[Pathologic findings in auditory brain stem evoked potentials in 10 children with brain stem tumors]

The authors examined brain stem acoustic evoked potentials (BAEP) in 10 children aged 2-14 years with tumours in the posterior cranial fossa infiltrating the cerebellum and brain stem. The tumours were diagnosed by computed tomography and in eight patients confirmed on operation. For stimulation a monaural click was used. The authors assessed the latency of waves, intervals between and investigated the presence of waves and evaluated their amplitudes. They compared the results with normal values. In abnormal findings the latency of components was delayed, the components were generated in a rostral manner from the site of the lesion in all children. In four patients with severe affections of the brain stem the investigated components were lacking. In nine patients the BAEP evoked by monaural stimulation helped to asses the lateralization of the lesion. In eight patients a bilateral abnormality of the V wave was recorded. The most sensitive indicator for assessment of the site of the lesion was assessment of the interval between two consecutive waves.