Lewy body dementia can occur alone or with other neurodegenerative conditions such as Alzheimer's or Parkinson's disease. It is the second most frequent cause of dementia in elderly adults and is associated with abnormal structures called Lewy-bodies found in certain areas of the brain.
Lewy bodies are abnormal protein deposits — smooth, round lumps in the nerve cells of the brain — that disrupt the brain's normal functioning. They're found throughout the outer layer or cerebral cortex of the brain and deep inside the midbrain and brainstem.
Frederich Lewy, a neurologist and contemporary of Alois Alzheimer, first identified these abnormal protein deposits in 1912.
Researchers don't yet understand if dementia with Lewy bodies is a distinct disease or a variation of Alzheimer's or Parkinson's disease. Symptoms can mimic those of Parkinson's disease such as loss of spontaneous movement or bradykinesia;, rigidity or stiff muscles that resist movement; tremor, and shuffling gait, or appear similar to those of Alzheimer’s disease, such as acute confusion, loss of memory, and loss of or fluctuating ability to comprehend information.
Symptoms of Lewy body dementia include:
Unlike Alzheimer’s disease, which tends to progress gradually, this disease often starts rapidly, with a fast decline in the first few months. Later, there may be some leveling off but Lewy body dementia typically progresses faster than Alzheimer's. A patient can survive from five to seven years with the disease.
Lewy body dementia is difficult to diagnose because its symptoms are similar to other conditions. An extensive neurological and neuropsychological evaluation will be conducted, including brain imaging in an effort to identify degeneration of the brain.
As with many dementias, a definitive diagnosis can only be made with an autopsy when Lewy bodies in brain tissue can be seen.
In addition to the most common symptoms, patients with Lewy body dementia may experience the following:
Because there is no cure for Lewy body dementia, doctors try to treat and manage symptoms of the disease. Medications used to treat Alzheimer's and Parkinson's disease have been effective in some patients but must be closely monitored because patients with Lewy body dementia tend to be highly sensitive to drugs that affect the brain and can experience adverse side effects.
Medicatiions are usually initially administered at a low dose and slowly increased over time.
Tranquilizers and anti-psychotic drugs such as haloperidol or thioridazine, are sometimes used to help lessen symptoms such as agitation or hallucinations.
Patients have been especially responsive to cholinesterase inhibitors, used to treat Alzheimer's, to improve memory and cognition and reduce hallucinations.
The drug Levodopa or other Parkinson's disease medications may be given to treat the Parkinson's disease-like symptoms, to improve muscle stiffness and improve walking.
Reviewed by health care specialists at UCSF Medical Center.