Dementia With Lewy Bodies

Background

• Dementia with Lewy bodies (DLB) is a progressive dementing illness associated with fluctuating cognitive impairment, visual hallucinations, and features of parkinsonism.
• DLB is the second most common type of degenerative dementia in older patients (after Alzheimer dementia) and is diagnosed in about 10%-15% cases of dementia.

Evaluation

• The central clinical feature is a progressive cognitive decline interfering with occupational or social functioning.
• Core features include:
  • fluctuating cognitive functioning with a variability in alertness and attention
  • recurrent visual hallucinations, characterized by being detailed and well-formed
  • features of parkinsonism
• Suggestive features include:
  • idiopathic rapid eye movement sleep behavior disorder (iRBD) may precede the clinical presentation of dementia with Lewy bodies (DLB) by years
  • severe neuroleptic sensitivity
  • low dopamine transporter uptake in basal ganglia on single photon emission computerized tomography (SPECT) or positron emission tomography (PET) imaging
• Suspect probable DLB if the patient has a central feature, plus ≥ 2 core features and plus ≥ 1 suggestive feature.
• DLB needs to be distinguished from other causes of dementia and other causes of parkinsonism.

Management

• Consider cholinesterase inhibitors for the treatment of dementia with Lewy bodies (DLB).
  • Rivastigmine is associated with improved scores on the Neuropsychiatric Inventory and the American Academy of Neurology (AAN) suggests considering this for treatment of dementia in DLB (Weak recommendation).
  • Donepezil improves cognitive function and may improve global function in patients with DLB.
  • Galantamine has also been reported to improve scores on the Neuropsychiatric Inventory.
• Memantine (Namenda) also appears effective for treating patients with DLB.
• Levodopa is reported to improve motor function in some patients with DLB.
• For new-onset agitation or alertness fluctuations:
  • Review medications for common culprits such as opioids or anticholinergics, and consider investigating for new systemic disorders associated with delirium or cognitive changes.
  • Avoid using antipsychotics to manage visual hallucinations, delusions, or behavioral disturbances when possible due to risk of serious sensitivity reaction in adults with DLB; when clinically warranted low-dose quetiapine may be relatively safer than other antipsychotics.