Complex Partial Seizures: Cerebellar Metabolism

Abstract

We used positron emission tomography (PET) with [18F]2-deoxyglucose to study cerebellar glucose metabolism (LCMRglu) and the effect of phenytoin (PHT) in 42 patients with complex partial seizures (CPS), and 12 normal controls. Mean .+-. SD patient LCMRglu was 6.9 .+-. 1.8 mg glucose/100 g/min (left = right), significantly lower than control values of 8.5 .+-. 1.8 (left, p < 0.006), and 8.3 .+-. 1.6 (right, p < 0.02). Only four patients had cerebellar atropy on CT/MRI; cerebellar LCMRglu in these was 5.5 .+-. 1.5 (p = 0.054 vs. total patient sample). Patients with unilateral temporal hypometabolism or EEG foci did not have lateralized cerebellar hypometabolism. Patients receiving phenytoin (PHT) at the time of scan and patients with < 5 years total PHT exposure had lower LCMRglu, but the differences were not significant. Thee were weak inverse correlations between PHT level and cerebellar LCMRglu in patients receiving PHT (r = -0.36; 0.05 < p < 0.1), as well as between length of illness and LCMRglu (r = 0.22; 0.05 < p < 0.1). Patients with complex partial seizures have cerebellar hypometabolism that is bilateral and due only in part to the effect of PHT.