Quantitative single photon emission tomography analysis for the diagnosis of transient global amnesia: adaptation of statistical parametric mapping.

We report two cases of transient global amnesia (TGA) diagnosed using a clinical criteria and single photon emission tomography (SPECT) with the aid of Statistical Parametric Mapping (SPM). Both patients underwent an initial SPECT study about 20 h after the disappearance of the amnesic episode, and a second study 3 weeks after the episode. We conducted quantitative cerebral blood flow (CBF) analyses using SPM on Matlab. This revealed regions with abnormal CBF in the first studies but not in the second. This method appears to be useful for diagnosis of TGA, especially in patients with suspected TGA in whom the amnesic episode disappears within a few days.