10. Raised ICP Flashcards
What are the types of brain hernias?
Subfalcine herniation
Tonsillar herniation
Uncal herniation
What are thee clinical features of raised ICP?
Headaches Nausea and vomiting Visual disturbances Confusion Seizures Amnesia Papilloedema Focal neurological signs
What is Cushing’s triad?
3 primary signs that indicate increased ICP
Hypertension, bradycardia, irregular breathing
What can cause too much blood within cerebral vessels?
Raised arterial pressure - malignant hypertension
Raised venous pressure - SVC obstruction
What can cause too much blood outside the cerebral vessels?
Haemorrhage - extradural, subdural, subarachnoid
What is malignant hypertension?
Systolic >180 or diastolic >120
What are the signs of malignant hypertension?
Retinal haemorrhages
Encephalopathy
Left ventricular hypertrophy
Reduced renal function
What happens in SVC obstruction?
Reduction in venous return from head and neck and upper limbs
Most common cause is malignancy
What will be seen on CT of extradural haematoma?
Biconvex shape
What will be seen on CT of subdural haematoma?
Concave/crescent shape
What is subarachnoid haemorrhage most commonly caused by?
Rupture of intracranial aneurysm (circle of Willis)
What is congenital hydrocephalus?
Present at birth
Build up of CSF
How do patients with congenital hydrocephalus present?
Enlargement of head circumference
Downward gaze
Delay in neurological development
What can cause obstructive hydrocephalus?
Aqueduct stenosis
Neural tube defects
Dandy-Walker syndrome (enlargement of 4th ventricle due to partial blockage of outlets)
What is communicating hydrocephalus?
Overproduction got CSF or reduced absorption of CSF (choroid plexus papilloma, infection and inflammation leading to scarring at subarachnoid space)
What are the acquired causes of hydrocephalus?
Intraventricular haematoma
Tumour
Infection
Trauma
What are the 4 types of cerebral oedema?
Vasogenic
Cytotoxic
Osmotic
Interstitial
What is vasogenic cerebral oedema?
Disruption of BBB
Breakdown of tight junctions = increased permeability
What is cytotoxic cerebral oedema?
Injury to cels of the brain
Derangement in ATP-dependent transmembrane pumps - intracellular accumulation of fluid
What is osmotic cerebral oedema?
Usually osmolarity of extracellular fluids is equal on both sides of BBB
What is interstitial cerebral oedema?
Increased pressure within ventricles, eventual damage to their linings
CSF can now be found in brain parenchyma
What investigations are done in raised ICP?
Vital signs, ECG, fundoscopy
FBC, U and Es, CRP, clotting, blood culture
CT scan, MRI
What is the management for raised ICP?
Primary survey and stabilise patient
Elevate head of bed, avoid pyrexia, analgesia
Anticonvulsants, sedation or neuromuscular blockade, mannitol or hypertonic saline
Ventriculostomy, decompressive craniectomy
