Disorders of Memory: Case Study: Alzheimer's Disease Flashcards
What is Alzheimer’s disease?
Alzheimer’s disease stands as a dementing illness. It is the most common of primary dementing illnesses (causing memory loss, confusion and disorientation).
What kind of condition is Alzhiemer’s?
Progressive
What is the biggest factor with Alzheimer’s?
Age
How can definite diagnosis of AD be achieved?
Can only be made on pathology (i.e. autopsy)
What can only be diagnosed in life?
Can only diagnose Dementia of the Alzheimer type
What is the ApoE (allele) mutation?
The only consistent genetic marker of increased risk of AD
What causes rare early onset of AD?
Autosomal dominant cause, mutation in 3 genes; amyloid precursor protein (APP), presenilin 1 (PSEN1), presenilin 2 (PSEN2)
What do these genes alter?
The production of amyloid β (Aβ) peptide, which is the principal component of senile plaques
How does down syndrome affect risk of AD?
People with down syndrome are unusually prone to developing AD
What can happen to people with preclinical AD and pathology to AD?
Can have sudden decompensation of AD symptoms die to a neurological injury
How is the onset of AD?
Insidious, gradual deterioration
What happens in Phase 1 of AD progress?
Failing memory (amnestic presentation), muddled inefficiency in activities of daily living (ADL), spatial disorientation, mood disturbance (agitated or apathetic)
What happens in Phase 2 of AD progress?
More rapid progress of deterioration, intellect and personality deteriorate, focal symptoms appear (dysphasia, dyspraxia, agnosia and acalculia), disturbance of posture and gait, increased muscle tome, delusion/hallucinations
What happens in Phase 3 of AD progress?
Terminal stage, profound apathy (bedridden), eventually lose neurological function, bodily wasting occurs
What are Mckhann et al’s criteria for diagnosis for AD?
Probable AD, Possible AD, Definite AD
What are the criteria for Probable AD?
Deficits in 2 or more areas of cognition; amnestic presentation is the most common. Progressive worsening of memory and/or other cognitive functions, no disturbance of consciousness, must be in the absence of other causes
What happens if a person has a deficit in only one area?
Classified as mild cognitive impairment (MCI), AD may be developed after MCI
What is the criteria of possible AD?
Made on the basis of dementia syndrome if they have variations in onset, presentation or clinical course, can be made in the presence of another disorder, which is not considered to be the cause of the dementia
What is the criteria for definite AD?
Histopathological evidence of AD obtained from biopsy or autopsy
What is the pathology of AD?
Grossly atrophied brain (shrunken); affects frontal and temporal lobes>parietal-occipital regions, extensive degeneration of neurons, accompanying glial cell proliferation, extensive amounts of senile plaques, extensive amount of neurofibrillary tangles
What is the course of neuropathological changes of AD?
Senile plaques and neurofibrillary tangles commence in the hippocampus/MTL, then spread posteriorly to the parietal cortex, then spreads to involve the frontal cortex
What do you see initially with AD?
MTL memory impairment, due to early predominance of hippocampal/MTL involvement
How is anterograde memory affect in AD?
Impaired new learning, impaired delayed recall, poor recognition memory
How is reterograde memory affected in AD?
Intact for remote memories, reduced for recent reterograde memories
When is wernicke-type aphasia due to and what is it characterised by?
Due to spread into posterior temporal lobe, word finding difficulties, fluent grammatical speech
What happens when AD spread into the parietal lobes?
Visuospatial deficits and topographical disorientation, dyspraxia, agnosia and acalcuia
What happens when AD spreads to the frontal lobes?
See behaviour change, apathy and agitation
What are treatments for AD?
Some pharmalogical treatment has been developed, trying to rebalance the action of acetylcholine. Best the medications can offer is longer plateau for better quality of life then sharp drop off
What are the differences and similarities for AD and normal aging?
Changes that occur with AD also occur in normally aging individuals but the pathological changes are considerably greater in AD, cognitive deterioration is evident in normal aging, cognitive function in DAT is significantly impaired relative to same aged peers
