Dementia

Resident Survival Guide

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: Fahimeh Shojaei, M.D.

Synonyms and keywords: dementia

Overview

Dementia is an acquired cognitive impairment in different cognitive areas such as attention, learning, memory, language, executive function, and motor function. Dementia may be classified according to the etiology into 5 groups including neurodegenerative, vascular, infectious, drug-related, and metabolic. The most common causes of dementia include alzheimer's Disease, parkinson's Disease, binswanger's Disease, dementia with Lewy bodies, frontotemporal lobar degeneration,thiamine deficiency,vitamin B12 deficiency, vitamin B6 deficiency, vascular dementia, marijuana abuse, AIDS neurosyphilis, and normal pressure hydrocephalus.

Classification

Dementia may be classified according to the etiology into 5 groups including neurodegenerative, vascular, infectious, drug-related, and metabolic.

Causes

Dementia may be caused by:

• Alzheimer's Disease
• Parkinson's Disease
• Binswanger's Disease
• Dementia with Lewy bodies
• Frontotemporal lobar degeneration
• Thiamine deficiency
• Vitamin B12 deficiency
• Vitamin B6 deficiency
• Vascular dementia
• Marijuana abuse
• AIDS
• Neurosyphilis
• Normal pressure hydrocephalus

Differential Diagnosis

Dementia causes must be differentiated from each other:

Cause of dementia	Clinical features											Associated features	Nature of progression	Histopathological findings
	Cognitive impairment
	Recall	Recollection	Cue requirement for recall	Infirngement of thoughts	Semantic memory	Procedural memory	Working memory	Awareness	Attention	Executive functioning issues	Visuo-spatial skills
Alzheimer's disease	+++ (Slow cognitive and functional decline with early loss of awareness)	+++	Not helpful	+++	++	-	++	+++	++	++	++	Focal neurological signs absent during early stage (may develop later) Mild extrapyramidal signs	Has the following clinical stages: Pre-clinical Mild cognitive impairment Advanced dementia (full blown dementia)	Neurofibrillary tangles Senile (neuritic) plaques
Lewy body dementia	++	-	Helpful	+++	+	+	+++	+	+++	+++	+++	Focal neurological signs present in the majority Strongly associated with extrapyramidal signs Autonomic changes	Early visual hallucinations Muscle rigidity Sleep disturbance	α-synuclein deposits present in neurons
Frontotemporal lobar degeneration	+/-	-	Helpful	+++	+	-	+++	+++	++	+++	-	Focal neurological signs present (motor neuron disease) Extrapyramidal signs present (familial frontotemporal lobar degeneration) Onset in young age Strong familial association Focal atrophy of frontal and temporal lobes Knife-edge atrophy noted on MRI Personality and behavioral changes Language impairment	Two major variants: Progressive nonfluent aphasia Semantic variant Progressive supranuclear palsy	Pick bodies Corticobasal degeneration Ubiquitinated inclusions
Vascular dementia	+ (Dysexecutive syndrome)	-	Helpful	+	+	+	++	-	++	+++	+	Focal neurological signs present typically Mild extrapyramidal signs Depression Mild motor signs in subcortical vascular dementia Slowed processing speed Presentation might be similar to Alzheimer's disease	Stepwise progression and focal neurologic signs (also known as multi-infarct dementia or poststroke dementia)	Multifocal and/or diffuse lesions (lacunes and microinfarcts) The following brain areas may be involved: Subcortical area Thalamus Frontobasallimbic system White matter lesions Hippocampal sclerosis Diffuse post-ischemic lesions
Normal pressure hydrocephalus
Parkinson's disease
Binswanger's disease
Thiamine deficiency
Marijuana abuse
AIDS
Neurosyphilis
Vitamin B12 deficiency
Vitamin B6 deficiency

References