Diagnosis of demyelination processes based on the visual evoked potential test using a checkerboard reversal pattern

Visual evoked potentials in response to checkerboard reversal pattern were evaluated in 160 patients: 24 with isolated retrobulbar optic neuritis, 100 with unquestionable and probable multiple sclerosis, 36 with paraparesis or with disseminated changes of unestablished aetiology (degenerative or inflammatory) and in 80 healthy controls. Normal visual evoked potentials were obtained in all controls. In all cases of present or past optic neuritis abnormal potentials were observed, usually unilateral. In multiple sclerosis patients with unquestionable diagnosis abnormal potentials were present in 92% of cases, and in patients with probable multiple sclerosis they were found in 58%, and in cases without retrobulbar neuritis they were present in 71% and 48% of cases respectively. The abnormalities were found most frequently in both optic nerves. It was tried to find out other correlations making possible partial differentiation of the axonal and demyelinating type of damage to the anterior part of the visual pathways.