Neurology
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Comparative Study
Intracranial ictal onset zone in nonlesional lateral temporal lobe epilepsy on scalp ictal EEG.
To determine the ictal focus and the role of seizure characteristics, fluorodeoxyglucose (FDG) PET, and subtraction ictal SPECT in patients diagnosed as having nonlesional lateral temporal lobe epilepsy by long-term scalp video-EEG monitoring. ⋯ An extratemporal ictal onset zone was encountered in patients with nonlesional lateral temporal lobe seizures based on scalp video-EEG monitoring. FDG-PET and subtraction SPECT had localizing value in no more than half of patients.
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Mutations in SCN1A, the gene encoding the alpha1 subunit of the sodium channel, have been found in severe myoclonic epilepsy of infancy (SMEI) and generalized epilepsy with febrile seizures plus (GEFS+). Mutations in SMEI include missense, nonsense, and frameshift mutations more commonly arising de novo in affected patients. This finding is difficult to reconcile with the family history of GEFS+ in a significant proportion of patients with SMEI. Infantile spasms (IS), or West syndrome, is a severe epileptic encephalopathy that is usually symptomatic. In some cases, no etiology is found and there is a family history of epilepsy. ⋯ The rate of SCN1A mutations in this cohort of SMEI patients suggests that other factors may be important in SMEI. Less severe mutations associated with GEFS+ could interact with other loci to cause SMEI in cases with a family history of GEFS+. This study extends the phenotypic heterogeneity of mutations in SCN1A to include IS.
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Microglia, the brain's intrinsic macrophages, bind (R)-PK11195 when activated by neuronal injury. The authors used [11C](R)-PK11195 PET to localize in vivo microglial activation in patients with multiple system atrophy (MSA). Increased [11C](R)-PK11195 binding was primarily found in the dorsolateral prefrontal cortex, putamen, pallidum, pons, and substantia nigra, reflecting the known distribution of neuropathologic changes in MSA. Providing an indicator of disease activity, [11C](R)-PK11195 PET can thus be used to characterize the in vivo neuropathology of MSA.