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: Shigetoshi Takaya[Show abstract] [Hide abstract]
ABSTRACT: Polyopia is one of rare, visual hallucinations. A 61-year-old man suffered from daily episodes of polyopia and generalized convulsions, and he was diagnosed as right temporal lobe epilepsy. MRI revealed right amygdalar swelling. FDG-PET showed hypometabolism in the right anterior temporal and the mesial occipital areas. Polyopia is thought to be caused by dysfunction of updating process of visual information in the visual association cortices. It was most likely that, in this patient, both mesial temporal and ipsilateral occipital areas were responsible for manifesting epileptic polyopia, as ictal onset zone and symptomatogenic zone, respectively.Journal of the Neurological Sciences 09/2006; 247(1):109-11. DOI:10.1016/j.jns.2006.04.010 · 2.26 Impact Factor
- Epileptic disorders: international epilepsy journal with videotape 04/2006; 8(1):81-5. · 0.90 Impact Factor
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ABSTRACT: Depressions of regional cerebral metabolism beyond the epileptogenic zone have been demonstrated in patients with intractable temporal lobe epilepsy. However, their clinical relevance, and the causes of prefrontal metabolic asymmetries are less well understood. We investigated 96 temporal lobe epilepsy patients by FDG-PET and neuropsychological assessment who had a corresponding unilateral temporal hypometabolism, left hemisphere speech dominance, full scale IQ of > 70 and no extratemporal lesion in MRIs. The regional glucose metabolism was determined in each patient in homologous regions including prefrontal cortex, and normalized to whole brain metabolism. Regional differences of > 10% were regarded as asymmetrical. Prefrontal metabolic asymmetries were more frequent in patients with left temporal lobe epilepsy (21 left, six right) and a history of secondarily generalized seizures. A multivariate analysis of variance revealed a main effect for prefrontal metabolic asymmetry on neuropsychological 'frontal lobe measures', including verbal and performance intelligence measures. Prefrontal metabolic asymmetry was not related to 'measures of episodic memory', presence of psychiatric symptoms or frontal interictal epileptiform discharges. We conclude that prefrontal metabolic asymmetry is associated with cognitive impairment. Patients with temporal lobe epilepsy of the left speech dominant hemisphere and a history of secondarily generalized seizures are at considerable risk of developing prefrontal metabolic asymmetry.Brain 12/1997; 120 ( Pt 12):2283-94. DOI:10.1093/brain/120.12.2283 · 10.23 Impact Factor