Dementia with Lewy bodies

Dementia with Lewy bodies is the second most frequent cause of hospitalization for dementia, after Alzheimer's disease.


Current estimates are that about 60 to 75% of diagnosed dementias are of the Alzheimer's and mixed (Alzheimer's and vascular dementia) type, 10 to 15% are Lewy Bodies type, with the remaining types being of an entire spectrum of dementias including frontotemporal, Pick's disease, alcoholic dementia, pure vascular dementia, etc.

Dementia  :- Dementia is progressive decline in cognitive function due to damage or disease in the brain beyond what might be expected from normal aging

Particularly affected areas may be memory, attention, language and problem solving, although particularly in the later stages of the condition, affected persons may be disoriented in time (not knowing what day, week, month or year it is), place (not knowing where they are) and person (not knowing who they are).

Multi-infarct dementia :- Multi-infarct dementia, also known as vascular dementia, is a form of dementia resulting from brain damage caused by stroke or transient ischemic attacks (also known as mini-strokes)..

Multi-infarct dementia is one type of vascular dementia. Vascular dementia is the second most common form of dementia after Alzheimer's disease (AD) in older adults. Multi-infarct dementia (MID) is thought to be an irreversible form of dementia, and its onset is caused by a number of small strokes or sometimes, one large stroke preceded or followed by other smaller strokes. The term refers to a group of syndromes caused by different mechanisms all resulting in vascular lesions in the brain. Early detection and accurate diagnosis are important, as vascular dementia is at least partially preventable.

 

The main subtypes of this disease are: mild cognitive impairment, multi-infarct dementia, vascular dementia due to a strategic single infarct (affecting the thalamus, the anterior cerebral artery, the parietal lobes or the cingulate gyrus), vascular dementia due to hemorrhagic lesions, and mixed Alzheimer's and vascular dementia.

Vascular lesions can be the result of diffuse cerebrovascular disease or focal lesions; usually both. Mixed dementia is diagnosed when patients have evidence of AD and cerebrovascular disease, either clinically or based on neuroimaging evidence of ischemic lesions. In fact vascular dementia and Alzheimer's disease often coexist, especially in older patients with dementia.

Parkinson's disease :- Parkinson's disease (paralysis agitans or PD) is a neurodegenerative disease of the substantia nigra, an area in the basal ganglia of the brain.

The disease involves a progressive disorder of the extrapyramidal system, which controls and adjusts communication between neurons in the brain and muscles in the human body.

It also commonly involves depression and disturbances of sensory systems.

Hallucination :- A hallucination is a sensory perception experienced in the absence of an external stimulus, as distinct from an illusion, which is a misperception of an external stimulus.    

Hallucinations may occur in any sensory modality - visual, auditory, olfactory, gustatory, tactile, or proprioceptive (sense of balance and position in space).

Psychological research has presented the idea that hallucinations may result from biases in what are known as metacognitive abilities.

These are abilities that allow us to monitor or draw inferences from our own internal psychological states (such as intentions, memories, beliefs and thoughts).

The ability to discriminate between self-generated and external sources of information is considered to be an important metacognitive skill and one which may break down to cause hallucinatory experiences.