Subacute necrotizing encephalomyelopathy (SNE) was first described in 1951 by Denis Leigh.1 Since then, well over 100 cases have been described, and probably as many as 100 more have been diagnosed (at postmortem examination) and not recorded. With an increased awareness of the clinical features of this disease comes an increase in early diagnosis. Such diagnosis is not easy, however, since there is a broad range of variability in symptoms and time of onset. Characteristically, most patients with SNE develop normally until about 1 year of age. the parents may note a gradual reduction in development. There is usually a loss of appetite with resultant weight loss.
Leigh's Disease
