Brain regional glucose uptake changes in isolated cerebellar cortical dysplasia: qualitative assessment using coregistrated FDG-PET/MRI.

We aimed to assess brain regional glucose uptake (rGlcU) changes in children with isolated cerebellar cortical dysplasia (CCD) using 18-fluoro-deoxy-glucose positron emission tomography (FDG-PET). Six children aged 9 months to 11 years at the time of diagnosis, carrying isolated CCD (with no other associated posterior fossa or supratentorial malformation) underwent a brain FDG-PET and a subsequent 3DT1-weighted MRI for coregistration. The MRIs acquired previously at the time of diagnosis were reviewed to record the cerebellar dysplastic features and classify the patients as having minor, moderate, or severe CCD. The individual rGlcU was assessed qualitatively on coregistrated FDG maps. Clinical data from birth, including neurological and neuropsychological (verbal and motor skills) disturbances, were recorded. We found rGlcU changes within the cerebellum of four patients matching with the location and extent of structural abnormalities: hypometabolism in three patients with severe CCD involving the vermis and both cerebellar hemispheres and focal hypermetabolism in one patient with moderate CCD associated with a nodular heterotopic gray matter. No obvious rGlcU changes were found in the two patients with minor CCD involving the vermis only. Supratentorial rGlcU changes found commonly involved the basal ganglia bilaterally. Coregistrated FDG-PET/MRI technique is useful in detecting cerebellar cell dysfunction associated with isolated CCD. Our results enhance the need for multimodal and quantitative studies to better evaluate local and remote functional disturbances caused by CCD.