Thalamic and cerebellar hypermetabolism and cortical hypometabolism during absence status epilepticus

Abstract

We report on a 17-year-old girl with absence status epilepticus who developed recurrent motionless confusional state and continuous generalised 3-4 Hz rhythmic delta waves on electroencephalogram (EEG). The patient had no history of absence, myoclonus or generalised convulsion. Her seizure was resistant to a combination of antiepileptic drugs including carbamazepine. Ictal positron emission tomography using [F]fluorodeoxyglucose ([F]FDG-PET) revealed hypermetabolism of the bilateral thalamus and cerebellum and hypometabolism of the frontal, parietal and posterior cingulate cortices. We diagnosed her seizure as absence status and obtained remission by changing medication. The findings of ictal metabolic alteration in previous studies and in our case confirm the pathogenic importance of the thalamus in absence status and that associated cortical deactivation and cerebellar activation may be related to the generation or maintenance of epileptic EEG discharges.

Cerebellar Contribution to Absence Epilepsy

“…It is challenging to apply positron emission tomography (PET) to investigate ictal phenomena and their interpretation [63]. That is why the case of absence status epilepticus is of particular interest in clarifying its pathogenesis with [18F]FDG-PET method [64]. The authors concluded that thalamus activation, hypometabolism in frontal, parietal, and posterior cingulate cortices, and hypermetabolism in the cerebellum favor the maintenance of absence status (3-4 Hz rhythmic delta waves in EEG).…”

Cerebellar contribution to absence epilepsy

“…It is challenging to apply positron emission tomography (PET) to investigate ictal phenomena and their interpretation [63]. That is why the case of absence status epilepticus is of particular interest in clarifying its pathogenesis with [18F]FDG-PET method [64]. The authors concluded that thalamus activation, hypometabolism in frontal, parietal, and posterior cingulate cortices, and hypermetabolism in the cerebellum favor the maintenance of absence status (3)(4) Hz rhythmic delta waves in EEG).…”

Altered dynamic functional connectivity of motor cerebellum with sensorimotor network and default mode network in juvenile myoclonic epilepsy

“…The cerebellum has been found to be associated with the production of several types of myoclonus ( 8 ), and its pathological involvement has been demonstrated in benign adult familial myoclonic epilepsy (BAFME) ( 9 ), juvenile absence epilepsy ( 10 ), non-convulsive partial status epilepsy ( 11 ), and JME ( 12 – 14 ). Additionally, it has been hypothesized that the increased inhibitory effect of cerebellum on the basal ganglia-related thalamocortical (BTC) pathway might potentially contribute to the motor symptoms in patients during seizures ( 15 ).…”