BS21. Neurophysiological assessment of autonomous nervous system in patients with Guillain–Barré syndrome in Brazil

Abstract

Guillain–Barré syndrome (GBS) is an acute inflammatory polyradiculoneuropathy with a high risk of clinical and subclinical autonomic dysfunction even in early stages of evolution, which carries an increase in their morbidity and mortality. In our study, we evaluated the incidence of early and subclinical autonomic disturbance in patients with GBS in a brazilian university center. We evaluated 14 patients with GBS confirmed by the criteria of Brighton and Hadden for demyelinating GBS (AIDP) or axonal GBS (AMAN), admitted in the neurology department of University of Sao Paulo Medical School, throughout the year 2016. The cases were also classified by Erasmus’s gravity score at admission. Autonomic evaluation was conducted in the first four weeks of the onset of symptoms, with patients at rest, without autonomic interfering drugs, just before nerve conduction studies. Autonomic studies consisted of sympathetic skin response (SSR) elicited by electric stimulation and heart rate variability (HRV) during deep breathing maneuver for one minute (expiration: inspiration ratio) and spectral analysis of a five minutes long recording during spontaneous breathing. Two out of ten patients with AIDP (20%) and two out of four patients with AMAN (50%) presented evidence of autonomic dysfunction at the time of the evaluation. These four patients presented an Erasmus score greater than or equal to 4 on the occasion and evolved with clinical dysautonomia during hospitalization. HRV was abnormal in three of these cases. SSR was absent in only one case. No patient with an Erasmus score less than 4 presented neurophysiologic evidence of autonomic dysfunction, but three out of ten (30%) eventually evolved with mild clinical dysautonomia during hospitalization. General sensitivity of neurophysiologic evaluation was 57%. No patient died or suffered severe dysautonomia in our sample. HRV and SSR were able to detect early dysautonomia in patients with GBS, especially in those with Erasmus score greater than or equal to 4. HRV seems to be more sensitive than SSR.