What Is Lewy Body Dementia?
Lewy body dementia also called dementia with Lewy bodies, is a progressive, degenerative type of dementia. Lewy body dementia is an umbrella term for dementia associated with the presence of Lewy bodies (abnormal deposits of the protein alpha-synuclein) in the brain.
Lewy body dementia is the second-most common type of progressive dementia after Alzheimer's disease.
What Are Symptoms of Lewy Body Dementia?
Symptoms of Lewy body dementia commonly include changes in thinking, behavior, movement, and sleep such as:
- Dementia - this refers to problems with memory, problem solving, decision making, processing information, planning, figuring out daily activities, and analytical thinking
- Cognitive instability such as those that involve altered concentration, short attention span, or problems with alertness
- Parkinson’s-like symptoms such as slow movement and walking, shuffling gait, rigidity or stiffness, tremors, and balance problems
- Behavioral changes include:
- Hallucinations - seeing or hearing things that are not really there
- Delusions and paranoia
- Changes in mood including depression, anxiety, agitation, and apathy
- Sleep disorders include:
- REM sleep behavior disorder, which involves acting out dreams
- Insomnia
- Excessive daytime sleepiness/taking long naps during the day
- Restless leg syndrome
- Temporary loss of consciousness with difficulties wakening
- Autonomic nervous system problems involve involuntary bodily functions such as:
- Problems with temperature regulation
- Problems with blood pressure regulation
- Constipation
- Urinary or bowel incontinence
- Sexual dysfunction
What Causes Lewy Body Dementia?
The cause of Lewy body dementia is unknown. It is believed that symptoms result from disruption of the information flow within the brain. A buildup of Lewy bodies (abnormal deposits of the protein alpha-synuclein) is associated with a loss of certain neurons that produce the neurotransmitters (chemical messengers within the brain) acetylcholine and dopamine. Acetylcholine is involved in memory and learning, and dopamine affects behavior, cognition, motivation, movement, sleep, and mood.
Risk factors for Lewy body dementia include:
- Age over 50 years
- Genetics – while not a genetic disease, having a family member with the disorder increases a person’s risk of developing it
- Certain diseases and health conditions are associated with a higher risk of Lewy body dementia, such as Parkinson's disease and REM sleep behavior disorder
How Is Lewy Body Dementia Diagnosed?
Lewy body dementia is diagnosed with an examination of mental status and cognition.
Imaging tests of the brain may be indicated including:
- Magnetic resonance imaging (MRI)
- Computed tomography (CT) scan
- Single photon emission computed tomography (SPECT or SPET)
- Positron emission tomography (PET) scan
Blood tests may include:
- Complete blood count (CBC)
- Chemistry panel
- Thyroid studies
- Vitamin B-12 levels
- Cerebral spinal fluid studies from a spinal tap (lumbar puncture)
- Tests for syphilis, Lyme disease, or HIV, if indicated
What Is the Treatment for Lewy Body Dementia?
If Lewy body dementia symptoms are mild, treatment may not be needed. At present, there are no medications that slow the rate of cognitive decline but drugs may be used to help manage symptoms such as agitation, hallucinations, and depression, and to improve cognition and alertness.
Medications used to treat Lewy body dementia include:
- Cholinesterase inhibitors such as donepezil (Aricept), rivastigmine (Exelon and Exelon Patch), galantamine (Razadyne) may help increase the neurotransmitter acetylcholine, which may improve memory and cognitive function
- Antipsychotics such as clozapine (Clozaril), quetiapine (Seroquel), aripiprazole (Abilify)
- Antidepressants such as venlafaxine (Effexor), paroxetine (Paxil, Seroxat), sertraline (Zoloft), fluoxetine (Prozac, Sarafem)
- Benzodiazepines for anxiety and sleep such as clonazepam (Klonopin)
- Dopamine precursors for Parkins
What Are Complications of Lewy Body Dementia?
Complications of Lewy body dementia include:
- Severe dementia and memory loss
- Immobility
- Poor nutrition
- Swallowing difficulties
- Depression
- Increased risk of falling due to balance problems
- Aggressive behavior
- Worsening Parkinson’s-like symptoms