Ictal FDGPET and SPECT in hemifacial seizures due to cerebellar epilepsy-Case report

The role of cerebellum in seizure generation is debatable. Semiology and electroencephalography (EEG) findings are non-specific and sometimes misleading, posing further difficulty in proving the epileptogenicity in pre-surgical workup. We report two cases of cerebellar lesions who presented with hemifacial seizures since the neonatal period and were refractory to antiepileptic drugs (AEDs). Both inter-ictal and ictal EEGs were non-contributory. Magnetic resonance imaging (MRI) showed a lesion in the cerebellum, in proximity to cerebellar peduncle in both the patients. (18) F-fluorodeoxyglucose-positron emission tomography (FDG-PET) and ictal single photon emission computed tomography (SPECT) showed focal hypermetabolism and hyperperfusion respectively, corresponding to the lesion on MRI in both the cases. Intraoperative electrocorticography showed rhythmic spikes confirming the epileptogenic nature of the lesion. Both patients were operated with a favorable surgical outcome. Histopathology was suggestive of a ganglioglioma in one child and a low-grade glioma in the other. Both cases illustrate that FDG-PET and SPECT can act as surrogate markers for invasive recordings to prove the epileptogenicity of cerebellar lesions, especially in resource limited settings.