The congenital bilateral perisylvian syndrome: imaging findings in a multicenter study. CBPS Study Group

To describe the neuroimaging findings and the clinical features in patients with the congenital bilateral perisylvian syndrome.

Evaluation including history, general and neurologic examinations, electroencephalogram, chromosomal studies, and imaging data were reviewed in 31 patients. Pathologic material was available in two patients.

All patients had similar neurologic dysfunction, primarily pseudobulbar paresis. Dysarthria and severe restriction of tongue movements were present in all. Motor milestones were delayed in 75% of the patients and language milestones in all. Mild to moderate intellectual deficits were documented in 75% of patients (full-scale IQ = 70). Pyramidal signs were observed in 70%. Seizures were present in 87% and were intractable to medical therapy in half of this group. MR revealed bilateral perisylvian and perirolandic malformations with exposure of the insula. The malformations were symmetrical in 80% of cases. Pathologic correlation revealed four layered polymicrogyria in the affected areas.

The congenital bilateral perisylvian syndrome is a homogeneous clinical-radiologic entity. The underlying abnormality is probably polymicrogyria.