Transient Global Amnesia Workup

Updated: Jul 27, 2018
  • Author: Roy Sucholeiki, MD; Chief Editor: Helmi L Lutsep, MD  more...
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Laboratory Studies

Lab studies may include the following:

  • CBC count with differential

  • Electrolyte panel

When a patient initially presents with transient global amnesia, stroke must be ruled out. This can be done using screening clotting tests, including prothrombin time (PT), activated partial throboplastin time (aPTT), and INR.


Imaging Studies

Brain MRI and/or CT scan

Any patient presenting with features of transient global amnesia should receive an imaging test to rule out a stroke possibility, especially if significant risk factors are present.

MRI with DWI can readily demonstrate acute ischemic changes early and guide management. In one study, higher resolution DWI imaging increased detection of hippocampal lesions in 27 patients with transient global amnesia, from 11 with standard resolution MRI to 22 with high resolution MRI. [19] If an MRI cannot be obtained readily, then at least a CT scan should be done initially if the patient is presenting to an emergency department.


Other Tests


These tests are important if the diagnosis of TGA is in doubt. If symptoms have occurred more than once, then at least a routine EEG should be done to help investigate a seizure possibility by demonstrating any interictal activity.