Dementia Flashcards
What is dementia?
- clinical syndrome of at least ~6 months duration of chronic + progressive impairments in 2+ domains of cognitive function
- principle abnormality is memory loss, severe enough to affect social or occupational life
- impairment in one of following: language, visuospatial fxn, abstraction, calculation, personality or executive fxns
-
“My Old Grandmother Converses Pretty Badly”
- Memory, Orientation, Grasp, Communication, Personality, Behaviour
- falls common in later stages
- can lead to immobility, incontinence, dysphagia + total dependency for ADLs
Who does dementia affect?
- females > males
- 10-15% of 65 year olds
- 30-50% of 85 year olds
- 5th commonest cause of death
Dementia can be sub-classified into cortical and subcortical dementia depending on where the lesion is.
What are the classical features of cortical dementia?
5 As
- amnesia
- aphasia
- apraxia
- agnosia
- acalculia
eg. Alzheimer’s, frontotemporal dementia, Creutzfeldt-Jakob disease
What are the classical features of subcortical dementia?
- forgetfulness
- slowing of thought process
- impaired ability to manipulate acquired knowledge
- apathy
- depression
- frontal lobe dysfunction
- motor disability
eg. Huntington’s, Parkinson’s dementia, AIDS dementia complex
The most common type of dementia is Alzheimer’s disease (55%).
What are key features of this type?
- insidious onset, slow progression over years
- risk factors: age, FHx, genetics, Down’s, cerebrovasc disease, hyperlipidaemia
- memory loss hallmark feature, starts w/ short-term memory
- disorientation to time + place
- nominal dysphagia
- misplacing items/getting lost
- apathy
- decline in ADLs
- personality change (loss of interest)
How is a diagnosis of Alzheimer’s made?
- MMSE + Blessed dementia scale
- unremarkable physical examination
- FBC -> rule out anaemia
- metabolic panel -> rule out abnormal Na, Ca, glucose levels
- TSH, Vitamin B12 (both can be associated w/ dementias)
- urine drug screen -> rule out rec drug use
-
CT -> exclude SOLs, few changes evident in early AD
- advanced disease: pronounced sulcal/gyral changes + global atrophy evident
- MRI -> inc sensitivity over CT
Vascular dementia is the second most common (20%) cause of dementia. What is this caused by?
- caused by chronic, reduced blood flow to brain
- due to blocked or diseased vascular system
- usually result of stroke or series of strokes
- if blood supply blocked longer than few secs, brain cells die, causing damage to cortex of brain - area associated w/ learning, memory and language
What is multi-infarct dementia?
- most common type of vascular dementia
- caused by mini strokes/TIAs
- often go unnoticed
- result in only temporary, partial blockages of blood supply
- brief impairments in consciousness or sight
- over time, more areas of brain damaged -> symptoms of dementia begin to appear
What are key diagnostic features of vascular dementia?
- history of stroke(s)
- difficulty solving problems
- apathy
- disinhibition
- slowed processing of information
- poor attention
- retrieval memory deficit
- frontal release reflexes - grasp, glabella tap, jaw-jerk
- impaired gait and balance
Often overlap between AD and VaD, memory may only be mildly affected in early stages of VaD unlike in AD.
What is Lewy Body dementia (DLB) (15%)?
- type of dementia closely associated w/ Alzheimer’s and Parkinson’s diseases (latter more so)
- characterised anatomically by presence of Lewy bodies - accumulations of alpha-synuclein and ubiquitin protein in neurons
- with DLB, loss of cholinergic neurons is thought to account for degradation of cognitive functioning, as in Alzheimer’s disease while the loss of dopaminergic neurons is thought to account for degradation of motor control, as in Parkinson’s disease
What are key characteristics of Lewy Body Dementia?
- insidious onset, progression gradual
-
triad:
- fluctuating cognitive impairment (confusion + lucid intervals)
- recurrent visual hallucinations
- motor features of parkinsonism
- cognitive and behavioural impairments precede motor phenomena
What are characteristics of Parkinson’s Disease with dementia?
- typical motor symptoms of PD present, precede cognitive impairment and are severe - so motor symptoms come first!
- diagnosed when cognitive symptoms begin a year after the onset of parkinson symptoms
What are key characteristics of frontotemporal dementia (5%)?
- onset often early (35-75), insidious and slow
- either behavioural, personality or language difficulties dominate
- eg. Pick’s disease
- slovenly appearance, impatience, irritability
- argumentative, lewd, tactless remarks, child-like + impulsive
- loss of empathy and concern for others
- progressive loss of language fluency or comprehension
- in FTD, changes in personality, language, habits, and activity generally precede the development of memory impairment, disorientation, or apraxias
- progressive self-neglect
- insight lost early
- neuroimaging shows frontal and/or temporal atrophy
What are other causes of dementia (5)% that have not been yet mentioned?
- hypothyroidism
- vit B12 deficiency
- Wernicke-Korsakoff’s syndrome
- normal pressure hydrocephalus
- neurosyphyllis
- AIDS
- Huntington’s disease
- progressive supranuclear palsy
- creutzfeldt-jakob disease
What are the differences between delirium and dementia?
The mini-mental state examinaiton also can be used to assess for dementia.
What does the MMSE involve?
