Dementia COPY Flashcards
What is dementia?
A syndrome characterised by:
- Progressive (usually irreversible) global cognitive deficit compared to baseline
- Significant impairment of normal functioning
- Definite Dx: symptoms lasting 6+ months
- Tentative Dx: symptoms lasting less than 6 months
What are the cognitive deficits seen in dementia?
- Memory impairment
- Impaired executive function
- Dysphagia
- Agnosia
- Apraxia: loss of motor function
- Personality disintegration
What is executive function?
A set of cognitive processes that enable planning, organising, and completion of tasks.
e.g. Problem solving, abstraction, reasoning, decision making, judgement, planning, organisation, processing
What are the common causes of dementia?
- Alzheimer’s disease (50-60%)
- Vascular dementia (20-25%)
- Mixed dementia
- Lewy body dementia (10-15%)
- Frontal-temporal dementia (7%)
- Other e.g. CJD, AIDS dementia, Alcohol dementia (3%)
What differential diagnoses must be excluded for a diagnosis of dementia?
- Delirium
- Depression
Name 3 reversible causes of dementia
- Subdural haematoma
- Normal pressure hydrocephalus
- Chronic alcohol misuse
- Metabolic
- Vitamin B12 deficiency
- Hypothyroidism
- Hypoglycaemia
- Neurosyphilis
What is the characteristic of fronto-temporal cortical dementia?
Prominent personality change, may manifest as frontal lobe syndrome
Describe the prevalence of dementia?
- 830,000 in the UK
- Over 65: 1 in 20
- Over 75: 1 in 10
- Over 85: 1 in 5
What is Alzheimer’s disease?
The commonest form of dementia. A degenerative disease of the brain with prominent cognitive and behavioural impairment. Significantly interferes with social and occupational function.
List 3 risk factors for Alzheimer’s disease
- Increasing age
- FHx of AD or early-onset AD
- Down’s syndrome
- FHx of Down’s syndrome
- Previous head injury
- Hypothyroidism
- Parkinson’s disease
Name 4 risk factors for Dementia
- Genetic: Apolipoprotein E
- Vascular: smoking, alcohol, obesity, HTN, DM, CV disease
- Other: Cholesterol diet, lower education, poor social network
Name 4 protective factors for Dementia
- Diet: Vitamin E and C
- Exercise
- Mental and social activity
- More complex work ➔ reduced hippocampal atrophy
What is the association between Alzheimer’s disease and Down’s syndrome
Chromosome 21:
- AD: the gene for amyloid precursor protein ➔ amyloid plaques
- DS: trisomy 21 People with Down’s syndrome have an extra Chromosome 21 ➔ accelerated production of amyloid plaques ➔ earlier dementia
What are the 3 symptomatic domains of Alzheimer’s disease?
- Cognitive
- Functional: ADLs
- Neuropsychiatric
- Mood/affect disturbances
- Aggression
- Anxiety
- Psychosis
- Sleep disturbances
Describe the memory problems in Alzheimer’s disease
- Early impairment of immediate and short-term memory, due to atrophy of the hippocampus.
- Long-term (remote) memory declines with progression
- Common to also have disorientation of time and place
List 4 early symptoms of Alzheimer’s disease
- Impaired immediate and short-term memory
- Disorientation of time and place
- Muddled efficacy with ADLs
- Spatial dysfunction
- Behavioural: Wandering, irritability
List 3 middle symptoms of Alzheimer’s disease
- Intellectual and personality deterioration
- Aphasia
- Apraxia
- Agnosia (inability to process sensory information)
- Impaired executive function
- Impaired visuospatial skills: getting lost, impaired driving
List 3 late symptoms of Alzheimer’s disease
- Fully dependent
- Physical deterioration
- Incontinence
- Gait abnormalities
- Spasticity Seizures (3%)
- Tremors
- Extrapyramidal signs
What psychotic symptoms may appear in Alzheimer’s disease?
Delusions (15%) - usually paranoid Hallucinations (10-15%) - auditory or visual
Name 3 behavioural disturbances present in Alzheimer’s disease?
Aggression Wandering Explosive temper Sexual disinhibition Incontinence
How does early-onset Alzheimer’s disease differ from typical AD?
More aphasia and apraxia Rapid course with severe intellectual decline Poor survival rate
List 3 factors associated with a poorer prognosis of Alzheimer’s disease
Greater severity at presentation Male Early-onset (<65) Parietal lobe damage Prominent behavioural problems Severe focal cognitive deficits - apraxia, aphasia Observed depression Absence of delusional misidentification syndrome
How can Alzheimer’s disease be assessed?
Mental state examination Cognitive testing: Clock drawing test, MMSE Bloods: FBC, LFT, U&Es, TSH, Vit B12, HIV etc. CT head: cortical atrophy esp in medial temporal lobes (hippocampus), ventricular enlargement
What is the pharmacological management of mild-moderate Alzheimer’s disease?
AChEIs: Donepezil, Rivastigmine, Galantine Use one with lowest acquisition cost
What is the indication for Memantine?
Moderate Alzheimer’s disease where AChEIs are contraindicated or not tolerated. Severe Alzheimer’s disease
What is the mechanism of action of Memantine?
- NMDA-receptor partial antagonist
- NMDA binds to glutamate (excitatory) in the CNS: role in long-term memory and learning.
Name 3 risk factors for Vascular dementia
Male Family or personal Hx of cardiovascular disease CV risk: smoking, diabetes, HTN, hyperlipidaemia
Which features are suggestive of Vascular dementia?
- Sudden onset
- Stepwise deterioration
- Cardiovascular risk factors
How can the presentation of vascular dementia be categorised?
- Cognitive deficits following a single stroke
- Deficits depend on site of infarct
- Multi-infarct dementia
- Stepwise deterioration in cognitive function
- Relative stability between strokes
- Binwangers disease: progressive small-vessel disease
- Gradual intellectual decline
- Generalised slowing
- Motor problems
Describe the presentation of Vascular dementia
Onset may follow a stroke More acute onset than Alzheimer’s disease Early: emotional and personality changes Cognitive deficits - fluctuate Behavioural slowing and anxiety Common: depression with affective lability and confusion, especially at night. Physical signs of arteriovascular disease and neurological impairment.
What is included in the routine dementia screen?
- TFTs
- Vit B12
- FBC, ESR and CRP: anaemia and vasculitis
- LFTs and U&Es
- Glucose
- CT head
Outline the management of Vascular dementia
Manage risk factors: Diet, exercise, smoking cessation, less alcohol
Medication: Aspirin, clopidogrel, statins, ACEi, Diabetes medication.
When would a CXR be done when investigating dementia?
Indication of malignancy, especially of small-cell lung cancer due to its paraneoplastic syndromes resembling neurological deficits in dementia.
Name 1 infectious causes of reversible dementia
- HIV
- Syphilis
- TB
- Meningitis
What personality and behavioural changes can occur in dementia?
Introverted and socially withdrawn Aggression Irritable Disinhibited Restless Wandering
Outline the pathophysiology of Alzheimer’s disease
Accumulation of amyloid plaques and neurofibrillary tangles of tau proteins (Tau deposits in hippocampus/medial temporal lobes).
Outline the pathophysiology of Vascular dementia
Thromboembolic or hypertensive infarctions of small/medium-sized vessels. Patients may present well depending on location of infarcts. They would have difficulties with other cognitive functions such as orientation.
Outline pathophysiology of Lewy body dementia
Accumulation of Lewy bodies (alpha-synuclein and ubiquitin) in the cerebrum and substantia nigra.
What are the characteristic clinical features of Lewy body dementia?
- Fluctuating cognitive impairment
- Spontaneous parkinsonism
- Vivid visual hallucinations
- Additional: REM sleep disturbance - treated with clonazepam
Why should antipsychotics be avoided in Lewy body dementia?
Antipsychotics can precipitate irreversible parkinsonism, autonomic dysregulation (similar to neuroleptic malignant syndrome), reduce consciousness, and increases mortality rates 2-3 fold.
Outline primary prevention of dementia
- Vascular and lifestyle factor modifications
- HTN, obesity, diabetes, heart failure, smoking, alcohol
- Intellectually stimulating activities
- Participation in social, physical, and intellectual activities
- Extensive social network
Outline secondary prevention of dementia
Identify any mild cognitive impairment (MCI) Biochemical marks in serum and CSF for amyloid and tau proteins PET scan - amyloid deposits Volumetric MRI - medial temporal lobe atrophy
Outline tertiary prevention of dementia
Cognitive training Psychosocial support for patient and carer AChE inhibitors (donepezil, rivastigmine, galantamine) NMDA antagonist (memantine) Antidepressants
Define mild cognitive impairment
Focal cognitive impairment that is not severe enough to interfere with daily life and function.
What percentage of people with Mild cognitive impairment progress to dementia?
10-15%
Differentiate dementia from delirium
Delirium has altered consciousness and attention. Dementia: Gradual onset, duration months to years, progressive deterioration, normal consciousness, perceptional disturbances occur later, normal sleep-wake cycle. Delirium: Acute onset, duration hours to weeks, fluctuating course, impaired consciousness, perceptional disturbances are common, disrupted sleep-wake cycle.
What is the indication for Memantine?
Severe dementia: typically MMSE <10
