D E M E N T I AD E M E N T I A

• Q:Q: What other types of dementia are What other types of dementia are there?there?

• Q:Q: Do they have the same Do they have the same pathophysiology as pathophysiology as Alzeimer Alzeimer dementia?dementia?

D E M E N T I AD E M E N T I A

Dementia is a syndrome due to disease of Dementia is a syndrome due to disease of the brain, usually of a chronic or the brain, usually of a chronic or progressive nature in which there is progressive nature in which there is disturbance of multiple cortical functions, disturbance of multiple cortical functions, calculations, learning capacity, language calculations, learning capacity, language and judgement. Consciousness is not and judgement. Consciousness is not clouded. Impaired cognitive function are clouded. Impaired cognitive function are commonly accompanied by and occasionally commonly accompanied by and occasionally preceded by deterioration in emotional preceded by deterioration in emotional control, social behavior and motivation.control, social behavior and motivation.

(World Health Organization, as cited in McCance & Huether, 2006)(World Health Organization, as cited in McCance & Huether, 2006)

D E M E N T I AD E M E N T I AClassification is based onClassification is based on

Etiologic factors:Etiologic factors:

• TraumaTrauma• TumoursTumours• Vascular Vascular

DisordersDisorders• InfectionsInfections

Location:Location:

• CorticalCortical• SubcorticalSubcortical• CombinedCombined

Cortical/SubcorticalCortical/Subcortical

(McCance & Huether, (McCance & Huether, 2006)2006)

Cortical DementiasCortical Dementias

Alzheimer DiseaseAlzheimer Disease

Pick DiseasePick Disease

(Cummings & Benson, 1992, as cited in McCance & (Cummings & Benson, 1992, as cited in McCance & Heuther, 2006)Heuther, 2006)

Subcortical DementiasSubcortical Dementias

Extrapyramidal Syndromes:Extrapyramidal Syndromes:• Parkinson Disease, Huntington Disease,Parkinson Disease, Huntington Disease,

Progressive supranuclear palsy, Wilson Progressive supranuclear palsy, Wilson Disease, Spinocerebellar degeneration, Disease, Spinocerebellar degeneration, idiopathic basal ganglia calcificationidiopathic basal ganglia calcification

HydrocephalusHydrocephalusDementia Syndromes of DepressionDementia Syndromes of Depression

(Cummings & Benson, 1992, as cited in McCance & (Cummings & Benson, 1992, as cited in McCance & Heuther, 2006)Heuther, 2006)

Subcortical DementiasSubcortical Dementias

Toxic and Metabolic encephalopathies:Toxic and Metabolic encephalopathies:• Systemic illness, endocrinopathies, Systemic illness, endocrinopathies,

deficiency states, drug intoxication, deficiency states, drug intoxication, heavy metal exposure, industrial heavy metal exposure, industrial dementiasdementias

(Cummings & Benson, 1992, as cited in McCance & (Cummings & Benson, 1992, as cited in McCance & Heuther, 2006)Heuther, 2006)

Combined Combined Cortical/SubcorticalCortical/Subcortical

DementiasDementias Multiinfarct dementiaMultiinfarct dementia

Infectious dementiaInfectious dementia• AIDS,, KuruAIDS,, Kuru

(Cummings & Benson, 1992, as cited in McCance & (Cummings & Benson, 1992, as cited in McCance & Heuther, 2006)Heuther, 2006)

D E M E N T I AD E M E N T I A

• Q:Q: What other types of dementia are What other types of dementia are there?there?

A: NUMEROUS!A: NUMEROUS!

• Q:Q: Do they have the same Do they have the same pathophysiology as pathophysiology as Alzeimer Alzeimer dementia?dementia?

Compare & Contrast:Compare & Contrast:Pathophysiology of Pathophysiology of

DementiaDementia• Alzheimer Disease Alzheimer Disease • Vascular DementiaVascular Dementia

• Frontotemporal Lobe DementiaFrontotemporal Lobe Dementia• Creutzfeldt-Jakob DiseaseCreutzfeldt-Jakob Disease

• Parkinson DiseaseParkinson Disease• Dementia with Lewy BodiesDementia with Lewy Bodies

Alzheimer DiseaseAlzheimer Disease

• Formation of Formation of neurofibrillary tanglesneurofibrillary tangles d/t d/t the chemical changes in tau (cause the chemical changes in tau (cause unknown)unknown)

• Normally, tau stabilizes microtubules of Normally, tau stabilizes microtubules of the healthy neuronthe healthy neuron

• Threads of tau clump together and tangleThreads of tau clump together and tangle• Result: Microtubules disintegrate = Result: Microtubules disintegrate =

breakdown of transportation and breakdown of transportation and communication with other neurons, communication with other neurons, leading to neuron deathleading to neuron death

(Linton & Lach, 2006)(Linton & Lach, 2006)

Alzheimer DiseaseAlzheimer Disease

• Beta amyloid plaquesBeta amyloid plaques form when form when amyloid precursor protein (APP – amyloid precursor protein (APP – important for neuron survival) becomes important for neuron survival) becomes fragmented and clumps together in fragmented and clumps together in diffuse plaques (cause unknown)diffuse plaques (cause unknown)

(Linton & Lach, 2006)(Linton & Lach, 2006)

Vascular DementiaVascular Dementia

• Disruption of neural systems Disruption of neural systems responsible for cognition d/t ischemia, responsible for cognition d/t ischemia, hemorrhagic brain lesions and hemorrhagic brain lesions and hypoperfusionhypoperfusion

• Hemorrhage or ischemia result in Hemorrhage or ischemia result in necrosis or cavitation (the formation of necrosis or cavitation (the formation of cavities) of brain tissuecavities) of brain tissue

• Also evidence of atherosclerotic diseaseAlso evidence of atherosclerotic disease• Risk factors include: HTH, DM, cardiac Risk factors include: HTH, DM, cardiac

abnormalities, hyperlipidemia, smokingabnormalities, hyperlipidemia, smoking

(Linton & Lach, 2006)(Linton & Lach, 2006)

Frontotemporal Lobe Frontotemporal Lobe DementiaDementia

3 Pathological Presentations3 Pathological Presentations

1.1. Abnormal accumulations of tau proteins Abnormal accumulations of tau proteins in neurons and glial cellsin neurons and glial cells

2.2. Tau negative but ubiquitin protein Tau negative but ubiquitin protein positive inclusions in areas of the brainpositive inclusions in areas of the brain

3.3. Presences of frontotemporal lobe Presences of frontotemporal lobe dementia with no distinctive pathologydementia with no distinctive pathology

(Linton & Lach, 2006)(Linton & Lach, 2006)

Creutzfeld-Jacob DiseaseCreutzfeld-Jacob Disease

• Conversion of normal prion proteins Conversion of normal prion proteins in the brain into abnormally shaped in the brain into abnormally shaped protease-resistant prion proteinsprotease-resistant prion proteins

• Results in neuronal dysfunction and Results in neuronal dysfunction and neuronal deathneuronal death

(Linton & Lach, (Linton & Lach, 2006)2006)

Parkinson DiseaseParkinson Disease

• Degeneration of basal ganglia and Degeneration of basal ganglia and extrapyramidal nervous systemextrapyramidal nervous system

• Loss of dopaminergic neurons in Loss of dopaminergic neurons in substantia nigra causes a series of substantia nigra causes a series of circuitry changes in the basal ganglia circuitry changes in the basal ganglia that lead to motor disturbancesthat lead to motor disturbances

(Linton & Lach, (Linton & Lach, 2006)2006)

Dementia with Lewy Dementia with Lewy BodiesBodies

• Occurring in the cerebral cortex, a Occurring in the cerebral cortex, a Lewy body is a inclusion in a neuron Lewy body is a inclusion in a neuron composed of the protein alpha- composed of the protein alpha- synucleinsynuclein

(Linton & Lach, 2006)(Linton & Lach, 2006)

D E M E N T I AD E M E N T I A

• Q:Q: What other types of dementia are What other types of dementia are there?there?A: NUMEROUS!A: NUMEROUS!

• Q:Q: Do they have the same Do they have the same pathophysiology as pathophysiology as Alzeimer dementia?Alzeimer dementia?A:A: No. Multiple etiological factors result No. Multiple etiological factors result in in multiple pathophysiological multiple pathophysiological processes. Yet, processes. Yet, relationships between relationships between various assaults to the various assaults to the brain do exist.brain do exist.

(Linton & Lach, 2006)(Linton & Lach, 2006)

D E M E N T I AD E M E N T I A

For example:For example:• Alzheimer disease often co-exists with Alzheimer disease often co-exists with

vascular dementia or Parkinson diseasevascular dementia or Parkinson disease

Also – a common themes: Also – a common themes: Problematic proteins!Problematic proteins!• Abnormal protein Abnormal protein

deposits/accumulations/clumpsdeposits/accumulations/clumps• Protein resistance and chemical changesProtein resistance and chemical changes• Change in shape/fragmentationChange in shape/fragmentation

(NIH/National Institute on Aging, 2007)(NIH/National Institute on Aging, 2007)

REFERENCESREFERENCESLinton, Adrienne Dill. Linton, Adrienne Dill. Matteson’s & McConnell’s Matteson’s & McConnell’s

Gerontological Concepts and Practice, 3rd EditionGerontological Concepts and Practice, 3rd Edition. Saunders . Saunders Book Company.Book Company.

NIH/National Institute on Aging (2007, June 14).Mix Of Disease Processes Found In Brains of Most People With Dementia. ScienceDaily. Retrieved January 28th 2009 from http://www.sciencedaily.com/releases/2007/06/070613163300.htm

McCance, K.L., & Huether, S.E. (2006). McCance, K.L., & Huether, S.E. (2006). Pathophysiology: The Pathophysiology: The biological basis for disease in adults and children (5th ed.)biological basis for disease in adults and children (5th ed.). . St.Louis, MI: Elsevir MosbySt.Louis, MI: Elsevir Mosby