Often atypical? The distribution of sensory disturbance in carpal tunnel syndrome

This study aimed to examine the disturbance of hand sensation in patients with carpal tunnel syndrome (CTS) and assess the usefulness of objective and subjective measures. The study included 64 patients with CTS confirmed by electrophysiological testing. Sensory assessment was made by objective (pressure aesthesiometry) and subjective (hand symptom diagram) measures in different anatomical areas. The results of the subjective and objective testing were correlated with nerve conduction studies by a kappa analysis. Sensory disturbance occurred more frequently in areas innervated by the median nerve (index finger, 94%) but also with great frequency in other areas (little finger, 39%). Pain occurred frequently in anticipated areas (wrist crease, 33%) but also in other areas (little finger, 11%). There was very poor correlation between objective measures and electrophysiological testing or subjective measures. This study does therefore not support the use of objective sensory assessment for the initial diagnosis of CTS. An atypical distribution of symptoms is a common occurrence and should not discourage diagnosis of CTS. The patient's description of symptoms remains the most important tool in diagnosis.