VISUAL-EVOKED POTENTIALS IN PSEUDOTUMOR C EREBRI

Obscurations and visual field defects are common symptoms in patients with pseudotumor cerebri. As in papilledema of other origin visual los s occurs late in the course of the disease. Visual evoked potentials ( VEP) have been described so far to be normal in the majority of cases with pseudotumor cerebri. In this study VEP's have been examined in si x patients with pseudotumor cerebri and visual loss on admission. VEP' s and visual acuity were measured on average for the following four mo nths. All six patients had initially abnormal VEP (n = 10, ten afflict ed eyes). P100 was either delayed (5/10) on average 22 ms outside the normal upper range (= mean +/- 3 SD) or absent (5/10). One patient sho wed a combination of reduced amplitude and delayed latency. VEP's chan ged corresponding to the clinical course normalized (3/6) or remained abnormal (2/6). One patient showed after an initial normalization of v isual acuity and VEP a relapse with renewed visual loss and abnormal V EP. We conclude, that VEPs are of value in the objective follow up of visual acuity in pseudotumor cerebri. Abnormal VEP's might herald recu rrence.