Functional cortical deafferentation from the subcortical structures in a patient with early myoclonic encephalopathy: a functional neuroimaging study.

We, for the first time, used functional neuroimaging analyses for a girl with early myoclonic encephalopathy (EME). The interictal single photon emission computed tomography (SPECT) and [18F]-fluoro-D-deoxyglucose positron emission tomography (FDG-PET) at 1 month of age showed hypoperfusion and hypometabolism of bilateral basal ganglia, thalami, and the right parietooccipital cerebral cortices, showing that there is profound dysfunction of the basal ganglia and thalamus as well as cerebral cortex. On the other hand, subtraction ictal SPECT of tonic spasms clearly showed hyperperfusion of the bilateral basal ganglia, thalami, brainstem, and deep cortical layer of bilateral frontoparietal cortices. The present study suggests that functional deafferentation of the cortex from subcortical structures exists in EME, and that these imaging abnormalities may provide insight into the pathophysiology of suppression-burst pattern in EME.