Association of Autonomic Symptoms in Carpal Tunnel Syndrome with Abnormalities in Sympathetic Skin Responses (P4.115)

OBJECTIVE: The purpose of our study is to determine the association of autonomic symptoms in Carpal tunnel syndromes with abnormalities in Sympathetic Skin Responses. BACKGROUND: Autonomic symptoms (AS) are frequently reported in patients with Carpal tunnel syndrome (CTS). The incidence of AS in CTS may be as high as 55% (Verghese et al. Muscle Nerve 2000;23:1209). According to George Phalen, the median nerve carries a large portion of the sympathetic nerve supply to the hand. Sympathetic skin responses (SSR) are well suited to evaluate the integrity of sudomotor fibers. DESIGN/METHODS: Patients with carpal tunnel syndrome confirmed by electrodiagnostic studies were evaluated for autonomic symptoms such as swelling, color changes, and sweating. Each of the AS were assigned a point. SSRs were obtained over the second digit (for median nerve) and fifth digit (for ulnar nerve). Patients with AS were compared to an asymptomatic group in terms of SSR latency and amplitude for median and ulnar nerves, along with median to ulnar nerve SSR ratios of both latency and amplitude. General linear models techniques were used to assess associations of interest. P-values less than 0.05 were considered significant and those between 0.05 and 0.1 were considered marginally significant. RESULTS: 61 patients with CTS were enrolled and assigned into two groups based on AS to symptomatic (33) and asymptomatic (28). There was marginal statistical significance comparing the symptomatic to the asymptomatic group based on the SSR median nerve amplitudes (399.30±377.53 & 429.54±352.39) with a P-value <0.06. The ulnar nerve to median nerve SSR amplitude ratio (symptomatic 3.1623 ± 4.422 & asymptomatic 2.0446 ± 1.725) had a P-value < 0.09. CONCLUSIONS: This study demonstrates a trend of SSRs being statistically significant for the ulnar to median nerve SSR ratio and the median SSR amplitude for AS in CTS. Study Supported by: Disclosure: Dr. Lugo has nothing to disclose. Dr. Ahmad has nothing to disclose. Dr. Schultz has nothing to disclose. Dr. Garcia has nothing to disclose. Dr. Alwaki has nothing to disclose. Dr. Sripathi has received research support from Allergan Inc.