Dementia Flashcards
What is Dementia?
Clinical syndrome caused by a number of brain disorders which cause memory loss, decline in other aspects of cognition and difficulties with activities of daily living.
Common causes of dementia?
- Alzheimer’s disease (most common cause)
- Vascular dementia (accounts for 25%)
- Dementia with lewy bodies
- Frontotemporal dementias
- Potentially treatable dementias
What is Alzheimer’s disease?
Most common cause of dementia. occurs in 50-70% of cases.
What is vascular dementia?
Brain damage due to cerebrovascular disease, either major stroke, multiple smaller unrecognised strokes (multi-infarct) or chronic changes in smaller vessels (subcortical dementia).
What is dementia with lewy bodies?
Occurs for 15% of cases. It is the deposition of abnormal protein (alpha-synuclein) within neurons of the brainstem and neocortex.
What is frontotemporal dementia?
Accounts for less than 5% of cases. It has a strong association with MND (particularly ALS - the most common).
Results in specific degeneration/atrophy of the frontal and temporal lobes of brain.
Some causes of potentially treatable dementias (<5% of cases)?
- Metabolic e.g. uraemia
- Toxic e.g. alcohol
- Vitamin deficiency - B12 and thiamine
- Traumatic - severe or repeated brain injury
- Infections e.g. HIV
- Intracranial lesions e.g. subdural haematoma, tumours
- Endocrine e.g. hypothyroidism
- Psychiatric - depression causing “pseudodementia”.
Rare causes of dementia and what is inheritance pattern?
Huntington’s disease
- Autosomal dominant trait
- Usually presenting between 30 to 50 years of age (but can vary).
What are the pathological hallmarks of Alzheimer’s disease?
- Loss of cortical neurones
- Neurofibrillary tangles - abnormal accumulations of a protein called tau that collect inside neurons.
- Senile plaques - extracellular proteins deposits containing amyloid beta protein. Found in the brain during Alzheimer’s disease and normal ageing.
Initial symptom of Alzheimer’s disease?
Usually forgetfulness
What genetic mutation occurs for huntington’s disease?
CAG repeat encoding poly-glutamine – has a toxic effect on cells leading to neuronal loss.
Caudate atrophy occurs with huntington’s disease. True/false?
True
What is caudate atrophy?
Loss of cells from the basal ganglia causing flattening of the normal convex curve of the lateral ventricles.
Clinical presentation of Alzheimer’s disease?
- Gradual onset, decline of particularly short-term memory.
- Autobiographical and political memory is well preserved.
- Poor concentration, poor sleep and low mood.
- Personality changes – disinhibited, lack of self-care.
- In end stages — hallucinations, poor dentitition, skin ulcers and loss of verbal communication.
Clinical presentation of vascular dementia?
Dysphasia, dyscalculia, frontal lobe symptoms.
Possible vascular risk factors
May have step wise decline
How many variants (syndromes) with frontotemporal dementia?
3 syndromes
Clinical presentation of frontotemporal dementia - what are the different syndromes?
Behavioural variant - behavioural changes, impulsivity, loss of social skills, apathy, obsessions and changes in diet.
Primary progressive aphasia - effortful non - fluent speech, speech errors, lack of grammar and lack of words.
Semantic dementia - impaired understanding of meaning of word, fluent but empty speech and difficulty retrieving names.
Clinical presentation for dementia with lewy bodies?
Dementia - common early involvement of reduced attention.
2 of:
- Visual hallucinations
- REM sleep behaviour disorder
- Extrapyramidal features (Parkinsonism) seen in 75%.
Clinical presentation for dementia in Parkinson’s disease?
80% after 15 - 20 years of Parkinson’s disease.
Must have Parkinsonism for at least 1 year prior to onset of dementia.
Clinical presentation is similar to dementia with Lewy Bodies.
Diagnostic criteria for dementia?
History consistent with global cognitive decline over months - year.
Decline in function level
No evidence of reversible cause
Imaging for dementia?
CT is currently standard.
MRI if young patient, fast progression or other atypical features.
Management of dementia?
Dementia cases are rarely reversible so management is supportive (treat the symptoms).
Vascular dementia: vascular risk factors +/- cholinesterase inhibitor.
Frontotemporal dementia: trial of trazadone/antipsychotics for behavioural features.
Safety management - controlled access to food/money/internet, other structured activities.
Dementia with lewy bodies:
- Small dose levodopa
- Trial cholinersterase inhibitors - rivastigmine.
