Dementia pathophysiology

	Dementia Microchapters
Patient Information
Overview
Classification
Causes Alzheimer's Disease; Parkinson's Disease; Binswanger's Disease; Dementia with Lewy bodies; Thiamine deficiency; Vascular dementia; Marijuana abuse; AIDS; Neurosyphilis; Normal pressure hydrocephalus; Vitamin B12 deficiency; Vitamin B6 deficiency;
Differential Diagnosis

	Dementia Microchapters
Patient Information
Overview
Classification
Causes Alzheimer's Disease; Parkinson's Disease; Binswanger's Disease; Dementia with Lewy bodies; Thiamine deficiency; Vascular dementia; Marijuana abuse; AIDS; Neurosyphilis; Normal pressure hydrocephalus; Vitamin B12 deficiency; Vitamin B6 deficiency;
Differential Diagnosis

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1];Associate Editor(s)-in-Chief: ,Sabeeh Islam, MBBS [2]

Overview

Chronic, progressive neurodegenerative disorder characterized by a global, nonreversible impairment in cerebral functioning.
Deteriorating course over up to 8-10 years.
Brain lesions are marked by neurofibrillary tangles, senile plaques, neuronal loss, and brain atrophy, with defects in acetylcholine synthesis at the cellular level.

While the pathogenesis of AD remains unclear, It is thought that dementia is the result of

Overproduction and/or decreased clearance of amyloid beta peptides
Accumulation of tau proteins
Accumulation of neurofibrillary tangles
Production of oxygen radicals and nitric oxide, and inflammatory processes
Decreased levels of cholinergic neurotransmission.
Over-excitation of the glutamate neurotransmitter system via N-methyl-D-aspartate receptors

These changes are usually present in the hippocampus, amygdala, cortex, and nucleus basalis

Genes involved in the pathogenesis of dementia include