9.1 Dementia and Delirium Flashcards
Describe the onset of Dementia
Dementia is a chronic, progressive disorder with insidious onset (wont know for a long time that they have it)
What are the 2 broad categories of symptoms in dementia?
- Cognitive symptoms
2. Non-cognitive symptoms
What are the cognitive symptoms in 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 in dementia?
Behaviour symptoms (agitation, aggression, wandering, sexual disinhibition) Depression and anxiety Psychotic symptoms (visual and auditory hallucinations; persecutory delusions) Sleep symptoms (insomnia, daytime drowsiness due to decreased cortical activity)
(Hallucinations = false perceptions) (Delusions = false beliefs)
How is dementia diagnosed?
Dementia is a diagnosis of exclusion - want to exclude organic causes of cognitive decline:
- Hypothyroidism
- Hypercalcaemia
- B12 deficiency
- Normal pressure hydrocephalus (abnormal gait, incontinence, confusion)
Also exclude delirium
Look for features of progressive cognitive decline, impairment of activities of daily living in a patient with a normal conscious level.
Comment on the consciousness of people with dementia and delirium.
Dementia = normal conscious level Delirium = conscious level is diminished with acute cognitive decline
What are the Macroscopic features seen in Alzheimer’s disease?
Global cortical atrophy Sulcal widening (due to gyri atrophy) Enlarged ventricles (primarily lateral and third affected)
What are the Microscopic features seen in Alzheimer’s disease?
Plaques = composed of amyloid beta (APP > Amyloid Beta via beta + gamma secretase)
Tangles = Hyperphosphorylated Tau - cannot stabilise microtubules = neuronal death
Which neurones are predominantly affected in Alzheimer’s disease?
Cholinergic (treatments target this)
Noradrenergic
Serotonergic
Those expressing Somatostatin
What is Vascular dementia?
Cognitive impairment caused by cerebrovascular disease (multiple small strokes)
What are the risk factors for vascular dementia?
Previous stroke/MI Hypertension Hypercholesterolaemia Diabetes Smoking
What is the presentation of vascular dementia like?
The presentation is stepwise (improvements seen then get worse), maybe with focal neurological features
How do we distinguish Lewy Body Dementia from Parkinson’s disease?
Dementia then movement disorder = Lewy body dementia
Movement disorder then dementia = Parkinson’s disease
What is the pathology behind Lewy Body Dementia?
Aggregation of alpha synuclein which form spherical intracytoplasmic inclusions. Main deposits are found across the brain:
- Substantia nigra (think parkinsons)
- Temporal lobe
- Frontal lobe
- Cingulate gyrus (just above corpus callosum - involved in motivation?)
What imaging techniques can be used in Lewy Body Dementia?
Can use antibodies to target the alpha-synuclein therefore labelling the alpha synuclein in the brain. The labelled alpha synuclein deposits can be seen using an MRI.
What is the presentation of Lewy Body Dementia?
Fluctuating cognition and alertness
Vivid visual hallucinations
Parkinsonian features (may cause repeated falls)
Why are antipsychotics (dopamine antagonists) not prescribed to those with Lewy Body Dementia?
Can cause neuroleptic malignant syndrome - a psychiatric emergency
What is the presentation of neuroleptic malignant syndrome?
mnemonic = FEVER F = Fever E = Encephalopathy (confusion) V = Vital signs instability (tachycardia, tachypnoea (v. sensitive sign), fluctuating BP) E = Elevated creatine phosphokinase R = Rigidity (caused by dopamine antagonism)
What is Frontotemporal dementia?
Also known as Pick’s dementia - due to picks deposits
It is the second most common cause of early onset dementia
Frontal and temporal lobe atrophy is seen
What are the symptoms of Frontotemporal dementia?
Symptoms mostly due to frontal lobe dysfunction:
- Behavioural disinhibition
- Inappropriate social behaviour
- Loss of motivation without depression (caused by damage to anterior cingulate cortex)
- Repetivie/ritualistic behaviours (repeating what people are saying)
- Expressive aphasia
What is the pathological process behind AIDS dementia?
Entry of HIV infected macrophages into the brain is thought to lead to indirect damage to neurones.
What is the onset of AIDS dementia like?
Insidious onset but rapid progression once established
What are the clinical features of AIDS dementia?
Related to global damage but also some manifestations of cerebellar involvement:
- Cognitive impairment
- Psychomotor retardation (slow thoughts and movements)
- Tremor
- Ataxia
- Dysarthria - slurred speech
- Incontinence
What is the management of demenita?
Use of the bio-psycho-social model
- Drugs = acetylcholinesterase inhibitors and NMDA antagonists
- Psychological = pretty much none available
- Social = Sensitive explanation of diagnosis, give results of any special investigations, inform patient they can no longer drive (need to inform DVLA), sort finances (will, power of attorney), day care and respite care, nursing home placement
