Sudomotor dysfunction in autoimmune autonomic ganglionopathy: a follow-up study.

OBJECTIVE: We have previously shown that sudomotor dysfunction in autoimmune autonomic ganglionopathy is severe, widespread, and predominantly post-ganglionic. However, the long-term changes in sudomotor function have not been studied in detail. Our objective was to characterize the long-term changes in sudomotor dysfunction in patients with autoimmune autonomic ganglionopathy. METHODS: Changes in sudomotor function were compared in a cohort of nine α3 nAChR antibody positive autoimmune autonomic ganglionopathy patients over an approximate 5-year period. Standard measurements of sudomotor function were used including the thermoregulatory sweat test and quantitative sudomotor axon reflex test. RESULTS: Total body anhidrosis on thermoregulatory sweat testing showed improvement in four of nine patients. Quantitative sudomotor axon reflex testing for both forearm and foot sites was variable with four of nine patients showing improvement in total sweat output. Distribution of sudomotor dysfunction at follow-up was post-ganglionic in seven of nine patients at the foot site and three of nine patients at the forearm site. Overall, sudomotor dysfunction was post-ganglionic in seven of nine patients throughout the follow-up period (62.4 ± 19.4 months). INTERPRETATION: Sudomotor dysfunction in autoimmune autonomic ganglionopathy was severe and widespread throughout the follow-up period for the majority of patients studied. Sudomotor dysfunction was predominantly post-ganglionic throughout the follow-up period.