PERIPHERAL AUTONOMIC POTENTIALS - CLINICA L USE IN LOCALIZING THE LEVEL OF SPINAL-CORD LESIONS

The peripheral autonomic potential (PAP), also known the sympathetic s kin response, is a neurophysiological parameter that can be used to as sess the completeness of spinal cord transection. We studied the PAP i n hands and feet of patients with spinal lesions. Forty two patients ( 17 female, 25 male) were included, aged 23 to 88 years (mean = 62, SD = 17). The spinal cord lesions included neoplasm, syringomyelia, myeli tis and spinal infarction. Thoracic or cervical lesions above T10 occa sionally lead to abnormal hand PAPs (71% vs. 22%; p = 0.02). Lower spi nal cord lesions below T7 was rarely associated with abnormal hand PAP s (27% vs. 73%, p = 0.02) For spinal lesions above L2 the PAP findings were most consistent with the sites of pathology with a sensitivity o f 78% and a specificity of 80%. These findings are compatible with the known anatomy of the sympathetic nervous system. Further electrophysi ological findings with clinical examples will be presented.