Overview
Lewy body dementia is a type of dementia characterized by the buildup of protein deposits called Lewy bodies in nerve cells of the brain. These deposits impact brain regions responsible for thinking, memory, and movement. Lewy body dementia is the second most common type of dementia after Alzheimer's disease. Symptoms of Lewy body dementia can include cognitive problems, visual hallucinations, changes in alertness and attention, Parkinson's disease symptoms such as rigid muscles, slow movement, trouble walking, and tremors. Other symptoms may include trouble with sleep, varying attention, depression, and apathy. The risk factors for developing Lewy body dementia include age, sex (it affects more men than women), and a family history of Lewy body dementia or Parkinson's disease. The condition is progressive, meaning it worsens over time, and may lead to severe dementia, aggressive behavior, depression, increased risk of falling and injury, and worsening parkinsonian symptoms.
Understanding the disease
Symptoms
The symptoms of Lewy body dementia include visual hallucinations (seeing things that aren't there), movement disorders such as rigid muscles, slow movement, tremors, and Parkinson's disease symptoms, poor regulation of body functions such as sudden drops in blood pressure upon standing, dizziness, falls, loss of bladder control, and bowel issues like constipation, cognitive problems such as confusion, poor attention, visual-spatial problems, and memory loss, trouble with sleep, such as rapid eye movement (REM) sleep behavior disorder, varying attention with episodes of drowsiness, long periods of staring into space, long naps during the day, or disorganized speech, and depression or apathy.
Development
Lewy body dementia develops when protein deposits called Lewy bodies form in nerve cells in the brain. These protein deposits affect brain regions involved in thinking, memory, and movement. Lewy body dementia is also known as dementia with Lewy bodies. The buildup of Lewy bodies is associated with Parkinson's disease, and people with Lewy bodies in their brains also have the plaques and tangles associated with Alzheimer's disease. The exact cause of Lewy body dementia is not known, but age, sex, and family history are risk factors.
Assessment and Diagnosis
Triage
You should see a doctor if Lewy body dementia is suspected. Some reasons to consult a doctor include:
- If you or someone you know is experiencing symptoms such as visual hallucinations, movement disorders, poor regulation of body functions, or cognitive problems.
- If you have concerns about memory loss, confusion, poor attention, or problems with sleep.
- If you or the person you know is experiencing changes in mood, such as depression or apathy.
- If you observe sudden drops in blood pressure upon standing, dizziness, falls, loss of bladder control, or bowel issues.
- If you suspect that the person is experiencing REM sleep behavior disorder. It's important to consult a doctor for a proper diagnosis, as Lewy body dementia can be challenging to diagnose due to its similarities to other conditions like Alzheimer's disease and Parkinson's disease. A healthcare professional will assess the individual's symptoms, medical history, and perform neurological exams to determine the best course of action.
Diagnosis
To diagnose Lewy body dementia, a combination of evaluations, tests, and assessments are typically employed. While no single test can definitively diagnose Lewy body dementia, a comprehensive approach that considers the patient's symptoms, medical history, and ruling out other potential conditions can lead to a diagnosis. The following steps may be involved in the diagnostic process:
- Neurological and physical exam: A doctor will conduct a neurological exam to assess various aspects, including reflexes, strength, walking, muscle tone, eye movements, balance, and the sense of touch.
- Assessment of mental abilities: A short cognitive test can be performed to assess memory and thinking skills, but more extensive tests may be needed to differentiate Lewy body dementia from Alzheimer's disease.
- Blood tests: Blood tests can help rule out other medical conditions that may affect brain function, such as vitamin B-12 deficiency or an underactive thyroid gland.
- Brain scans: Magnetic resonance imaging (MRI) or computed tomography (CT) scans may be ordered to identify stroke, bleeding, or tumors, and to rule out other conditions like Alzheimer's disease.
- Imaging tests: Specialized imaging tests such as Fluorodeoxyglucose PET brain scans or Single-photon emission computerized tomography (SPECT) can provide additional information to help diagnose Lewy body dementia.
- Sleep evaluation: A polysomnogram may be conducted to check for REM sleep behavior disorder, and an autonomic function test can help identify signs of heart rate and blood pressure instability.
- Heart test: In some countries, myocardial scintigraphy may be ordered to assess blood flow to the heart, though this test is not used in the United States.
- Emerging biomarkers: Research continues on potential biomarkers that may enable earlier diagnosis of Lewy body dementia. It is important to note that diagnosing Lewy body dementia can be challenging, and the process may take time. A healthcare professional with experience in dementia diagnosis, such as a neurologist, may be consulted to ensure
Management and Treatment
Complications
Potential complications of Lewy body dementia include severe dementia, aggressive behavior, depression, increased risk of falling and injury, and worsening of parkinsonian symptoms such as tremors.
Preparing for medical consultation
To prepare for an appointment for Lewy body dementia, you should:
- Discuss your symptoms with a healthcare professional, who may refer you to a specialist like a neurologist or psychiatrist.
- If you're a caregiver, closely monitor the person with Lewy body dementia for any falls, loss of consciousness, or adverse reactions to medications.
- Be prepared to ask questions of doctors, social workers, and other members of the care team.
- Look after your own well-being by seeking help from friends or family, considering in-home health services, exercising, and maintaining a healthy diet.
- Consider joining a support group for caregivers or people with Lewy body dementia.
- Get blood tests to rule out any physical problems affecting brain function, such as vitamin B-12 deficiency or an underactive thyroid gland.
- Be prepared for a neurological and physical exam, which may include assessing reflexes, strength, walking, muscle tone, eye movements, balance, sense of touch, and cognitive abilities. Remember that no single test can diagnose Lewy body dementia, and the diagnosis is based on your symptoms and ruling out other conditions.