Supplementary Motor Area Meningioma and Postoperative Hemorrhage Presenting With Acquired Narcissistic Personality Traits: A Case Report.

Meningiomas involving the supplementary motor area (SMA) are known to cause motor deficits, but acquired narcissistic personality changes following such lesions rarely described. We report a rare case of a 63-year-old woman who developed acquired narcissistic personality traits following the resection of a right frontal parasagittal meningioma involving the SMA, complicated by postoperative hemorrhage. Although previously cooperative, she manifested transient grandiosity, entitlement, and lack of empathy, temporarily meeting Diagnostic and Statistical Manual of Mental Disorders-5 criteria. Her symptoms improved with pharmacotherapy and rehabilitation. We hypothesize that while the SMA is not a canonical hub in the triple network model, this focal damage induced connectional diaschisis, disrupting functional connectivity to distant Salience and Default Mode Network hubs implicated in social cognition. This case suggests that acquired narcissistic personality traits can emerge from lesions in non-hub regions through remote network dysfunction, highlighting the importance of evaluating functional connectivity in acquired personality disorders.