Temporary Global Amnesia With Insular Infarction in a Young Female: A Case Report

Several neurological conditions, including transient global amnesia (TGA), may present an isolated sudden-onset temporary amnestic symptom. TGA is a benign, self-remitting neurological condition associated with hippocampal dysfunction. Meanwhile, certain other neurological conditions, such as cerebral ischemic stroke and hippocampal epilepsy, require appropriate therapeutic interventions. An isolated temporary amnestic symptom caused by extra-limbic brain regions has not been widely reported yet. We report a case of a 37-year-old female with systemic lupus erythematosus (SLE) who suddenly developed a transient amnestic symptom, with no other neurological symptoms, during an outdoor activity on a hot sunny day. Anterograde amnesia resolved after approximately two hours from the onset. She visited the hospital three days later. Brain MRI revealed an acute infarction in the left anterior insular cortex. A 2 mm thin-slice MRI on both hippocampi revealed no diffusion restriction. She was diagnosed with insular cortex infarction, possibly associated with SLE. Single antiplatelet therapy with aspirin 100 mg/day was started on the same day and oral prednisolone with 10 mg/day was started on the next day. This report is the first of its kind to describe a possible association between temporary amnesia and insular cortex damage. This case implies that the anterior insular cortex may play a potential role in forming episodic memories. Damages in this area may present a sudden-onset transient amnestic symptom. Clinicians should pay close attention to this non-hippocampal area on brain MRI when investigating amnestic patients.