CSF and Raised ICP Flashcards
Where is CSF produced?
Choroid plexus
Where is CSF absorbed?
Arachnoid complex
What is hydrocephalus?
Increased CSF resulting in an increased ICP.
What are the three causes of hydrocephalus?
Obstruction
Decreased Resorption
Overproduction
List some causes of obstructive hydrocephalus.
Inflammation
Pus
Tumours
List some causes of decreased resorption of CSF
Post SAH Sub Arachnoid Haemorrhage
Meningitis
List some causes of overproduction of CSF.
Very rare tumour affecting the choroid plexus.
What are the two types of hyrdocephalus?
Non communicating
Communicating
What is non communicating hydrocephalus?
Obstruction within the ventricular system
Within ventricles or aqueduct etc
What is communicating hydrocephalus?
Obstruction out-with the ventricular system
List some examples of causative agents of communicating hydrocephalus.
Sub arachnoid haemorrhage
Bacterial Meningitis
What is Hydrocephalus ex vacuo
Loss of the brain parenchyma in order to accommodate increased CSF
A brain with hydrocephalus ex vacuo will appear like?
Dilated ventricles
Give some examples of conditions that might result in hydrocephalus ex vacuo.
Severe dementia
Alzheimer’s
Give some causes of an increased ICP.
Space occupying lesion diffuse lesion (oedema) Increased Venous Volume Hypoxia Hypercapnia
What are the main affects of a raised ICP?
Midline shift
Pressure on cranial nerves
Reduced Cerebral blood pressure
Herniation
A subfalcine herniation is what?
Cerebral hemisphere displaces under the falx cerebri
A subfalcine herniation commonly presents as….
Weakness in contralateral leg
A tentorial herniation is what?
Temporal lobe if forced below the tentorial cerebri
What is tentorial herniation also known as?
Uncal
A uncal/tentorial herniation presents as what?
Pupilliary dilation - lack of response to light
Loss of ocular movement ipsilaterally
A cerebellar herniation is what?
Cerebellum is forced down through foramen magnum
Why is a cerebellar herniation so often fatal?
Compression of vital respiratory centres
A raised ICP commonly presents with….
Papilloedema Headache N+V Neck Stiffness Reduced Consciousness
If hydrocephalus occurs before closing of the cranial sutures what happens?
Cranial enlargement to accommodate increased CSF
A brain affected by hydrocephalus looks like.
Flattened gyri and full sulci
