Can a stroke present with visual hallucinations?

Visual Hallucinations as a Presentation of Stroke

Yes, stroke can present with visual hallucinations, particularly when the lesion affects the occipital, parietal, or callosal regions of the brain. Visual hallucinations are an uncommon but recognized manifestation of stroke that clinicians should be aware of when evaluating patients with new-onset visual perceptual changes.

Types of Stroke Associated with Visual Hallucinations

• Occipital lobe strokes are most commonly associated with visual hallucinations, particularly when there is damage to the visual cortex but sparing of Brodmann areas 19,20, and 37 1
• Right parieto-occipital strokes can present with visual hallucinations in the left visual field 2
• Posterior callosal strokes have been reported to cause transient visual hallucinations 3
• Visual hallucinations occur in approximately 16.7% of acute stroke patients 4

Characteristics of Stroke-Related Visual Hallucinations

• Hallucinations may be elementary (simple shapes, lights) or complex (formed images like people, animals) depending on the location and extent of the lesion 5
• They are often lateralized to the side opposite the brain lesion 2
• Visual hallucinations in stroke are frequently self-limited and may resolve within days to weeks 4
• Hallucinations may be triggered by eye closure or darkness in some cases 3
• They are commonly associated with homonymous hemianopia (visual field defect) 1

Risk Factors and Associations

• Smaller lesion size has been paradoxically associated with a higher frequency of visual hallucinations in hemianopic patients 1
• Sleep disturbances before or during admission are associated with increased risk of visual hallucinations in stroke patients 4
• Visual hallucinations may occur without other obvious neurological deficits, making diagnosis challenging 2

Diagnostic Considerations

• Brain imaging (CT or MRI) is essential for diagnosis, with MRI being more sensitive for detecting acute stroke in the posterior circulation 6
• Diffusion-weighted imaging is particularly useful for identifying acute infarction 6
• Symptoms may not become apparent immediately and can develop hours or days after the stroke 6
• Other causes of visual hallucinations (medication effects, psychiatric disorders, delirium, dementia) should be excluded 2

Clinical Implications

• Visual hallucinations may be the sole or primary presenting symptom of stroke, particularly in posterior circulation strokes 2
• The presence of visual hallucinations should prompt consideration of stroke in the differential diagnosis, especially in elderly patients or those with vascular risk factors 2
• Stroke should be considered in patients presenting with new-onset visual hallucinations, even in the absence of other focal neurological deficits 3

Management Considerations

• Prompt neuroimaging is recommended for patients with new-onset visual hallucinations to rule out stroke 7
• Patient education about the nature of the hallucinations is important to reduce anxiety 7
• Most stroke-related visual hallucinations resolve spontaneously and do not require specific treatment beyond management of the underlying stroke 4
• Neuroleptics and benzodiazepines should be avoided during stroke recovery as they may impede recovery 7

Understanding that visual hallucinations can be a manifestation of stroke is crucial for prompt diagnosis and appropriate management, potentially improving outcomes for affected patients.