The clinical manifestations and outcome in 13 patients with bilateral basal ganglia lesions and neurological dysfunction are reported from the Child Neurology Unit, Vall D’Hebron University Hospital, Barcelona, Spain. Lesions were demonstrated by CT, MRI, or ultrasound, and in 4 patients who died the pathology was subacute necrotizing encephalomyelopathy (SNE) (2), hypoxic-ischemic encephalopathy (HIE) (1), and intracranial hemorrhage (1). Extrapyramidal signs included dystonia in 9 patients, hypotonia in 2, athetosis 1, and rigidity 1. Consciousness was altered in 5, and seizures occurred in 3. The outcome was poor in the majority, with motor sequelae and/or cognitive impairment. 
COMMENT. Based on a review of the literature, the authors tabulate the causes of infantile bilateral striatal syndrome (IBSS) under acute and subacute/chronic categories. Acute causes include SNE, HIE, trauma, hemolytic-uremic syndrome, infections, and MELAS. Chronic causes include SNE, Huntington disease, Wilson disease, acanthocytosis, SSPE, glutaric aciduria, and familial metabolic disorders. The pathological findings were necrosis and neuronal loss. CT demonstrated hypodensities and the MRI showed hyperintense T2 weighted images in the basal ganglia.
The physiology of basal ganglia disorders is reviewed and an hypothesis for basal ganglia function is proposed by Hallett M, Clinical Director, NINDS, NIH, Bethesda . A direct path linking the putamen and globus pallidus is a positive feedback circuit that selects specific motor synergies to carry out a desired action whereas an indirect path inhibits these synergies, eg. dystonia results from overactivity of the putamen and the direct pathway; chorea is explained by underactivity of the indirect pathway.