12. Dementia, delirium and toxic insults Flashcards
define dementia
a syndrome characterised by deterioration in cognition resulting in behavioural problems and impairment in the activities of daily living. Decline in cognition is extensive, often affecting multiple
domains of intellectual functioning
A chronic, progressive syndrome of insidious onset
What are the causes of confusion in elderly patients?
Delirium, depression, dementia, drugs and metabolic (endocrine)
Define depression.
change in mood and feeling of self-worth
What drugs may cause confusion in the elderly?
morphine, coccaine, alcohol, zopiclone
What metabolic conditions may cause confusion in the elderly?
o Hypothyroidism
o Hypercalcaemia
o B12 deficiency
o Normal pressure hydrocephalus
what are the Cognitive symptoms of dementia
- Impaired memory (temporal lobe involvement)
- Impaired orientation (temporal lobe involvement)
- Impaired learning capacity ((temporal lobe involvement)
- Impaired judgement (frontal lobe involvement)
what are the non-Cognitive symptoms of dementia
- Behavioural symptoms
- Depression and anxiety
- Psychotic features
- Sleep symptoms
what are the Behavioural symptoms of dementia
- Agitation
- Aggression (frontal lobe involvement)
- Wandering
- Sexual disinhibition (frontal lobe involvement)
what are the Psychotic features of dementia
- Visual and auditory hallucinations (hallucinations=false perceptions)
- Persecutory delusions (delusions=false beliefs)
what are the Sleep symptoms of dementia
- Insomnia
* Daytime drowsiness (decreased cortical activity)
how is dementia diagnosed?
- By exclusion
• Exclude organic causes of cognitive decline
• Exclude delirium - Look for features of progressive cognitive decline, impairment of activities of daily living in a patient with a normal conscious level (cf. delirium where conscious level is diminished with acute cognitive decline)
symptoms of Normal pressure hydrocephalus
Abnormal gait
Incontinence
Confusion
What are 5 different types of dementia?
- Alzheimer’s Dementia
- Dementia with Lewy body
- Vascular Dementia
- Fronto-Temporal Dementia
- AIDS-Dementia Complex
What are 2 common tests used to test cognition?
- mini mental state examination (MMSE)
- montreal cognitive assessment
What are the macroscoptic changes in alzheimers?
Causes global atrophy of brain lobes: Mostly frontal, parietal and temporal lobes. Less so for occipital lobes.
Also causes:
- Sulcus widening
- Enlarged ventricles (primarily lateral and third affected)
What are the microscoptic changes in alzheimers?
Plaques
• Composed of amyloid beta
Tangles
• Hyperphosphorylated tau
What is the pathophysiology in alzheimer’s?
- senile amyloid plaques
- neurofibrillary tau tangles
- results in neuronal death
- Since neurogenesis is limited in the CNS any neurones that die are unlikely to be replaced
what is the amyloid hypothesis for Alzheimer’s pathophysiology
- Excess of interneuronal amyloid (Abeta) peptides, due to overproduction or diminished clearance of beta-amyloid
- Formation of dense amyloid oligomers, which are deposited as diffuse plaques
- Inflammatory process through microglial activation, cytokine formation, and activation of the complement cascade
- Formation of neuritic plaques, causing synaptic and neuritic injury and cell death
what is the tau hypothesis for Alzheimer’s pathophysiology
- abnormal aggregation of the tau protein
- Tau accumulates into intraneuronal masses known as neurofibrillary tangles and as dystrophic neurites
- The abundance of tangles is roughly proportional to the severity of clinical disease and cognitive decline
What is the normal function of beta amyloid and tau proteins?
Amyloid: essential role in neural growth and repair
Tau: stability of microtubules
risk factors for Alzheimer’s
- head injury
- increased serum cholesterol and homocysteine levels
- Lifestyle factors including smoking, midlife obesity, and a diet high in saturated fats
What genes are associated with alzheimer’s?
Early-onset : - β-amyloid precursor protein (β-APP) - Presenilin 1 - Presenilin 2. Late-onset : - Apolipoprotein E gene
What is the clinical presentation of alzheimer’s
- Memory loss → loss of recent first
- Disorientation to time and place
- misplacing items/getting lost
- Nominal dysphasia → Proper names and low-frequency words decline first
- Apathy
- Decline in ADLs
- Personality/mood change
What are the pharmacological options alzheimers?
- AcetylCholinesterase inhibitors (+ memantine)
- Antidepressants
- Antipsychotics (controversial)`
non pharmacological interventions for Alzheimer’s
- Carer support
- OT
- Community services
- ID bracelets
Give examples of AChE inhibitors.
Donepezil, galantamine, rivastigmine
What is memantine and how best prescribed?
NMDA receptor antagonist
- blocks glutamate
- best when combined with AChE inhibitors but can be given as monotherapy in severe cases