The Role of Confirmatory Testing in Carpal Tunnel Syndrome: Electrodiagnostic Study, Ultrasound and CTS-6.

Carpal tunnel syndrome (CTS) is the most common upper extremity compressive neuropathy. The reference standard for the diagnosis of CTS remains an area of controversy. The diagnosis can be established clinically, but options for confirmatory testing include electrodiagnostic studies, ultrasound and diagnostic aids such as the CTS-6 score. This review article summarises the current evidence for each confirmatory testing modality, contrasts their advantages and disadvantages and discusses future directions for investigation. Level of Evidence: Level V (Diagnostic).

Sensitivity, Specificity, and Reliability of the CTS-6 for Carpal Tunnel Syndrome Administered by Medical Assistants.

PURPOSE: The CTS-6 can be used clinically to diagnose carpal tunnel syndrome (CTS) and has demonstrated high levels of interrater reliability when administered by nonexpert clinicians. Our purpose was to assess sensitivity (Sn), specificity (Sp), and interrater reliability of the CTS-6 when administered by medical assistants (MAs). METHODS: A series of patients presenting to an academic, upper-extremity surgery clinic were screened using CTS-6 between May and June of 2023. The CTS-6 was first administered by one of seven MAs and then by one of four fellowship-trained upper-extremity surgeons. In addition to recording baseline demographics, the results of each of the six history and examination components of the CTS-6 were recorded, as was the cumulative CTS-6 score (0-26). Surgeons were blinded to the scores obtained by the MAs. Interrater reliability (Cohen's kappa) was determined between the groups with respect to the diagnosis of CTS and the individual CTS-6 items. Sensitivity/specificity was calculated for the MA-administered CTS-6, using the score obtained by the surgeon as the reference standard. A CTS-6 score >12 was considered diagnostic of CTS. RESULTS: Two hundred eighteen patients were included, and 26% had a diagnosis of CTS. The MA group demonstrated a Sn/Sp of 84%/91% for the diagnosis of CTS. Interrater reliability was substantial (Cohen's kappa: 0.72, 95% confidence interval: 0.62-0.83) for MAs compared with hand surgeons for the diagnosis of CTS. For individual CTS-6 components, agreement was lowest for the assessment of two-point discrimination (fair) and highest for the assessment of subjective numbness (near perfect). CONCLUSIONS: The CTS-6 demonstrates substantial reliability and high Sn/Sp when administrated by MAs in an upper-extremity clinic. These data may be used to inform the development of CTS screening programs and future investigations in the primary care setting. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.

Point of care ultrasound combined with CTS-6 to diagnose idiopathic carpal tunnel syndrome.

BACKGROUND: This study aimed to demonstrate the effectiveness of our new diagnostic chart using point of care ultrasound combined with CTS-6 for diagnosing idiopathic carpal tunnel syndrome. METHODS: We conducted a retrospective analysis of the data of patients who visited our department and received point of care ultrasound combined with CTS-6 from 2020 to 2023. Data regarding age, sex, initial and final diagnosis, cross-sectional area of the median nerve, CTS-6 score, and electrodiagnostic severity were obtained and statistically analyzed. RESULTS: Of the 177 wrists included in our study, 138 (78 %) were diagnosed with carpal tunnel syndrome, while 39 (22 %) were not (non-carpal tunnel syndrome). With our diagnostic method, 127 wrists (72 %) were diagnosed initially with carpal tunnel syndrome, 23 wrists (13 %) with non-carpal tunnel syndrome, and the rest 27 wrists (15 %) as borderline. Our initial diagnoses of carpal tunnel syndrome and non-carpal tunnel syndrome were maintained in all cases except for two. Cross-sectional area, CTS-6 score, and electrodiagnostic severity showed a positive correlation. A post hoc analysis showed that the new scoring system (CTS-6 score + 2 × cross-sectional area) with a cutoff value of 31.25 points showed a sensitivity as high as 95 % and a specificity of 100 %. CONCLUSIONS: Our findings suggest that most suspected idiopathic carpal tunnel syndrome cases can be diagnosed correctly using the diagnostic chart. Although additional tools, including electrodiagnostic studies, may be needed for borderline cases, the use of point of care ultrasound combined with CTS-6 may be a recommendable first-line confirmatory test because point of care ultrasound and CTS-6 could be complementary tools, and this chart may be especially beneficial for atypical or outlier cases. LEVEL OF EVIDENCE: Diagnostic III.

Influence of Electrodiagnostic Studies on Surgery for Carpal Tunnel Syndrome: A Retrospective Analysis of Data from a Single Urban Institution.

Background: This study aimed to clarify the influence of preoperative electrodiagnostic (EDX) utilisation and its severity on surgically treated patients with carpal tunnel syndrome (CTS). Methods: This retrospective study analysed the data of patients who underwent CTS surgery at our facility from 2012 to 2022. Data regarding age, sex, affected side, diabetes mellitus, rheumatoid arthritis, haemodialysis and insurance type were collected, along with the following clinical information: utilisation of EDX, steroid injection, number of items of preoperative physical examination and history taking, intervals between symptom onset and the initial visit and between the initial visit and surgery, type of surgical procedure and surgery categorisation (primary or revision). EDX data (EDX severity, interval between EDX and surgery and concomitant nerve lesions) were also investigated. Univariate and multivariate analyses were conducted to assess the influence of EDX utilisation and severity on clinical parameters. Results: Of the 343 hands enrolled in our study, 304 (89%) underwent preoperative EDX assessment. EDX severity was classified as normal, mild, moderate or severe in 6 (2%), 18 (6%), 102 (34%) and 178 hands (58%), respectively. After the univariate and multivariable analyses, more items of preoperative physical examination and history taking were associated with non-EDX utilisation, whereas younger age, female sex and steroid injection were associated with milder EDX. Conclusions: Increased number of items of preoperative physical examination and history taking or steroid injection were independently associated with non-EDX utilisation or milder EDX, respectively, suggesting that when thorough clinical evaluation is conducted, hand surgeons may be less likely to request for EDX before surgery. Moreover, their treatment recommendation may be influenced by EDX severity. Level of Evidence: Level III (Diagnostic).

Factors Associated with Change in Diagnosis of Carpal Tunnel Syndrome after Electrodiagnostic Studies.

Background: Hand surgeons sometimes place more weight on clinical findings and may not always consider the results of electrodiagnostic studies (EDX) in the diagnosis of carpal tunnel syndrome (CTS). The aim of this study is to determine factors associated with a change in diagnosis of CTS after EDX. Methods: This is a retrospective study of all patients with an initial clinical diagnosis of CTS who underwent EDX at our hospital. We identified patients whose diagnosis changed from CTS to non-CTS after EDX and used univariate and multivariate analysis to determine if age, sex, hand dominance, unilateral symptoms, history of diabetes mellitus, rheumatoid arthritis, haemodialysis, cerebral lesion, cervical lesion, mental disorder, initial diagnosis by a non-hand surgeon, the number of examined items in CTS-6 and a CTS-negative EDX result were associated with a change in diagnosis after EDX. Results: A total of 479 hands with a clinical diagnosis of CTS underwent EDX. The diagnosis was changed to non-CTS in 61 hands (13%) after EDX. Univariate analysis demonstrated that unilateral symptoms, cervical lesion, mental disorder, initial diagnosis by a non-hand surgeon, the number of examined items and a CTS-negative EDX result were significantly associated with a change in diagnosis. In the multivariate analysis, only the number of examined items was significantly associated with a change in diagnosis. Conclusions: EDX results were particularly valued in hands where the initial diagnosis was uncertain for CTS. In hands with an initial diagnosis of CTS, the performance of sufficient history-taking and physical examination was more valued at the final diagnosis than EDX results or other aspects of the patient's background. The process of confirming a clear initial clinical diagnosis of CTS using EDX may be of little value for decision-making at the final diagnosis. Level of Evidence: Level III (Therapeutic).

Correlation of Carpal Tunnel Syndrome 6 Score and Physical Exam Maneuvers With Electrodiagnostic Test Severity in Carpal Tunnel Syndrome: A Blinded Prospective Cohort Study.

PURPOSE: Although carpal tunnel syndrome (CTS) can be diagnosed clinically with the Carpal Tunnel Syndrome 6 (CTS-6) evaluation tool, the relationship between disease severity and CTS-6 score has not been elucidated. The purpose of our study was to determine the correlation of the CTS-6 score and other physical examination maneuvers with the carpal tunnel severity grade by electrodiagnostic testing (EDT). We hypothesized that the CTS-6 score, Durkan test, and Semmes Weinstein Monofilament Testing (SWMT) positively correlate with EDT severity. METHODS: We prospectively enrolled 105 consecutive patients who presented to the office with suspected CTS, excluding those with previous surgery, previous EDT from an outside facility, or concomitant neuropathy. Four fellowship-trained hand surgeons obtained the CTS-6 score, time to obtain a positive Durkan compression test, and SWMT of the thumb, index, and middle fingers. All patients were sent for EDT. Hand surgeons were blinded to the results of the EDT, and the electrodiagnosticians were blinded to the clinical data. We used the Bland criteria (0-6) to grade CTS severity on EDT. This grade was compared with the CTS-6 score, Durkan time, and SWMT results. RESULTS: Using Spearman correlation coefficients, we found a weakly positive correlation between a higher CTS-6 score and a higher severity grade on EDT. The mean CTS-6 score based on EDT grading were the following: (1) 14.8 (grade 0), (2) 16.0 (grade 1), (3) 14.8 (grade 2), (4) 16.7 (grade 3), (5) 18.7 (grade 4), (6) 18.3 (grade 5), and (7) 22.4 (grade 6). We also found a statistically significant association between the SWMT and a higher CTS-6 score as well as a higher severity grade on EDT. Durkan compression test did not appear to correlate with the EDT grade. CONCLUSIONS: The CTS-6 and SWMT show a positive correlation with EDT severity in CTS on the basis of the Bland criteria. The time to a positive Durkan test did not show any correlation. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.

The Utility of the Carpal Tunnel Syndrome-6 for Predicting the Outcomes of Carpal Tunnel Release.

PURPOSE: Considering the cost of, discomfort with, and time required for nerve conduction testing, the Carpal Tunnel Syndrome-6 (CTS-6) is often used to determine the likelihood of the presence of carpal tunnel syndrome. We sought to determine whether the CTS-6, designed as a diagnostic instrument, could serve a dual purpose and predict the outcome of carpal tunnel release (CTR) based on postoperative changes in the Boston Carpal Tunnel Questionnaire (BCTQ) score. METHODS: This prospective observational study enrolled 118 adults before they underwent open CTR at a tertiary center. A primary regression analysis was used to determine the association between preoperative CTS-6 scores and changes in the BCTQ score at ≥6 months after surgery. Additional demographic, social, electrodiagnostic, and mental health variables were assessed for associations with changes in the BCTQ score. The secondary outcomes included single questions rating satisfaction with the result of CTR as well as symptom changes and the Decision Regret Scale. Noneffective CTR was defined as a BCTQ score change of <1.0 point or reported dissatisfaction. RESULTS: Postoperatively, the BCTQ score improvement averaged 1.38 ± 0.77. Although 102 of 109 patients (94%) noted symptom improvement, 94 of 109 (86%) were satisfied with the result of CTR, and 78 of 109 patients (72%) demonstrated a meaningful change in the BCTQ score. Preoperative CTS-6 scores were not correlated with changes in BCTQ scores. CTS-6 scores were not associated with Decision Regret Scale scores, reported satisfaction, or the single-question assessment of symptom changes. Satisfaction, decision regret, and the single symptom change question were correlated with changes in the BCTQ score and each other. Dissatisfied patients were distinguished by a differential improvement in the BCTQ score (1.5 vs 0.7), but no preoperative variable consistently predicted noneffective CTR. CONCLUSIONS: The CTS-6 score does not predict changes in BCTQ scores after CTR. Patient satisfaction with surgical results is associated with postoperative changes in carpal tunnel symptoms but is not predictable using preoperative information. A single question of symptom change may offer an efficient assessment of CTR outcomes. TYPE OF STUDY/LEVEL OF EVIDENCE: Prognostic II.

Surgeons' Recommendations for Neurodiagnostic Testing With High Pretest Probability of Idiopathic Median Neuropathy at the Carpal Tunnel.

PURPOSE: The utility of electrodiagnostic tests (EDx) for patients with a high pretest probability of idiopathic median neuropathy at the carpal tunnel (IMNCT) based on characteristic symptoms and signs is debated. Decision-making and care strategies could be informed by a better understanding of factors associated with surgeon recommendations for electrodiagnostic testing. METHODS: Ninety-one upper-extremity surgeons participated in an online, survey-based experiment. Participants viewed 7 vignettes of patients with carpal tunnel syndrome, with the following factors randomized in each vignette: patient age, gender, magnitude of incapability, symptom intensity and the presence of nocturnal symptoms, palmar abduction weakness, and positive provocative tests results. We sought patient and surgeon factors associated with ordering EDx and surgeon-rated comfort with performing carpal tunnel release (CTR) without EDx. RESULTS: Surgeons recommended EDx for over half of the patient vignettes, with notable variation (median, 57%; interquartile range, 14-100), and felt relatively neutral, on average, offering CTR without EDx. Twenty-six (29%) out of 91 surgeons ordered EDx for all patient scenarios, and 18 surgeons (20%) did not order testing for any scenario. A lower likelihood of EDx was associated with older age and positive provocative tests results. Greater surgeon comfort offering CTR without EDx was associated with older patients, the presence of nocturnal symptoms, palmar abduction weakness, and positive provocative tests results. CONCLUSIONS: Upper-extremity surgeons are neutral regarding diagnosing IMNCT based on electrodiagnostic evidence of pathology and are relatively more comfortable offering surgery without EDx in older patients that present with key aspects of carpal tunnel syndrome. There is notable variation in care, with half of all surgeons always or never ordering EDx. CLINICAL RELEVANCE: Future studies can investigate whether a treatment strategy offering surgery to patients with a high pretest probability of IMNCT and only using EDx in intermediate probability scenarios can limit use of testing without affecting patient health.

The Reliability of the CTS-6 for Examiners With Varying Levels of Clinical Experience.

PURPOSE: To assess the interrater reliability of the CTS-6 for examiners with varying levels of clinical expertise. We also aimed to analyze this instrument's sensitivity (Sn) and specificity (Sp), using the CTS-6 score obtained by a hand surgeon as a reference standard. METHODS: Three examining groups consisting of medical students, occupational hand therapists, and hand surgeons examined a consecutive series of patients in an academic upper-extremity clinic. A total of 3 examiners (1 from each group) recorded a CTS-6 score for each patient. The examiners were blinded to the scores from the other groups. The interrater reliability was determined between the groups with respect to the diagnosis of CTS and the individual CTS-6 components. Sn and Sp were calculated for each of the groups using the CTS-6 obtained by the hand surgeons as the reference standard. RESULTS: Two hundred seven patients were included. For the diagnosis of CTS (CTS-6 score of 12 or greater as determined by a hand surgeon), there was substantial agreement between the 3 groups (Fleiss kappa 0.73; 95% CI [0.65 -0.82]; P < .05). For individual CTS-6 components, the agreement between the groups was highest for assessing subjective numbness and lowest for assessing a Tinel sign (Fleiss kappa of 0.77 and 0.49, respectively). The Sn/Sp for diagnosing CTS was 87%/91% for the medical student group and 81%/95% for the occupational hand therapist group. CONCLUSIONS: The CTS-6 can be reliably used as a screening and diagnostic tool for CTS by clinicians with a variety of experience levels and without specific fellowship training in upper-extremity surgery. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic I.

Evaluation of a Comprehensive Telemedicine Pathway for Carpal Tunnel Syndrome: A Comparison of Virtual and In-Person Assessments.

PURPOSE: We evaluated a comprehensive telemedicine pathway for carpal tunnel syndrome (CTS). Our primary aim was to compare telemedicine and in-person administration of the six item CTS-6 instrument (CTS-6) in patients undergoing carpal tunnel release (CTR) and to determine whether surgical plans determined via telemedicine were altered by in-person assessments. We additionally aimed to assess agreement between telemedicine and in-person examinations. METHODS: In this prospective investigation, patients referred to a hand surgeon for evaluation of CTS were offered a telemedicine pathway. A modified, virtual CTS-6 was administered during the telemedicine consultation and a virtual exam was performed. Patients indicated for CTR were evaluated in person on the day of surgery. Agreement between the telemedicine and in-person CTS-6 and exam findings was determined. Patients were evaluated via telemedicine postoperatively to determine satisfaction with the program and assess surgical complications. RESULTS: A total of 32 cases were included. The mean CTS-6 score administered via telemedicine was 17.7, compared with 16.8 in person; this difference was not statistically significant. There were no cases indicated for CTR during the telemedicine visit that had a subsequent change in management based on the in-person evaluation. Agreement was lowest for the sensory assessment (63%). The Phalen and Durkan compression tests demonstrated high levels of agreement (97% and 94%, respectively). Satisfaction was high for patients in the telemedicine CTS pathway. CONCLUSIONS: Overall agreement between telemedicine and in-person administration of the CTS-6 is high for patients with CTS. In patients indicated for CTR via telemedicine, an in-person examination does not appear to alter management. The telemedicine examination of hand sensation demonstrates lower levels of agreement with the in-person assessment. Telemedicine can serve as an alternative to conventional, in-person clinic visits for the diagnosis and postoperative management of uncomplicated, primary CTS. TYPE OF STUDY/LEVEL OF EVIDENCE: Diagnostic II.

A Comparison of 6 Diagnostic Tests for Carpal Tunnel Syndrome Using Latent Class Analysis.

Background: Nerve conduction studies (NCS), ultrasonography (US), Carpal Tunnel Syndrome 6 (CTS-6), Wainner, Lo, and Kamath are clinical diagnostic tools that can be used to diagnose carpal tunnel syndrome (CTS). Latent class analysis (LCA) is a proven statistical technique that can be used to evaluate diagnostic tests in a lack of a reference standard. Given that there is no accepted reference standard, we elected to perform an LCA to evaluate the 6 clinical diagnostic tests. Methods: One hundred eighty-seven wrists were prospectively evaluated by a board-certified hand surgeon using US, the CTS-6, Wainner, Lo, and Kamath. The NCS were performed by an electrophysiologist according to the standards of the American Association of Neuromuscular & Electrodiagnostic Medicine. The LCA was performed to evaluate individual performance and pairwise combinations of the tests. Results: The NCS demonstrated the highest estimated sensitivity of 97%, and the Wainner had the highest estimated specificity of 97%. Alternatively, the Lo had the lowest estimated sensitivity (36%), and NCS had the lowest estimated specificity (40%). When evaluating pairwise combinations, positive US and NCS demonstrated the highest overall sensitivity at 86%, and negative US and NCS had a specificity of 83%. Conclusions: There is no perfect clinical diagnostic test, with the 6 clinical diagnostic tests having differing sensitivities and specificities. Pairwise combinations of the test can be used to complement one another.

A Prospective Comparison of Diagnostic Tools for the Diagnosis of Carpal Tunnel Syndrome.

PURPOSE: Nerve conduction studies (NCS), CTS-6, Wainner, Kamath, and Lo are diagnostic tests that are used to diagnose carpal tunnel syndrome (CTS). To our knowledge, no study has compared the sensitivity and specificity of these 5 tests with one another. The purpose of this study is to compare NCS, CTS-6, Wainner, Kamath, and Lo using clinical diagnosis by a hand fellowship-trained orthopedic surgeon as reference standard. METHODS: A hand fellowship-trained surgeon completed the CTS-6, Wainner, Kamath, and Lo diagnostic tools. Cutoff values for a positive test were based on values in the literature, if available. The NCS were performed by a certified electrodiagnostic physician according the standards of the American Association of Neuromuscular and Electrodiagnostic Medicine and were interpreted using absolute latencies, relative latencies, and combined sensory index. Sensitivity, specificity, positive predictive value, negative predictive value, positive likelihood ratio, and negative likelihood ratio were calculated for the tests using clinical diagnosis as the reference standard. RESULTS: A total of 408 wrists from 250 patients were analyzed in the study. The NCS had the highest sensitivity (94%) but also the lowest specificity (50%) of any of the diagnostic tests. Using a cutoff of 18, CTS-6 had the highest specificity (99%). The NCS had the highest area under the curve at 74%, followed closely by the Kamath at 69%. CONCLUSIONS: The NCS were traditionally felt to be a strong confirmatory test given their high specificity. However, this prospective series demonstrated that NCS had the lowest specificity of any diagnostic test. CLINICAL RELEVANCE: Consideration should be given to using alternative diagnostic tests/tools based on the results of this study.

An Experimental Survey on the Effect of Using the CTS-6 Tool on the Diagnosis of Carpal Tunnel Syndrome by Hand Surgeons.

BACKGROUND: This controlled randomized experiment tested the research hypothesis that providing the CTS-6 quantitative diagnostic information to hand surgeons affects the diagnosis of carpal tunnel syndrome. METHODS: Surgeon members of American Association for Hand Surgery participated in an online survey. Demographic and practice pattern information was collected. Few surgeons routinely use diagnostic questionnaires or algorithms. Each member was given four clinical scenarios. The respondents were randomized, The experimental group was given the same scenarios as the control group plus the quantitative results of the CTS-6 diagnostic tool. RESULTS: There were statistically significant differences between the groups in the diagnostic decisions. Using the CTS-6 quantitative diagnostic tool affected the diagnosis of carpal tunnel syndrome, especially for patients with the lowest number of findings associated with carpal tunnel syndrome. CONCLUSIONS: While accurate diagnostic decisions are dependent on the incorporation of all of the pertinent information gathered during the history and physical exams, the results of the CTS-6 may help the clinician focus their thinking and revise their diagnostic probabilities.

Prospective comparison of the six-item carpal tunnel symptoms scale and portable nerve conduction testing in measuring the outcomes of treatment of carpal tunnel syndrome with steroid injection.

BACKGROUND: We prospectively studied patients clinically diagnosed with carpal tunnel syndrome (CTS) and treated with the injection of corticosteroid into their carpal tunnel in order to compare changes in the six-item CTS symptoms scale and portable nerve conduction study (NCS) parameters as outcome tools. Our pilot study was the first to assess the utility of the six-item CTS symptom scale (CTS-6) with steroid injections as a patient-directed outcome measure for the treatment of CTS. METHODS: We enrolled patients who presented to our county hospital orthopedic surgery clinic from August 2012 through August 2013. The patients were clinically diagnosed with CTS. After completing the six-item CTS symptoms scale questionnaire, portable NCS was obtained. Each patient then received an injection of 1 ml of triamcinolone acetonide 40 mg/ml mixed with 1 ml of 1 % lidocaine into the carpal tunnel. Six weeks postinjection, each patient repeated a CTS-6 questionnaire and underwent a repeat portable NCS. The CTS-6 and NCS results were analyzed using the paired samples t test. A Pearson correlation was used to assess the correlation between the changes in the CTS-6 and the NCS measurements. Statistical significance was set at P < 0.05. RESULTS: Thirty-two wrists in 20 patients were evaluated. There was a statistically significant difference between the CTS-6 scores before and after injection. There were also statistically significant changes in the five of the NCS parameters. None of the correlations between the CTS-6 and the NCS parameters were statistically significant. CONCLUSIONS: The six-item CTS symptoms scale and portable NCS are both useful measures for evaluating the results of steroid injections. The CTS-6 is an effective tool because of its ease of use, low cost, correspondence with changes in NCS, and ability to monitor the outcome of steroid treatment for carpal tunnel syndrome.