General, Dementia, Delirium, Falls Flashcards
Definition of polypharmacy
- ≥5 drugs, hyperpolypharmacy ≥ 10 drugs
Examples of adverse drug reaction tools/scales
- Naranjo Adverse Drug Reaction Probability Scale
- WHO-UMC Causality Categories
- ADRAC criteria
Example of a prescribing cascade:
- NSAIDs → oedema, HTN, interpreted as a new medical condition → prescribing of thiazide → hypokalaemia, weakness, dizziness
- Thiazides and gout
Interventions effective in reducing risk of falls and hip fractures in elderly
- Exercise programmes
- Tai Chi reduces risk of falling
- Vitamin D supplementation → does not reduce risk of falls
Features of CAM (Confusion Assessment Method) for detection of delirium
- Must have 1 and 2 PLUS either 3 or 4
- Acute onset and fluctuating course
- Inattention
- Disorganised thinking
- Altered level of consciousness
- Sensitive (94-100%) and specific (90-95%)
Most common cause of chronic incontinence in the elderly
- Urge incontinence
Notes on donepezil
- Cholinesterase inhibitor
- Modest improvement in cognitive function in mild to moderate Alzheimer’s dementia → symptomatic improvement only. Benefit in 40-70%.
- Also helpful in non-cognitive improvement such as apathy and psychosis
- Adverse effects (all dose related, start low):
- Diarrhoea
- Bracycardia
- Headache
- Nausea
- Urinary frequency
- Vivid dreams (could trial swap to morning)
Contraindications
* Gastric ulcer
* Ureteric obstruction
* Heart block, bradyarrhythmia
- Other options - galantamine, rivastigmine
- Patients who don’t respond to donepezil/galantamine may respond to rivastigmine (inhibits an additional enzyme that breaks down ACh)
- Effect is usually only seen for 6-12 months and then patients gradually worsen again
Notes on memantine
- NMDA antagonist
- Moderate to severe AD
- Lowers seizure threshold - seizures CI
- Well tolerated - GI, dizziness, drowsiness, headache
- Crossover studies with cholinesterase inhibitors and memantine → associated with improved caregiver rating of patients functioning and decreased rate of decline in cognitive test scores over periods of up to 3 years
- No benefit of adding in memantine in late stages of AD
Cognitive domains
- Learning and memory
- Language
- Executive function
- Complex attention
- Preceptual-motor
- Social cognition
Cortical vs subcortical dementias
Cortical dementias
- Alzheimer’s, frontotemporal dementia, CJD, posterior cortical atrophy
- Main symptoms → aphasia, memory impairment, apraxia, dyscalculia, impaired abstraction and judgement
Subcortical dementias
- Vascular dementia, parkinson’s disease, PSP, Huntington’s
- Main symptoms → motor and cognitive slowing, slowed memory retrieval, apathy, personality changes, executive function, language relatively preserved
Dementia with Lewy bodies has cortical and subcortical features
Notes on mild cognitive impairment
- Intermediate between normal cognition and dementia
- 5-6% > 70 years
- Deficit in ≥1 domain in the absence of impairment in function
- Amnestic and non-amnestiv subtypes (2:1)
- Amnestic more likely to progress to AD
- Rate of progression 5% per annum
Note ICD 11 definitions currently under review → MCI not listed, mild neurocognitive disorder (uncertain prognosis except in setting of memory clinic where 50% go on to develop dementia). Definition seems to be the same for MCI
Notes on Alzheimer’s disease
- Most common form (60-80%)
- Increased incidence w/ increasing age
- Memory impairment most common presentation
- Episodic memory → semantic → procedural
- Visuoconstructional deficits, spatial disorientation and dyspraxia
- Less ability to judge distance with tasks (bad drivers)
- Lost in familiar environments, lack of insight
- Early onset uncommon but often atypical and has a rapid onset
- Progressive atrophy of cerebral cortex and hippocampus
- Pathophysiology → amyloid plaques and neurofibrillary tangles, deficit of acetylcholine
- Risk factors:
- Family history → often early onset, AD inheritance (1% cases) → mutations in APP, APOE, PSEN1 and PSEN2
- Low vitamin D
- Down syndrome (100% > 40 years)
- Head injuries
- Depression
- Chronic hypertension
Notes on vascular dementia
- Second most common form dementia - often with AD
- Evidence of clinical stroke or subclinical vascular brain injury and cognitive impairment
- Risk factors and management as for most chronic CVS diseases
- Features:
- More significant decline in executive function rather than memory loss
- FDG PET → patchy hypo metabolism in multiple areas
- Can get bradykinesia → typically affects lower limbs more than upper limbs
Pathological lesions on imaging
- White matter hyperintensities
- Lacunar infarcts
- Perivacular spaces
- Cerebral microbleeds
- Cortical superficial sclerosis
Notes on fronto-temporal dementias
- Heterogenous group of disorders
- Behavioural variant FTD
- Socially inappropriate, early apathy, loss of sympathy/empathy, sterotyped behaviour, hyper-orality and dietary changes, executive deficits with relative sparing of episodic memory or visuo-spatial dysfunctions
- Language variants
- Overlap with MND, PSP, CBD
- Focal degeneration of frontal or temporal lobes → often marked asymmetry
- Generally 40-75 years, no gender predominance
- AD inheritance in 10-25%
Notes on Dementia with Lewy Bodies
- Mean age diagnosis 75 years
- <5% cases
- M>F
- Makes up 15-20% dementia
- Lewy bodies in brainstem, limbic system, cortex → abnormal protein aggregate forms an inclusion body
- Alpha synuclein, ubiquitin, and associated enzymes
- Features → probable diagnosis requires ⅔
- Parkinsonism, early prominent dementia
- Visual hallucinations
- Cognitive fluctuations
- Prominent exectuive dysfunction, visuo-spatial dysfunction, inattention
- Other features → REM sleep disorder, neuroleptic sensitivity (support diagnosis, but not diagnostic)
- Higher rates of morbidity, mortality, carer stress and poorer quality of life compared to AD
DLB and Parkinson’s disease
- Risk increases with age
- Lewy body dementia describes both DLB and PDD (common clinical and pathological features) → likely two points on a continuous spectrum
- One year rule
Notes on Chronic Traumatic Encephalopathy
- Syndrome associated with multiple mild head injuries, not necessarily requiring loss of consciousness
- Frontal effects - disinhibition, blunted emotional responses
Notes on anti-amyloid therapies
Safety concerns
* **ARIA (amyloid related imaging abnormalities) **
* Oedema or haemorrhage
* Lecanemab - 12% ARIA-E, 17% ARIA-H
* Donanemab - 24% ARIA-E, 31% ARIA-H
* >90% asymptomatic - most common symptoms headache, visual disturbance, dizziness, confusion
