DEMENTIA
• Q: What other types of dementia are there?
• Q: Do they have the same pathophysiology as
Alzeimer dementia?
DEMENTIA
Dementia is a syndrome due to disease of the
brain, usually of a chronic or progressive nature in
which there is disturbance of multiple cortical
functions, calculations, learning capacity, language
and judgement. Consciousness is not clouded.
Impaired cognitive function are commonly
accompanied by and occasionally preceded by
deterioration in emotional control, social behavior
and motivation.
(World Health Organization, as cited in McCance & Huether, 2006)
DEMENTIA
Classification is based on
Etiologic factors:
Location:
• Trauma
• Tumours
• Vascular Disorders
• Infections
• Cortical
• Subcortical
• Combined
Cortical/Subcortical
(McCance & Huether, 2006)
Cortical Dementias
Alzheimer Disease
Pick Disease
(Cummings & Benson, 1992, as cited in McCance & Heuther, 2006)
Subcortical Dementias
Extrapyramidal Syndromes:
• Parkinson Disease, Huntington Disease,
Progressive supranuclear palsy, Wilson Disease,
Spinocerebellar degeneration, idiopathic basal
ganglia calcification
Hydrocephalus
Dementia Syndromes of Depression
(Cummings & Benson, 1992, as cited in McCance & Heuther, 2006)
Subcortical Dementias
 Toxic and Metabolic encephalopathies:
• Systemic illness, endocrinopathies, deficiency
states, drug intoxication, heavy metal exposure,
industrial dementias
(Cummings & Benson, 1992, as cited in McCance & Heuther, 2006)
Combined
Cortical/Subcortical
Dementias
 Multiinfarct dementia
Infectious dementia
• AIDS,, Kuru
(Cummings & Benson, 1992, as cited in McCance & Heuther, 2006)
DEMENTIA
• Q: What other types of dementia are there?
A: NUMEROUS!
• Q: Do they have the same pathophysiology as
Alzeimer dementia?
Compare & Contrast:
Pathophysiology of Dementia
• Alzheimer Disease
• Vascular Dementia
• Frontotemporal Lobe Dementia
• Creutzfeldt-Jakob Disease
• Parkinson Disease
• Dementia with Lewy Bodies
Alzheimer Disease
• Formation of neurofibrillary tangles d/t the
chemical changes in tau (cause unknown)
• Normally, tau stabilizes microtubules of the
healthy neuron
• Threads of tau clump together and tangle
• Result: Microtubules disintegrate = breakdown
of transportation and communication with
other neurons, leading to neuron death
(Linton & Lach, 2006)
Alzheimer Disease
• Beta amyloid plaques form when amyloid
precursor protein (APP – important for neuron
survival) becomes fragmented and clumps
together in diffuse plaques (cause unknown)
(Linton & Lach, 2006)
Vascular Dementia
• Disruption of neural systems responsible for
cognition d/t ischemia, hemorrhagic brain
lesions and hypoperfusion
• Hemorrhage or ischemia result in necrosis or
cavitation (the formation of cavities) of brain
tissue
• Also evidence of atherosclerotic disease
• Risk factors include: HTH, DM, cardiac
abnormalities, hyperlipidemia, smoking
(Linton & Lach, 2006)
Frontotemporal Lobe Dementia
3 Pathological Presentations
1. Abnormal accumulations of tau proteins in
neurons and glial cells
2. Tau negative but ubiquitin protein positive
inclusions in areas of the brain
3. Presences of frontotemporal lobe dementia
with no distinctive pathology
(Linton & Lach, 2006)
Creutzfeld-Jacob Disease
• Conversion of normal prion proteins in the
brain into abnormally shaped protease-resistant
prion proteins
• Results in neuronal dysfunction and neuronal
death
(Linton & Lach, 2006)
Parkinson Disease
• Degeneration of basal ganglia and
extrapyramidal nervous system
• Loss of dopaminergic neurons in substantia
nigra causes a series of circuitry changes in the
basal ganglia that lead to motor disturbances
(Linton & Lach, 2006)
Dementia with Lewy Bodies
• Occurring in the cerebral cortex, a Lewy body is
a inclusion in a neuron composed of the protein
alpha- synuclein
(Linton & Lach, 2006)
DEMENTIA
• Q: What other types of dementia are there?
A: NUMEROUS!
• Q: Do they have the same pathophysiology as
Alzeimer dementia?
A: No. Multiple etiological factors result in
multiple pathophysiological processes. Yet,
relationships between various assaults to the
brain do exist.
(Linton & Lach, 2006)
DEMENTIA
For example:
• Alzheimer disease often co-exists with vascular
dementia or Parkinson disease
Also – a common themes: Problematic proteins!
• Abnormal protein deposits/accumulations/clumps
• Protein resistance and chemical changes
• Change in shape/fragmentation
(NIH/National Institute on Aging, 2007)
REFERENCES
Linton, Adrienne Dill. Matteson’s & McConnell’s
Gerontological Concepts and Practice, 3rd Edition. Saunders 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). Pathophysiology: The biological basis for disease in adults
and children (5th ed.). St.Louis, MI: Elsevir Mosby