Visual hallucinations in patients with acute stroke: a prospective exploratory study

Background and purpose: The incidence, underlying physiopathology, features and association with lesion topography of visual hallucinations in acute stroke have scarcely been investigated.

Methods: Patients with a diagnosis of acute stroke (ischaemic or haemorrhagic) in any vascular territory, admitted within 24 h after the onset of symptoms, were consecutively included in the study. Patients with a previous history of psychosis or cognitive impairment were excluded. They and/or their caregivers answered a structured hallucination and sleep questionnaire at admission, within the first 15 days and at the clinical follow-up 3-6 months after discharge. Lesion location (IMAIOS online atlas) and leukoaraiosis (Wahlund scale) were determined by magnetic resonance imaging or computed tomography scan. Subsets of patients also underwent a neuropsychological evaluation (N = 50) and an electroencephalogram (N = 33) before discharge.

Results: In all, 77 patients with a mean age of 71 ± 12 years were included of whom 57.1% were men. The incidence of visual hallucinations was 16.7%. These hallucinations were mostly complex, in black and white and self-limited. The appearance of hallucinations was not influenced by age, sex, neuropsychological performance during admission or modified Rankin scale score at discharge. Visual hallucinations were associated with occipital cortex lesions (P = 0.04), and with sleep disturbances during and before admission (P = 0.041 and P = 0.03 respectively).

Conclusions: Visual hallucinations are relatively frequent in patients with acute stroke and they are self-limited. Patients with occipital lesions and sleep disturbances are more likely to suffer them.