Personality changes following neurosurgical procedures pose a major concern for patients and remain poorly understood both by clinicians and neuroscientists. Here we report a case of a female patient in her 50s who underwent resection of a large sagittal sinus meningioma with bilateral extension, including resection and ligation of the superior sagittal sinus, that resulted in borderline personality disorder and symptoms resembling the Gastaut-Geschwind syndrome. Clinical observations were further reflected and experimentally quantified with a series of behavioral and neuroimaging tasks assessing self-other voice discrimination, one of the established markers for self-consciousness. In all tasks, the patient consistently confused self- and other voices - i.e., she misattributed other-voice stimuli to herself and self-voice stimuli to others. Moreover, behavioral findings were corroborated with scalp EEG results. Specifically, the same EEG microstate, that was in healthy participants associated with hearing their own voice, in this patient occurred more often for other-voice stimuli. We hypothesize that the patient's preexisting psychological problems were significantly aggravated by postoperative decompensation of a fragile steady-state combination of direct frontal lobe compression and preoperative development of a large venous collateral hemodynamic network that followed gradual occlusion of the superior sagittal sinus. Resection of the sagittal sinus together with the tumor impacted venous drainage of brain areas associated with self-consciousness. These findings are of high relevance for developing experimental biomarkers of post-surgical personality alterations.

The authors have declared no competing interest.

The Swiss National Science Foundation (grant no. 320030_182497 to K.S.), with co-partners C.M.M., O.B.; the Pictet Foundation to K.S., O.B., and C.M.M; the Swiss National Science Foundation (grant no. 320030_184677 to C.M.M.). This research was supported by two donors advised by CARIGEST SA (Fondazione Teofilo Rossi di Montelera e di Premuda and a second one wishing to remain anonymous) to O.B.

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