Neurologic Complications of Methanol Poisoning: A Clinicoepidemiological Report from Poisoning Treatment Centers in Tehran, Iran

Abstract

Background: In this study we sought to investigate clinical findings (with a focus on neurologic effects) and also to analyze outcomes of a series of patients with methanol poisoning admitted to two poisoning treatment centers in Tehran, Iran. Methods: In this prospective cross-sectional study, methanol-poisoned patients admitted to departments of forensic medicine and toxicology of Loghman Hakim and Baharloo hospitals in Tehran during October 2010 to October 2011 were included; and their data were recorded in predesigned checklists. Results: Twenty-eight methanol poisoned patients (82.1% men) with mean age of 29.3±4.6 years were studied. Most patients (67.9%) had metabolic acidosis at presentation. On admission, all patients had different degrees of decrease in consciousness, who the majority of them (57.1%) were admitted with mildly reduced consciousness (grade I of Grady coma scale). Headache and vertigo were observed in 7.1% and 17.9% of patients, respectively. Most patients (53.6%) had no ocular effects, while 46.6% of patients developed impaired vision. All patients received sodium bicarbonate. Ethanol as antidote and folic acid were given to 18 patients (64.2%) and 16 patients (57.1%), respectively. Six patients (21.4%) underwent hemodialysis. Over half of the patients (53.6%) fully recovered and were discharged without complications. Four patients (14.3%) developed total blindness. Four patients (14.3%) left the hospital against medical advice by self-discharge (they had no significant complication at the time of discharge). Five patients (17.9%) died; who compared to survived cases had significantly lower blood pH (P=0.028), higher coma grade (P<0.001) and more delayed presentation to hospital (P=0.004). Age had no significant impact on mortality. Conclusion: Methanol poisoning causes major neurologic effects such as coma and blindness. It is also responsible for high mortality.