Dementia with Lewy bodies
Dementia with Lewy bodies is a synuclein-related neurodegenerative dementia defined by dementia plus parkinsonism, fluctuating attention, visual hallucinations, and REM sleep behavior disorder arising within about two years of each other. Diagnosis is clinical; acetylcholinesterase inhibitors treat cognitive symptoms and first-generation antipsychotics must be avoided because of severe neuroleptic sensitivity.
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What this article covers
- Overview
Definition: dementia with Lewy bodies (DLB) is a progressive neurodegenerative dementia defined by the combination of dementia with parkinsonian motor features, fluctuating attention, recurrent…
- Epidemiology
Second most common neurodegenerative dementia: DLB ranks behind only Alzheimer disease among neurodegenerative dementias.
- Risk factors
Advancing age: the dominant demographic risk factor, as with other neurodegenerative dementias.
- Pathophysiology
Alpha-synuclein deposition: Lewy bodies, intracytoplasmic eosinophilic inclusions composed of aggregated alpha-synuclein, are the chief pathologic feature and are distributed through cortical and…
- Clinical features
Central feature - dementia: progressive cognitive decline sufficient to interfere with daily function, often with more prominent visuospatial and executive dysfunction than the early amnestic pattern typical of Alzheimer disease.
- Differential diagnosis
Alzheimer disease dementia: shows hippocampal atrophy on brain MRI and typically lacks parkinsonism except in late-stage disease; hallucinations and REM sleep behavior disorder are far less common…
- Diagnosis
Diagnostic basis: the clinical diagnosis of DLB rests on the combination of dementia with the core features of parkinsonism, fluctuating attention, recurrent visual hallucinations, and REM sleep…
- Management
First step - treat cognitive symptoms with an acetylcholinesterase inhibitor: rivastigmine (1.5 mg PO twice daily, increased by 1.5 mg twice daily at intervals of at least 2 weeks to 3 mg to 6 mg…
- Complications
Neuroleptic malignant syndrome-like reactions: severe, potentially life-threatening rigidity, fever, and autonomic instability can follow exposure to first-generation (and some second-generation) antipsychotics.
- Prognosis
Progressive and typically faster than Alzheimer disease: DLB follows a relentlessly progressive course, generally with a shorter survival than Alzheimer disease from symptom onset.
- Prevention
No established primary prevention: there is no proven strategy to prevent the underlying synuclein pathology of DLB.
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