Dementia With Lewy Body disease (DLB):
Dementia with Lewy Body disease is a type of Lewy Body Dementia in which it is difficult to remember new information and a loss of memory occurs. This particular type of dementia is the second most common after Alzheimer’s disorder. The age of onset can occur between the ages of 50 to 85 years old, however symptoms can start to reveal themselves when the individual is younger. Studies have shown that men are more likely to develop dementia with Lewy bodies as compared to women. Dementia with Lewy bodies occurs due to a deposit of misfolded alpha-synuclein proteins in neurons called Lewy bodies, particularly in the cortex and substantia nigra (two regions of the brain). The cortex is the outermost layer surrounding the brain and the substantia nigra is located in the midbrain and is responsible for initiating movement. Neurons in the cerebral cortex produce acetylcholine (responsible for muscle movement) while neurons in the substantia nigra produce dopamine (responsible for feelings of motivation).
Lewy Bodies:
Dr. Friedrich Lewy was a German neurologist who first discovered Lewy bodies. His findings include that in a brain which is free of disease the protein alpha-synuclein helps neurons communicate with each other. In dementia with Lewy bodies, alpha-synuclein starts forming clumps which deters neurons from communicating with each other, causing neurons to undergo apoptosis (programmed cell death). This leads to widespread damage in the brain and leads to decreased functioning in specific areas. Lewy bodies in the cerebral cortex affect perception, information processing and language capabilities. Lewy bodies in the limbic cortex affect emotion and behavior leading to the individual having mood swings and lashing out at loved ones. Lewy bodies in the hippocampus greatly affects memory which is a symptom of the early stages. Lewy bodies in the substantia nigra (located in the basal ganglia in the midbrain) affect movement. Finally, Lewy bodies in the brain stem affect sleep and alertness during the daytime.
Symptoms:
The early symptoms of dementia with Lewy bodies closely resemble those of Alzheimer’s disorder. These symptoms are detrimental to the cognitive capabilities to the brain and include:
Disorganized Speech
Difficulty focusing
Visual hallucinations
Poor Memory
Depression
Visual-spatial Problems
Apathy
Fluctuating Attention
Decreased Depth perception
The later stage symptoms are similar to the symptoms of Parkinson’s disease yet they are milder. These symptoms include:
Parkinsonism: slowness, tremors, and difficulty walking or moving hands or legs
Reduced facial expressions
Resting tremors
Autonomic Nervous System dysfunction: This part of the nervous system controls blood pressure, digestive process, sweating and is affected by DLB.
Sleep Disorders:
In certain individuals, years before they develop dementia with Lewy bodies they develop a disorder known as REM Sleep Behavior Disorder (RBD). REM(rapid eye movement) is one of the five sleep cycles characterized by vivid dreaming. It lasts for ten minutes and occurs during the first 90 minutes of sleeping and repeats as the sleep cycles repeats throughout the night. Research conducted by the National Sleep Foundation has shown that REM sleep helps an individual’s learning, memory as well as mood. Individuals dealing REM Sleep Behavior Disorder punch, yell, and scream while they are sleeping and have difficulty distinguishing their dreams from reality. If your loved one is experiencing RBD visit your doctor to check if these are the early signs of DLB.
Difference Between DLB and other Neurodegenerative Disorders:
Parkinson’s disease as well as DLB are both caused by the build up of Lewy bodies (tangled alpha-synuclein proteins in neurons). Individuals with these disorders both have movement problems yet patients dealing with Parkinson’s generally tend to keep their cognitive ability intact until the extremely late stages of the disease. DLB is also different than Alzheimer’s disorder in the sense that DLB causes hallucinations in the early stages while individuals with Alzheimer’s experience hallucinations in the later stages of the disorder. Another key distinguishing factor between DLB and both Parkinson’s and Alzheimer’s is that it is usually preceded by RBD.
Treatment:
Currently, there is no treatment for dementia with Lewy bodies however there are remedies to ease symptoms. Cognitive symptoms respond to treatments aimed at individuals dealing with Alzheimer’s such as cholinesterase inhibitors which increase acetylcholine availability. Motor symptoms respond to drugs geared toward individuals with Parkinson’s disorder such as carbidopa-levodopa (takes place of the neurotransmitter dopamine). However, carbidopa-levodopa does have its side effects. The individual can experience hallucinations, as well as other psychiatric or behavioral problems. Due to this, medical professionals prescribe this medicine in low dosages to begin with. After the initial diagnosis of DLB, the patient will benefit from having a strong support team behind them. Medical professionals such as neurologists, physical therapists, speech therapists, and occupational therapists can help the individual get on the road to recovery. Consult with your loved ones doctor before implementing any treatment methods.
References: