- What is Lewy Body Disease?
- What are the symptoms of DLBD?
- Diagnosing DLBD
- Treatment options
- Current research in LBD
- Useful Resources
What is Lewy Body Disease?
Lewy Body Disease (LBD) is a form of dementia characterized by a loss of two different types of neurons; those that produce acetylcholine (cholinergic) and those that produce dopamine. The clinical expression of this situation is a loss of cognitive function similar to Alzheimer's Disease (AD) and a deficit in motor function that resembles Parkinson's Disease (PD). In the United States alone, LBD affects 1.3 million people. The disease is more prevalent in people between the ages of 50 and 85 and affects both men and women in equal proportions. There is no known cure. Treatment is focused on treating the symptoms. Lewy Body Disease is progressive, meaning it gets worse with time.
Other names for LBD include diffuse Lewy Body Disease (DLBD), senile dementia of Lewy type, cortical Lewy Body Disease and Dementia with Lewy Bodies (DLB). The condition was first defined in 1912 by Dr Friedrich Heinrich Lewy (1885-1950), a German neurologist. Lewy discovered spherical inclusions in the brains of people who had had Parkinson's disease. These bodies contained clumps of the proteins ubiquitin and alpha synuclein.
What is Dementia?
Dementia may be defined as a change in abilities that is more than would be expected from normal aging. Loss of function is severe enough to profoundly affect normal activities and relationships with other people. Approximately ten percent of all dementia is of this type. The overlap in clinical expression with both AD and PD makes this condition difficult to diagnose.
What are the symptoms of LBD?
The disease is characterized by loss of memory, confusion, muscle stiffness, problems with posture and movement, hallucinations (usually seeing people or animals that are not there), changes in attention and alertness and a condition called REM sleep behaviour disorder; acting out dreams. This latter symptom may occur up to 40 years before diagnosis as LBD and could possibly be an early signal of neurodegenerative disease. However, not everyone who acts out their dreams has LBD. Symptoms of Lewy Body Disease may fluctuate. For example, a person may be perfectly able to operate a microwave oven in the morning, haven't a clue of how to use it at lunchtime and then be able to use it correctly again at dinner time.
A definitive diagnosis of LBD is confirmed by the presence of Lewy Bodies during post mortem examination of the brain. Clinical features that help distinguish the disease from AD or PD are the presence of fluctuations, hallucinations and the trembling and stiffness associated with Parkinson's.
As indicated earlier, there is no cure for LBD. Treatment is palliative and consists of pharmaceutical and caregiving support. In terms of medication, a delicate balance must be struck between treating the cognitive/emotive symptoms and managing motor symptoms. Treating the hallucinations and psychosis may make the movement dysfunction worse, while treating the movement disorder may worsen cognitive and emotive symptoms.
Cholinesterase inhibitors may be used to treat cognitive problems. Options in this class include donepezil, rivastigmine and galantamine. Donepezil appears to be more effective in patients with DLB compared to those with Alzheimer's disease. Memantine, an NMDA-type glutamate antagonist, may also be of use. Sinemet may help with tremors and stiffness. Patients with LBD may also suffer from a condition called sialorrhea, an excess of saliva. Injecting Botulinum toxin may help with this symptom. Clonazepam may be used to alleviate REM disorder. Modanafil or methylphenidate may be used to improve mental alertness during the daytime.
Caregivers for people with LBD need to be patient, adaptable and responsive to dramatic swings between good days and bad days. Parkinsonian symptoms and mental decline may best be served through communication, adapting the home environment and adept handling of schedule and activities. Sudden changes in behavior may be triggered by changes in the living environment or schedule. Physical symptoms such as constipation, bladder infection, dehydration, injuries from falls and other problems the patient may not feel free to discuss. Keep the living environment simple and encourage exercise. Speak slowly and enunciate words carefully.
Current research in LBD
Research is currently being conducted at University Hospital in Bordeaux to detect alterations in the expression of dopaminergic and cholinergic symptoms. IVBM and DATSCAN imaging are being used here. Improvements in imaging technology may make diagnosing the condition easier and while the patient is still alive. Other studies, also in France, are investigating deep brain stimulation to improve cognitive function; memory in particular.
- Lewy Body Society - This is a registered charity charged with the mission of funding research into LBD. The Society hopes to promote a community focus for patients with LBD along with their families and caregivers. British actress, June Brown, MBE, who plays the character of Dot Branning in the popular British soap, Eastenders, is a patron of the charity.
- The Lewy Bodies information page of the National Institute of Neurological Disorders and Stroke (NINDS) is a good source of information.