Post-Stroke Psychosis and Neuropsychiatric Disturbances in an Older Adult: A Diagnostic Challenge and Case Report

Abstract

Post-stroke neuropsychiatric disturbances may manifest as affective, cognitive, behavioral, or psychotic symptoms and may represent a diagnostic challenge, particularly when structural epilepsy coexists with brain lesions involving different vascular territories. We present the case of a 67-year-old man with a history of arterial hypertension, type 2 diabetes mellitus, and obstructive sleep apnea syndrome, who had experienced ischemic strokes in the territories of the right posterior cerebral artery and the left middle cerebral artery approximately one month before admission, with residual nonfluent aphasia and right upper-limb paresis. Fifteen days before admission, he experienced a late-onset focal seizure and was started on lacosamide. He subsequently developed progressive anxiety, depressed mood, psychomotor agitation, cognitive decline, behavioral changes, persecutory delusions, ideas of reference, and visual and auditory hallucinations. During the evaluation, he was conscious, without evident fluctuations in the level of consciousness or clinical findings consistent with delirium. Metabolic and infectious studies did not identify an alternative cause. Brain computed tomography showed right occipital and left frontoparietal encephalomalacia, as well as cerebral small-vessel disease, without evidence of intracranial hemorrhage or a new acute ischemic event. Video-EEG monitoring did not record epileptiform activity or electrographic seizures during the monitoring period. Brain magnetic resonance imaging was requested to rule out additional structural lesions; however, the study could neither be completed nor retrieved because the patient was transferred to another institution. During the observed hospital stay, he remained neurologically stable, without new focal deficits or recurrent seizures. He received symptomatic treatment with olanzapine, lacosamide was continued, and he underwent joint evaluation by the Neurology and Psychiatry services. The exact doses, subsequent pharmacological adjustments, and longitudinal course of the psychiatric symptoms could not be established because institutional follow-up was lost after the transfer. This case highlights the complexity of distinguishing post-stroke psychiatric manifestations from a new cerebrovascular event, delirium, nonconvulsive epileptic activity, postictal states, and primary psychiatric disorders. Integration of the clinical timeline, mental status examination, neuroimaging, and electrophysiological studies is essential to guide diagnosis and establish individualized treatment.