developmental regression

Leigh syndrome, first described by Denis Leigh in 1951, is a severe progressive neurometabolic disorder characterized by bilateral symmetric necrotic lesions in subcortical regions of the central nervous system. Originally termed subacute necrotizing encephalomyelopathy, this disorder represents a final common phenotype for various genetic defects affecting energy metabolism.

West Syndrome, also known as infantile spasms, is a rare but severe form of age-dependent epileptic encephalopathy that typically manifests in infancy. This devastating condition is characterized by the triad of infantile spasms, hypsarrhythmia on EEG, and developmental regression. Early recognition and prompt intervention are crucial for optimizing outcomes in affected infants.