Psychosis
Psychosis can be caused by stroke but is very uncommon, with an incidence of approximately 1%. Pre-existing cortical atrophy increases the risk for poststroke psychosis. Auditory hallucinations can be directly caused by acute stroke, mostly described after lesions of the brain stem, but rarely reported after cortical strokes. A cross-sectional study of 641 stroke patients identified four patients who developed postcortical stroke auditory hallucinations.31 All of them occurred after an ischemic lesion of the right temporal lobe, and all resolved without pharmacotherapy in a few months. Stroke can also cause delusions, which sometimes are persistent to the point of constituting a delusional disorder, eg, delusions of parasitosis.32 If psychotic symptoms appearing soon after stroke are mild and not distressing to the patient, drug treatment may not be necessary. Significant persistent or disruptive psychosis should usually be treated with antipsychotics since the risk of untreated psychosis usually is greater than the risk of increased mortality reported in some studies of patients with dementia receiving antipsychotics. However, long-term treatment may not be needed since most poststroke psychotic symptoms in patients without dementia will resolve