Ch 30 MCI And Ad Flashcards
Neuropathology of Alzheimer’s disease
Synaptic and neuronal loss associated with
- progressive deposition of amyloid in the form of diffuse neuritic plaques
- Accumulation of tau in the form of neurofibrillary tangles in neuropil threads
Disease progression of AD
Cell atrophy loss and reduction in the production and function of neurotransmitters: -Choline Aceto-transferase -Serotonin -Norepinephrine
Neuropathological progression of Alzheimer’s follows what spread
Temporal to frontal and eventually involves multiple brain systems
What cortex are implicated in the early stage of Alzheimer’s?
Hippocampus and entorhinal cortex in the early stage
Frontal temporal and parietal association areas with disease progression
Temporal lobe and association areas where most atrophy occurs
What structures are relatively spared until the late stage in Alzheimer’s?
Primary motor, visual, auditory, somatosensory cortices are relatively unaffected until the end
Suspected non-Alzheimer pathophysiology SNAP
Biomarker evidence of neurodegeneration without prominent presence of amyloid
Primary age related Tauopthy (PART)
Cognitive impairment with Alzheimer’s like onset but slow clinical progression
What is the single largest risk factor for Alzheimer’s?
Agr, over 65
What chromosomes are identified for early onset familial Alzheimer’s?
Chromosomes 1, 14, 21
What other condition is associated with chromosome 21?
Down syndrome
Older individuals with down syndrome typically develop plaques consistent with Alzheimer’s
Prevalence of Alzheimer’s over age 65
10%
Average age at diagnosis of Alzheimer’s
75
Mostly 70-79
Percentage of individuals over 85 meeting criteria for Alzheimer’s
50%
Race and Alzheimer’s
Blacks, Latinos more than whites
Related to cardio vascular risks, medical conditions, access and education
Percentage of patients with Alzheimer’s who have a familial variant of the disease
5%
Early onset symptoms presenting between ages 40 to 60
Average life expectancy of Alzheimer’s
Once the diagnosis made, average life expectancy is 5 to 10 years
Percentage of dementia cases accounted for by Alzheimer’s
70%
When AD strikes later in life, does it progress at a faster or slower rate?
Slower
Early stages of Alzheimer’s marked by
Insidious deficits in episodic memory
Involves acquisition and storage
Neurodiagnostic workup in cases with suspected Alzheimer’s
MRI
Biomarker blood chemistry studies
Neurologic exam
Neuropsych eval
Neuroimaging tools for diagnosing Alzheimer’s
PET scan
Amyloid imaging to identify pathology
Tau imaging
CSF analysis for amyloid and tau
What is the most predictive of progression from MCI to Alzheimer’s?
Initial severity of cognitive impairment is most predictive of progression to Alzheimer’s
Neuropsychological profile is also predictive
Which part of the brain shows to increased tracer uptake in MCI and Alzheimer’s?
Posterior cingulate and parietal regions
The correlation between degree of atrophy and level of cognitive impairment
0.5 to 0.6
What can be observed on PET or SPECT results in stage 2 Alzheimer’s
Bilateral parietal
Hypo metabolism or hypo perfusion
Medication’s for AD
Acetylcholinesterase inhibitors eg donazepil, rivastigmine, galantamine
NMDA receptor antagonists
Memantine
Chromosome 21 is related to the development of
Amyloid plaques
On which chromosome is Apoe E4 located
19
Which pathological change has the strongest relationship with cognitive decline in Alzheimer’s?
TAU
Where are neurofibrillary tangles found in the context of Alzheimer’s?
Hippocampal and amygdaloid areas, brainstem nuclei
nucleus Basilis of Meynert in the forebrain,
nucleus raphe nucleus in the midbrain, locus cerulus at the anterior Pontine level
