title: Diffusion-weighted MRI in transient global amnesia precipitated by cerebral angiography.
abstract: BACKGROUND
  Transient global amnesia is a well-described complication of cerebral angiography. Speculation about the pathophysiology exists but is as yet unsubstantiated. Diffusion-weighted MRI is a new imaging technique that is very sensitive in detecting acute ischemia. Its use in the evaluation of transient amnesia precipitated by cerebral angiography has not previously been reported.
  
  
  METHODS
  A 44-year-old man underwent posterior circulation cerebral angiography for the investigation of episodic vertigo. Shortly after completion of the procedure, he was noted to have symptoms of transient global amnesia. Diffusion-weighted MRI at 6 and 44 hours after the procedure demonstrated increased signal in the right hippocampus and other areas within the posterior circulation bilaterally consistent with ischemia from emboli. Abnormalities on conventional MRI images performed at the same time points were noted only in retrospect. A follow-up MRI at 2 months was normal.
  
  
  CONCLUSIONS
  Ischemia from cerebral emboli may cause transient global amnesia precipitated by cerebral angiography. Diffusion-weighted MRI may be useful in defining the pathophysiology.
authors.affiliation: Stanford Stroke Center, Department of Neurology, Stanford University, Palo Alto, Calif. 94304-1705, USA.
authors.forename: A R
authors.initials: AR
authors.lastname: Woolfenden
authors.forename: M W
authors.initials: MW
authors.lastname: O'Brien
authors.forename: R E
authors.initials: RE
authors.lastname: Schwartzberg
authors.forename: A M
authors.initials: AM
authors.lastname: Norbash
authors.forename: D C
authors.initials: DC
authors.lastname: Tong
mesh_terms: D000328:Adult; D000647:Amnesia / Q000175:diagnosis* / Q000209:etiology*; D002533:Cerebral Angiography / Q000009:adverse effects*; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D013575:Syncope / Q000000981:diagnostic imaging