Electrophysiological study of a case of diffuse loss of sweating with segmental hyperhidrosis associated with areflexia.

Electrophysiological investigations were carried out on a 43 year-old man with segmental hyperhidrosis in three radicular territories, generalized anhidrosis elsewhere and areflexia. A recurrent labial herpetic rash and a history of sweating disorders in his grandfather were the only associated clinical data. Sympathetic skin response was found to be absent in anhidrotic territories, including the hands and feet, although it was present in hyperhidrotic territories. Peripheral adrenergic sympathetic fibers evaluated by photoplethysmography were normally responsive, as were visceral vegetative regulations involved in cardiovascular control during postural changes or exercise. The present case is compared to the previously described Ross Syndrome, associating segmental hypohidrosis, areflexia and tonic pupils. Our results and observations in the literature are consistent with the occurrence of lesions affecting postganglionic cholinergic fibres of the sympathetic system.