Functional imaging in periventricular nodular heterotopia with the use of FDG-PET and HMPAO-SPECT

We analyzed the interictal [F-18]fluoro-2-deoxy-D-glucose positron emission tomography (FGD-PET) and single photon emission computed tomography with t echnetium-99m-hexamethyl-propyleneamine oxime (HMPAO-SPECT) in two epilepti c patients with periventricular nodular heterotopia (PNH). In both cases, w e found both the glucose metabolism and the perfusion of PNH to be almost i dentical to those of the normal cerebral cortex. The metabolic activity and perfusion in the heterotopic gray matter in a subependymal white matter ar ea probably represent the glucose metabolism and perfusion of the abnormall y located gray matter rather than a subclinical ictal phenomenon. FDG-PET a nd HMPAO-SPECT were thus found to be a useful complement to magnetic resona nce imaging in the evaluation of PNH.