High prevalence of infantile encephalitic beriberi with overlapping features of Leigh's disease.

Infantile encephalitic beriberi (IEBB) is a rare form of thiamine deficiency and is poorly described. A proportion of Leigh's disease (LD) patients have similar clinical picture and response to thiamine as beriberi, leading to confusion in diagnosis and management. Data on IEBB and LD is scarce and status of thiamine deficiency in India is controversial. We report several infants with life-threatening respiratory and central nervous system symptoms that overlap between IEBB and LD. Majority had low erythrocyte transketolase levels and responded dramatically to thiamine supplementation suggesting a diagnosis of IEBB. However, presence of characteristic lesions on brain imaging and residual damage in several patients on follow-up does not rule out LD completely. Our study highlights the importance of thiamine deficiency in India, especially in the breast-feds and its overlapping features with LD. Awareness of this common mode of presentation may save patients' lives by early diagnosis and timely thiamine supplementation.