/recent workers.

RESULTS

Data were available for 27,157 adults, including 17,524 current/recent workers. The overall lifetime prevalence of clinician-diagnosed CTS among current/recent workers was 6.7%. The 12-month prevalence was 3.1%, representing approximately 4.8 million workers with current CTS; 67.1% of these cases were attributed to work by clinicians, with overrepresentation of certain I&O categories.

CONCLUSIONS

CTS affected almost 5 million U.S. workers in 2010, with prevalence varying by demographic characteristics and I&O.

Personal and workplace psychosocial risk factors for carpal tunnel syndrome: a pooled study cohort

BACKGROUND

Between 2001 and 2010, six research groups conducted coordinated multiyear, prospective studies of carpal tunnel syndrome (CTS) incidence in US workers from various industries and collected detailed subject-level exposure information with follow-up symptom, physical examination, electrophysiological measures and job changes.

OBJECTIVE

This analysis of the pooled cohort examined the incidence of dominant-hand CTS in relation to demographic characteristics and estimated associations with occupational psychosocial factors and years worked, adjusting for confounding by personal risk factors.

METHODS

3515 participants, without baseline CTS, were followed-up to 7 years. Case criteria included symptoms and an electrodiagnostic study consistent with CTS. Adjusted HRs were estimated in Cox proportional hazard models. Workplace biomechanical factors were collected but not evaluated in this analysis.

RESULTS

Women were at elevated risk for CTS (HR=1.30; 95% CI 0.98 to 1.72), and the incidence of CTS increased linearly with both age and body mass index (BMI) over most of the observed range. High job strain increased risk (HR=1.86; 95% CI 1.11 to 3.14), and social support was protective (HR=0.54; 95% CI 0.31 to 0.95). There was an inverse relationship with years worked among recent hires with the highest incidence in the first 3.5 years of work (HR=3.08; 95% CI 1.55 to 6.12).

CONCLUSIONS

Personal factors associated with an increased risk of developing CTS were BMI, age and being a woman. Workplace risk factors were high job strain, while social support was protective. The inverse relationship between CTS incidence and years worked among recent hires suggests the presence of a healthy worker survivor effect in the cohort.

Therapeutic ultrasound for carpal tunnel syndrome

BACKGROUND

Therapeutic ultrasound may be offered to people experiencing mild to moderate symptoms of carpal tunnel syndrome (CTS). The effectiveness and duration of benefit of this non-surgical intervention remain unclear.

OBJECTIVES

To review the effects of therapeutic ultrasound compared with no treatment, placebo or another non-surgical intervention in people with CTS.

SEARCH METHODS

On 27 November 2012, we searched the Cochrane Neuromuscular Disease Group Specialized Register, CENTRAL (2012, Issue 11 in The Cochrane Library), MEDLINE (January 1966 to November 2012), EMBASE (January 1980 to November 2012), CINAHL Plus (January 1937 to November 2012), and AMED (January 1985 to November 2012).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing any regimen of therapeutic ultrasound with no treatment, a placebo or another non-surgical intervention in people with CTS.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, extracted data and assessed the risk of bias in the included studies. We calculated risk ratio (RR) and mean difference (MD) with 95% confidence intervals (CIs) for primary and secondary outcomes. We pooled results of clinically homogenous trials in a meta-analysis using a random-effects model, where possible, to provide estimates of the effect.

MAIN RESULTS

We included 11 studies including 414 participants in the review. Two trials compared therapeutic ultrasound with placebo, two compared one ultrasound regimen with another, two compared ultrasound with another non-surgical intervention, and six compared ultrasound as part of a multi-component intervention with another non-surgical intervention (for example, exercises and splint). The risk of bias was low in some studies and unclear or high in other studies, with only two reporting that the allocation sequence was concealed and six reporting that participants were blinded. Overall, there is insufficient evidence that one therapeutic ultrasound regimen is more efficacious than another. Only two studies reported the primary outcome of interest, short-term overall improvement (any measure in which patients indicate the intensity of their complaints compared with baseline, for example, global rating of improvement, satisfaction with treatment, within three months post-treatment). One low quality trial with 68 participants found that when compared with placebo, therapeutic ultrasound may increase the chance of experiencing short-term overall improvement at the end of seven weeks treatment (RR 2.36; 95% CI 1.40 to 3.98), although losses to follow-up and failure to adjust for the correlation between wrists in participants with bilateral CTS in this study suggest that this data should be interpreted with caution. Another low quality trial with 60 participants found that at three months post-treatment therapeutic ultrasound plus splint increased the chance of short-term overall improvement (patient satisfaction) when compared with splint alone (RR 3.02; 95% CI 1.36 to 6.72), but decreased the chance of short-term overall improvement when compared with low-level laser therapy plus splint (RR 0.87; 95% CI 0.57 to 1.33), though participants were not blinded to treatment, it was unclear if the random allocation sequence was adequately concealed, and there was a potential unit of analysis error. Differences between groups receiving different frequencies and intensities of ultrasound, and between ultrasound as part of a multi-component intervention versus other non-surgical interventions, were generally small and not statistically significant for symptoms, function, and neurophysiologic parameters. No studies reported any adverse effects of therapeutic ultrasound, but this outcome was only measured in three studies. More adverse effects data are required before any firm conclusions on the safety of therapeutic ultrasound can be made.

AUTHORS' CONCLUSIONS

There is only poor quality evidence from very limited data to suggest that therapeutic ultrasound may be more effective than placebo for either short- or long-term symptom improvement in people with CTS. There is insufficient evidence to support the greater benefit of one type of therapeutic ultrasound regimen over another or to support the use of therapeutic ultrasound as a treatment with greater efficacy compared to other non-surgical interventions for CTS, such as splinting, exercises, and oral drugs. More methodologically rigorous studies are needed to determine the effectiveness and safety of therapeutic ultrasound for CTS.

Sonography of the median nerve in CMT1A, CMT2A, CMTX, and HNPP

INTRODUCTION

In this study we compare the ultrasound features in the median nerve in patients with different types of Charcot-Marie-Tooth (CMT) disease and hereditary neuropathies with liability to pressure palsies (HNPP) as a typical entrapment neuropathy.

METHODS

Median nerve ultrasound and conduction studies were performed in patients with CMT1A (n = 12), MFN2-associated CMT2A (n = 7), CMTX (n = 5), and HNPP (n = 5), and in controls (n = 28).

RESULTS

Median nerve cross-sectional area (CSA) was significantly increased in CMT1A, whereas, in axonal CMT2A, fascicle diameter (FD) was enlarged. CSA correlated with nerve conduction slowing in CMT1A and with axonal loss, as shown by motor and sensory nerve amplitudes in both CMT1A and CMT2A. A relatively low wrist-to-forearm-ratio (WFR <0.8) or a relatively high WFR (>1.8) appeared to be unlikely in MFN2 and Cx32 mutations of CMT2A and CMTX, respectively.

CONCLUSION

Differences in CSA, FD, and WFR of the median nerve can be helpful in defining subtypes of hereditary neuropathies.

Prevalence and incidence of carpal tunnel syndrome in US working populations: pooled analysis of six prospective studies

OBJECTIVES

Most studies of carpal tunnel syndrome (CTS) incidence and prevalence among workers have been limited by small sample sizes or restricted to a small subset of jobs. We established a common CTS case definition and then pooled CTS prevalence and incidence data across six prospective studies of musculoskeletal outcomes to measure CTS frequency and allow better studies of etiology.

METHODS

Six research groups collected prospective data at > 50 workplaces including symptoms characteristic of CTS and electrodiagnostic studies (EDS) of the median and ulnar nerves across the dominant wrist. While study designs and the timing of data collection varied across groups, we were able to create a common CTS case definition incorporating both symptoms and EDS results from data that were collected in all studies.

RESULTS

At the time of enrollment, 7.8% of 4321 subjects met our case definition and were considered prevalent cases of CTS. During 8833 person-years of follow-up, an additional 204 subjects met the CTS case definition for an overall incidence rate of 2.3 CTS cases per 100 person-years.

CONCLUSIONS

Both prevalent and incident CTS were common in data pooled across multiple studies and sites. The large number of incident cases in this prospective study provides adequate power for future exposure-response analyses to identify work- and non-work-related risk factors for CTS. The prospective nature allows determination of the temporal relations necessary for causal inference.

Natural history and predictors of long-term pain and function among workers with hand symptoms

OBJECTIVE

To evaluate predictors of hand symptoms and functional impairment after 3 years of follow-up among workers with different types of hand symptoms including carpal tunnel syndrome (CTS). Functional status and job limitations were also analyzed as key secondary objectives.

DESIGN

Cohort design of 3 years duration.

SETTING

Working population-based study.

PARTICIPANTS

Newly employed workers without a preexisting diagnosis of CTS (N=1107). Subjects were categorized into 4 groups at baseline examination: no hand symptoms, any hand symptoms but not CTS (recurring symptoms in hands, wrist, or fingers without neuropathic symptoms), any hand symptoms of CTS (neuropathic symptoms in the fingers and normal nerve conduction study), or confirmed CTS (CTS symptoms and abnormal nerve conduction study). Among workers with hand pain at baseline, subject and job characteristics were assessed as prognostic factors for outcomes, using bivariate and multivariate regression models.

INTERVENTIONS

Not applicable.

MAIN OUTCOME MEASURE

The primary outcome assessed by questionnaire at 3 years was "severe hand pain" in the past 30 days.

RESULTS

At baseline, 155 workers (17.5% of 888 followed workers) reported hand symptoms, of which 21 had confirmed CTS. Presence of hand pain at baseline was a strong predictor of future hand pain and job impairment. Subjects with confirmed CTS at baseline were more likely than workers with other hand pain to report severe hand pain (adjusted prevalence ratios 1.98 [95% confidence interval 1.11-3.52]) and functional status impairment (adjusted prevalence ratios 3.37 [95% confidence interval 1.01-11.29]). Among subjects meeting our case definition for CTS at baseline, only 4 (19.1%) reported seeing a physician in the 3-year period.

CONCLUSIONS

Hand symptoms persisted among many workers after 3-year follow-up, especially among those with CTS, yet few symptomatic workers had seen a physician.

[Neurography for diagnosing carpal tunnel syndrome]

BACKGROUND

A number of evidence-based guidelines now recommend that a nerve conduction study should be used to confirm the existence of carpal tunnel syndrome before any surgery takes place.

METHOD

The article is based on a search in PubMed, a personal literature archive (1980-2011) and long clinical experience of neurological and neurophysiological diagnostics.

RESULTS

Both motor and sensory nerve fascicles must be tested after adequate warming up. An extended nerve conduction study with supplementary tests to compare velocities and latencies in median and ulnar nerves, increases the diagnostic precision. Given normal or mild findings, surgery can usually be avoided as the first choice of treatment, because many patients with mild carpal tunnel syndrome recover spontaneously.

INTERPRETATION

The gold standard for diagnosis of carpal tunnel syndrome should be a combination of a clinical examination and a nerve conduction study.

Compression and entrapment neuropathies

Peripheral nerve entrapments are frequent. They usually appear in anatomical tunnels such as the carpal tunnel. Nerve compressions may be due to external pressure such as the fibular nerve at the fibular head. Malignant or benign tumors may also damage the nerve. For each nerve from the upper and lower limbs, detailed clinical, electrophysiological, imaging, and therapeutic aspects are described. In the upper limbs, carpal tunnel syndrome and ulnar neuropathy at the elbow are the most frequent manifestations; the radial nerve is less frequently involved. Other nerves may occasionally be damaged and these are described also. In the lower limbs, the fibular nerve is most frequently involved, usually at the fibular head by external compression. Other nerves may also be involved and are therefore described. The clinical and electrophysiological examination are very important for the diagnosis, but imaging is also of great use. Treatments available for each nerve disease are discussed.

Relationship between electrodiagnostic severity and neuropathic pain assessed by the LANSS pain scale in carpal tunnel syndrome

OBJECTIVE

The aim of the study was to investigate the relationship between the presence of neuropathic pain assessed by the Leeds Assessment of Neuropathic Symptoms and Signs (LANSS) scale and electrophysiological findings in patients with carpal tunnel syndrome (CTS).

METHODS

We studied 124 hands with idiopathic CTS with pain complaints involving hand and wrist. All hands were assessed by the LANSS with which a score of 12 or more is defined as pain dominated by neuropathic mechanisms. These hands were assigned to minimal, mild, moderate, severe, or extreme severe groups according to the results of the median nerve conduction studies.

RESULTS

A LANSS score ≥ 12, suggestive of pain dominated by neuropathic mechanisms, was defined in 59 (47.6%) CTS hands. Pain intensity was significantly higher in CTS hands with a LANSS score ≥ 12 (P < 0.001). Among electrophysiological findings, compound muscle action potential amplitude was significantly lower in hands with a LANSS score ≥ 12 compared with hands with a LANSS score < 12 (P = 0.020). Severity of CTS was not significantly different between LANSS ≥ 12 and LANSS < 12 groups. Electrophysiological severity was significantly higher in CTS hands with evoked pain (P = 0.005) and allodynia (P < 0.001) in LANSS subscore analysis.

CONCLUSION

We suggest that the presence of pain dominated by neuropathic mechanisms in CTS is not related to electrophysiological CTS severity. Neuropathic pain should be assessed carefully in patients with CTS, and an appropriate treatment plan should be chosen, taking into account the clinical and electrophysiological findings together with the true pain classification.

Cumulative keyboard strokes: a possible risk factor for carpal tunnel syndrome

Background

Contradictory reports have been published regarding the association of Carpal Tunnel Syndrome (CTS) and the use of computer keyboard. Previous studies did not take into account the cumulative exposure to keyboard strokes among computer workers. The aim of the present study was to investigate the association between cumulative keyboard use (keyboard strokes) and CTS.

Methods

Employees (461) from a Governmental data entry & processing unit agreed to participate (response rate: 84.1 %) in a cross-sectional study. Α questionnaire was distributed to the participants to obtain information on socio-demographics and risk factors for CTS. The participants were examined for signs and symptoms related to CTS and were asked if they had previous history or surgery for CTS. The cumulative amount of the keyboard strokes per worker per year was calculated by the use of payroll’s registry. Two case definitions for CTS were used. The first included subjects with personal history/surgery for CTS while the second included subjects that belonged to the first case definition plus those participants were identified through clinical examination.

Results

Multivariate analysis used for both case definitions, indicated that those employees with high cumulative exposure to keyboard strokes were at increased risk of CTS (case definition A: OR = 2.23;95 % CI = 1.09-4.52 and case definition B: OR = 2.41; 95%CI = 1.36-4.25). A dose response pattern between cumulative exposure to keyboard strokes and CTS has been revealed (p < 0.001).

Conclusions

The present study indicated a possible association between cumulative exposure to keyboard strokes and development of CTS. Cumulative exposure to key-board strokes would be taken into account as an exposure indicator regarding exposure assessment of computer workers. Further research is needed in order to test the results of the current study and assess causality between cumulative keyboard strokes and development of CT.

Assessment of median nerve with MR neurography by using diffusion-tensor imaging: normative and pathologic diffusion values

PURPOSE

To determine normative diffusion values of the median nerve at several anatomic locations in healthy men and women of variable age and to compare these normative values with those in patients with carpal tunnel syndrome.

MATERIALS AND METHODS

After ethics board approval and written informed consent were obtained, 45 healthy volunteers (30 women, 15 men) and 15 patients (10 women, five men) were studied. Volunteers were divided into three age groups. Magnetic resonance (MR) neurography with diffusion-tensor imaging (DTI) was performed in all study participants at 3.0 T by using a single-shot echo-planar imaging sequence (repetition time msec/echo time msec, 10 123/40; b=1200 sec/mm2). Fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of the median nerve were determined by two readers at three locations: the levels of the distal radioulnar joint, pisiform bone, and hamate bone.

RESULTS

Normative FA and ADC values were calculated for men and women, different age groups, and different anatomic locations. FA and ADC did not differ between men and women (P=.28 and P=.38, respectively). FA decreased and ADC increased when moving from proximal to distal locations (P<.001). FA decreased and ADC increased significantly with age (P<.001). There was a significant difference between healthy volunteers and patients with carpal tunnel syndrome (P<.001 for both FA and ADC). An FA threshold of 0.47 and an ADC threshold of 1.054×10(-3) mm2/sec might be used in the diagnosis of carpal tunnel syndrome.

CONCLUSION

Normative diffusion values for MR neurography of the median nerve with DTI depend on the anatomic location and age but not on sex. Age-specific FA and ADC threshold values might be used to diagnose carpal tunnel syndrome.

Splinting for carpal tunnel syndrome

BACKGROUND

Carpal tunnel syndrome (CTS) is a condition where one of two main nerves in the wrist is compressed, which can lead to pain in the hand, wrist and sometimes arm, and numbness and tingling in the thumb, index and long finger. Splinting is usually offered to people with mild to moderate symptoms. However, the effectiveness and duration of the benefit of splinting for this condition remain unknown.

OBJECTIVES

To compare the effectiveness of splinting for carpal tunnel syndrome with no treatment, placebo or another non-surgical intervention.

SEARCH METHODS

We searched the Cochrane Neuromuscular Disease Group Specialized Register (10 January 2011), CENTRAL, NHSEED and DARE (The Cochrane Library 2011, Issue 4), MEDLINE (January 1966 to December 2011), EMBASE (January 1980 to January 2012), AMED (January 1985 to January 2012), and CINAHL Plus (January 1937 to January 2012), using no time limits. We searched the reference lists of all included trials and relevant reviews for further relevant studies.

SELECTION CRITERIA

All randomised and quasi-randomised trials comparing splinting with no treatment (or a placebo) or with other non-surgical treatments were eligible for inclusion. We also included studies comparing one splint type or regimen versus another. We excluded studies comparing splinting with surgical treatment. There were no language restrictions. We included all patients diagnosed with carpal tunnel syndrome unless they had undergone surgical release.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, and performed data extraction. Two authors also independently performed the assessment of risk of bias. We calculated measures of effect as risk ratios (RR) for dichotomous outcomes and mean differences (MD) for continuous outcomes, with 95% confidence intervals (CI) reported and statistical significance set at P < 0.05 for all outcome comparisons.

MAIN RESULTS

The review included 19 studies randomising 1190 participants with carpal tunnel syndrome. Two studies compared splinting with no treatment, five compared different splint designs, one compared different splint-wearing regimens, seven compared splint delivered as a single intervention with another non-surgical intervention, and five compared splint delivered alongside other non-surgical interventions with another non-surgical intervention. Only three studies reported concealing the allocation sequence, and only one reported blinding of participants. Three studies measured the primary outcome, short-term overall improvement at three months or less. One low quality study with 80 wrists found that compared to no treatment, splints worn at night more than tripled the likelihood of reporting overall improvement at the end of four weeks of treatment (RR 3.86, 95% CI 2.29 to 6.51). However, the lack of patient blinding and unclear allocation concealment suggests this result should be interpreted with caution. A very low quality quasi-randomised trial with 90 wrists found that wearing a neutral splint more than doubled the likelihood of reporting 'a lot or complete relief' at the end of two weeks of treatment compared with an extension splint (RR 2.43, 95% CI 1.12 to 5.28). The third study which measured short-term overall improvement did not report outcome data separately per group. Nine studies measured adverse effects of splinting and all found either no or few participants reporting discomfort or swelling due to splinting; however, the precision of all RRs was very low. Differences between groups in the secondary outcomes - symptoms, function, and neurophysiologic parameters - were most commonly small with 95% CIs incorporating effects in either direction.

AUTHORS' CONCLUSIONS

Overall, there is limited evidence that a splint worn at night is more effective than no treatment in the short term, but there is insufficient evidence regarding the effectiveness and safety of one splint design or wearing regimen over others, and of splint over other non-surgical interventions for CTS. More research is needed on the long-term effects of this intervention for CTS.

Deteriorating tactile sensation in patients with hand syndromes associated with diabetes: a two-year observational study

AIMS

To observe the natural history of hand function during a two-year period in participants with hand syndromes associated with diabetes and to determine factors related to changing function.

METHODS

Hand function was measured over three annual visits using Disability of the Arm, Shoulder and Hand (DASH) and SF-36v2 questionnaires, grip strength, light touch and 9-hole peg tests. Light touch was tested with WEST monofilaments at 7 sites on the hand (score 35 to 0). Data were analyzed using repeated-measures ANOVA, Spearman's correlation, and Wilcoxon signed-rank tests.

RESULTS

Participants (n=60) were aged 61 ± 10.5 years, 57% female, diagnosed with diabetes and at least one of four associated hand disorders. Presentations of carpal tunnel syndrome, or past release (n=27, 45%) and trigger finger (n=24, 40%) were common. Tactile sensation was reduced during the two-year period (median, range; 30 months, 25-40 months). Initial median (inter-quartile range) scores for the dominant hand of 25.5 (22-28.5) were reduced to 23 (21.5-27). This sensory loss was weakly associated with HbA1c (r=0.30, p=0.05) and occurred predominantly in participants with trigger finger (p=0.05).

CONCLUSIONS

Light touch perception was reduced in longstanding diabetic hand syndromes. Tactile abnormalities that were detected by clinical examination progressed during a two year period and were related to metabolic control and musculoskeletal diagnosis.

Exercise and mobilisation interventions for carpal tunnel syndrome

BACKGROUND

Non-surgical treatment, including exercises and mobilisation, has been offered to people experiencing mild to moderate symptoms arising from carpal tunnel syndrome (CTS). However, the effectiveness and duration of benefit from exercises and mobilisation for this condition remain unknown.

OBJECTIVES

To review the efficacy and safety of exercise and mobilisation interventions compared with no treatment, a placebo or another non-surgical intervention in people with CTS.

SEARCH METHODS

We searched the Cochrane Neuromuscular Disease Group Specialised Register (10 January 2012), CENTRAL (2011, Issue 4), MEDLINE (January 1966 to December 2011), EMBASE (January 1980 to January 2012), CINAHL Plus (January 1937 to January 2012), and AMED (January 1985 to January 2012).

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials comparing exercise or mobilisation interventions with no treatment, placebo or another non-surgical intervention in people with CTS.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed searches and selected trials for inclusion, extracted data and assessed risk of bias of the included studies. We calculated risk ratios (RR) and mean differences (MD) with 95% confidence intervals (CIs) for primary and secondary outcomes of the review. We collected data on adverse events from included studies.

MAIN RESULTS

Sixteen studies randomising 741 participants with CTS were included in the review. Two compared a mobilisation regimen to a no treatment control, three compared one mobilisation intervention (for example carpal bone mobilisation) to another (for example soft tissue mobilisation), nine compared nerve mobilisation delivered as part of a multi-component intervention to another non-surgical intervention (for example splint or therapeutic ultrasound), and three compared a mobilisation intervention other than nerve mobilisation (for example yoga or chiropractic treatment) to another non-surgical intervention. The risk of bias of the included studies was low in some studies and unclear or high in other studies, with only three explicitly reporting that the allocation sequence was concealed, and four reporting blinding of participants. The studies were heterogeneous in terms of the interventions delivered, outcomes measured and timing of outcome assessment, therefore, we were unable to pool results across studies. Only four studies reported the primary outcome of interest, short-term overall improvement (any measure in which patients indicate the intensity of their complaints compared to baseline, for example, global rating of improvement, satisfaction with treatment, within three months post-treatment). However, of these, only three fully reported outcome data sufficient for inclusion in the review. One very low quality trial with 14 participants found that all participants receiving either neurodynamic mobilisation or carpal bone mobilisation and none in the no treatment group reported overall improvement (RR 15.00, 95% CI 1.02 to 220.92), though the precision of this effect estimate is very low. One low quality trial with 22 participants found that the chance of being 'satisfied' or 'very satisfied' with treatment was 24% higher for participants receiving instrument-assisted soft tissue mobilisation compared to standard soft tissue mobilisation (RR 1.24, 95% CI 0.89 to 1.75), though participants were not blinded and it was unclear if the allocation sequence was concealed. Another very low-quality trial with 26 participants found that more CTS-affected wrists receiving nerve gliding exercises plus splint plus activity modification had no pathologic finding on median and ulnar nerve distal sensory latency assessment at the end of treatment than wrists receiving splint plus activity modification alone (RR 1.26, 95% CI 0.69 to 2.30). However, a unit of analysis error occurred in this trial, as the correlation between wrists in participants with bilateral CTS was not accounted for. Only two studies measured adverse effects, so more data are required before any firm conclusions on the safety of exercise and mobilisation interventions can be made. In general, the results of secondary outcomes of the review (short- and long-term improvement in CTS symptoms, functional ability, health-related quality of life, neurophysiologic parameters, and the need for surgery) for most comparisons had 95% CIs which incorporated effects in either direction.

AUTHORS' CONCLUSIONS

There is limited and very low quality evidence of benefit for all of a diverse collection of exercise and mobilisation interventions for CTS. People with CTS who indicate a preference for exercise or mobilisation interventions should be informed of the limited evidence of effectiveness and safety of this intervention by their treatment provider. Until more high quality randomised controlled trials assessing the effectiveness and safety of various exercise and mobilisation interventions compared to other non-surgical interventions are undertaken, the decision to provide this type of non-surgical intervention to people with CTS should be based on the clinician's expertise in being able to deliver these treatments and patient's preferences.

Value of Gilliatt's pneumatic tourniquet test for diagnosis of carpal tunnel syndrome

OBJECTIVES

In 1953, Gilliatt and Wilson described the pneumatic-tourniquet test to diagnose the carpal tunnel syndrome (CTS). It was originally carried out by inflating a brachial cuff at suprasystolic pressure, looking for the appearance of dysesthesiae; several authors later proposed to perform it at infrasystolic pressure, arguing that it would better reflect the elevated venous pressure supposed to be present in CTS. The purpose of this study was to compare both methods.

METHODS

This prospective randomized controlled study included 49 patients and compared both methods to perform Gilliatt's test with more commonly used provocative tests (Tinel, Phalen, Durkan, and Weber). The following end-points were considered: typical clinical presentation, altered neurophysiological tests, abnormal ultrasound findings and early resolution of symptoms after surgical decompression.

RESULTS

For all these end-points, no significant difference was observed in sensibility nor specificity, whether Gilliatt's test was performed supra- or infra-systolic. In addition, Gilliatt's test proved to have less diagnostic value than Phalen and Durkan tests for sensibility.

CONCLUSION

This study did not permit to distinguish the two versions of Gilliatt's test but to open a discussion about the utility of such a test to diagnose the CTS.

Surface electromyography features in manual workers affected by carpal tunnel syndrome

INTRODUCTION

Alterations in surface electromyographic (sEMG) signals of the abductor pollicis brevis muscle were evaluated in 24 non-manual workers and 40 manual workers (25 asymptomatic and 15 reporting CTS symptoms).

METHODS

The initial value (IV) and the normalized rate of change (NRC) of average rectified value (ARV), mean frequency of the power spectrum (MNF), and muscle fiber conduction velocity (MFCV) were calculated during contractions at 20% and 50% of maximal voluntary contraction (MVC). Neuromuscular efficiency (NME) and kurtosis of the sEMG amplitude distribution were estimated.

RESULTS

With respect to controls, manual workers showed higher NME, lower ARV IV, and reduced myoelectric manifestations of fatigue (lower MNF NRC for both contraction levels, and lower MFCV NRC at 50% MVC). Kurtosis at 20% MVC showed higher values in symptomatic manual workers than in the other two groups.

CONCLUSIONS

Kurtosis seems to be a promising parameter for use in monitoring individuals who develop CTS.

Relationship between intraneural vascular flow measured with sonography and carpal tunnel syndrome diagnosis based on electrodiagnostic testing

OBJECTIVES

The purpose of this study was to document and analyze intraneural vascular flow within the median nerve using power and spectral Doppler sonography and to determine the relationship of this vascular flow with diagnosis of carpal tunnel syndrome based on electrodiagnostic testing.

METHODS

Power and spectral Doppler sonograms in the median nerve were prospectively collected in 47 symptomatic and 44 asymptomatic subjects. Doppler studies were conducted with a 12-MHz linear transducer. Strict inclusion criteria were established for postexamination assessment of waveforms; routine quality assurance was completed; electrodiagnostic tests were conducted on the same day as sonographic measurements; and the skin temperature was controlled. Included waveforms were categorized by location and averaged by individual for comparative analysis to electrodiagnostic testing.

RESULTS

A total of 416 waveforms were collected, and 245 were retained for statistical analysis based on strict inclusion criteria. The mean spectral peak velocity among all waveforms was 4.42 (SD, 2.15) cm/s. At the level of the pisiform, the most consistent data point, mean peak systole, was 3.75 cm/s in symptomatic patients versus 4.26 cm/s in asymptomatic controls. Statistical trending showed an initial increase in the mean spectral peak velocity in symptomatic but diagnostically negative cases, with decreasing velocity as diagnostic categories progressed from mild to severe.

CONCLUSIONS

An inverse relationship may exist between intraneural vascular flow in the median nerve and an increasing severity of carpal tunnel syndrome based on nerve conduction results. Randomized controlled trials are needed to determine whether spectral Doppler sonography can provide an additive benefit for diagnosing the severity of carpal tunnel syndrome.

A blinded placebo-controlled randomized trial on the use of astaxanthin as an adjunct to splinting in the treatment of carpal tunnel syndrome

BACKGROUND

Nutritional supplementation is a potential adjunct in the conservative management of carpal tunnel syndrome (CTS). This study investigated whether astaxanthin (a beta-carotenoid) increased the effectiveness of splinting in managing CTS.

METHODS

This is a triple-blinded randomized controlled trial where 63 patients with electrodiagnostically confirmed CTS were randomly allocated into either the experimental group (n = 32) (astaxanthin-4-mg capsules + splinting) or the control group (n = 31) (placebo + splinting). Medications were taken for 9 weeks followed by a 3-week washout. The primary outcome measure was the Symptom Severity Scale (SSS). Secondary outcome measures in the study included physical impairments, disability, and health status measures. Electrodiagnostic testing was performed before entry into the study and again at 12 weeks. All other outcomes were measured at baseline, 6, and 12 weeks.

RESULTS

There was a reduction in symptoms as measured by the SSS over the course of treatment in both groups (p = 0.002), but no differences between the groups (p = 0.18). The Disability of Arm, Shoulder and Hand questionnaire and the Short Form 36-item Health Survey showed no effects over time or between treatment groups. The baseline difference between the groups in the level of total cholesterol and low-density lipoproteins remained constant over the course of the study. Impairment measures demonstrated no significant changes in grip, dexterity, or sensation.

CONCLUSION

At present, the role for astaxanthin as an adjunct in conservative management of CTS has not been established.

Prevalence of carpal tunnel syndrome among dairy workers

BACKGROUND

The purpose of this study was to determine the prevalence of carpal tunnel syndrome (CTS) among dairy workers.

METHODS

Sixty-six dairy parlor workers and 58 non-parlor workers at dairies in Texas, New Mexico, and Colorado participated in structured interviews regarding demographics, work history, and hand symptoms. All participants had nerve conduction studies performed on both hands across the carpal tunnel. A CTS case definition was based on the presence of characteristic CTS symptoms and an abnormal median mononeuropathy across the carpal tunnel.

RESULTS

The prevalence of CTS among the dairy parlor workers was 16.6% and 3.6% among non-parlor workers. The difference was found to be statistically significant (P < 0.05) with an odds ratio of 5.3, CI (1.1-25.5).

CONCLUSIONS

The results of this study indicate that CTS is a significant challenge for dairy parlor workers. The prevalence of CTS was found to be significantly higher among dairy workers performing tasks in the milking parlor as opposed to workers performing tasks in other areas of the dairy farm. The results emphasize the need for administrative and engineering controls to limit the exposure to physical risk factors that are associated with upper limb disorders such as CTS.

Correlation between the severity of carpal tunnel syndrome and color Doppler sonography findings

OBJECTIVE

Carpal tunnel syndrome (CTS) represents one of the most prevalent peripheral entrapment mononeuropathies. The purpose of our study was to assess the potential correlation between intraneural hypervascularization, flexor retinaculum bowing, and median nerve cross-sectional area and the severity of CTS in cases confirmed by nerve conduction study.

SUBJECTS AND METHODS

Sixty consecutive patients with classic or probable symptoms of CTS were enrolled in the study. A control group consisting of 27 healthy volunteers who were never diagnosed with CTS or had any symptoms of CTS was recruited among institution employees. All symptomatic patients were initially examined by a hand surgeon and subsequently referred for sonographic and electrophysiologic examinations.

RESULTS

A total of 90 wrists (in 60 patients) were included in the study. Twenty-eight (31.1%) had mild CTS, 33 had moderate disease, and 29 had severe disease. We detected significant correlation between median nerve hypervascularization and the severity of CTS (p = 0.01, logistic regression) for moderate CTS and (p = 0.04) for severe disease. We also detected a significant correlation in flexor retinaculum bowing and median nerve cross-sectional area with increase in the severity of CTS (p < 0.001 and < 0.008; chi-square test and analysis of variance, respectively).

CONCLUSION

Our study suggests that the severity of CTS strongly correlates with color Doppler sonography findings, and this technique may represent a reliable complementary tool in CTS examination.

Ergonomic positioning or equipment for treating carpal tunnel syndrome

BACKGROUND

Non-surgical treatment, including ergonomic positioning or equipment, are sometimes offered to people experiencing mild to moderate symptoms from carpal tunnel syndrome (CTS). The effectiveness and duration of benefit from ergonomic positioning or equipment interventions for treating CTS are unknown.

OBJECTIVES

To assess the effects of ergonomic positioning or equipment compared with no treatment, a placebo or another non-surgical intervention in people with CTS.

SEARCH METHODS

We searched the Cochrane Neuromuscular Disease Group Specialized Register (14 June 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (2011, Issue 2, in The Cochrane Library), MEDLINE (1966 to June 2011), EMBASE (1980 to June 2011), CINAHL Plus (1937 to June 2011), and AMED (1985 to June 2011). We also reviewed the reference lists of randomised or quasi-randomised trials identified from the electronic search.

SELECTION CRITERIA

Randomised or quasi-randomised controlled trials comparing ergonomic positioning or equipment with no treatment, placebo or another non-surgical intervention in people with CTS.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, extracted data and assessed risk of bias of included studies. We calculated risk ratios (RR) and mean differences (MD) with 95% confidence intervals (CI) for the primary and secondary outcomes. We pooled results of clinically and statistically homogeneous trials, where possible, to provide estimates of the effect of ergonomic positioning or equipment.

MAIN RESULTS

We included two trials (105 participants) comparing ergonomic versus placebo keyboards. Neither trial assessed the primary outcome (short-term overall improvement) or adverse effects of interventions. In one small trial (25 participants) an ergonomic keyboard significantly reduced pain after 12 weeks (MD -2.40; 95% CI -4.45 to -0.35) but not six weeks (MD -0.20; 95% CI -1.51 to 1.11). In this same study, there was no difference between ergonomic and standard keyboards in hand function at six or 12 weeks or palm-wrist sensory latency at 12 weeks. The second trial (80 participants) reported no significant difference in pain severity after six months when using either of the three ergonomic keyboards versus a standard keyboard. No trials comparing (i) ergonomic positioning or equipment with no treatment, (ii) ergonomic positioning or equipment with another non-surgical treatment, or (iii) different ergonomic positioning or equipment regimes, were found.

AUTHORS' CONCLUSIONS

There is insufficient evidence from randomised controlled trials to determine whether ergonomic positioning or equipment is beneficial or harmful for treating carpal tunnel syndrome.

Therapeutic ultrasound for carpal tunnel syndrome

BACKGROUND

Therapeutic ultrasound may be offered to people experiencing mild to moderate symptoms of carpal tunnel syndrome (CTS). The effectiveness and duration of benefit of this non-surgical intervention remain unclear.

OBJECTIVES

To review the effects of therapeutic ultrasound compared with no treatment, placebo or another non-surgical intervention in people with CTS.

SEARCH METHODS

We searched the Cochrane Neuromuscular Disease Group Specialized Register (22 February 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library, 2011, Issue 1), MEDLINE (January 1966 to February 2011), EMBASE (January 1980 to February 2011), CINAHL Plus (January 1937 to February 2011), and AMED (January 1985 to February 2011).

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing any regimen of therapeutic ultrasound with no treatment, a placebo or another non-surgical intervention in people with CTS.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials for inclusion, extracted data and assessed the risk of bias in the included studies. We calculated risk ratio (RR) and mean difference (MD) with 95% confidence intervals (CIs) for primary and secondary outcomes. We pooled results of clinically homogenous trials in a meta-analysis using a random-effects model, where possible, to provide estimates of the effect.

MAIN RESULTS

We included 11 studies randomising 443 patients in the review. Two trials compared therapeutic ultrasound with placebo, two compared one ultrasound regimen with another, two compared ultrasound with another non-surgical intervention, and six compared ultrasound as part of a multi-component intervention with another non-surgical intervention (for example, exercises and splint). The risk of bias was low in some studies and unclear or high in other studies, with only three reporting that the allocation sequence was concealed and six reporting that participants were blinded. Overall, there is insufficient evidence that one therapeutic ultrasound regimen is more efficacious than another. Only two studies reported the primary outcome of interest, short-term overall improvement (any measure in which patients indicate the intensity of their complaints compared with baseline, for example, global rating of improvement, satisfaction with treatment, within three months post-treatment). One low quality trial with 68 participants found that when compared with placebo, therapeutic ultrasound may increase the chance of experiencing short-term overall improvement at the end of seven weeks treatment (RR 2.36; 95% CI 1.40 to 3.98), although losses to follow-up in this study suggest that these data should be interpreted with caution. Another low quality trial with 60 participants found that at three months, post-treatment therapeutic ultrasound plus splint increased the chance of short-term overall improvement (patient satisfaction) when compared with splint alone (RR 3.02; 95% CI 1.36 to 6.72), but decreased the chance of short-term overall improvement when compared with low-level laser therapy plus splint (RR 0.87; 95% CI 0.57 to 1.33), though participants were not blinded to treatment and it was unclear if the random allocation sequence was adequately concealed. Differences between groups receiving different frequencies and intensities of ultrasound, and between ultrasound as part of a multi-component intervention versus other non-surgical interventions, were generally small and not statistically significant for symptoms, function, and neurophysiologic parameters. Only four studies measured adverse effects, none of which identified adverse effects due to therapeutic ultrasound. However, more data on this outcome are required before any firm conclusions on the safety of this intervention can be made.

AUTHORS' CONCLUSIONS

There is only poor quality evidence from very limited data to suggest that therapeutic ultrasound may be more effective than placebo for either short- or long-term symptom improvement in people with CTS. There is insufficient evidence to support the greater benefit of one type of therapeutic ultrasound regimen over another or to support the use of therapeutic ultrasound as a treatment with greater efficacy compared to other non-surgical interventions for CTS, such as splinting, exercises, and oral drugs. More methodologically rigorous studies are needed to determine the effectiveness and safety of this intervention for CTS.

Electrodiagnostic evaluation of carpal tunnel syndrome

Carpal tunnel syndrome (CTS) is the most common nerve entrapment. Electrodiagnostic (EDX) studies are a valid and reliable means of confirming the diagnosis. This monograph addresses the various EDX techniques used to evaluate the median nerve at the wrist. It also demonstrates the limitations of EDX studies with a focus on the sensitivity and specificity of EDX testing for CTS. The need to use reference values for populations such as diabetics and active workers, where normative values differ from conventional cutoffs used to confirm suspected CTS, is presented. The value of needle electromyography (EMG) is examined.

Dynamic Doppler evaluation of the radial and ulnar arteries in patients with carpal tunnel syndrome

OBJECTIVE

The objective of our study was to evaluate the blood flow characteristics of the radial and ulnar arteries of the hands of patients with carpal tunnel syndrome (CTS) either in the neutral position or in provocative positions using color Doppler imaging.

SUBJECTS AND METHODS

Subjects with relevant complaints of CTS and positive Tinel sign and/or Phalen maneuver were recruited. Nerve conduction studies were performed to confirm the diagnosis of CTS. Forty-four hands of 22 patients with CTS (bilateral involvement) and 24 hands of 12 healthy volunteers were included in the study. Pulsed and color Doppler evaluations with the hands in the neutral, Phalen, and reverse Phalen positions were performed of the radial and ulnar arteries using a 5-13-MHZ linear-array transducer (Logiq 9).

RESULTS

All of the CTS patients and control subjects were women; their mean ages were 50.77 ± 7.69 (SD) and 46.42 ± 4.32 years, respectively. When hands were evaluated in the neutral position, the flow volume, peak systolic velocity, end-diastolic velocity, and diameter values of both the radial and ulnar arteries were significantly greater in patients with CTS than in control subjects (all p < 0.05). When compared with the measurements obtained with hands at the neutral position, the decreases in the amount of blood flow during the Phalen and reverse Phalen maneuvers were significantly greater in the CTS group than the control group. The amount of blood flow decrease was not correlated with the disease duration.

CONCLUSION

Blood flow in the hands of CTS patients differs from that of healthy individuals both at rest and during certain hand movements. Future studies, also with simultaneous monitoring of sympathetic innervation, could be beneficial to confirm the association between blood flow and the sympathetic nerves of the hand.

Diurnal variation in clinical and electrophysiologic parameters associated with carpal tunnel syndrome

OBJECTIVE

Patients with carpal tunnel syndrome (CTS) often report aggravated symptoms in the early morning. In this study, we aimed to identify diurnal variations in clinical and electrophysiologic parameters of patients with CTS.

DESIGN

A cross-sectional clinical and electrophysiologic study was designed. First, electrophysiologic examinations were performed at 2 p.m. to confirm the diagnosis of patients who had been clinically labeled with CTS. Patients who were electrophysiologically and clinically diagnosed with CTS were included in the study, and electrophysiologic examinations were repeated at 7 p.m. and 7 a.m. A total of 64 hands with CTS (27 bilateral, 10 unilateral) and 40 control hands were studied. Grip and pinch strength of all the patients included in the study were measured using a hand dynamometer. Finally, a CTS clinical symptom severity scale and functional status scale were used to measure the symptoms and functional impairment, respectively.

RESULTS

The median motor nerve distal latency and median F-minimum latency were found to be prolonged in the CTS group in the morning, and the grip strength was also markedly reduced at this time. Similar results were obtained for the median palm mixed nerve conduction velocity and amplitude.

CONCLUSIONS

This study demonstrated that the clinical and electrophysiologic parameters of CTS patients were clearly different in the morning hours, with the symptoms of CTS manifesting at that time.

Carpal tunnel syndrome: the role of occupational factors

Carpal tunnel syndrome (CTS) is a fairly common condition in working-aged people, sometimes caused by physical occupational activities, such as repeated and forceful movements of the hand and wrist or use of hand-held, powered, vibratory tools. Symptoms may be prevented or alleviated by primary control measures at work, and some cases of disease are compensable. Following a general description of the disorder, its epidemiology and some of the difficulties surrounding diagnosis, this review focusses on the role of occupational factors in causation of CTS and factors that can mitigate risk. Areas of uncertainty, debate and research interest are emphasised where relevant.

Diagnostic accuracy of ultrasonography vs. electromyography in carpal tunnel syndrome: a systematic review of literature

A plethora of research investigates sonography vs. electrodiagnostic testing (EDX) for diagnosis of carpal tunnel syndrome (CTS). Through database searches, hand searches and communication with authors, 582 abstracts published from 1999 to 2009 were identified. A comprehensive systematic review process resulted in inclusion of 23 studies. Significant methodologic discrepancies among the studies limited the ability to complete a meta-analysis to identify specific diagnostic thresholds. Instead, the data were reviewed to provide implications for clinical utility of sonography as a screening tool as a compliment to EDX and to suggest continued and future research. The largest cross-sectional area of the median nerve within the carpal tunnel region has high potential for clinical screening, especially in individuals with severe CTS. Identifying swelling of the nerve through comparative measurements, qualitative analysis and Doppler techniques all require further investigation. Screening protocols may be enhanced through exploration of sonography in patients with mild CTS and false-negative EDX.

Comparison of the Diagnostic Utility of Electromyography, Ultrasonography, Computed Tomography, and Magnetic Resonance Imaging in Idiopathic Carpal Tunnel Syndrome Determined by Clinical Findings

Background:

Carpal tunnel syndrome (CTS) is the most common nerve entrapment syndrome. It is sometimes difficult to diagnose, and a late diagnosis may result in permanent nerve damage. Electromyography (EMG), ultrasonography (US), magnetic resonance imaging (MRI), and computed tomography (CT) may be performed for the diagnosis. The diagnostic accuracy of these tests is well documented, but most of these studies accept EMG as the gold standard.

Objective:

To evaluate the diagnostic accuracy of EMG, MRI, CT, and US for the diagnosis of carpal tunnel syndrome with the use of clinical findings as the gold standard.

Methods:

Patients suspected to have CTS on presentation to the outpatient clinic were evaluated. The tests were performed after a detailed physical examination. Both wrists of the 69 patients in the study were investigated.

Results:

The diagnostic accuracies of all the tests were found to be sufficient. Although EMG seemed to have the highest sensitivity and specificity, there was no statistically significant difference between the tests.

Conclusion:

EMG or US could be used as the first-step test in most cases. If they are both available, EMG should be the first choice. They may be performed together when diagnosis is challenging. CT may especially be preferred for bone-related pathological conditions, whereas MRI may be preferred for soft tissue-related pathological conditions. Even though imaging studies have been proven to be powerful diagnostic tools for CTS, no conclusive information currently exists to support replacing EMG with imaging studies.

Job Analysis Techniques for Distal Upper Extremity Disorders

Distal upper extremity (DUE) work-related musculoskeletal disorders (WMSDs) are among the most costly injuries suffered in industry today. These WMSDs are reported in both office (computer use) and manufacturing environments. Job physical exposure analysis techniques for DUE WMSDs range from simple checklists to quantitative models. A summary of literature review of biomechanical, physiological, psychophysical and epidemiological bases for job physical exposure risk factors for DUE WMSDs is provided. Several job analysis methods suitable for manufacturing environments are reviewed and discussed. A comparative analysis of Rapid Upper Limb Assessment (RULA), Threshold Limit Value for Hand Activity Level (TLV for HAL), and the Strain Index is provided along with results from validation studies and advantages and disadvantages of each method. Three examples from industries are provided to demonstrate applications of RULA, TLV for HAL, and the Strain Index. Last, issues with current job analysis methods when a worker rotates to different jobs and/or when a job consists of several tasks are discussed as well as the need for more robust models to account for these variations in physical exposure in real-world environments.

Clinical quality measures for intraoperative and perioperative management in carpal tunnel surgery

BACKGROUND

Previous research documents suboptimal preoperative or postoperative care for patients undergoing surgery. However, few existing quality measures directly address the fundamental element of surgical care: intra-operative care processes. This study sought to develop quality measures for intraoperative, preoperative, and postoperative care for carpal tunnel surgery, a common operation in the USA.

METHODS

We applied a variation of the well-established RAND/UCLA Appropriateness Method. Adherence to measures developed using this method has been associated with improved patient outcomes in several studies. Hand surgeons and quality measurement experts developed draft measures using guidelines and literature. Subsequently, in a two-round modified-Delphi process, a multidisciplinary panel of 11 national experts in carpal tunnel syndrome (including six surgeons) reviewed structured summaries of the evidence and rated the measures for validity (association with improved patient outcomes) and feasibility (ability to be assessed using medical records).

RESULTS

Of 25 draft measures, panelists judged 22 (88%) to be valid and feasible. Nine intraoperative measures addressed the location and extent of surgical dissection, release after wrist trauma, endoscopic release, and four procedures sometimes performed during carpal tunnel surgery. Eleven measures covered preoperative and postoperative evaluation and management.

CONCLUSIONS

We have developed several measures that experts, including surgeons, believe to reflect the quality of care processes occurring during carpal tunnel surgery and be assessable using medical records. Although quality measures like these cannot assess a surgeon's skill in handling the instruments, they can assess many important aspects of intraoperative care. Intraoperative measures should be developed for other procedures.

Factor analysis of carpal tunnel syndrome questionnaire in relation to nerve conduction studies

OBJECTIVE

This study aims to assess the Boston Carpal Tunnel Syndrome Questionnaire (BCTQ) structure and its relation to nerve conduction studies (NCS).

METHODS

A total of 403 patients with clinical and/or electrophysiological definition of CTS were evaluated with the instrument. The structure of the questionnaire was assessed by means of factor analysis. Factors obtained were compared with NCS.

RESULTS

Factor analysis showed that three factors represented nearly 60% of the variance of the instrument. Factor one is related to all the function domain questions and to the weakness and difficulty in grasping questions of the symptom domain; factor two to questions that assess numbness and tingling, and to the pain-awakening question of the symptom domain; and factor three, to pain questions of the symptom domain. Factor two had a stronger correlation with latencies of NCS and with the neurophysiological scale than the other two factors.

CONCLUSIONS

BCTQ assesses function and symptoms in patients with CTS by means of questions related to numbness and tingling sensation, pain and functional status. Questions related to numbness and tingling (factor two) better reflected the pathophysiology of the median nerve.

SIGNIFICANCE

Factor-2 sensory-related questions of BCTQ may be more useful in diagnosis, follow-up and assessing therapeutic outcome in CTS.

Comparison of research case definitions for carpal tunnel syndrome

OBJECTIVE

The aim of this study was to assess agreement between different case definitions of carpal tunnel syndrome (CTS) for epidemiological studies.

METHODS

We performed a literature search for papers suggesting case definitions for use in epidemiological studies of CTS. Using data elements based on symptom questionnaires, hand diagrams, physical examinations, and nerve conduction studies collected from 1107 newly-hired workers, each subject in the study was classified according to each of the case definitions selected from the literature. We compared each case definition to every other case definition, using the Kappa statistic to measure pair-wise agreement on whether each subject met the case definition.

RESULTS

We found six unique papers in a 20-year period suggesting a case definition of CTS for use in population-based studies. We extracted seven case definitions. Definitions included different parameters: (i) symptoms only, (ii) symptoms and physical examination, (iii) symptoms and either physical examination or median nerve conduction study, and (iv) symptoms and nerve conduction study. When applied to our study population, the prevalence of CTS using different case definitions ranged from 2.5-11.0%. The percentage of misclassification was between 1-10%, with generally acceptable levels of agreement (kappa values ranged from 0.30-0.85).

CONCLUSIONS

Different case definitions resulted in widely varying prevalences of CTS. Agreement between case definitions was generally good, particularly between those that required very specific symptoms or the combination of symptoms and physical examination or nerve conduction. The agreement observed between different case definitions suggests that the results can be compared across different research studies of risk factors for CTS.

Accuracy of in-office nerve conduction studies for median neuropathy: a meta-analysis

PURPOSE

Carpal tunnel syndrome is the most common focal neuropathy. It is typically diagnosed clinically and confirmed by abnormal median nerve conduction across the wrist (median neuropathy [MN]). In-office nerve conduction testing devices facilitate performance of nerve conduction studies (NCS) and are used by hand surgeons in the evaluation of patients with upper extremity symptoms. The purpose of this meta-analysis was to determine the diagnostic accuracy of this testing method for MN in symptomatic patients.

METHODS

We searched the MEDLINE database for prospective cohort studies that evaluated the diagnostic accuracy of in-office NCS for MN in symptomatic patients with traditional electrodiagnostic laboratories as reference standards. We assessed included studies for quality and heterogeneity in diagnostic performance and determined pooled statistical outcome measures when appropriate.

RESULTS

We identified 5 studies with a total of 448 symptomatic hands. The pooled sensitivity and specificity were 0.88 (95% confidence interval [CI], 0.83-0.91) and 0.93 (95% CI, 0.88-0.96), respectively. Specificities exhibited heterogeneity. The diagnostic odds ratios were homogeneous, with a pooled value of 62.0 (95% CI, 30.1-127).

CONCLUSIONS

This meta-analysis showed that in-office NCS detects MN with clinically relevant accuracy. Performance was similar to interexaminer agreement for MN within a traditional electrodiagnostic laboratory. There was some variation in diagnostic operating characteristics. Therefore, physicians using this technology should interpret test results within a clinical context and with attention to the pretest probability of MN, rather than in absolute terms.

Physical examination has a low yield in screening for carpal tunnel syndrome

BACKGROUND

physical examination is often used to screen workers for carpal tunnel syndrome (CTS). In a population of newly hired workers, we evaluated the yield of such screening.

METHODS

our study population included 1,108 newly hired workers in diverse industries. Baseline data included a symptom questionnaire, physical exam, and bilateral nerve conduction testing of the median and ulnar nerves; individual results were not shared with the employer. We tested three outcomes: symptoms of CTS, abnormal median nerve conduction, and a case definition of CTS that required both symptoms and median neuropathy.

RESULTS

of the exam measures used, only Semmes-Weinstein sensory testing had a sensitivity value above 31%. Positive predictive values were low, and likelihood ratios were all under 5.0 for positive testing and over 0.2 for negative testing.

CONCLUSION

physical examination maneuvers have a low yield for the diagnosis of CTS in workplace surveillance programs and in post-offer, pre-placement screening programs.

Upper Limb Neurodynamic Test 1 and symptoms reproduction in carpal tunnel syndrome. A validity study

The aim of this study was to estimate the validity of the Upper Limb Neurodynamic Test 1 (ULNT1) for the diagnosis of Carpal Tunnel Syndrome (CTS) with blind comparison to a reference criterion of a compatible clinical presentation and abnormal nerve conduction. 47 subjects with suspected CTS were enrolled. All patients were tested with nerve conduction studies and ULNT1. Considering results as positive in the presence of reproduction of symptoms on affected upper limb, or side-to-side differences in elbow extension, or symptoms modified by lateral neck side-bending, we estimated sensitivity as 91.67%, specificity as 15%, positive likelihood ratio as 1.0784, negative likelihood ratio as 0.5556, and post-test probability for negative test as 40%. Using a new criterion, i.e. the reproduction of symptoms only in the first three digits of the affected hand, we estimated sensitivity as 54.17%, specificity as 70%, positive and negative likelihood ratios as 1.8056 and 0.6548, respectively, and post-test probability for positive test as 68%. Our investigation suggests that the reproduction of the typical current CTS symptoms in the affected hand during ULNT1 testing, improves estimation of the probability of the presence of this condition, even if this test alone cannot be used to diagnose CTS.