Flash-pattern visual evoked potentials and limited lesions of the occipital lobe

Four patients with restricted lobe lesions and one patient with large occipital lesions were selected for VEP studies to full-field and half-field flash pattern stimuli. The abnormalities of the responses were more important with full-field stimuli. In three patients with inner side occipital lobe damage, the P100 component disappeared ipsilaterally to the lesion, but N140 remained normal on bilateral occipital leads. In one patient with outer side occipital lobe damage, P100 was normal on bilateral occipital leads, but N140 disappeared ipsilaterally to the lesion. In one patient with large occipital lesion, P100 and N140 both disappeared ipsilaterally to the lesion. It appears that the P100 component is related to the inner and that N140 is related to the outer area of the occipital lobe.