title: A Tc-99m SPECT study of regional cerebral blood flow in patients with transient global amnesia.
abstract: OBJECTIVE
  This study aimed to determine whether regional cerebral blood flow (rCBF) is abnormal in patients who have Transient Global Amnesia (TGA).
  
  
  METHODS
  We obtained noninvasive rCBF measurements using Tc-99m-ethyl cysteinate diamer Single Photon Emission Computed Tomography (SPECT) in 7 patients diagnosed with TGA within 4 days of onset of the amnestic episode while the patients were still symptomatic and in 17 age-matched healthy control subjects. We assessed memory functioning using the Hopkins's Verbal Learning Test (HVLT) and Statistical Parametric Mapping to compare rCBF across diagnostic groups.
  
  
  RESULTS
  The patients with TGA were significantly impaired in their performance on the 20-minute delayed recall of the HVLT. They also exhibited significantly decreased rCBF on their SPECT scans in the inferior and middle frontal gyrus bilaterally, with more prominent left-sided reductions in the superior temporal, precentral, and postcentral gyri, as well as increased rCBF primarily in the right hemisphere within the middle temporal, superior temporal, and inferior frontal gyri, cerebellum, and thalamus, compared with the normal control group.
  
  
  CONCLUSIONS
  These findings suggest that lateralized abnormalities in brain functioning are an important component of the pathophysiology of TGA. Lateralized abnormalities may disrupt functions that are relatively specific to the left hemisphere, including receptive language, symbolic representation, and the processing of local features in the environment, while preserving anterograde memory processes. Increased flow to the right hemisphere centered on regions that subserve the functions of expressive language and visuospatial processing, and may represent processes that compensate for flow reductions to the left hemisphere.
authors.affiliation: Department of Radiology, College of Medicine, The Catholic University of Korea, Seoul, 150-713 South Korea.
authors.forename: Yong An
authors.initials: YA
authors.lastname: Chung
authors.forename: Jaeseung
authors.initials: J
authors.lastname: Jeong
authors.forename: Dong Won
authors.initials: DW
authors.lastname: Yang
authors.forename: Bong-Joo
authors.initials: BJ
authors.lastname: Kang
authors.forename: Sung Hoon
authors.initials: SH
authors.lastname: Kim
authors.forename: Soo Kyo
authors.initials: SK
authors.lastname: Chung
authors.forename: Hyung Sun
authors.initials: HS
authors.lastname: Sohn
authors.forename: Bradley S
authors.initials: BS
authors.lastname: Peterson
mesh_terms: D000368:Aged; D020236:Amnesia, Transient Global / Q000000981:diagnostic imaging* / Q000523:psychology; D001921:Brain / Q000098:blood supply / Q000000981:diagnostic imaging*; D001931:Brain Mapping; D002560:Cerebrovascular Circulation; D003545:Cysteine / Q000031:analogs & derivatives; D005260:Female; D006801:Humans; D008297:Male; D011939:Mental Recall; D008875:Middle Aged; D009483:Neuropsychological Tests; D015609:Organotechnetium Compounds; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D015609:Organotechnetium Compounds; C059659:technetium Tc 99m bicisate; D003545:Cysteine