A Case of Transient Global Amnesia with Two Tiny High Signal Intensities at the Head of Both Hippocampi on Diffusion-Weighted Magnetic Resonance Imaging / 신경정신의학

ABSTRACT

We report on a patient with transient global amnesia (TGA) showing increased tiny signal intensities at the head of both hippocampi on diffusion-weighted image (DWI) performed on the second day after the onset of symptoms. The T1-weighted image using 3-tesla magnetic resonance imaging (MRI) showed no signal changes, but the T2-weighted image showed slight signal changes at the same portion of both hippocampi. Single photon emission computed tomography (SPECT) performed on the 4th day after the onset of TGA showed no perfusion abnormalities. This patient experienced an extreme emotional stress before the onset of TGA, and the patient's TGA started by a simultaneous Valsava-like maneuver. We discuss the venous congestion/ischemia hypothesis for TGA. This case confirms that DWI is a sensitive and useful tool for evaluating the early stage of TGA.