Lewy body disease


Dementia with Lewy bodies is a neurodegenerative disease with the accumulation of alpha-synuclein proteins in the cytoplasm of neurons and neuroglia.

Eosinophilic cytoplasmic neuron inclusions with aggregates of normal and abnormal proteins.

Initially presents as a cognitive disorder.

Along with Parkinson’s disease, accounts for dementia with Lewy bodies responsible for 10-15% of cases of dementia.

Progressive dementia that develops within 1 year of the onset of clinical signs of Parkinsonism.

Accumulation of Lewy bodies in the deep cortical layers, particularly the anterior frontal and temporal lobes and in the nuclei of the brainstem.

Lewy bodies in neocortical and paralimbic regions.

Many patients with dementia with Lewy bodies also have cortical amyloid plaques as seen in Alzheimer’s disease.

Dementia with Lewy bodies associated with neurochemical changes with decreased choline acetyltransferase.

Patients with dementia with Lewy bodies have increased number of functioning cortical postsynaptic muscarinic receptors, so that these receptors are more responsive to acetylcholine than in patients with Alzheimer’s dementia.

Also associated with dopaminergic deficits.

Diagnosis of dementia with Lewy body disease is primarily clinical without a definitive laboratory or diagnostic test.

Early symptoms are impaired attention, executive functioning, and visual-spatial abilities, followed by memory loss.

It is characterized by chronic rapid eye movement behavior disorder with early visuospatial impairment and Parkinsonism and frontoparietal dementia, characterized by a behavior variant or less often, a language impairment variant.

Most commonly patient exhibits disinhibition and the language impairment is semantic dementia in which the meaning of the patient’s speech is unclear.

Patients with dementia with Lewy bodies score poorly on Mini Mental State Examinations (MMSE) on areas involving attention, construction and clock drawing.

Dementia with Lewy bodies core features are cognitive fluctuations, visual hallucinations and Parkinsonism, and the presence of two of these features is required to establish the diagnosis.

Dementia with Lewy bodies associated with fluctuations in alertness and attention lasting from minutes to days, and is highly suggestive of the diagnosis.

Dementia with Lewy bodies associated with pseudodelerium of fluctuating alertness and attention in 50-75% of patients.

Visual hallucinations occur with 80% of patients with dementia with Lewy bodies.

A reduced sense of smell and increased CSF alpha-synuclein are tied to the diagnosis of Lewy body disease.

Dementia with Lewy bodies associated with daytime drowsiness, lethargy and episodes of disorganized speech.

Hallucinations may be vivid, pleasurable, and benign.

Associated with Parkinson’s disease in 75% of cases.

Dementia with Lewy bodies suggested by the presence of rapid eye movement sleep behavior disorder, low dopamine transporter activity, and neuroleptic sensitivity.

Dementia with Lewy bodies associated with REM sleep disorder is manifested by vocalizing and moving around in about 50% of patients, and usually precedes dementia.

Neuroleptic sensitivity to D2 receptor blocking agents such as haloperidol suggest the diagnosis of dementia with Lewy bodies.

Dementia associated with autonomic dysfunction occurs early in the disease process and cause hypotension with repeated falls, syncope, neurocardiovascular instability, incontinence, impotence, and impaired swallowing.

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