From the Guidelines
Dementia with Lewy Bodies (DLB) is a progressive brain disorder characterized by abnormal protein deposits called Lewy bodies that develop in nerve cells, causing problems with thinking, movement, behavior, and mood, and is the second most common type of dementia after Alzheimer's disease. The hallmark symptoms of DLB include visual hallucinations, fluctuating cognition with varying levels of alertness and attention, movement disorders resembling Parkinson's disease, acting out dreams during sleep, and autonomic dysfunction affecting blood pressure, temperature regulation, and digestion 1. Diagnosis is based on clinical symptoms, as no single test can definitively identify DLB.
Key Characteristics of DLB
- Visual hallucinations
- Fluctuating cognition with varying levels of alertness and attention
- Movement disorders resembling Parkinson's disease
- Acting out dreams during sleep (REM sleep behavior disorder)
- Autonomic dysfunction affecting blood pressure, temperature regulation, and digestion
Treatment and Management
Treatment typically involves medications like cholinesterase inhibitors (rivastigmine, donepezil) to help with cognitive symptoms, though at lower doses than used for Alzheimer's due to sensitivity 1. Levodopa may help with movement symptoms but can worsen hallucinations. Antipsychotics should generally be avoided as people with LBD are extremely sensitive to these medications and may experience severe side effects. The disease progresses over time, typically lasting 5-8 years from diagnosis, though this varies widely.
Outcome Measures in Clinical Trials
The selection of appropriate outcome measures is fundamental to the design of any successful clinical trial for DLB, and existing outcome measures require validation in the DLB population 1. The Montreal Cognitive Assessment (MoCA) is a reliable assessment that includes items that assess attention and executive functions, making it a more valid instrument for DLB trials 1.
Clinical Recommendations
The decision to initiate a trial of therapy with a cholinesterase inhibitor or memantine should be based on individualized assessment, considering the patient’s preferences, prior expressed wishes, and collaboration with family or substitute decision makers 1. The choice of pharmacologic agents should be based on tolerability, adverse effect profile, ease of use, and cost of medication. Deprescribing of cholinesterase inhibitors or memantine should occur gradually, and treatment reinitiated if the individual shows clinically meaningful worsening of cognition, functioning, neuropsychiatric symptoms, or global assessment that appears to be related to cessation of therapy 1.
From the Research
Definition and Characteristics of Dementia with Lewy Bodies (DLB)
- Dementia with Lewy bodies (DLB) is a complex disease involving cognitive, behavioral, and neurological symptoms, including progressive memory loss, visual hallucinations, parkinsonism, cognitive fluctuations, and rapid eye movement sleep behavior disorder (RBD) 2.
- DLB is characterized by the accumulation of aggregated α-synuclein protein in Lewy bodies and Lewy neurites, similar to Parkinson's disease (PD) 3.
- The disease is the third most common of all neurodegenerative diseases, behind Alzheimer's disease and Parkinson's disease (PD), with a median age of onset of 76.3 years 2.
Clinical Features and Diagnosis
- DLB is clinically characterized by complex visual hallucinations, spontaneous motor parkinsonism, prominent cognitive fluctuations, and rapid eye movement sleep behavior disorder 4.
- Neuropsychiatric features and autonomic dysfunction are also common in DLB patients 4.
- The new diagnostic criteria and specific diagnostic biomarkers, such as single-photon emission computed tomography (SPECT) of the dopamine system and α-synuclein-specific biomarkers, help improve detection rates and diagnostic accuracy 5.
Treatment and Management
- Cholinesterase inhibitors, such as rivastigmine, galantamine, and donepezil, have been shown to be effective in managing the cognitive and behavioral symptoms of DLB 2, 6.
- Memantine can improve clinical global impression of change in patients with mild to moderate DLB 2.
- Levodopa can treat parkinsonism in some DLB patients, but the dose is often limited due to the risk of agitation or worsening of visual hallucinations 2.
- Other treatment options, such as zonisamide, valproic acid, and pimavanserin, may also be effective in managing specific symptoms of DLB 2.