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Learning Objectives
What is the difference between delirium and dementia?
Common causes of an acute confusional state
Types of dementia
Case study
Delirium
Also known as Acute Confusional State
Arises during a number of different acute illnesses
Present in up to 20% of hospital admissions
“A temporary mental state with a sudden onset, usually reversible,
including symptoms of poor attention, inability to concentrate, disorientation, anxiety and sometimes
hallucinations”
A lcohol
D rugs
E lectrolytes
L iver failure
I nfection
R etention
I ntracranial pressure
U rea
M etabolic disease
DeliriumCauses
Drugs There are LOTS of drugs that are known to precipitate
confusion
Alcohol
Benzodiazepines (e.g. Diazepam, Lorazepam)
Opiates (e.g. Morphine, Codeine)
Tricyclics (e.g Amitryptiline)
Digoxin
Lithium
Electrolyte DisturbanceAny electrolyte imbalance can cause confusion
Abnormal values cause cells in the brain to swellOsmosis because cells contain lots of potassium
HyponatraemiaVomiting and diarrhoeaBuild up of fluid in the body (e.g heart failure)
HypercalcaemiaMalignancyHyperparathyroidism
Liver DiseaseCirrhosis
AlcoholHepatitisDrugs
CarcinomaPrimary hepatomaCarcinoma
VascularIschaemia
InfectionHepatitisEpstein-Barr virus
MetabolicWilson’s disease
Liver DiseaseAnything that leads to hepatic failure prevents
toxic blood metabolites from being processed in the liver
Metabolites then remain in the blood and cause disturbance in the brain
InfectionNumber of acute infections can cause delirium
Mechanism unknown, but probably due to inflammatory response disrupting neurotransmitters
UTI
Pneumonia
Sepsis
Meningitis and encephalitis
Malaria
RetentionOne of the most common causes of confusion in
hospital
Both urinary and faecal
Unknown aetiologyMultiple studiesNobody knows why this should cause confusion
Hypothesised that faeces become impacted due to constipation, which presses on bladder
Intracranial PressureBrain metastases
Space occupying lesionsIncrease pressure in craniumDamage to brain tissue
Increased volume in brainOedemaHydrocephalus
TraumaSpace occupying haematomaDirect damage to brain tissue
Urea Often arises from renal failure
Chronic kidney diseaseAcute renal failureNephrotoxic drugs
Urea and other waste products normally excreted by the kidneys remain in the blood
Acute confusional state caused by build up of toxins in the brain, disrupting neurotransmission
Metabolic DiseaseVitamin deficiency
Especially B1 and B12Involved in nerve conduction
Hypoxia (respiratory disease)Lack of oxygenBrain is not well perfused
Thyroid diseaseLevels of thyroxine linked to precipitating
confusion
PresentationAcute onset
Fluctuating course
Impaired consciousness
Impaired cognition
Disorientation
Poor attention
Agitation
Sleep cycle disturbed
Hallucinations
HistoryUsual medical history
Any recent illness?
Good medication history
Obtain a collateral history from relatives or friendsThe patient will probably not be very cooperative!
Examination A B C
Conscious level
Vitals O2 Sats BP Pulse Temperature
ENT, respiratory, cardiovascular, abdominal exams Check for lymphadenopathy and constipation
Mini mental state exam
InvestigationsBlood glucose
ABC-DEFG
Bloods FBC U&E LFT TFT Vitamin B12 Calcium Cardiac enzymes
ABG
Urine dipstick
Blood cultures
ECG
Chest / abdo x-ray
CT Brain
(Lumbar puncture)
ManagementTreat underlying cause
Constipation – laxativesUrinary retention – catheterise Infection – antibioticsElectrolytes – fluids, slow calcium production
Stop drugs suspected of causing confusion Replace with others if possible
Measure cognitive function regularlyMini mental state examination
Management Supportive
Clock, calendar in room Familiar objects from home Staff consistency Involve family and carers
Helpful in stopping patients wandering
Medical treatment Antipsychotic medication - haloperidol
Haloperidol is for scared patients
Other antipsychotics for other hallucinations or delusions e.g quetiapine
DeliriumAcute illness
Sudden onset
Altered consciousness
Hallucinations
Fluctuating disorientation and memory loss
Thorough history and examination
Treat underlying cause and stop precipitating drugs
DRUGS CONSTIPATION INFECTION
DementiaAlzheimer’s Disease
Vascular Dementia
Lewy Body Dementia
Fronto-temporal Dementia
“A progressive decline in cognitive function due to damage or disease in the brain beyond what might be
expected from normal aging”
Alzheimer’s DiseaseMost common type of dementia
Accounts for up to 60% of all casesMore common in women
Risk increases with ageApprox. 25-33% of 85 year olds in the West
Some evidence of hereditary linkUp to 10% more likely to develop Alzheimer’s if a
first degree relative has it
Key FeaturesMemory impairment
Ability to learn new informationRecall previously learned facts
Cognitive disturbancesAgnosia – inability to recognise people or objectsApraxia – difficulty with sequencingLanguage disturbanceHigher functioning such as planning
Key FeaturesPersonality well preserved
No fluctuation in symptomsSTEADY decline
No problems with loss of consciousness
No hallucinations or behavioural problems until very late in the illness
Sleep-wake cycle often reversed
Eventually loss of central functions e.g continence
PathologyDue to deposition of abnormal proteins
throughout the brain
Beta-amyloid plaquesThese cause destruction of neurones and therefore
cognitive decline
Neurofibrillary tanglesDeposits of protein known as Tau which become
‘tangled’ causing neurone loss
Vascular DementiaAssociated with other vascular problems
Ischaemic Heart DiseaseTIA or strokeSmoking
Similar features to Alzheimer’s
Characteristic ‘stepwise’ pattern of decline
Vascular Dementia Course
Time
Severi
ty
• ‘Stepwise’ decline
• Abrupt decline in cognition with each event
Vascular event
Dementia with Lewy Bodies
Very similar in pathology to Alzheimer’s
Additional protein deposits in the brain stem known as Lewy Bodies
Similar course
Additional features of:ParkinsonismHallucinations from the outset (usually disturbing)
Fronto-temporal DementiaAlso known as Pick’s Disease
Tau deposition similar to Alzheimer’s
General cognitive decline
Additional features of:Personality changeDisinhibition Inappropriate actions
HistoryVery important – has the decline been
sudden or steady?
Like delirium, it is important to take a collateral history from a friend or relativeThe patient will probably be unable to tell you
accurately themselves
Rule out all causes of delirium before diagnosing dementiaAcute illness? Medication? Constipation?
InvestigationsDiagnosis is usually clinical and based on the
history given by friends, family or carers
Mini mental state examinationA score of 23 or less indicates probable dementia
Standard battery of investigations for delirium
CT Brain if unsureGeneralised cerebral atrophyEnlargement of ventricles
Treatment Very few treatment options
No cure
Most promising currently are anti-acetylcholinesterase inhibitors Donepezil Rivastigmine
Theory that lack of neurones, and therefore acetylcholine, slows cognition
These drugs prevent reuptake of acetylcholine in the synapse, therefore maximizing cognitive function
Unclear as to how much these drugs slow decline
SupportSupport for patient, family and carers is very
importantVisits from specialist nurse Incontinence controlCounselling
Keep family informed as to what the course of the illness will be and what to expect
There is no effective treatment
Delirium or Dementia?Delirium Dementia
Onset Sudden Gradual
Duration Acute Chronic
Cause Acute illness Brain disorder
Course Often reversible Progressive
Disorientation Early Late
Stability Variable Mostly stable
Consciousness Altered early Very late
Attention Span Often reduced Slightly reduced
Hallucinations Common Uncommon
Memory Variable Lost
Need for treatment Urgent Desirable
Case Study75 year old male presents with marked memory
loss, difficulty recognising family. No loss of consciousness or hallucinations. His daughter lives in New Zealand and is able to visit once a year.
He complains of burning pain on urination for four days
PMHLung cancer
Liver metastases CKD Stage IV
Medication and Family History
Atenolol
Digoxin
Simvastatin
Aspirin
Omeprazole
Father had Alzheimer’s disease
ExaminationTemperature 38.2ºC
Pulse 100
BP 130/80
Respiratory rate 14
O2 Sats 99% on room air
Mini mental state exam - 23
Chest clear
Differential Diagnosis? Delirium
Possible UTI Several risk factors in PMH Medication Fever
Dementia Family history Sustained inability to recognise people No hallucinations Mental state not fluctuating
InvestigationsBlood glucose 6.5
BloodsHb 130WCC 24CRP 150LFT NormalTFT NormalU&E NormalCalcium normalDigoxin level normal
Arterial Blood GasesPaO2 14kPaPaCO2 5kPa
Blood culturesNo significant
growth
ECGSinus rhythmNo abnormality
Diagnosis?Delirium secondary to urinary tract infection
5 day course of ciprofloxacin to treat
Patient returns four weeks later with daughter
She says he is still confused
Burning sensation has disappeared
Diagnosis?Alzheimer’s disease
Many elderly patients will have multiple risk factors for developing an acute confusional state
Start on anti-acetylcholinesterase inhibitorDonepezil
Advice and support to family
RememberMake sure you rule out all other causes before
jumping to conclusions
Not all elderly people presenting with confusion will have dementia
Not everyone presenting with UTI and confusion will be delirious
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