Intractable seizures from infancy can be associated with dentato-olivary dysplasia.

Five children with severe developmental delay had intractable fits of various types but tonic, often extensor, seizures were prominent from an early stage. Onset was in the neonatal period in 4 cases. EEGs were severely abnormal and showed a "burst-suppression" pattern in the first months of life. There were no metabolic or consistent neuroradiological abnormalities. A distinctive form of dentato-olivary dysplasia was found in all cases. Inferior olives were hook-shaped, coarse and lacking undulations, while dentate nuclei showed a compact arrangement of interconnected islands. The clinico-pathological findings form a novel nosological entity.