Organic Mental Disorders Flashcards
What is delirium?
A syndrome manifesting as acute or fluctuating cognitive impairment associated with altered consciousness and impaired attention
Presenting features of delirium
-Impaired consciousness: drowsiness / coma in hypoactive delirium, hypervigilance / agitation in hyperactive delirium, or both in mixed delirium hypervigilance / agitation in hyperactive delirium, or both in mixed delirium
-Impaired attention: easily distractible, problems with attention tests e.g. serial sevens
-Impaired cognition: short-term/recent memory problems, disorientation to time and place, language abnormalities e.g. rambling, impaired ability to understand
-Perceptual and thought disturbance: misinterpretations, illusions, hallucinations(especially visual hallucinations), delusions of persecution / misidentification
-Sleep-wake cycle disturbance: daytime drowsiness, night-time hyperactivity
-Mood disturbance: depression, euphoria, anxiety, fear, apathy are common
Subtypes of delirium
-Hypoactive
=Decreased activity levels
=Decreased speech
=Subdued
=Quietly confused
=Disorientated
=Apathetic
=Increased sleep
-Hyperactive:
=Restless or wandering
=Agitated or aggressive
=Delusional
=Hallucinations
=Disorientated
=Poor sleep
-Mixed
=Fluctuates between hyper and hypoactive states
Epidemiology of delirium
-10-30% of hospitalised, medically ill patients
-Up to 87% develop delirium in ICU
-Increased risk in:
=Elderly (>65 years), alongside infants and young children
=Elderly (>65 years), alongside infants and young children
=Vulnerable brain
==dementia (present in 2/3 delirium cases)
== previous serious head injury
==alcohol misuse
=Polypharmacy
=Sensory impairment
Aetiology of delirium
-Anything that disturbs homeostasis (often multifactorial)
=Multiple severe insults in healthy individuals e.g. head injury then sedation then surgery
=Minor insult in those with vulnerable brains e.g. constipation, UTI
Commonest causes:
=Medication, especially anticholinergics, opiates or benzodiazepine
=Systemic illness, especially infection
Differential diagnosis of delirium
-Normal score on standardised testing?: subjective cognitive impairment
-Acute or fluctuating?: Likely delirium
-Depressive symptoms? Depression (reassess cognition once treated)
-Activities of daily living unaffected: mild cognitive impairment
-Progressive worsening over at least 6 months: dementia
-Stable impairment: stable cognitive impairment
Delirium vs dementia
Delirium
-Acute, hours to weeks
=Impaired attention
=Fluctuating course
=Altered consciousness
=New illness/ medication
=Common perceptual disturbance
=Disrupted sleep-wake cycle
=Usually orientation impaired for time and unfamiliar people/places
=Speech incoherent, rapid or slow
=Why aren’t they listening?
Dementia
=Gradual, months, years, progressive deterioration
=Normal attention, consciousness, sleep cycle
=Orientation impaired in late stages, perceptual disturbance
=Word finding difficulties
=Why do they keep asking the same question?
Assessment of delirium
-History
=Collateral is crucial
=Temporal pattern
=Consciousness level
-Examination
=Conscious level: lowered, hyper-aroused or normal
=Standardised cognitive test essential e.g. AMT4
=Physical exam (including neurological): find reversible causes
=MSE
-Medication review
-Thorough investigations to find reversible causes
=Blood tests (FBC, U&E, LFT, Calcium, Glucose, CRP)
=CXR, ECG, Urinalysis
Management of delirium
-Treat any underlying medical condition: hospitalisation in medical ward
-Psycho / Environmental
=Calm, consistent, reassuring nursing staff
=Encourage presence of friend/family member
=Maximise visual acuity e.g. glasses, appropriately lit environment;
=Maximise visual acuity e.g. glasses, appropriately lit environment ;and hearing ability e.g. hearing aids, quiet environment
=Orientation aids e.g. clocks, calendars, familiar objects
-Bio / Medication:
=only if severely distressed, at high risk or unable to tolerate essential investigations/treatment
=Consider Haloperidol 0.5mg (oral first, IM if refuses)
=Avoid benzodiazepine (unless substance withdrawal) and high-dose antipsychotic
-Social / Legal: Lack capacity for accepting treatment or attempting to leave
Prognosis of delirium
-Delirium usually resolves once cause is treated
-Average duration of delirium is 7 days, but can last weeks/months after insult is treated insult is treated
-High mortality
-Increased length of stay, risk of pressure sores, falls, dementia
What is dementia?
A syndrome of acquired, progressive, generalised, cognitive impairment associated with functional decline, lasting at least 6 months
Presenting features of dementia
-Cognitive impairment: often memory problems, can also include problems with language, praxis, perception, executive function
-Functional decline: problems with basic or instrumental activities of daily living
-Behavioural and psychological symptoms of dementia (BPSD) e.g. psychosis
-Neurological symptoms e.g. seizure
Subtypes of dementia
-Alzheimer’s (62%)
=Early memory loss, gradual onset and progression
-Vascular dementia (17%)
=Focal neurology. Evidence of cerebrovascular disease. May be stepwise progression
-Mixed (10%)
=Feaures of both Alzheimer’s and vascular dementia
-Lewy body dementia (4%)
=Fluctuating cognition, visual hallucinations, Parkinsonism
-Frontotemporal dementia (2%)
=Change in behaviour and conduct, dietary changes, emotional blunting, prominent language problems
-Parkinson disease with dementia (2%)
=Diagnosis of Parkinson’s disease prior to dementia onset. Dementia features similar to Lewy Body
Epidemiology of dementia
-1% of total UK population, rising steeply with age(around 30% of those over 90 years old)
-Alzheimer’s more common in women
-Vascular more common in men
Pathophysiology of dementia
-Alzheimer dementia: Mixture of genetic and non-genetic factors leads to beta-amyloid plaques and neurofibrillary tau tangles
=Genetics: Late onset: Apolipoprotein E./ Early onset: amyloid precursor protein, presenilin-1, presenilin-2
=Non-genetic: vascular risk factors, head injury, low educational attainment, depression
-Vascular: Multiple small infarcts or single strategic infarct
-Lewy body dementia: Neuronal deposits of alpha synuclein
