EPIDEMIOLOGY AND CLINICAL PRESENTATION OF A SEASONAL ATAXIA IN WESTERN NIGERIA

The epidemiological and clinical presentation in 37 patients (males/fe males 1.5:1, median age 37 years, range 12-85 yrs) with a seasonal ata xic syndrome of unknown etiology peculiar to parts of Western Nigeria is reported. All patients belonged to the low socio-economic strata, a nd all subsisted on a monotonous diet of high-carbohydrate meals with minimal protein supplementation. All patients consumed a stew containi ng the roasted larvae of Anaphe venata, a seasonal protein supplement peculiar to the area of endemicity in their last meals prior to the on set of disease. The clinical features seen in the patients studied wer e mainly those of acute cerebellar ataxia in all, with ophthalmoplegia s and encephalopathy in the more severe cases. These features are rema rkably similar to those of acute thiamine deficiency and the results i n concert provide clinical and epidemiological support for an etiologi cal hypothesis of acute thiamine deficiency in this seasonal ataxic sy ndrome.