Persistent Working Memory Impairment Associated with Cerebral Infarction in the Anterior Cingulate Cortex: A Case Report and a Literature Review.

A 52-year-old man experienced sudden-onset global amnesia and left limb ataxia. An embolism of the right anterior cerebral artery resulted in anterior cingulate cortex (ACC) infarction, and working memory dysfunction persisted. The ACC, prefrontal cortex, and bilateral superior parietal lobule exhibited decreased activity on single-photon emission computed tomography (SPECT). The ACC handles working memory formation and is essential for the executive function. The areas showing a decreased activity on SPECT were responsible for the working memory, which corresponded to the observed symptoms. This is the first case in which limited ACC infarction resulted in permanent working memory dysfunction, and SPECT revealed the decreasing working memory in the associated region.