Regional cerebral glucose metabolism in clinical subtypes of cerebral palsy.

Twenty-three children with 4 clinical subtypes of cerebral palsy were studied using 2-deoxy-2(18F)fluoro-D-glucose (FDG) and positron emission tomography (PET). Subtypes included spastic quadriparesis (N = 6), spastic diplegia (N = 4), infantile hemiplegia (N = 8), and choreoathetosis (N = 5). FDG-PET images were correlated with magnetic resonance imaging or computed tomography. Although the location of glucose metabolic abnormalities corresponded, in general, to abnormalities of brain structure demonstrated by structural imaging studies, the distribution of metabolic impairment almost invariably extended beyond the region of anatomic involvement. The following observations in specific subtypes of cerebral palsy were determined with FDG-PET: (1) In spastic diplegic patients, PET revealed focal areas of cortical hypometabolism in the absence of apparent structural abnormality; (2) A relatively normal pattern of cortical metabolism was observed in most patients with choreoathetoid cerebral palsy, despite marked hypometabolism in the thalamus and lenticular nuclei; and (3) In patients with infantile hemiplegia, FDG-PET disclosed symmetric cerebellar glucose metabolism with absence of crossed cerebellar hypometabolism (diaschisis). This finding is contrary to the typical persistence of crossed cerebellar diaschisis in adult patients with acquired cerebral lesions and suggests metabolic recovery due to developmental plasticity. The possibility that FDG-PET may be clinically useful in identifying the cerebral palsy patient with potential learning handicap and in the study of functional recovery or sparing following brain injury should be explored further.