title: Late postictal residual perfusion abnormality in epileptogenic zone found on 6-hour postictal SPECT.
abstract: BACKGROUND
  Temporal evolution of regional hyperperfusion in the late postictal stage in epilepsy has not been clearly defined.
  
  
  OBJECTIVE
  To establish the late temporal evolution of the perfusion in epileptogenic zones using 6-hour postictal SPECT.
  
  
  METHODS
  Ictal 99mTc-hexamethylpropyleneamine oxime (99mTc-HMPAO) SPECT was performed in 10 patients with intractable epilepsy (4 temporal lobe epilepsy, 6 neocortical epilepsy) followed by delayed acquisition and another 6-hour postictal SPECT after reinjection of 99mTc-HMPAO. The delayed acquired SPECT was subtracted from the reinjection SPECT to yield the 6-hour postictal SPECT. Interictal SPECT was acquired on another day. Late postictal perfusion was examined visually, and asymmetric indexes were compared with each other on ictal, 6-hour postictal, and interictal SPECT.
  
  
  RESULTS
  Ictal SPECT images of delayed acquisition were visually and quantitatively similar to those of early acquisition. In 7 of 10 patients, 6-hour postictal SPECT showed hyperperfusion. In one patient, the 6-hour postictal SPECT image showed less perfusion than the interictal SPECT image in the epileptogenic zone.
  
  
  CONCLUSIONS
  Late postictal hyperperfusion was found in more than half of the patients. Postictal perfusion abnormalities did not come back to the interictal phase 6 hours after ictus and these were identified on ictal/postictal 99mTc- HMPAO SPECT.
authors.affiliation: Institute of Radiation Medicine, Seoul National University Medical Research Center, Seoul, Korea.
authors.forename: D S
authors.initials: DS
authors.lastname: Lee
authors.forename: S K
authors.initials: SK
authors.lastname: Lee
authors.forename: S K
authors.initials: SK
authors.lastname: Kim
authors.forename: K W
authors.initials: KW
authors.lastname: Kang
authors.forename: E
authors.initials: E
authors.lastname: Kang
authors.forename: K H
authors.initials: KH
authors.lastname: Lee
authors.forename: I Y
authors.initials: IY
authors.lastname: Hyun
authors.forename: J
authors.initials: J
authors.lastname: Chung
authors.forename: M C
authors.initials: MC
authors.lastname: Lee
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D004569:Electroencephalography; D004827:Epilepsy / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon