Thalamic abnormalities in children with continuous spike‐wave during slow‐wave sleep: An F‐18‐fluorodeoxyglucose positron emission tomography perspective

Abstract

SUMMARYObjective: Thalamic injury has been implicated in the development of continuous spike-wave during slow-wave sleep (CSWS) in children with epilepsy. We studied thalamic abnormalities in children with CSWS using F-18-fluorodeoxyglucose (FDG)-positron emission tomography (PET) imaging. Methods: Twenty-three patients (12 male; mean age 9 years) with CSWS and normal thalami on brain magnetic resonance imaging (MRI) underwent FDG-PET. Thalamic glucose metabolism, represented by standardized uptake value normalized to whole brain (nSUV, RT for right thalamus and LT for left thalamus), and its asymmetry-absolute asymmetry index (AAI): |(RT-LT)|*100/ [(RT+LT)/2]-was calculated. These values were compared with those from 10 normal healthy controls (five female; mean age 11.1 years). Results: Thalamic glucose metabolism was abnormal in 18 patients (78.3%). Thalamic nSUV was decreased (n = 6) or increased (n = 1) bilaterally in seven children without any asymmetry. Abnormal thalamic symmetry [AAI = 3.7-31.5% (0.8-3.3% in controls)] was seen in 11 children. Of these, six children had a unilateral thalamic metabolic abnormality (increased metabolism, n = 3 and decreased metabolism, n = 3), whereas 5 of 14 children had abnormal asymmetry index with bilaterally normal (n = 4) or increased (n = 1) thalamic metabolism. No clear association of thalamic metabolic abnormalities was seen with the stage of evolution of CSWS (prodromal, acute, or residual) or with the cortical FDG abnormalities. Significance: Functional thalamic abnormalities, both unilateral and bilateral, are frequently seen in patients with CSWS. FDG-PET is a sensitive and quantifiable modality to detect these changes. KEY WORDS: Continuous spike-wave during slow-wave sleep, Electrical status epilepticus in sleep, Thalamus, F-18-fluorodeoxyglucose positron emission tomography.The association between epilepsy and sleep is well recognized, and activation of epileptiform discharges during non-rapid eye movement (non-REM) sleep is frequently seen.1-3 Continuous spike-wave during slow-wave sleep (CSWS) represents an extreme form of sleep-potentiation of epileptiform activity, manifesting on electroencephalography (EEG) with electrical status epilepticus in sleep (ESES).4,5 CSWS is defined as an age-related epileptic encephalopathy that is characterized by a combination of epilepsy, neuropsychological impairment, and typical EEG findings with a diffuse pattern of spike-waves in ≥85% of slow-wave sleep.6-8 CSWS occurs during early childhood,

No evidence of thalamic metabolic abnormality associated with continuous spike‐and‐wave during sleep

“…1 Although their findings contrast with our results, it is noteworthy that their methodology remains fairly distinct. 2 Even in our cohort, not everybody had thalamic abnormality.…”

“…In their discussion, Agarwal et al 1 suggest that the discrepancy between their results and ours could be due to patient selection; our study indeed included seven patients with LKS, whereas such patients were excluded from their study. Based on this comment, we further analyzed our FDG-PET data and compared, using similar SPM methodology as described in Ligot et al, 2 relative metabolism in the 7 LKS patients, the 10 non-LKS CSWS patients, and the pseudo-controls.…”

“…To the Editor, We read with great interest the paper by Agarwal et al, 1 in which they report the existence of abnormal thalamic glucose metabolism in 78.3% of 23 children with an epileptic encephalopathy with continuous spike-andwaves during slow-wave sleep (CSWS). Thalamic metabolic abnormalities were identified by comparing patients' [ 18 F]fluorodeoxyglucose-positron emission tomography (FDG-PET) data with that of 10 age-matched healthy controls.…”

Transient microstructural brain anomalies and epileptiform discharges in mice defective for epilepsy and language‐related NMDA receptor subunit gene Grin2a

“…Hence, thalamic DTI anomalies have already been reported in absence seizures and in temporal lobe epilepsy . Functional thalamic abnormalities were also found in patients with CSWSS . Similarly, changes in the hippocampus and in the corpus callosum might have long‐term influence on cognitive abilities; as a matter of fact, adult Grin2a KO mice show impaired spatial memory .…”

Status Epilepticus: An Update of Classification and Treatment of a Challenging Neurological Emergency

“…Thalamic functional rather than structural impairment has been associated to CSWSS pattern [20]. An abnormal thalamic glucose metabolism was detected by using F-18-fluorodeoxyglucosepositron emission tomography (FDG-PET) in patients with CSWSS and normal thalami at brain MRI scan [21]. A peculiar malrotation of the left hippocampal portion has been reported as a brain structural abnormality associated to febrile CSE, expecially in males [22].…”