Correspondence between clinical presentation and electrophysiological testing for potential carpal tunnel syndrome

Diagnostic accuracy of sensory and motor tests for the diagnosis of carpal tunnel syndrome: a systematic review

BACKGROUND

Carpal tunnel syndrome (CTS) is the most common entrapment mononeuropathy of the upper extremity. The previous systematic review of the diagnostic tests for CTS was outdated. The objective of this study was to compile and appraise the evidence on the accuracy of sensory and motor tests used for the diagnosis of CTS.

METHODS

MEDLINE, CINAHL, and Embase databases were searched on January 20, 2020. Studies assessing at least one diagnostic accuracy property of the sensory or motor tests for CTS diagnosis were selected by two independent reviewers. Diagnostic test accuracy extension of the PRISMA guidelines was followed. Risk of bias and applicability concerns were rated using QUADAS-2 tool. Any reported diagnostic accuracy property was summarized. Study characteristics and any information on the accuracy of the sensory and motor tests for CTS diagnosis were extracted.

RESULTS

We included sixteen clinical studies, assessing thirteen different sensory or motor tests. The most sensitive test for CTS diagnosis was the Semmes-Weinstein monofilament test (with 3.22 in any radial digit as the normal threshold) with sensitivity from 0.49 to 0.96. The tests with the highest specificity (Sp) were palmar grip strength (Sp = 0.94), pinch grip strength (Sp from 0.78 to 0.95), thenar atrophy (Sp from 0.96 to 1.00), and two-point discrimination (Sp from 0.81 to 0.98).

CONCLUSIONS

The evidence was inconclusive on which sensory or motor test for CTS diagnosis had the highest diagnostic accuracy. The results suggest that clinicians should not use a single sensory or motor test when deciding on CTS diagnosis.

TRIAL REGISTRATION

PROSPERO CRD42018109031 , on 20 December 2018.

Diagnosing Carpal Tunnel Syndrome: Diagnostic Test Accuracy of Scales, Questionnaires, and Hand Symptom Diagrams-A Systematic Review

OBJECTIVE

To summarize and evaluate research on the accuracy of clinical diagnostic scales, questionnaires, and hand symptom diagrams/maps used for diagnosis of carpal tunnel syndrome (CTS).

DESIGN

Systematic review of diagnostic test accuracy.

LITERATURE SEARCH

A comprehensive literature search of the MEDLINE, CINAHL, and Embase databases was conducted on January 20, 2020.

STUDY SELECTION CRITERIA

Studies that assessed at least 1 diagnostic accuracy property of the scales, questionnaires, and hand symptom diagrams used for the diagnosis of CTS.

DATA SYNTHESIS

The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines were followed. Risk of bias and applicability concerns were assessed using the revised Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2) tool. Diagnostic accuracy properties were summarized.

RESULTS

Out of 4052 citations after removing duplicates, 21 articles met the inclusion criteria. Twelve articles reported on the diagnostic accuracy of scales and questionnaires, including the Bland questionnaire, Kamath and Stothard questionnaire, 6-item carpal tunnel syndrome symptoms scale (CTS-6), Boston Carpal Tunnel Questionnaire, Wainner clinical prediction rule, and Lo clinical prediction rule. Positive likelihood ratios ranged from 0.94 for the Boston Carpal Tunnel Questionnaire to 10.5 for the CTS-6, and negative likelihood ratios ranged from 1.04 to 0.05 for the same diagnostic tools, respectively. Nine studies reported the diagnostic accuracy of the Katz and Stirrat hand symptom diagram. Positive and negative likelihood ratios ranged from 1.42 to 8 and from 0.78 to 0.05, respectively. Only 4 studies had high methodologic quality.

CONCLUSION

Limited evidence supports high accuracy of the CTS-6, Kamath and Stothard questionnaire, and Katz and Stirrat hand symptom diagram. Other scales have lesser and more conflicting evidence. Further high-quality studies are necessary to examine the diagnostic accuracy of these tests to assist ruling in or ruling out CTS. J Orthop Sports Phys Ther 2020;50(11):622-631. Epub 16 Sep 2020. doi:10.2519/jospt.2020.9599.

Role of Biomechanical Factors in Resolution of Carpal Tunnel Syndrome Among a Population of Workers

OBJECTIVES

Identify if Carpal tunnel syndrome (CTS) symptoms vary by measured biomechanical exposures.

METHODS

A nested prospective cohort within a large, multicenter, 8-year cohort study. The CTS case definition was tingling/numbness in 2+ median nerve-served digits plus a nerve conduction study consistent with CTS. Workers were assigned to: (1) low (strain index [SI] less than or equal to 6.1), and (2) high (SI more than 6.1) job groups.

RESULTS

Among 1201 workers, 106 had CTS. Those in the high SI group became and remained symptom-free for at least 3 months, faster than the low SI group, adjusted hazard ratio (HR) = 2.07 (95% confidence interval [CI] = 1.21 to 3.56, P = 0.008). Only surgical release trended towards resolving CTS. Light duty had no impact, and job change was associated with delayed symptoms resolution.

CONCLUSIONS

High biomechanical exposures paradoxically predicted faster improvement in CTS and light duty did not result in symptom resolution.

False-Positive Rates for Nerve Conduction Studies and Ultrasound in Patients Without Clinical Signs and Symptoms of Carpal Tunnel Syndrome

PURPOSE

The purpose of the study was to determine the rate of false positives for nerve conduction studies (NCSs) and ultrasound (US) in a population without signs and symptoms of carpal tunnel syndrome (CTS) using a CTS-6 score of 0 as the reference standard.

METHODS

Patients were included in this study if they were referred for NCSs for a reason other than CTS (cubital tunnel syndrome and/or cervical radiculopathy) and they had a CTS-6 score of 0. An US measurement of the cross-sectional area (CSA) of the median nerve at the level of the carpal tunnel inlet was performed by a certified ultrasound technician. An a priori CSA cutoff of 10 mm² or greater measured using US at the carpal tunnel inlet qualified as a positive diagnosis. The NCSs were performed and interpreted according to national standards by a certified electrodiagnostician. All patients in this study were considered to not have a diagnosis of CTS based on the CTS-6 of 0.

RESULTS

Forty hands with a CTS-6 of 0 were included in this study. The US was positive in 9 of 40(23%) and NCS was positive in 17 of 40 (43%). There were only 2 patients with a false-positive US that did not also have a positive NCS. However, there were 11 patients who had a false-positive NCS that did not have a positive US.

CONCLUSIONS

This prospective cohort series has demonstrated that US has a lower false-positive rate than NCSs in asymptomatic patients as measured by the CTS-6 diagnostic tool. Studies with a low false-positive rate are preferred when ordering a confirmatory diagnostic test. Therefore, if a confirmatory diagnostic test is desired, we recommend that US be used rather than NCSs.

TYPE OF STUDY/LEVEL OF EVIDENCE

Diagnostic II.

Evaluation of thenar muscles by MRI in carpal tunnel syndrome

In the present study, the thenar muscles were evaluated using magnetic resonance imaging (MRI), in addition, the correlations between thenar muscle changes, clinical findings and electrodiagnostic results from patients with carpal tunnel syndrome were investigated. The subjects were 13 patients (17 wrists) who were clinically diagnosed with carpal tunnel syndrome. In all patients, a medical history was obtained and physical examination was performed, in addition to assessment using the Kapandji scoring system, visual analogue scale (VAS), quick-disabilities of the arm, shoulder and hand (Q-DASH) score, electrodiagnostic results of the median nerve, and MRI of the thenar muscles. Thenar muscle volume was not significantly correlated with clinical data or the electrodiagnostic results. The thenar muscle major axis was significantly correlated with grasp power (P<0.05) and the Kapandji score (P<0.05), while the thenar muscle minor axis was significantly correlated with abductor pollicis brevis distal motor latency (APB DML) (P<0.01). In addition, the thenar muscle minor axis/thenar muscle major axis ratio was significantly correlated with APB DML and Kanatani's stage. Notably, thenar muscle thinness was significantly correlated with the severity of electrodiagnostic changes, while the grasp power and Kapandji score were correlated with thenar muscle thickness. Furthermore, it was demonstrated that thenar muscle thinness was significantly correlated with the severity of electrodiagnostic changes; in addition, there was a significant correlation between the thenar muscle major axis and the grasp power or Kapandji score. Taken together, these results revealed that thenar muscle atrophy did not affect patient-based assessments, including VAS and Q-DASH, but reflected electrodiagnostic results, particularly DML and severity. The results of the present study suggest that thenar muscle atrophy can be used to estimate the severity of carpal tunnel syndrome.

Patient-Reported Disability Measures Do Not Correlate with Electrodiagnostic Severity in Carpal Tunnel Syndrome

Background:

Electrophysiologic studies including electromyography and nerve conduction studies play a role in the evaluation of carpal tunnel syndrome (CTS), despite evidence that these studies do not correlate with CTS-specific symptom scores. There is a lack of evidence comparing electrophysiologic data with general measures of function.

Methods:

Fifty patients presenting for CTS treatment over an 8-month period were analyzed retrospectively. All patients completed surveys including the Quick Disabilities of the Arm, Shoulder, and Hand questionnaire (DASH) and the Medical Outcomes Study 12-Item Short-Form Survey [(physical component summary 12, mental component summary (MCS-12)]. Electromyography and nerve conduction studies were performed on all patients and compared with outcome scores.

Results:

Analysis demonstrated no relationship between DASH or MCS-12 and electrodiagnostic severity. No significant correlations were noted between DASH or MCS-12 and median motor or sensory latency. There was a moderate–weak correlation (rho = 0.34) between more severe electrophysiologic grade and better function based on physical component summary 12.

Conclusions:

Electrodiagnostic severity grades do not correlate with patient-reported disability, including the DASH and MCS–12 surveys. There is a counterintuitive correlation between more-severe electrodiagnostic findings and decreased physical disability. These findings indicate that disability may not correlate with electrodiagnostic severity of median neuropathy in CTS.

Does electrodiagnostic evidence correlate with mood and function in patients with a pre-diagnosis of carpal tunnel syndrome?

Objectives

This study aims to investigate if function and mood involvement correlate in female patients who have a pre-diagnosis of carpal tunnel syndrome (CTS) and its correlation with physical examination and electrodiagnostic findings.

Patients and methods

A total of 170 patients between the ages of 18-65 who applied to Physical Medicine and Rehabilitation outpatient clinics with CTS symptoms between May 2014 and December 2015 were enrolled. The mean age of patients was 44.6±11 years. Before electrophysiological testing (electromyography; EMG), Disabilities of the Arm, Shoulder and Hand questionnaire (QuickDASH), Beck Depression Inventory, Tinnel, Phalen and Durkan tests, grip and pinch strength measurement by JAMAR hand dynamometer were performed. The patients also used a Visual Analog Scale (VAS) to determine the severity of their symptoms during the day and at night.

Results

In 98 patients (57.6%) the diagnosis of CTS was confirmed by EMG, while 72 patients (42.4%) had normal electrodiagnostic findings. In patients who had normal EMG, Beck Depression Inventory and QuickDASH scores were not significantly different from the patients who had an electrodiagnosis of CTS. Pain experienced in the night was significantly higher in patients who had an electrodiagnosis of CTS, and these patients had significantly higher Beck Depression Inventory and QuickDASH scores.

Conclusion

The lack of electrodiagnostic evidence in patients who have CTS symptoms does not show that function and mood are not affected in these patients. However, mood is significantly affected in patients with severe CTS.

Prospective Evaluation of Sleep Improvement Following Carpal Tunnel Release Surgery

PURPOSE

Sleep disturbance due to nighttime awakening is a well-documented symptom of carpal tunnel syndrome. While relief of nighttime waking following carpal tunnel release (CTR) has been demonstrated, the effect of CTR on overall sleep quality has not been fully investigated. We hypothesized that CTR would result in significant improvement in overall sleep quality as well as patients' overall satisfaction with their sleep habits.

METHODS

Cases of carpal tunnel syndrome with positive nerve studies, and treated with CTR, were prospectively enrolled. Demographic data, electromyography (EMG) severity, Quick Disabilities of the Arm, Shoulder, and Hand questionnaire, and Insomnia Severity Index (ISI) scale data were collected.

RESULTS

A total of 398 patients were enrolled, with 99% available at 2 weeks and 64% available at 3-month final follow-up. At final follow-up, average Quick Disabilities of the Arm, Shoulder, and Hand score improved significantly from the preoperative value. Average ISI score on all 7 sleep categories on the survey improved significantly from before surgery to the first postoperative visit. However, the total ISI score did not further improve significantly between the 2-week and the 3-month postoperative visits. The ISI score improvements did not correlate with EMG severity.

CONCLUSIONS

Patients undergoing CTR demonstrated significant improvement in mean scores for 7 aspects of sleep quality. Sleep improvement was unrelated to preoperative EMG severity and was experienced within 2 weeks of surgery.

TYPE OF STUDY/LEVEL OF EVIDENCE

Therapeutic II.

Subjective symptoms of carpal tunnel syndrome correlate more with psychological factors than electrophysiological severity

AIM

Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy and is one of the most common requests for electrodiagnosis. We aimed to note the relationship of subjective symptom severity of CTS, with objective electrophysiological severity and psychological status of patients.

PATIENTS AND METHODS

One hundred and forty-four consecutive patients of CTS referred to neurophysiology laboratory of a tertiary care hospital over 1 year were prospectively studied. Boston CTS Assessment Questionnaire (BCTSAQ) and visual analog scale (VAS) were used to assess subjective symptom severity. Psychological status was assessed by Hospital Anxiety and Depression Scale (HADS). Electrophysiological severity of CTS was estimated by median motor distal latency and median to ulnar peak sensory latency difference across the wrist. Each parameter in both hands was scored from 0 to 3 depending on the severity grade, and a composite electrophysiological severity score (CEPSS) was calculated for each patient by summing up the scores in both hands. Statistical analysis was done by Spearman's rank correlation test.

RESULTS

There was significant correlation of BCTSAQ with VAS (P = 0.001), HADS anxiety score (P < 0.001), and HADS depression score (P = 0.01). CEPSS had no significant correlation with VAS (P = 0.103), HADS anxiety score (P = 0.211), or HADS depression score (P = 0.55). CEPSS had a borderline correlation with BCTSAQ (P = 0.048).

CONCLUSIONS

While the subjective symptoms of CTS are well correlated with psychological factors, their correlation with objective electrophysiological severity is weak. Hence, prompt treatment of psychological comorbidity is important in symptomatic management of CTS; decision about surgical intervention should be based on electrophysiological severity rather than symptom severity.

Pre-operative electrodiagnostic testing predicts time to resolution of symptoms after carpal tunnel release

The purpose of this study was to determine if nerve conduction studies predict time to resolution of symptoms after carpal tunnel release. A total of 56 patients undergoing open carpal tunnel release were prospectively enrolled. Pre-operative presence of nocturnal symptoms and daytime numbness/tingling were documented. Pre-operative nerve conduction studies were reviewed and classified as mild, moderate, or severe. After open carpal tunnel release, patients were contacted by phone within 48 hours, at 1 week, and then at 2-week intervals for up to 9 months or until both nocturnal and daytime symptoms had resolved. This study found that patients with mild or moderate carpal tunnel syndrome experience a faster time to resolution of daytime numbness and tingling when compared with patients with severe carpal tunnel syndrome. Nocturnal symptoms resolved quickly in both groups. The results of this study are in contrast to previous studies that found little to no value of nerve conduction studies in predicting post-operative functional and subjective outcomes.

LEVEL OF EVIDENCE

IV.

Comparative study between physical examination, electroneuromyography and ultrasonography in diagnosing carpal tunnel syndrome

OBJECTIVE

To evaluate the sensitivity of electromyography and ultrasonography in diagnosing carpal tunnel syndrome (CTS), in comparison with physical examination, which is considered to be the gold standard.

METHODS

In this cross-sectional study, the medical files of 56 patients with 70 hands affected by CTS who were attended between March 2010 and June 2012 were reviewed. The study included patients with a clinical diagnosis of CTS. The sensitivity of the complementary examinations was analyzed and compared with physical examination.

RESULTS

Nocturnal symptoms were found in 96.4%, thenar atrophy in 62.5% and abnormal sense of touch in 50%. The sensitivities found were: ultrasonography, 67.1% (95% CI: 55.7%-78.6%); an association of physical examination tests, 95.7% (95% CI: 90.0%-100%); and electromyography, 98.6% (95% CI: 95.7%-100%). The presence of atrophy, abnormalities of the sense of touch and longer-duration symptoms increased the sensitivity of ultrasonography and physical examination.

CONCLUSION

The sensitivity of ultrasonography for CTS was lower than that of electromyography and physical examination.

Entrapment neuropathy of the wrist, forearm, and elbow

This review discusses key diagnostic points and treatment guidelines for compression neuropathies of the wrist, forearm, and elbow. Recent treatment progress is reviewed, controversies are highlighted, and consensus is summarized. Limited or mini-open releases and endoscopic carpal tunnel releases are considered equally safe and efficient. Both methods are currently mainstays of surgical treatment.

Effects of varying case definition on carpal tunnel syndrome prevalence estimates in a pooled cohort

OBJECTIVE

To analyze differences in carpal tunnel syndrome (CTS) prevalence using a combination of electrodiagnostic studies (EDSs) and symptoms using EDS criteria varied across a range of cutpoints and compared with symptoms in both ≥1 and ≥2 median nerve-served digits.

DESIGN

Pooled data from 5 prospective cohorts.

SETTING

Hand-intensive industrial settings, including manufacturing, assembly, production, service, construction, and health care.

PARTICIPANTS

Employed, working-age participants who are able to provide consent and undergo EDS testing (N=3130).

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

CTS prevalence was estimated while varying the thresholds for median sensory latency, median motor latency, and transcarpal delta latency difference. EDS criteria examined included the following: median sensory latency of 3.3 to 4.1 milliseconds, median motor latency of 4.1 to 4.9 milliseconds, and median-ulnar sensory difference of 0.4 to 1.2 milliseconds. EDS criteria were combined with symptoms in ≥1 or ≥2 median nerve-served digits. EDS criteria from other published studies were applied to allow for comparison.

RESULTS

CTS prevalence ranged from 6.3% to 11.7%. CTS prevalence estimates changed most per millisecond of sensory latency compared with motor latency or transcarpal delta. CTS prevalence decreased by 0.9% to 2.0% if the criteria required symptoms in 2 digits instead of 1.

CONCLUSIONS

There are meaningful differences in CTS prevalence when different EDS criteria are applied. The digital sensory latency criteria result in the largest variance in prevalence.

Changes in treatment plan for carpal tunnel syndrome based on electrodiagnostic test results

This study evaluated how often the treatment plan for carpal tunnel syndrome (CTS) changed based on electrodiagnostic test results. Secondly, we assessed factors associated with a change in the treatment plan for CTS. One-hundred-and-thirty English-speaking adult patients underwent electrodiagnostic testing in a prospective cohort study. Treatment plan was recorded before and after testing. Treatment plan changed in 25 patients (19%) based on electrodiagnostic test results. The plan for operative treatment before testing decreased significantly after testing (83% versus 72%). The best logistic regression model for no change in treatment plan included a prolonged or non-recordable median distal sensory latency (normal, prolonged, or non-recordable), and explained 24% of the variation. For surgeons that manage CTS on the basis of objective pathophysiology rather than symptoms, electrodiagnostic test results often lead to changes in recommended treatment.

No correlation between sonographic and electrophysiological parameters in carpal tunnel syndrome

A prospective study was carried out to investigate any correlation between electrophysiological and sonographic findings in patients with a clinical diagnosis of carpal tunnel syndrome. A total of 113 patients (113 wrists) in 90 women and 23 men, with a mean age of 60 years, underwent sonographic and electrophysiological examination. Fifty-five patients (48%) had mild, 43 (38%) moderate and 12 (11%) had severe conduction disturbances and three patients had normal conduction. Sonographic measurements showed a cross-sectional area of the median nerve of 9.9 mm(2) at the forearm and 17.8 mm(2) at the tunnel inlet. The mean anteroposterior diameter (height) of the nerve at the tunnel inlet was 2.7 mm, and the lowest height inside the tunnel was 1.8 mm. No correlation was found between sonographic and electrophysiological parameters.

Evaluation of the scratch collapse test for the diagnosis of carpal tunnel syndrome

This prospective study measured and compared the diagnostic performance characteristics of various clinical signs and physical examination manoeuvres for carpal tunnel syndrome (CTS), including the scratch collapse test. Eighty-eight adult patients that were prescribed electrophysiological testing to diagnose CTS were enrolled in the study. Attending surgeons documented symptoms and results of standard clinical manoeuvres. The scratch collapse test had a sensitivity of 31%, which was significantly lower than the sensitivity of Phalen's test (67%), Durkan's test (77%), Tinel's test (43%), CTS-6 lax (88%), and CTS-6 stringent (54%). The scratch test had a specificity of 61%, which was significantly lower than the specificity of thenar atrophy (96%) and significantly higher than the specificity of Durkan's test (18%) and CTS-6 lax (13%). The sensitivity of the scratch collapse test was not superior to other clinical signs and physical examination manoeuvers for CTS, and the specificity of the scratch collapse test was superior to that of Durkan's test and CTS-6 lax. Further studies should seek to limit the influence of a patient's clinical presentation on scratch test performance and assess the scratch test's inter-rater reliability.

Pain and carpal tunnel syndrome

PURPOSE

Pain is not a classical symptom of carpal tunnel syndrome (CTS), with the exception of numbness that is so intense that it is described by patients as painful. The primary aim of our study was to determine which factors correlated with pain for patients diagnosed with CTS.

METHODS

We prospectively assessed all patients diagnosed with CTS in our unit over a 1-year period. We recorded demographic details for all patients, including past medical history, body mass index, smoking, and occupation. The diagnosis and severity of carpal tunnel syndrome were established through a combination of history, clinical assessment, and nerve conduction studies. Of 275 patients diagnosed and treated for CTS, 183 were women (67%), the mean age was 55 years (range, 22-87 y), and 166 cases were bilateral (60%). The mean body mass index was 29.5 kg/m2 (range, 17-48 kg/m2), and 81 patients smoked (30%). Patients completed a Short Form-McGill pain questionnaire (SF-MPQ) as a measure of pain at initial presentation. We assessed outcome 1 year after intervention using the Quick Disabilities of the Arm, Shoulder, and Hand (QuickDASH) score.

RESULTS

We found no association between pain according to the SF-MPQ and the positive clinical signs of CTS or positive nerve conduction studies. Multivariate analysis demonstrated that smoking and bilateral disease independently correlated with the overall SF-MPQ, with similar findings on subanalysis. Independent factors associated with an increased improvement in the QuickDASH at 1 year were the presentation QuickDASH score, positive nerve conduction studies, and smoking.

CONCLUSIONS

The only independent factors that correlated with pain at presentation of CTS were smoking and bilateral disease. Pain according to the SF-MPQ was not associated with classical clinical findings of the disease or with positive findings on nerve conduction testing.

TYPE OF STUDY/LEVEL OF EVIDENCE

Prognostic I.