Combined VEP testing (pattern-reversal VEPs and two types of motion-onset VEPs (M-VEPs) to linear and radial motion was performed in 81 patients with NB verified by laboratory results - positive PCR or intrathecal antibodies production. In 33 (40%) patients the VEPs were delayed: M-VEPs were pathological in 22 (27%) patients, reversal VEPs in 5 (6%) patients and both VEP types in 6 (7%) patients.
Our findings suggest that the VEP testing (especially the M-VEPs) can confirm the CNS involvement. Much higher sensitivity of M-VEPs in comparison with reversal VEPs can result from rather selective (earlier) involvement of the magnocellular system or the dorsal stream of the visual pathway.