L2 Alzheimer's Disease and Dementia Flashcards
Briefly describe dementia.
Dementia is an umbrella term for a number of things - it is a syndrome not a diagnosis.
Symptoms include memory loss, problem-solving or language.
Dementia is progressive.
Who discovered Alzheimer’s and how?
Alois Alzheimer. In 1901-5, he discovered a young woman called Auguste D in a Frankfurt asylum suffering from memory loss, disorientation, hallucinations and delusions. A post-mortem of Auguste D showed a thinned cerebral cortex, senile plaque (previously only seen in older people) and neurofibrillary tangles.
What is Braak Staining?
This is a method of pathologically defining Alzheimer’s by using the spatiotemporal pattern of neurofibrillary degeneration.
Shading is used on an image of the brain to indicate the distribution of NFTs (neurofibrillary tangles) with darker shades representing increasing densities.
What do you need to do in order to diagnose AD?
You need to pathalogically prove it. You need to discover the presence of plaques and tangles in the brain as well as the psychological symptoms seen in life.
Describe the overlap between AD and Parkinson’s. What does this mean?
- Approximately 25% of all patients with AD develop parkinsonism.
- 50% of all cases of PD develop AD-type dementia after 65 years of age.
- 70% of patients with sporadic AD display PD pathology.
This means that it is very hard to determine diagnosis.
What is the 1984 NINCDS – ADRDA criteria for AD? Why is this a problem?
1) The clinical diagnosis of AD could only be designated as ‘probably’ while the patient was alive and could not be made definitely until AD is confirmed as the post-mortem.
2) The clinical diagnosis of AD could be assigned only when the disease had advanced to the point of causing significant functional disability and met the threshold criterion of dementia.
This is a problem because you have to wait a certain amount of time for someone to deteriorate before you can say they have AD.
Describe the psychiatric changes in AD.
- Anxiety and withdrawal form social activity (most common change).
- Inattentiveness, mild cognitive dulling, social and emotional withdrawal and agitation.
- Apathy and disengagement.
- Delusions and hallucinations (these are psychotic symptoms).
- Agitation and anxiety.
What is the new criteria for AD? (Updated in 2014).
The presence of an early and significant episodic memory impairment (isolated or associated with other cognitive or behavioural changes that are suggestive of a mild cognitive impairment that includes the following features:
a) Gradual and progressive change in memory function reported by the patients or informant over more than 6 months.
b) Objective evidence on an amnestic syndrome of the hippocampal type.
What in vivo evidence of Alzheimer’s pathology do you need in order to diagnose AD?
You only need two of the following:
1) Decreased Abeta1-42 together with increased T-tau or P-tau in the CSF.
2) Increased tracer retention on amyloid PET.
3) AD autosomal dominant mutation in PSEN1, PSEN2 or APP. Note these conditions are very rare (5% of cases).
What are some exclusion criteria for AD diagnosis and why are they used?
- Sudden onset.
- Early occurrence of gait disturbances, seizures, major and prevalent behavioural changes.
- Early hallucinations.
These are used because even though these symptoms are seen in AD, they occur at much later stages so you would not expect to see them at the point of diagnosis.
What does AD in the preclinical (before appearance of symptoms) or prodromal stage (period between appearance of symptoms and full development of the disease) both require?
Presence of amyloid in the brain as shown from a scan.
What is AD classified as? What does this mean?
It is classified as posterior dementia. This means that you get temporal and parietal lobe involvement, but no frontal love involvement.
What is a typical clinical feature of AD and what is it followed by?
Amnestic Syndrome is where you have early degeneration of the medial temporal lobe before the degeneration spreads. This is followed by Selective Amnesia (language impairments), Complex Attention (divided and selective attention switching), Visuospatial (sustained attention and executive functioning skills) and finally a global deficit.
What are the other variants of AD?
- Visual variant = areas affected include posterior occipitoparietal, occipitotemporal or (more rarely) the primary visual cortex.
- Linguistic variant = lateral temporal regions.
- Vascular/Mixed Dementia = where the white matter in the brain has poor blood supply so as you get older you see silent strokes that slow the processing speed of the brain.
- Dementia with Lewy Bodies = instead of being caused by abnormal amyloid or Tau, the Lewy bodies are caused by alpha-synuclein (the same protein that causes PD).
What is FMD?
Functional Memory Disorder. This is a dysfunction of memory that significantly affects their professional and/or private life. There is a psychosocial burden and significant psychological stress.
Patients have low verbal memory and attentional capacity that appears in the absence of cognitive impairment major psychiatric disease (e.g. severe depression).
