Dementia Flashcards
What are the general symptoms of dementia?
- Cognitive impairment e.g. memory loss, dysphasia
- Behavioural and psychological symptoms of dementia (BPSD) e.g. psychosis, agitation, disinhibition
- Difficulties with activities of daily living (ADLs)
What are the most common causes of dementia and what are their pathologies?
- Alzheimer’s disease (AD): 50-75%= atrophy of the cerebral cortex and formation of amyloid plaques and neurofibrillary tangles. Neuroinflammation and reduction in cholinergic neurones. Mis-cleavage of the amyloid precursor protein by β and γ secretase, instead of the usual α-secretase, leads to the formation of β-amyloid (aka Aβ). Get (1) Senile plaques (Extracellular deposits of beta amyloid) (2) Neurofibrillary tangles (Intracellular aggregations of hyperphosphorylated tau proteins- esp in memory forming areas of the brain). It is amount and location of these which allows for AD diagnosis
- Vascular dementia (VD): 20%= reduced blood supply to the brain
- Dementia with Lewy-body (DLB): 15-20%= Lewy bodies (abnormal deposits of protein inside nerve cells) in substantia nigra
- Frontotemporal dementia (FTD): 2% aka Pick disease= Atrophy of frontal and temporal lobes
Alzheimers specific symptoms?
4 A’s
- Amnesia: Memory loss of recent events, difficult learning new info
- Aphasia: expressive first, with word-finding difficulties common.
- Agnosia e.g. difficulty naming objects in hand with eyes closed.
- Apraxia: impaired motor planning skills e.g. dressing apraxia.
- Other signs olfactory disturbances, seizures
- Typical onset after 65, MRI shows dilated ventricles and tissue atrophy
Specific VD symptoms
- Stepwise increases in the severity of symptoms — subcortical ischaemic vascular dementia may present insidiously with gait and attention problems and changes in personality (e.g. depression and delusions).
- Focal neurological signs (such as hemiparesis (weakness on one side) or visual field defects) may be present.
DLB specific symptoms
- Parkinsonism (resting tremor, rigidity, bradykinesia, postural instability)
- Fall/syncope and hallucinations predominant feature.
- Fluctuation changes in cognition.
- Visual hallucinations e.g. lilliputian hallucinations of children or animals. Not auditory hallucinations, so figures don’t speak back.
- REM sleep behaviour disorder- often noticed by a partner, often first thing noticed
FTD specific symptoms
- Personality change and behavioural disturbance (such as apathy or social/sexual disinhibition) may develop insidiously.
Other cognitive functions (such as memory and perception) may be relatively preserved.
- Usually younger-onset (45-70). 20% have an autosomal dominant inheritance.
What is the difference between DLB and parkinsons with lewy bodies
DLB is diagnosed when cognitive symptoms predate the emergence of motor parkinsonism by a year or more.
Parkinson’s disease dementia is diagnosed when motor parkinsonism occurs prior to, or within 1 year of, the development of cognitive problems.
Risk factors for dementia?
- Age — older age is the strongest risk factor for dementia
- Mild cognitive impairment (MCI)
3.Learning disability - Genetics
Early onset= mutations in amyloid precursor protein gene (APP) or the presenilin genes (PSEN1 or PSEN2)
Late onset= Apolipoprotein E (ApoE) - Cardiovascular disease
- Cerebrovascular disease for vasc dementia
- Parkinson’s disease (PD)
- Lower educational attainment, Hypertension , Hearing impairment, Smoking, Obesity, Low social engagement and support, Alcohol consumption, Traumatic brain injury (TBI), Air pollution
What is the timescale of dementia symptoms?
- Insidious onset with a slow (months to years) progressive course is consistent with a degenerative process, while an abrupt change, stepwise decline, or a gradual decline may suggest a vascular cause.
- An acute or subacute course may suggest infection, a metabolic disorder, an expanding brain lesion, the effects of medication, or hydrocephalus.
- Rapid onset suggests an acute confusional state or delirium.
How do we diagnose a dementia patient?
History
- Timescale of symptomd
- Impact on ADLs
- BPSD symptoms
- Cormorbidities/risk factors
Examination
Focal neurological signs e.g. Coordination and gait abnormalities.
Sensory findings — such as peripheral neuropathy.
Motor symptoms — hemiparesis, tremor, rigidity, bradykinesia.
Bloods
Cognitive assessment tools
Which congnitive assessment tools are used?
- 6-item Cognitive Impairment Test (6-CIT)- out of 28 Scores of 0–7 are considered normal and 8 or more significant.
- Abbreviated Mental Test Score- Score out of 10 with 7/8 cut off
Differences for dementia
- Normal-age related memory changes
- Mild cognitive impairment (MCI) - impairement that doesnt impact on ADLs or progress over time
- Depression- Depression masquerading as dementia is probably the most common differential diagnosis
- Delirium- Acute onset
- Vitamin deficiency
- Thiamine leading to Wernicke-Korsakoff’s syndrome
- Vitamin B12 deficiency can lead to cognitive impairment (including confusion and irritability), ataxia, and gait disturbance - Hypothyroidism
- Symptoms include include depression, and impaired concentration and memory. - Medicines that affect cognition e.g. benzos, anticholinergics, antiepileptics
- Normal pressure hydrocephalus = cognitive impairment, urinary incontinence, and gait disorder
How to treat Alzheimers ?
1st line: Acetylcholinesterase (AChE) inhibitors (donepezil (5mg OD), galantamine (8mg for 4 weeks then 16-24 maintance- CI in urine or gastro obstruction), and rivastigmine (1.5mg BD up to 6mg BD))
2nd line: Memantine (a N-methyl-D-aspartic acid receptor antagonist)
- All CI in preg + BFing
For people with non-Alzheimer’s dementia the use of AChE inhibitors or memantine is unlicensed, but they may be prescribed by a specialist for people with:
Mild to moderate dementia with Lewy bodies:
Donepezil or rivastigmine are recommended first line.
Galantamine is an option if donepezil and rivastigmine are not tolerated.
Severe dementia with Lewy bodies:
Donepezil or rivastigmine are recommended.
Vascular dementia:
AChE inhibitors or memantine are options if the person has suspected comorbid Alzheimer’s disease, Parkinson’s disease dementia, or dementia with Lewy bodies.
People with frontotemporal dementia should not be offered AChE inhibitors or memantine.
Which drugs are used for non cognitive symptoms of dementia?
- Drug treatments for non-cognitive symptoms may include antipsychotics
- Risperidone and haloperidol are the only antipsychotics licensed for treating non-cognitive symptoms of dementia, although other antipsychotics are often prescribed off-label for this purpose.
Side affects of Acetylcholinesterase inhibitors
Donepezil- Rarely, extrapyramidal symptoms, sinoatrial block, atrioventricular (AV) block, liver dysfunction (including hepatitis), and neuroleptic malignant syndrome (NMS
Galantamine- weight loss (monitor the person’s weight during treatment with galantamine. Rarely, exacerbation of Parkinson’s disease, hepatitis, and serious skin reactions
Rivastigmine- Temporary stop if causes GI symptoms
Ability to drive- AChE inhibitors can cause fatigue, dizziness, somnolence and muscle cramps, and can induce syncope or delirium
