Congenital Perisylvian Syndrome: MRI and Glucose PET Correlations

Congenital perisylvian syndromes are late migration/cortical organization disorders associated with distinctive clinical and imaging features. The clinical, magnetic resonance imaging, and 2-deoxy-2-[18F] fluoro-d-glucose (FDG) positron emission tomography scan findings of six children (age range: 3.2-16.7 years; 5 males) with congenital perisylvian syndrome were evaluated. The patients presented with heterogenous neurologic impairments, depending upon the involved hemisphere and the extension of perisylvian malformation. Two manifested bilateral malformation and four manifested unilateral. The characteristic MRI finding consisting of a vertically oriented sylvian fissure continuous with the central and postcentral sulcus was associated with variable extension of bordering polymicrogyric cortex. The positron emission tomography scans of all patients revealed perisylvian metabolic abnormalities corresponding to the magnetic resonance imaging-defined abnormality. Variable extent of abnormal glucose metabolism was also observed in areas with normal magnetic resonance imaging features. All patients with unilateral magnetic resonance imaging abnormality exhibited abnormal glucose metabolism also in the contralateral side. The two patients with bilateral malformation had more extensive positron emission tomography abnormalities than the morphologic anomalies on MRI. Although MRI remains the diagnostic gold standard to detect the lesion, positron emission tomography scan is helpful to evaluate the full functional extension of the cortical anomaly, thereby contributing to the definition of the clinical severity of the syndrome.