Lewy Body Disorders (LBD) were first identified in the early 1900s and diagnostic criteria were established in 1996 and revised in 2007. First, in 1912, German neurologist Friedrich Lewy observed abnormal protein deposits that disrupted the normal functioning of the brain during pathology studies on the brains of Parkinson's patients, and these deposits were later named "Lewy Bodies". Today it is known that these deposits contain a protein called alpha-synuclein.
Which Diseases Include Lewy Body Disorders?
Lewy body is not a concept belonging to a single disease, but a common name for a group of diseases. These include Parkinson's Disease, Lewy Body Dementia and Pure Autonomic Disability. Parkinson's Disease is classically characterized by resting tremor, rigidity, bradykinesia and balance problems. These symptoms are often accompanied by autonomic symptoms such as constipation, bladder dysfunction, erectile dysfunction and hyperhidrosis.
Although these symptoms used to be described as one of the Parkinson's plus syndromes in Parkinson's patients, they are also recognized as one of the Lewy Body Disorders. In all Lewy Body Diseases, there is a neuropathologic accumulation of alpha-synuclein in neurons.
What is Lewy Body Dementia?
Lewy Body Dementia is a disease that occurs with the addition of rapidly progressive dementia, hallucinations and falls to the aforementioned disorders. There are two ways in which Lewy Body Dementia can be considered together with dementia. The first one is the development path resembling Alzheimer's dementia. In this development, there is also amyloid deposition in the brain from a molecular biological point of view.
The other, different from this, is through the accumulation of alpha-synuclein. In short, Lewy Body Dementia can be said to have two forms and developmental pathways. The first one may resemble Alzheimer's disease due to the similarity of faulty protein accumulation and may cause diagnostic confusion. The second one may initially cause diagnostic confusion more in the direction of Parkinson's disease.
What are the Symptoms of Lewy Body Dementia?
In general, the following symptoms may raise suspicions about this disease:
- Fluctuations in alertness and thinking ability
- Recurrent visual hallucinations
- Parkinson's disease symptoms
- Falls
- Restlessness and agitation during the REM period of sleep, abnormal movements in bed
- Antipsychotic drugs used to treat abnormal behavior worsen symptoms
How is Lewy Body Dementia Diagnosed?
There is no definitive test for the diagnosis of Lewy Body Dementia. Neurological examination, cognitive diagnostic tests, blood tests, imaging methods do not provide definitive diagnostic information. Metabolic tests showing dopamine transport involvement in the brain support the diagnosis. Polysomnographic evaluation may support the diagnosis of REM Behavioral Disorder specific to the REM period and the diagnosis of LBD. Tests measuring autonomic functions strengthen the diagnostic suspicion. Myocardial scintigraphy can support the diagnosis by showing the rate of blood flow through the heart.
What are the Treatment Options for Lewy Body Dementia?
Cholinesterase inhibitors and Memantine as an NMDA antagonist may be useful in selected patients due to its similarity to Alzheimer's disease. As previously mentioned, the fact that antipsychotics increase symptoms is also a diagnostic factor.
REFERENCES
- Parkinson's Foundation, "Lewy Body Dementia"
- Parkinson's Foundation, "Understanding Parkinson's: Non-Movement Symptoms - Dementia"
- Parkinson's Foundation Podcast, "Episode 87: What is Lewy Body Dementia and How Does it Relate to Parkinson's?"
- Hippocrates Health Science Journal, "What is Dementia with Lewy Bodies?"