title: Lateral temporal hyperperfusion in postictal psychosis assessed by 99mTc-HMPAO SPECT.
abstract: Postictal psychosis is a rare complication of epileptic seizure characterized by reversible psychotic symptoms after flurries of seizure attack. It has been attributed to a phenomenon similar to Todd's paralysis without definitive proof. We studied regional cerebral blood flow (rCBF) of six patients with postictal psychosis by (99m)Tc-HMPAO SPECT scan. Baseline rCBF was compared with the rCBF during postictal psychosis. An asymmetry index (ASI) was calculated as 200 x [(ipsilateral ROI count density - contralateral ROI count density)/(ipsilateral ROI count density + contralateral ROI count density)] %. Significant differences could be found between ASIs during postictal psychosis and interictal state SPECT scan over the lateral temporal neocortex region (P = 0.017). Although hyperperfusion abnormality in SPECT can be found in Todd's paralysis, such findings are more commonly found in cerebral hyperactivity conditions. Taking into account the clinical characteristics of postictal psychosis, namely a preceding lucid interval and crescendo-decrescendo clinical course, these may be an alternative psychopathogenic mechanism for the development of postictal psychosis.
authors.affiliation: Division of Neurology, University Department of Medicine, Universty of Hong Kong, Hong Kong.
authors.forename: G C Y
authors.initials: GC
authors.lastname: Fong
authors.forename: W Y
authors.initials: WY
authors.lastname: Ho
authors.forename: T H
authors.initials: TH
authors.lastname: Tsoi
authors.forename: K Y
authors.initials: KY
authors.lastname: Fong
authors.forename: S L
authors.initials: SL
authors.lastname: Ho
mesh_terms: D000293:Adolescent; D000328:Adult; D002545:Brain Ischemia / Q000000981:diagnostic imaging*; D004292:Dominance, Cerebral / Q000502:physiology; D004569:Electroencephalography; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008297:Male; D008875:Middle Aged; D019965:Neurocognitive Disorders / Q000000981:diagnostic imaging*; D012039:Regional Blood Flow / Q000502:physiology; D019690:Technetium Tc 99m Exametazime; D013702:Temporal Lobe / Q000098:blood supply* / Q000000981:diagnostic imaging; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D019690:Technetium Tc 99m Exametazime