[Brain stem auditory and visual evoked potentials in children and adolescents with Guillain-Barré syndrome].

Guillain-Barré syndrome (GBS) is the most common acquired polyradiculoneuropathy in childhood. It has been conventionally regarded as a disease exclusively of the peripheral nervous system. The involvement of the central nervous system (CNS) in patients with GBS has been rarely described. The purpose of the study was to delineate the extent of subclinical neurological changes of CNS in children and adolescents with this syndrome. Thirty patients aged 8-18 years with GBS were treated in the Chair and Department of Developmental Neurology. The upper and lower limbs paresis dominated in clinical pictures of these patients. Cranial nerve involvement was noticed in 9 children. An ascending bulbar paralysis was noted in four cases. Sensory symptoms were found in all children. The nerve conduction velocities were abnormal in all examined patients with GBS. The control group for neurophysiological studies consisted of 66 healthy children and adolescents at the matched age. Evoked potentials (EP) were registered by means of Multiliner (Toennies, Germany). Brainstem evoked potentials (BAEP) and visual evoked potentials (VEP) were always performed in the same conditions with the same equipment for the children and adolescents in the GBS and control group, according to the guidelines of the International Federation of Clinical Neurophysiology (IFCN). The following BAEP parameters were considered: the latencies of waves I to V, interpeak latencies I-III, III-V and I-V. The latencies of N75, P100, N145 as well as the amplitudes of N75/P100, P100/N145 for mono- and binocular stimulations of VEP were analysed. BAEP showed abnormalities in 6 cases and VEP in 5 cases. The statistically significant prolongation of the latencies of waves III, V and interpeak I-V were found in children and adolescents with GBS. The BAEP changes may reflect impairment at the brainstem level in these patients. In VEP recording in GBS the prolongation of latencies P100 and N145 without changes in amplitudes were found. These parameters were statistically significant in comparison to the control group. VEP results suggest the involvement of visual pathway in examined children and adolescents. EP can be used as a complementary method for the evaluation of clinically silent lesion in the auditory and optical tracts in GBS.