AN ATYPICAL FORM OF TRANSIENT GLOBAL AMNESIA AFTER GASTROINTESTINAL ENDOSCOPY. A COMPLICATED DIAGNOSIS

Abstract

Background: Transient global amnesia (TGA) is a clinical syndrome of unknown physiology characterized by a sudden onset of anterograde amnesia and a milder reduction of retrograde episodic long-term memory, without compromise of other neurologic functions. It is usually accompanied by vanishing punctate magnetic resonance imaging (MRI) diffusion-weighted imaging (DWI) lesions in hippocampal CA1 area. Episodes of TGA are of brief duration, usually lasting up to 24h. However, episodes with atypical characteristics have been also described.

Methods: We report a case of prolonged amnestic syndrome, lasting up to 24 hours, following gastrointestinal (GI) endoscopy and previous sedation with general anesthetics.

Results: A 70-year-old female was admitted to the Emergency Department, with profound anterograde amnesia and variable retrograde amnesia, after recovery from sedation due to GI endoscopy, a few hours earlier. Α thorough diagnostic workup excluded alternative causes of amnesia. The Brain MRI performed 24h following symptoms onset, revealed hyperintense DWI punctate signal within the lateral part of the right hippocampus, consistent with acute hippocampal ischemia. She was ultimately diagnosed with TGA related to a medical procedure.

Conclusion: Our patient’s clinical and imaging features were consistent with the diagnosis of TGA. This case highlights that clinical neurologists should not be deterred by atypical amnestic symptoms lasting >24-hours, if the patient’s clinical/radiologic presentation is consistent with TGA. However, they should carefully rule out other conditions that need immediate treatment.