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.