What is Dementia with Lewy Bodies?
Dementia with Lewy bodies (DLB) is a loss of cognitive abilities in the elderly whose nerve cells contain abnormal aggregates of protein. These same protein aggregates are also found in patients with Alzheimer’s disease and Parkinson’s disease. In post mortem brain biopsies, the neurons of individuals with DLB reveal clumps of alpha-synuclein and ubiquitin protein under the microscope. It’s been estimated that DLB is responsible for 10 to 15 percent of all dementia in the elderly. As many as 1.3 million people may suffer from DLB in the U.S.
Dementia with Lewy Bodies is also called Lewy body dementia, diffuse Lewy body disease, cortical Lewy body disease, and senile dementia of Lewy type.
What Are Lewy Bodies?
Lewy bodies are abnormal aggregates of alpha-synuclein, ubiquitin and other proteins that develop inside nervous tissue. They were first detected by the German neurologist Frederick Lewy in 1912. Dr. Lewy was a colleague of Alois Alzheimer, the German neuropathologist who gave his name to the senile dementia characterized by short term memory loss and other behavioral changes.
Lewy bodies were first identified in post mortem brain studies of Parkinson’s disease patients. They are also found in the brains of sufferers from multiple system atrophy (MSA), and Alzheimer’s disease. In these three types of dementia, Lewy bodies are restricted to particular parts of the brain whereas in Lewy body dementia, Lewy bodies are more widely distributed throughout the brain.
What Causes Lewy Body Dementia?
The precise causes ofDLB are unknown. While scientists do not suspect a strong genetic connection, there is some evidence that the disease is associated with the PARK11 gene, also linked to Parkinson’s disease.
What Are the Signs and Symptoms of Lewy Body Dementia?
There’s a great deal of variation in how DLB manifests from individual to individual. Nonetheless, most patients with this disorder show disturbances related to memory, language abilities, cognitive reasoning and the ability both to judge simple distances and to carry out simple commands. Parkinson’s-like motor dysfunction is also characteristic of the disease including shuffling gait, a greatly reduced range of facial expressions, stiff movements and a characteristic palsy known as “cogwheeling.” Occasionally, fluctuations in autonomic processes such as changes in heart rate and blood pressure can occur.
One of the most disturbing aspects of Lewy body dementia is that individuals afflicted with it actively hallucinate, seeing people and things who aren’t there such as people in chairs and pets on beds.
Symptoms are characterized by exacerbations and remissions that can fluctuate over very short time intervals. Over the years this has led to the suspicion on the part of many caregivers that people with DLB
How a Diagnosis of Lewy Body Dementia Is Made
Since the definitive diagnosis of DLB can only be made after a patient’s death when the abnormal brain proteins are identified, diagnosis relies upon deductive criteria.
A pattern of falls and vasovegal episodes (syncope), delusions and hallucinations and extreme sensitivity to antipsychotic medications are all strongly suggestive of the Lewy body dementia diagnosis.
Lewy Body Dementia Treatment
As of yet there is no medical treatment specifically targeted at the underlying causes of Lewy body dementia. Management, therefore, is based on alleviating symptoms associated with the disease.
Cholinesterase inhibitors are sometimes prescribed to minimize the Parkinson’s-like motor ability dysfunctions, but these frequently have the effect of worsening the hallucinations and delusions associated with the disease. Similarly, the neuroleptic drugs prescribed for managing psychiatric symptoms may worsen motor symptoms although low doses of atypical antipsychotics, such as quetiapine, have been found to be helpful in managing these patients.
Lewy body dementia is progressive; over time, patients become incapable of caring for themselves. Good care giving depends on customizing the patient’s schedule, activities and home environment to accommodate to his or her diminishing motor abilities and psychiatric hygiene. The burden on caregivers can be immense. Changes in routine can often trigger behavioral changes.
Six Things To Know About Lewy Body Dementia
- The disease is characterized by the presence of abnormal proteins called Lewy bodies inside the brain.
- Lewy body disease is difficult to distinguish from Parkinson’s disease and Alzheimer’s disease.
- The symptoms of Lewy body dementia include hallucinations, motor dysfunction, delusions, cognitive impairments, disturbances in autonomic processes, depression and anxiety.
- Lewy body dementia is most in males over 65. Patients may live as long as eight years after the onset of symptoms.
- There is no cure for Lewy body dementia. Treatment of the disease is geared towards managing the symptoms.