Leigh syndrome associated with West syndrome.

Leigh syndrome (LS) (sub-acute necrotizing encephalomyelopathy) is characterized by symmetric brain lesions occurring mainly in the basal ganglia and associated with variable clinical manifestations such as hypotonia, psychomotor retardation, and feeding difficulties. Patients with LS may develop seizures. Only three patients with LS have been identified in the literature as having West syndrome (WS). We have seen 12 children with LS in the past 20 years, and noticed that as many as five of them developed WS. This report discusses five LS children with WS, comparing them with seven LS children without WS. In all five patients, infantile spasms developed after LS had become evident, in addition to other type(s) of seizures. The onset of LS in all the patients with WS was before 10 months of age. Although not statistically proven, early onset of LS, spasticity, nystagmus, apnea, poor feeding, and cardiac problems seemed to be associated with the development of WS. We were not able to conclude that certain types of symptoms or examination results of patients with LS indicated the development of WS. The association of LS with WS did not markedly influence the prognoses of the children. WS may not be a rare complication of LS, especially in infants under 12 months of age. This report is the first review of LS associated with WS.