Burn-associated peripheral polyneuropathy. A search for causative factors.

This study sought to evaluate the timing of burn-associated polyneuropathy (BAPN) and its relationship to burn severity or size. Seventeen burned subjects were studied 1 wk after thermal burns. Eleven subjects remained in the study to complete 6-wk follow-up studies. Nerve conduction studies were done on at least three nerves in two unburned limbs; results were numerically summarized by calculating Z scores for each parameter. A composite Z score, termed Ztotal, measured global nerve function. One week postburn, motor and sensory distal latencies were prolonged (mean Z, -0.72 and -0.85, respectively), motor conduction velocities slowed (mean Z, -1.31) and sensory nerve action potentials reduced in amplitude (mean Z, -0.66). Associations of Ztotal scores with total burn surface area and depth were not statistically significant. Those with severe neuropathy had higher levels of c-reactive protein (Spearman correlation, -0.624; P = 0.0129). There were no significant changes in Z scores at 6 wk. We conclude that BAPN is common after thermal injury, and the electrophysiologic manifestations of BAPN are present within the first week. Thermal injuries may induce an inflammatory cascade that results in alterations of nerve function.