Early thalamic lesions in patients with sleep-potentiated epileptiform activity

Department of Neurology, Children’s Hospital Boston, Harvard Medical School, Boston, MA, USA.
Neurology (Impact Factor: 8.29). 04/2012; 78(22):1721-7. DOI: 10.1212/WNL.0b013e3182582ff8
Source: PubMed


To compare the prevalence and type of early developmental lesions in patients with a clinical presentation consistent with electrical status epilepticus in sleep either with or without prominent sleep-potentiated epileptiform activity (PSPEA).
We performed a case-control study and enrolled patients with 1) clinical features consistent with electrical status epilepticus in sleep, 2) ≥1 brain MRI scan, and 3) ≥1 overnight EEG recording. We quantified epileptiform activity using spike percentage, the percentage of 1-second bins in the EEG tracing containing at least 1 spike. PSPEA was present when spike percentage during non-REM sleep was ≥50% than spike percentage during wakefulness.
One hundred patients with PSPEA (cases) and 47 patients without PSPEA (controls) met the inclusion criteria during a 14-year period. Both groups were comparable in terms of clinical and epidemiologic features. Early developmental lesions were more frequent in cases (48% vs 19.2%, p = 0.002). Thalamic lesions were more frequent in cases (14% vs 2.1%, p = 0.037). The main types of early developmental lesions found in cases were vascular lesions (14%), periventricular leukomalacia (9%), and malformation of cortical development (5%). Vascular lesions were the only type of early developmental lesions that were more frequent in cases (14% vs 0%, p = 0.005).
Patients with PSPEA have a higher frequency of early developmental lesions and thalamic lesions than a comparable population of patients without PSPEA. Vascular lesions were the type of early developmental lesions most related to PSPEA.

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Available from: Yaman Z Eksioglu, Oct 01, 2015
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    • "Although the lack of evidence supporting a difference in thalamic metabolism between CSWS patients and pediatric pseudo-controls observed in this study does not obviously exclude thalamic involvement in CSWS activity or in pediatric epilepsy pathophysiology in general, it does not support a primary and specific role of the thalamus in the development of the CSWS EEG pattern. This finding contrasts with the structural neuroimaging studies suggesting an association between thalamic lesions and CSWS activity in patients with symptomatic CSWS epilepsies (Guzzetta et al., 2005; Sanchez Fernandez et al., 2012). When considering the EEG pattern of CSWS, the striking feature is that it occurs exclusively during non-REM sleep, which strongly suggests that the physiological mechanisms characterizing this period of sleep are involved in the important increase in frequency and diffusion of the epileptic discharges. "
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    ABSTRACT: Previous studies investigating cerebral metabolic changes associated with continuous spike-wave during sleep (CSWS) compared the metabolism of children with CSWS with that of healthy adults, precluding any assessment in brain areas showing physiologic age-related metabolic changes. Here, we investigated the metabolic and connectivity changes characterizing the acute phase of CSWS activity by comparing awake brain metabolism of children with CSWS with that of pediatric pseudo-controls. Positron emission tomography using [18F]-fluorodeoxyglucose (FDG-PET) was performed in 17 awake children with cryptogenic CSWS (5 girls, age: 5 to 11 years). Voxel-based analyses identified significant metabolic changes in CSWS patients compared with 18 pediatric pseudo-controls (12 girls, age: 6 to 11 years, non-CSWS focal cryptogenic epilepsy with normal FDG-PET). CSWS-induced changes in the contribution of brain areas displaying metabolic changes to the level of metabolic activity in other brain areas were investigated using pathophysiological interaction. Hypermetabolism in perisylvian regions bilaterally and hypometabolism in lateral and mesial prefrontal cortex, precuneus, posterior cingulate cortex and parahippocampal gyri characterized the acute phase of CSWS (p < 0.05 FWE). No change in thalamic metabolism was disclosed. Altered functional connectivity was found between hyper- and hypometabolic regions in CSWS patients compared with pediatric pseudo-controls. This study demonstrates hypometabolism in key nodes of the default mode network (DMN) in awake patients with CSWS, in relation with a possible phenomenon of sustained remote inhibition from the epileptic foci. This hypometabolism might account for some of the acquired cognitive or behavioral features of CSWS epileptic encephalopathies. This study failed to find any evidence of thalamic metabolic changes, which supports the primary involvement of the cortex in CSWS genesis.
    Epilepsy research 07/2014; 108(5). DOI:10.1016/j.eplepsyres.2014.03.014 · 2.02 Impact Factor
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    • "One of our symptomatic patients had a right anterior temporal arachnoid cyst which could be a coincidental finding. However the presence of convergent EEG findings emanating from the right centrotemporal area may suggest a causal relationship [16] [19]. The most commonly reported cortical malformation in the etiology of symptomatic ESES is polymicrogyria. "
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    ABSTRACT: Objective: The aim of this study was to evaluate the clinical and imaging characteristics, treatment results, and prognosis of patients with electrical status epilepticus during sleep (ESES). Method: A total of 22 patients with ESES pattern on EEG were retrospectively studied. Results: The first neurological symptoms were seen at a mean age of 4.4years. The first symptoms in 77% of the patients were seizures. Other symptoms were hyperactivity, restlessness, insomnia, disinhibition, autistic behavior, speech retardation and deterioration in school performance. Diagnosis of ESES was made at a mean age of 7.45years, approximately 3years after the first symptom. Magnetic resonance imaging (MRI) was abnormal in 36% of the patients. Single photon emission computed tomography (SPECT) showed focal hypoperfusion after resolution of ESES involving left temporoparietal and right posterior temporal areas in four patients including three with normal MRI, and one with periventricular leukomalacia without focal cortical lesion. First line treatment with valproic acid monotherapy was not effective. Electrical status epilepticus during sleep disappeared in 82% of the patients on clobazam and 70% of the patients on clonazepam in combination with valproic acid within a few months. Topiramate was not found to be effective. A significant decrease in intelligence quotient (IQ) scores was found in 66% of the patients compared to the baseline. Conclusions: ESES should be considered in children with new onset behavioral, cognitive, and speech problems with or without seizures. The high frequency of focal seizures and focal findings on SPECT suggest a focal origin. Clonazepam and clobazam were most effective in our cohort.
    Brain & development 05/2014; 37(2). DOI:10.1016/j.braindev.2014.04.007 · 1.88 Impact Factor
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    ABSTRACT: Ever since Gloor et al.(1) demonstrated that thalamo-cortical interactions were responsible for generalized seizures, alterations of thalamic function have been investigated in the pathophysiology of epilepsy. Today, the thalamus (in its regulatory, synchronizing actions with the cortex) has been assigned diverse roles. To name just two: 1) in potentiating seizure occurrence during sleep(2); and 2) in its electrical stimulation, treatment of seizures.(3) In addition, recent neuroimaging work has demonstrated heretofore poorly documented anatomic thalamic pathology in generalized epilepsy,(4) and perhaps not coincidentally, in autism.(5).
    Neurology 04/2012; 78(22):1708-9. DOI:10.1212/WNL.0b013e3182583103 · 8.29 Impact Factor
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