[Visual evoked potential in multiple sclerosis].

Visual Evoked Responses (VER) by binocular flash stimulation were carried out in 30 cases of "definite" (15 cases-Group I) and of "probable" (15 cases-Group II) Multiple Sclerosis (MS). VER were recorded bilaterally by reference occiput-mastoid. Averaging of 50 responses (time base 200-500-1000 msec) was considered; measures were made by registration on X-Y Plotter. Abnormal VER by increased latencies of III and/or IV peak (Ciganek) were present uni- or bilaterally in most of the subjects (73,3% of the I Group; 66,6% of the II Group). Percentage of abnormal VER is quite higher than clinical involvement of visual pathways; it is present in 3 out of 5 patients also, in whom clinical findings were confined to spinal cord. The results are discussed with reference to the previous literature. Recording of VER seems useful in detecting involvement of visual pathways without clinical evidence.