title: Transient global amnesia: a study with Tc-99m ECD SPECT shortly after symptom onset and after recovery.
abstract: OBJECTIVE
  Transient global amnesia (TGA) is characterized by sudden loss of memory of recent events, transient inability to retain new information, and retrograde amnesia. We investigated the changes of regional cerebral blood flow in patients with TGA shortly after symptom onset and after recovery using Tc-99m-ethyl cysteinate dimer single-photon emission computed tomography (Tc-99m ECD SPECT) and statistical parametric mapping (SPM) analysis.
  
  
  METHODS
  Six right-handed patients with TGA were studied using Tc-99m ECD SPECT shortly after symptom onset and after recovery. As a control group, six healthy individuals were also studied. Images were analyzed using SPM8 using voxel-based analysis to estimate the differences between TGA patients and controls.
  
  
  RESULTS
  There was significant hypoperfusion in the left hippocampus, left thalamus, and bilateral cerebellum. In the follow-up SPECT scan, hypoperfusion in hippocampus and thalamus were restored, while hypoperfusion was noted in the temporoparietal region.
  
  
  CONCLUSIONS
  Our results suggest that the underlying mechanism of TGA may be temporary ischemia in the hippocampus and thalamus. There was significant restoration of perfusion in the hippocampus and thalamus after recovery from TGA.
authors.affiliation: Department of Nuclear Medicine, Ewha Womans University School of Medicine, Seoul, Korea. yohan2727@hanyang.ac.kr.
authors.forename: Bom Sahn
authors.initials: BS
authors.lastname: Kim
authors.forename: Sang Soo
authors.initials: SS
authors.lastname: Cho
authors.forename: Joon Young
authors.initials: JY
authors.lastname: Choi
authors.forename: Young Hwan
authors.initials: YH
authors.lastname: Kim
mesh_terms: D020236:Amnesia, Transient Global / Q000000981:diagnostic imaging / Q000209:etiology*; D001921:Brain / Q000000981:diagnostic imaging*; D002560:Cerebrovascular Circulation; D003545:Cysteine / Q000008:administration & dosage / Q000031:analogs & derivatives*; D005260:Female; D006801:Humans; D007090:Image Interpretation, Computer-Assisted / Q000379:methods; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds / Q000008:administration & dosage*; D019275:Radiopharmaceuticals / Q000008:administration & dosage*; D012680:Sensitivity and Specificity; D015899:Tomography, Emission-Computed, Single-Photon / Q000379:methods*
chemical_list: D015609:Organotechnetium Compounds; D019275:Radiopharmaceuticals; C059659:technetium Tc 99m bicisate; D003545:Cysteine