title: Ictal single photon emission computed tomography in occipital lobe seizures.
abstract: OBJECTIVE
  Ictal single photon emission computed tomography (SPECT) has been evaluated as an adjunctive localizing technique in temporal lobe epilepsies and, to a lesser degree, in some extratemporal epilepsies. The purpose of this study was to determine whether occipital lobe seizures are associated with distinctive ictal cerebral blood perfusion (rCP) patterns.
  
  
  METHODS
  SPECT was used with the tracer 99mTc HMPAO to image ictal rCP in 6 patients in whom clinical, EEG, and imaging data indicated occipital lobe seizures.
  
  
  RESULTS
  Two patterns of rCP were seen. Four patients had hyperperfusion that was restricted to the occipital lobe, and two patients had hyperperfusion of the occipital lobe and the ipsilateral mesial temporal lobe, with hypoperfusion of the lateral temporal lobe. The latter 2 patients had clinical and surface EEG evidence of temporal lobe involvement in the seizure discharge.
  
  
  CONCLUSIONS
  Ictal rCP patterns in occipital lobe seizures are distinct from those in temporal lobe seizures and may vary according to whether or not ipsilateral temporal lobe structures are involved in the ictal discharge.
authors.affiliation: Department of Neurology, Institute of Neurological Sciences, Southern General Hospital NHS Trust, Glasgow, Scotland.
authors.forename: R
authors.initials: R
authors.lastname: Duncan
authors.forename: A
authors.initials: A
authors.lastname: Biraben
authors.forename: J
authors.initials: J
authors.lastname: Patterson
authors.forename: D
authors.initials: D
authors.lastname: Hadley
authors.forename: A M
authors.initials: AM
authors.lastname: Bernard
authors.forename: J
authors.initials: J
authors.lastname: Lecloirec
authors.forename: J P
authors.initials: JP
authors.lastname: Vignal
authors.forename: P
authors.initials: P
authors.lastname: Chauvel
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D003937:Diagnosis, Differential; D004569:Electroencephalography; D004827:Epilepsy / Q000000981:diagnostic imaging* / Q000503:physiopathology; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000503:physiopathology; D007839:Functional Laterality / Q000502:physiology; D006801:Humans; D008279:Magnetic Resonance Imaging; D009778:Occipital Lobe / Q000098:blood supply* / Q000000981:diagnostic imaging / Q000503:physiopathology; D012039:Regional Blood Flow / Q000502:physiology; D019690:Technetium Tc 99m Exametazime; D013702:Temporal Lobe / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D019690:Technetium Tc 99m Exametazime