Neurology News

Teaching NeuroImage: Unilateral Temporal Lobe Hypoperfusion

A 51-year-old man developed sudden-onset anterograde amnesia several hours after a typical migraine attack. He had no medical history or vascular risk factors other than a migraine disorder since early adulthood. There were no deficits in other cognitive domains and no loss of personal identity. Symptoms resolved within 24 hours. CT brain and angiogram during the episode were normal; however, CT perfusion imaging (Figure, A) performed 3 hours after symptom onset revealed an area of focal left temporal hypoperfusion. An MRI of the brain (Figure, B and C) performed 48 hours later did not show any corresponding areas of ischemic change or punctate diffusion-weighted imaging lesions as previously described in 69% of cases with highest sensitivity at 12–24 hours.1 Transient global amnesia is associated with migraine, and migraine in turn has an association with vascular pathology.2 This case underlines that transient temporal hypoperfusion may play an important role in the pathogenesis of transient global amnesia.

Figure CT Perfusion and MRI of the Brain

CT perfusion 3 hours postsymptom onset (A) demonstrating left medial temporal lobe hypoperfusion. Diffusion-weighted (B) and T2-FLAIR (C) brain MRI sequence images at 48 hours postsymptom onset demonstrating no evidence of infarct in the medial temporal lobe. FLAIR = fluid-attenuated inversion recovery; MTT = mean transit time; rCBV/rCBF = relative cerebral blood volume/flow; Tmax = time to maximum; TTP = time to peak.

Author Contributions

E. Tallon: drafting/revision of the manuscript for content, including medical writing for content. S. Hanratty: major role in the acquisition of data. K. Boyle: major role in the acquisition of data; study concept or design.

Study Funding

No targeted funding reported.


The authors report no disclosures relevant to the manuscript. Go to for full disclosures.


The authors thank the patient and their family for their participation and interest in this publication.


  • Go to for full disclosures. Funding information and disclosures deemed relevant by the authors, if any, are provided at the end of the article.

  • Submitted and externally peer reviewed. The handling editor was Resident and Fellow Section Editor Whitley Aamodt, MD, MPH.

  • Teaching slides

  • Received July 9, 2022.
  • Accepted in final form April 25, 2023.