Dementia with Lewy bodies (DLB) is a neurodegenerative disorder with parkinsonism, progressive cognitive decline, prominent executive dysfunction, behavioral and sleep disturbances, and visuospatial impairment.
Core clinical features are: cognitive fluctuations; recurrent visual hallucinations; rapid eye movement (REM) sleep behavior disorder; and one or more spontaneous cardinal motor features of parkinsonism: bradykinesia, rest tremor, or rigidity. Supportive clinical features include sensitivity to antipsychotic agents, postural instability and falls, syncope, autonomic dysfunction, delusions and nonvisual hallucinations, apathy, anxiety, and depression.
Diagnosis is made clinically and can only be confirmed pathologically by the presence of Lewy bodies. Many patients have concomitant Alzheimer disease-type pathology.
Treatment requires a multidisciplinary approach, with emphasis on behavioral and psychological symptoms. This includes both nonpharmacologic/behavioral and pharmacologic interventions, as well as supportive care. The main goal of treatment is to improve or stabilize cognition, behavior, and activities of daily living, and to maintain safety.
First-line pharmacologic treatment for cognitive impairment and behavioral symptoms is cholinesterase inhibitors. Clonazepam or melatonin is effective for REM sleep behavior disorder. Levodopa/carbidopa can be used for motor symptoms, although adverse effects may be restrictive and response limited.
The use of antipsychotic drugs for acute management of behavioral disturbance should be avoided as far as possible because of the risk of increased mortality. Low-dose atypical antipsychotics may be used with caution if necessary.
Dementia is defined as a progressive cognitive decline of sufficient magnitude to interfere with normal social or occupational functions, or with usual daily activities.
DLB is characterized by the following core clinical features (the first 3 typically occur early, and may persist throughout the course): fluctuating cognition; recurrent visual hallucinations; REM sleep behavior disorder; and one or more spontaneous cardinal motor symptoms of parkinsonism: bradykinesia, rest tremor, or rigidity. Prominent or persistent memory impairment may not necessarily occur in the early stages but is usually evident with progression. Deficits on tests of attention, executive function, and visuoperceptual ability may be especially prominent and occur early.
Disease course is progressive, although treatment may help some cognitive, sleep, motor, and behavioral symptoms. DLB should be distinguished from neurocognitive disorder associated with Parkinson disease, although there are areas of clinical overlap.
In the DSM-5-TR (Diagnostic and Statistical Manual of Mental Disorders, 5th ed., text revision), DLB is classified as a major neurocognitive disorder with Lewy bodies.
History and exam
Key diagnostic factors
- visual hallucinations
- motor symptoms
- rapid eye movement (REM) sleep behavioral disturbance
Other diagnostic factors
- severe antipsychotic sensitivity
- repeated falls and syncope
- orthostatic hypotension
- urinary symptoms
- attentional and visual processing abnormalities
- auditory hallucinations
- older age
- familial occurrence
1st investigations to order
- serum thyroid-stimulating hormone (TSH)
- serum vitamin B12
- CT head
- MRI head
Investigations to consider
- metabolic panel
- serum folate
- serum Venereal Disease Research Laboratory
- urine drug screen
- HIV testing
- single-photon emission CT (SPECT)/positron emission tomography (PET)
- quantitative EEG
- cerebrospinal fluid (CSF) analysis
- neuropsychological testing
- MIBG myocardial scintigraphy
- Alzheimer disease
- Parkinson disease
- Frontotemporal dementia
- Management of REM sleep behavior disorder
- ACR appropriateness criteria: dementia
Alzheimer disease and other kinds of dementia
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