Alzheimer’s disease versus vascular dementia - emergency department perspective
Overview
Dementia is a syndrome with multiple causes.
In the ED the role is usually not to make a definitive subtype diagnosis but to: recognise cognitive impairment, exclude and treat reversible contributors (especially delirium), identify findings that suggest a vascular contribution, assess capacity, and ensure clear, timely handover to specialist services.
Recommendations below are aligned with UK guidance (NICE NG97; RCEM Silver Book II and RCEM Care of Older People QIP; Mental Capacity Act Code of Practice).
Pathology and typical clinical course
- Alzheimer’s disease: a neurodegenerative disorder with insidious onset and gradual, steady decline in memory and other cognitive domains. Early loss of insight and personality change are common. Sleep disturbance and behavioural symptoms occur frequently. Specialist assessment (neuropsychology, imaging) is required to confirm diagnosis (NICE NG97).
- Vascular dementia: cognitive impairment related to cerebrovascular disease (large infarcts, lacunes, small‑vessel disease or chronic hypoperfusion). Onset may be sudden or stepwise, with fluctuating deficits tied to new vascular events. Focal neurological signs and gait disturbance are more likely. If vascular dementia is suspected, structural imaging is indicated (MRI preferred; CT acceptable when MRI is unavailable or contraindicated) (NICE NG97).
Key bedside distinctions (ED‑relevant)
The following features help prioritise investigations and immediate management; none are diagnostic in isolation and mixed pathology is common.