Selective autonomic screening in Guillain-Barré syndrome

Background : Autonomic dysfunction is a common and important complication in Guillain-Barre syndrome (GBS) and may be the cause of significant morbidity or death. Objectives : To show the possible autonomic involvement in patients with GBS. Materials and Methods : The sympathetic skin response (SSR) and the parameters of heart rate variability gathered from a 24-h electrocardiogram recording were studied in 14 patients with GBS [13 with acute inflammatory demyelinating polyneuropathy (AIDP) and one with acute motor axonal neuropathy (AMAN)]. Results : In two of the patients, SSR couldn't be elicited. In the rest of the patients, amplitude of SSR was found to be decreased when compared with the control subjects. In the time domain analysis of the 24-h electrocardiogram, SDNN (the standard deviation of all R-R intervals), SDANN (the standard deviation of the averages of R-R intervals during all 5-min periods that constitute the 24-h day), SDNN index (mean of the standard deviations of all R-R intervals for all 5-min segments of the 24-h recording); in the frequency domain analysis HF(high frequency), LF(low frequency), VLF (very low frequency) and total power were found decreased in patients when compared with the control subjects. When the mean values with standard deviations of controls were compared with the patients' values one by one, the pregnant patient with AMAN had increased heart rate variability parameters. The remaining 13 patients had decreased values. Conclusions : These findings reflect an involvement of both the parasympathetic and sympathetic systems in GBS. Our results suggest that SSR and heart rate variability parameters may be used for early detection of any autonomic dysfunction in patients with GBS.