• In 14 patients with tuberculosis treated with ethambutol hydrochloride, pattern-reversal visual evoked potentials (VEPs) were recorded to monocular, whole-field stimulation before the commencement of treatment and one month and three months subsequently. In six subjects, the VEPs showed changes in the latency and amplitude of the P100 component at the one- or three-month interval. In three cases, the VEP changes reversed after cessation of treatment. In five of the six cases, changes were not associated with a change in visual function, as measured by clinical neuro-ophthalmologic examination. Our findings confirm the usefulness of VEPs in the detection of subclinical optic nerve disease and suggest their use in routine monitoring of ocular function in patients treated with ethambutol.
Visual evoked responses (VERs) were recorded on 52 chronic alcoholics patients without Wernicke-Korsakoff syndrome, 22 of whom had cerebellar ataxia, and eight chronic alcoholics with Wernicke-Korsakoff syndrome. Abnormal VERs were found in 23% of patients without and 37% of patients with Wernicke-Korsakoff syndrome. The main VER abnormalities of all the alcoholic groups were prolonged latency and reduced amplitude of the P100 component. Improvement followed a six month period of abstinence. VERs may be useful in the early detection of alcohol induced brain damage, and in following the progress of patients with the condition.
Eighty two patients with isolated optic neuritis were studied prospectively to determine the frequency with which multiple sclerosis developed and the factors which increased its risk. Patients were followed for 6 to 264 months (mean, 57 months). Twenty six patients (32%) developed clinically definite or probable multiple sclerosis during the period of follow-up. Actuarial analysis predicted that 42% would develop multiple sclerosis by 7 years. Of those patients who developed multiple sclerosis, 92% had symptoms within 4 years of the first attack of optic neuritis. The highest incidence of multiple sclerosis occurred in the 21-40 year age group. There was an increased risk of MS in patients with HLA-DR2 and HLA-B7 tissue types. The frequency of HLA-DR4 was increased in patients with optic neuritis alone compared to controls and to patients with multiple sclerosis, but further studies are required to confirm this finding.