MONDO_0015518 (infantile bilateral striatal necrosis) is several syndromes of bilateral symmetric spongy degeneration of the caudate nucleaus, putamen and globus pallidus characterized by developmental regression, choreoathetosis and dystonia progressing to spastic quadriparesis. IBSN can be familial or sporadic. Also known as: IBSN, infantile striatonigral degeneration, infantile striatonigral necrosis.