Ictal motor signs and interictal regional cerebral hypometabolism.
ABSTRACT Early motor manifestations are the main components of focal seizures involving the frontal lobe. We examined the relationship between the initial ictal motor manifestations and interictal abnormalities of cerebral glucose consumption (rCMRGlc) as assessed by PET in 48 consecutive patients with focal seizures of neocortical origin. Group data analysis revealed that patients with predominantly unilateral clonic seizures had a significant contralateral perirolandic hypometabolism and to a lesser degree a contralateral frontomesial hypometabolism. Patients with predominantly focal tonic manifestations showed a hypometabolism within the frontomesial and perirolandic regions that was unilateral in all patients with lateralized tonic seizures. Patients with versive seizures had mainly contralateral metabolic depressions without a consistent regional pattern. Patients with hypermotor seizures had metabolic depressions involving frontomesial, anterior cingulate, perirolandic, and anterior insular/frontal operculum areas. In all patient groups, bilateral and symmetric hypometabolism of the thalamus and cerebellum was observed. We propose that this pattern of distinctly abnormal metabolic brain regions demonstrates not only possible epileptogenic zones but also symptomatogenic brain regions as shown by the associations between clinical manifestations and sets of abnormal brain regions, particularly if epileptogenic zones are in a clinically silent neocortical brain region. The detection and possible differentiation of symptomatogenic and epileptogenic zones might improve the effectiveness of presurgical noninvasive studies.
- SourceAvailable from: Andreas AlexopoulosEpileptic disorders: international epilepsy journal with videotape 04/2006; 8(1):81-5. · 1.17 Impact Factor
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ABSTRACT: Some studies suggest that the pattern of glucose hypometabolism relates not only to the ictal-onset zone but also reflects seizure propagation. We investigated metabolic changes in patients with occipital lobe epilepsy (OLE) that may reflect propagation of ictal discharge during seizures with automatisms.Frontiers in neurology. 01/2014; 5:135.
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ABSTRACT: The article summarises the role of input and consequent phasic events in the dynamism of non-rapid eye movement (NREM) sleep and in homeostatic slow-wave economy during sleep. Then, an overview of the mechanism of how micro-arousals in NREM sleep gate epileptic events in absence epilepsy (AE) and in sporadic and autosomal dominant nocturnal frontal lobe epilepsy (NFLE/ADNFLE) is presented. The ictal type of generalised spike-wave discharges (SWDs) are associated with a special vigilance level in between NREM, rapid-eye movement (REM) and wake state. This transitional state is characterised by input-driven bidirectional fluctuations. Among them, SWDs are linked to A1 type A phases of CAP and therefore seem to be associated with shifts towards NREM sleep (sleep induction). In ADNFLE (and presumably in NFLE), micro-arousals release epileptic events in NREM sleep probably due to epileptic sensitisation of the cholinergic arousal system by the known acetylcholine (ACh) receptor mutations affecting the arousal system, giving rise to the epileptic (and also parasomniac) episodes. In both kinds of these system epilepsies (AE and NFLE), epileptic events can be released by phasic events during NREM sleep. The difference is that absences are activated in reactive states with a sleep-promoting, antiarousal effect, while in NFLE the epileptic disorder is interwoven with the cholinergic arousal function. The role of arousal/antiarousal in NFLE and AE fits nicely with the hypothesis that these epilepsies are disorders of two antagonistic thalamo-frontal systems involved in functions NREM sleep and wakefulness.Epilepsy research 08/2013; · 2.48 Impact Factor