Role of high dose intravenous methylprednisolone and visual evoked potential (VEP) in the management of methyl alcohol poisoning: A case series report

Abstract

To study the effectiveness of high dose intravenous methylprednisolone and to discuss the role of visual evoked potential (VEP) as a marker of severity and of improvement in methyl alcohol poisoning.In an outbreak of methanol poisoning, a total of six patients presented to JNMCH, AMU. Meticulous history was taken followed by examination. They were treated with high dose IV methyl prednisolone and later underwent visual evoked potential testing. The patients were examined daily till the time of discharge and then followed up at 1 month.Following treatment with high dose IV methyl prednisolone, 100% of cases showed improvement in vision which was judged on the basis of visual acuity and visual evoked potential assessment at the time of presentation. As recorded by VEP, 4 patients (66.6%) had prolonged P100 latency while no response was recorded in 2 patients (33.3%). In 3 (50%) of the 6 cases, improvement in visual acuity of at least two lines of Snellen chart was observed at 1 month follow-up while two patients (33.3%) improved from doubtful light perception to counting fingers at least 2 metres and one patient (16.6%) improved from perception of light present to counting finger at least 2 metres. Early presentation and timely intervention improves visual outcome in methanol poisoning. High-dose IV methylprednisolone seems to have benefits in the treatment of methanol optic neuropathy. The VEP examination appears to be a sensitive marker for diagnosis and prognosis of even subclinical impairment of the optic system due to methanol poisoning.