title: Increased contralateral cerebellar uptake of technetium-99m-HMPAO on ictal brain SPECT.
abstract: Crossed cerebellar diaschisis (CCD) is a well-known brain SPECT finding in stroke patients. Two reports, however, have described supratentorial and contralateral cerebellar hyperperfusion (crossed cerebellar hyperperfusion) on ictal brain SPECT in epileptic patients. The purpose of this study was to assess the usefulness of crossed cerebellar hyperperfusion (CCH) for the detection of epileptic foci on ictal scan.
  
  
  METHODS
  Twelve patients with complex partial seizures having characteristic clinical, electroencephalographic (EEG) and brain SPECT findings were included. Fifteen to 20 mCi 99mTc-HMPAO were injected intravenously during the seizure period or the aura for the ictal SPECT study. The SPECT findings were visually assessed to determine whether the finding of CCH was valuable in the localization of ictal foci.
  
  
  RESULTS
  Epileptic foci were found in the right temporal (n = 6), left temporal (n = 4), right occipital (n = 1) and left frontal (n = 1) areas. CCH was observed in 8 (75%) of the 12 patients. In two patients, contralateral cerebellar uptake was more obvious than that in the epileptic foci. In the interictal scans, cerebellar activity, which was increased in ictal period, was equalized in seven of eight patients, while perfusion was diminished in the remaining patient.
  
  
  CONCLUSIONS
  CCH is a frequent finding of ictal brain SPECT and may aid in the lateralization of epileptic foci.
authors.affiliation: Department of Radiology and Neurology, Yonsei University College of Medicine, Seoul, Korea.
authors.forename: J H
authors.initials: JH
authors.lastname: Won
authors.forename: J D
authors.initials: JD
authors.lastname: Lee
authors.forename: T S
authors.initials: TS
authors.lastname: Chung
authors.forename: C Y
authors.initials: CY
authors.lastname: Park
authors.forename: B I
authors.initials: BI
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging; D002531:Cerebellum / Q000098:blood supply / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D017029:Epilepsy, Complex Partial / Q000000981:diagnostic imaging* / Q000503:physiopathology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D015609:Organotechnetium Compounds; D010091:Oximes; D011877:Radionuclide Imaging; D019690:Technetium Tc 99m Exametazime
chemical_list: D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime