Week 236 - Dementia Flashcards
Name at least two other types / causes of dementia besides Alzheimer’s and Vascular?
Lewy Body Dementia (DLBT) or Parkinson’s dementia
Fronto-temporal e.g. Pick’s
Also rarer forms e.g. Huntington’s dementia, CJD, HIV and alcohol
What is the main difference between Parkinson’s dementia and Lewy Body dementia (both Parkinson’s related dementia)?
Parkinson’s dementia: prominent motor features which pre-date dementia by at least 6months
Lewy Body dementia: mild motor symptoms, onset of cognitive and motor Sx similar (time-wise)
How does Alzheimer’s Disease present?
Insidiously with gradual deterioration
What neuropathic changes occur typically in AD?
- Formation of neurofibrillary tangles and amyloid plaques
- Cholinergic transmission deficit
What changes are you likely to see in a CT head of a patient with Alzheimer’s Disease?
Widening of sulci
Enlargement of ventricles
Atrophy / shrinking of brain
What are the risk factors for Alzheimer’s?
Age Female gender Genetics Head injury Environmental e.g. Oxidative stress
What are the two most common forms of dementia?
Alzheimer’s Diease followed by Vascular Dementia
Common to have a mixed diagnosis of the two
How does vascular dementia present?
Sudden onset
Stepwise deterioration
Mood/behaviour changes
Insight preserved
What neuropathological changes occur in Vascular Dementia?
Atherosclerosis
Single or multiple thrombotic or embolism enfarcts
Small vessel disease
What are the risk factors for vascular dementia?
Smoking Diabetes High cholesterol HTN Male gender
How does Lewy Body Dementia (DLB) present?
Fluctuating cognition Vivid visual hallucinations Mild Parkinsonian features Repeated falls Memory loss (may not be marked early in disease!)
What neuropathological changes are seen in DLB?
Lewy Bodies: abnormal aggregate of protein (synuclein fibrils) develop inside nerve cells
a) Classical - brainstem: round, brown, eosinophilic cytoplasmic inclusion with halo of radiating fibrils
b) Cortical: still made of alpha-synuclein fibrils but lacks halo
How does Fronto-temporal Dementia (such as Pick’s Disease) present?
Apathy; reduced motivation; self-neglect
Disinhibition; reduced social awareness, lack of judgement
Personality changes and social inappropriateness
Memory loss is variable but language difficulties are prominent
More common in men, with onset
What are the main differentials for dementia?
Secondary dementia due to underlying illness
Mild cognitive impairment (MCI)
Depression
Acute confusional state / delirium
What is the prevalence of mod/severe dementia >65 and >80 in the UK?
>65 = 5% >80 = 20%
What are the three key features of dementia?
1) Global impairment of higher cortical function
2) Occurring in clear consciousness
3) Progressive and present for >6 months
What five main areas of cognition are important to assess according to the ICD 10 Diagnostic Criteria?
Memory
Executive functioning (abstract thinking, judgement, reasoning)
Motor skills (Praxis)
Language (expressive and receptive)
Gnosis (ability to recognise objects, faces, sensory information)
What is the key difference between dementia and MCI?
Dementia: global impairment of intellect, memory and personality resulting in impaired performance in activities of daily living
MCI: cognitive decline >expected for age and edu level but does not notably interfere with activities of daily living
What pharmacological options should be considered for Alzheimer type dementia and Lewy Body dementia ?
- Mild-Mod consider anti-cholinesterase meds
- Mod-Advanced consider Memantine (NMDA antagonist)
What treatment options should be considered for Vascular Dementia?
Consider: low dose aspirin; statin
Appropriate BP and blood glucose management
Life-style advice re smoking, low fat diet
Name 3 anti-cholinesterases
Aricept - Donepezil
Exelon - Rivastigmine
Reminyl - Galantamine
How do anti-cholinesterases work?
Increase concentration of acetylcholine (neurotransmitter) at synaptic cleft by reducing aceytylcholine breakdown
How do NMDA antagonists work? (E.g. Memantine)
Blocks the effects of pathologically high levels of glutamate by uncompetitively binding to NMDA receptors (on which glutamate acts a remember glutamate is the major excitatory neurotransmitter in the CNS)
Name 3 genes associated with early onset Alzheimer’s Disease
Presenilin 1 and Presenilin 2
Beta amyloid precursor protein gene (APP)
