Electrodiagnostic Study on Neuropathies in String Players

ABSTRACT

OBJECTIVE: To determine the frequency, involved nerves and sites of entrapment neuropathy in string players. METHOD: The subjects were 24 string playing musicians and age matched 24 normal controls. Questionnaire, physical examination were taken in the musicians and the electrodiagnostic study was performed in both the musician and the control groups. Electrodiagnostic study included nerve conduction study of median and ulnar nerves. The distal motor latency, segmental motor conduction velocity, distal sensory latency, and amplitude of sensory nerve action potentials were measured. Each parameter of nerve conduction study was compared in two groups and was correlated to the string playing duration. RESULTS: Three musicians (12.5%) were diagnosed as entrapment neuropathy One, left ulnar neuropathy at the elbow and the wrist and left median neuropathy at the wrist; Two, left ulnar neuropathy at the elbow. Ulnar motor conduction velocity of right forearm segment and left elbow segment were significantly reduced in the musicians compared to those of the controls (P<0.05). The distal sensory latency of left ulnar nerve was significantly prolonged in musicians compared to that of the controls (P<0.05). The string playing duration significantly correlated with the distal motor latency of right median nerve (R=0.632, P<0.05) and the distal sensory latency of left median nerve (R=0.518, P<0.05). CONCLUSIONS: These results suggest that some entrapment neuropathies could be developed due to cumulative trauma in string players. Elbow and wrist segment of left ulnar nerve, forearm segment of right ulnar nerve are possible sites of entrapment neuropathy in string players.