CEREBELLAR HYPOMETABOLISM IN FOCAL EPILEPSY IS RELATED TO AGE-OF-ONSET AND DRUG INTOXICATION

Purpose: We wished to investigate the cerebellar depression of regiona l cerebral glucose metabolism (rCMRGlu) in patients with focal epileps y. Method: In 170 consecutive patients with medically refractory, foca l epilepsy the rCMRGlu was measured in cerebellum and brain. Results: rCMRGlu was markedly decreased in both cerebellar hemispheres and slig htly in brain. The cerebellum to brain rCMRGlu ratio was significantly decreased in patients with seizure manifestation in infancy, but was normal due to a progressive decrease in brain rCMRGlu in later age. A subgroup of patients with focal epilepsy involving the frontal lobe ha d a reduced cerebellum/brain rCMRGlu ratio, whereas in patients with m esiotemporal lobe epilepsy (MTLE), the rCMRGlu was decreased to the sa me degree in cerebellum and brain. The difference in the cerebellum/br ain rCMRGlu ratio between the two groups was accounted for by the youn ger age of the patients with focal epilepsy involving the frontal lobe , however. In another subgroup of patients with a documented history o f critical drug intoxications, the cerebellar rCMRGlu was severely dec reased, resulting in a significantly reduced cerebellum/brain rCMRGlu ratio. Conclusion: Our retrospective study suggests that the cerebellu m is particularly vulnerable in infancy to ongoing epileptic activity and high dosage of antiepileptic drugs (AEDs).