CSF, Hydrocephalus and Lumbar Puncture Flashcards
What is hydrocephalus?
A general condition where there is excess CSF within the intracranial space, specifically the intraventricular spaces within the brain
How is CSF produced?
Majority produced by choroid plexus that pumps sodium into the subarachnoid space with water following from the blood vessels
Describe the pathway of CSF
From the lateral ventricles, CSF travels into the 3rd ventricle then into the cerebral aqueduct and into the fourth ventricle. It then exits the fourth ventricle and flows through the subarachnoid space over and around the brain and spinal cord. It is eventually reabsorbed into the venous system through numerous arachnoid granulations along the dural venous sinuses
What are the two kinds of hydropcephalus?
Communicating/non-obstructive
Non-communicating/obstructive
Describe the pathophysiology of communicating hydrocephalus
In most cases, CSF production is greater than CSF resorption, and so the ventricular system dilates and ICP rises
Rarely, there is overproduction of CSF and communicating hydrocephalus develops
What are the signs and symptoms of communicating hydrocephalus?
In young children, disproportional increase in head circumference compared to the rest of the face and failure to thrive
In those who’s sutures have fused ie older children and up, present with symptoms of increased intracranial pressure: headache, N&V, papilloedema, gait, disturbance, 6th cranial nerve palsy, upgaze difficulty
What are the causes of communicating hydrocephalus?
Infection
Subarachnoid haemorrhage
Post-operative
Head trauma
When does non-communicating hydrocephalus occur?
Whenever there is any physical obstruction to the normal flow of CSF before it leaves the ventricles
What are the causes of non-communicating hydrocephalus?
Aqueductal stenosis Tumours/masses Cysts Infection Haemorrhage/haematoma Congenital malformations
What is the first sign of development of hydrocephalus on MRI?
Dilation of the temporal horns of the lateral ventricles
What signs of hydrocephalus can be seen on MRI?
Dilation of temporal horns of lateral ventricles
Third ventricle becomes ballooned
Lateral ventricle size increases
Peripheral sulci effaced
How is acute hydrocephalus treated?
Surgically- placement of external ventricular drain (EVD- catheter passed into lateral ventricle through scalp)
Some patients may have successful weaning off EVD but many will need a shunt inserted
What is the main complication of EVD?
High infection risk
How is communicating hydrocephalus treated?
Surgical- shunt placement, ventriculo-peritoneal most used
How is non-communicating hydrocephalus treated?
Surgical- shunt may be necessary but can be avoided if obstructing lesion is removed
Third ventriculostomy can also be used, often in conjunction with shunt