DEMENTIA Flashcards
What is dementia?
A syndrome associated with global deterioration of intellect, behaviour and personality, often with a focus of loss of memory.
What are the two most common causes of dementia?
Alzheimer’s disease
Vascular dementia
What is the prevalence of dementia in persons aged between 50 and 70?
1%
What is the prevalence of dementia in those ages 90?
50%
What is the earliest symptom of dementia?
Loss of episodic memory for recent events
Subsequent to loss of memory, what are the symptoms associated with dementia?
Abnormal behaviour - Loss of inhibition Loss of intellect Mood changes Difficulty coping with ordinary routines Disorientation in place, time and person Loss of self-care Double incontinence Paranoia
When taking a history of dementia, what must you always do?
Take a collateral history as patient often loses insight. The collateral history should be taken away from the patient as things such as personality change are hard to discuss in front of the patient.
What are the key things to determine when taking a history from someone with suspected dementia?
Rate of intellectual decline
Specificities of decline
Activities of daily living and social interaction
Nutritional status
Drug history
General health and relevant disorders (eg stroke)
Family history of dementia
What makes up your differential diagnosis for someone presenting with progressive loss of memory and intellect?
Primary neurodegenerative disease
Metabolic disorders: Hypothyroidism, Vit B12 and folate deficiency Mitochondrial cytopathies Wilson's disease
Infection:
HIV
Prion - Creutzfeldt-Jakob disease
Syphilis
Vasculitis
Space occupying lesions
Pseudodementia (depression)
Normal pressure hydrocephalus
What routine blood tests would you do to rule out potentially treatable causes of dementia?
Thyroid function tests
Vit B12 and folate levels
WCC indicating infection
Blood cultures:
Syphilis
What specific blood tests might you perform to rule out potentially treatable causes of dementia?
Caeruplasmin - Wilson’s disease
HIV - AIDS dementia
Autoantibodies - Vasculitis and inflammatory diseases
What would CT or MRI rule out as a treatable cause of dementia?
Space-occupying lesions
Normal pressure hydrocephalus
You would also see the widespread cortical atrophy
What is normal pressure hydrocephalus?
A type of brain malfunction caused by decreased absorption of cerebrospinal fluid (CSF). Its typical symptoms are gait disturbance, urinary incontinence, and dementia or mental decline.
How is normal pressure hydrocephalus diagnosed?
CT or MRI - Enlarged ventricles without cortical atrophy
Lumbar puncture with removal of 50ml gives some symptomatic relief.
What is the most common EEG change in a dementia patient?
Widespread delta waves
What investigations should be performed if symptoms of dementia are suggestive of mitochondrial disease?
Muscle biopsy
What are the genetic diseases associated with dementia?
Huntington mutations - Huntington’s chorea
Amyloid precursor protein (APP) on chromosome 21 - Alzheimer’s disease
Presenilin 1 and 2 - Alzheimer’s disease
Apolipoprotein E4 - Alzheimer’s disease
Prion protein gene mutation - familial Creutzfedt-Jakob disease
Tau and progranulin mutations - Fronto-temporal lobe degeneration.
Which common genetic disorder is associated with Alzheimer’s and can you think why this might be?
Down syndrome patients with three copies of chromosome 21 have therefore an increased gene dosage of the amyloid precursor protein (the gene for which is also found on chromosome 21).
Down syndrome patients develop Alzheimer’s by the fourth or fifth decade of their life.
What is the underlying pathology in Alzheimer’s disease?
Presence of senile plaques and neurofibrillary tangles in the brain.
Senile plaques consist of dystrophic neurites clustered round a core of beta-amyloid protein, which is derived from the large precursor protein APP.
Also seems to an element of deficiency of acetylcholine biochemically.
What are the clinical features of dementia caused by Alzheimer’s disease?
Progressive episodic memory loss (evolving over years)
Dysphasia
Apraxia
Topographical disorientation
Seizures and myoclonus are common in late disease
Rarely any pyramidal or extra-pyramidal features
Which parts of the brain are most severely atrophic in Alzheimer’s?
Temporal lobes and hippocampus.
What are the more specific features of Alzheimer’s that younger patients present with?
Prominent visual perceptual deficits
Prominent visuospatial deficits
Both as a result of posterior cortical atrophy
Logopenic progressive aphasia
What are the treatment options for patient’s diagnosed with Alzheimer’s disease?
Acetylcholinesterase inhibitors (for moderate not for mild disease - MMSE 10-20) such as:
Donepezil
Galantamine
Rivastigmine
Memantine in moderate to severe disease, often used in conjunction with acetylcholinesterase inhibitor
What is the prognosis of someone with Alzheimer’s disease?
Very poor, most will die within 8 years. Cause of death will be bronchopneumonia.
What is dementia with Lewy bodies (DLB)?
Form of dementia associated with prominent early visual hallucinations, memory disturbance and fluctuations in the clinical course from day to day, as well as extra-pyramidal features similar to Parkinson’s.
Is memory affected in dementia with Lewy bodies (DLB)?
Yes but not as much as in Alzheimer’s disease.
What are Lewy bodies?
Lewy bodies are abnormal aggregates of protein that develop inside nerve cells.
What are the medical management options for someone diagnosed with dementia with Lewy bodies?
Acetylcholinesterase inhibitors:
Donepezil
Galantamine
Rivastigmine
Levodopa - there is a characteristic poor response to L-dopa (compared with Parkinson’s) which can help diagnosis, but it is often still prescribed to help with movement problems.
What are the side effects of the acetylcholinesterase inhibitors?
Nausea Vomiting Diarrhoea Headaches Fatigue Muscle cramps
With regard to dementia, what does FTLD stand for?
Fronto-temporal lobar dementia
What is frontotemporal lobar dementia?
Also called Pick’s disease. Dementia associated with atrophy in the frontal and anterior temporal lobes, with the parietal lobes largely spared. This is in contrast with Alzheimers disease. It is a tauopathy because it is associated with the protein tau (along with PSP and corticabasal degeneration)
What is the underlying pathology of frontotemporal lobar dementia?
Pick bodies - dark-staining aggregates of tau proteins in neurological tissue.
Is frontotemporal lobar dementia more common in men and women?
Women
What is the peak age of incidence of frontotemporal lobar dementia?
40-60 (younger than sporadic Alzheimers)
What are the medical management options for someone diagnosed with frontotemporal lobar dementia?
SSRI’s (eg sertraline) can help control loss of inhibition and overeating.
What is the prognosis for someone diagnosed with frontotemporal lobar dementia?
2-5 years
What is the second most common cause of dementia after Alzheimer’s?
Multi-infarct (vascular) dementia, although it often co-exists with Alzheimer’s.
What is multi-infarct dementia?
Dementia caused by accumulation of bilateral multi-focal ischeamic events.
What is the main risk factor for multi-infarct dementia?
Hypertension
How is the diagnosis of multi-infarct dementia made?
History - often stepwise fashion of symptom progression
Multiple areas of large vessel infarction and/or prominent small vessel disease on CT or MRI.
How is someone with diagnosed with muli-infarct dementia managed?
Control hypertension, hyperlipideamia, hypercholesterolaemia and other risk factors, using statins, and antiplatelet agents such as aspirin and dipyridamole.
