Delirium - causes inside the brain

Question 1

CAUSES OF DELIRIUM

i) which two parts of the brain are going wrong in delirium?
ii) name the five main causes of delirium inside the brain
iii) name one thing that can cause each of the above, that leads to confusion/delirium
iv) is delirium caused by ischaemic stroke?

Answer 1

i) cerebral cortex (needs to be bilateral and majority of ceb cortex) and sometimes temporal lobes
ii) intracranial infection, inflammation (autoimmune), epilepsy, vascular causes (ischaemia or bleeding in the skull), raised ICP

iii) infection - meningitis, viral encephalitis (usually herpes), HIV
inflammation - autoimmune encephalitis, cerebral vasculitis (inflam of arteries in brain) giant cell arteritis
epilepsy - in a full generalised seizure, focal seizure (usually aff temporal lobe - can go on for hours/days), post ictal state
vascular - sub arach haemmorhage, hypoxic brain injury (drowning), venous infarction (clot > back pressure)
raised ICP (squashing of the brain > midline shift) - oedema, subdural haematoma, acute hydrocephalus > squashes cortex and causes delirium

iv) no - only affects a small part of the brain

Question 2

IDENTIFYING THE CAUSE

WHAT IS SEEN IN THE PATIENT

i) name three things that may be seen if the patient has infection in the brain? name two things that may predispose a patient to infection?
ii) name three things that may be seen if the patient has an autoimmune cause of delirium?
iii) what may be seen if epilepsy is causing delirium? (2) what can predispose patients to this (3)
iv) name two things that point to a vascular (bleeding) cause of delirium? name two predisposing factors
v) name three signs of a raised ICP causing delirium? name three things that can cause raised ICP

Answer 2

i) fever, seizure, headache (irritation of meninges)
- pre dis if immune deficiency or breach in the skull (trauma base of skull fracture)

ii) seizures (focal), focal signs eg weak arm, facial droop, subacute onset (over weeks)

iii) focal seizure > dramatic fluctuation (responsive then sometimes unresponsive), involuntary movement
- may see bruises, friction burns, incontinence - show a seizure has taken place
- predis if already have epilepsy, stroke, tumour, ETOH > something affecting part of the cerebral cortex leading to focal seizures

iv) headache (stretching meninges), focal signs (pressure on part of the cortex), hypertension
- pre dis if vascular RF or anticoag use

v) headache (pushing on meninges), focal signs (push on part of cortex), pupils (squashing of CNIII > dilated and unreactive pupil on that side)
- head injury, stroke (swelling > pressure on ipsi and contralateral side of brain), tumour

Question 3

i) what does fever suggest?
ii) what do seizures/focal signs suggest?
iii) what causes headache?
iv) what can cause change in pupil size?
v) name five underlying features that can predispose to brain causes of delirium

Answer 3

i) infective cause
ii) involvement of a specific part of the brain
iii) pushing on the meninges
iv) space occupying lesion
v) immune deficient, recent head injury, epilepsy, recent stroke, tumour, ETOH excess, vascular risk eg on anti coags or hypertension