EVOLUTIONAL CHANGES OF CORTICAL HYPOMETABOLISM IN WESTS SYNDROME

The pathophysiological basis of the epileptic encephalopathy West's sy ndrome remains unknown. We have done serial positron emission tomograp hy (PET) with fluorine-18-labelled 2-deoxy-3-fluoro-D-glucose (FDG) in twelve patients with newly diagnosed West's syndrome. Throughout foll ow-up, PET revealed diffuse or focal cortical hypometabolism in eleven patients, whereas magnetic resonance imaging (MRI) showed morphologic al abnormalities in only five. At disease onset, PET showed cortical h ypometabolism in eight patients (diffuse in three, focal in five). The second PET showed normal metabolism in six of these patients but foca l abnormalities in three of the four with normal results on first PET. In all seven patients with normal findings on the second PET, tonic s pasms ceased after initial treatment and no epileptic seizure occurred thereafter. In the five patients with cortical hypometabolism on the second PET, tonic spasms persisted or recurred, or partial seizures ap peared. However, in two patients PET abnormalities disappeared in acco rdance with the later resolution of epileptic seizures. All patients w ith normal MRI and second PET results had normal psychomotor developme nt. Diffuse or focal cortical hypometabolism that cannot be detected b y MRI or computed tomography is common in patients with West's syndrom e. However, this anomaly is not permanent and changes with clinical sy mptoms. These functional abnormalities in the cerebral cortex may be a ssociated with the development of West's syndrome.