CSF and Hydrocephalus Flashcards
Where can CSF travel from the lateral ventricles?
Goes from lateral ventricle through the foramen of Munro into the third ventricle. Then it goes through the cerebral aqueduct of sylvius to get to the fourth ventricle. It exits through either paired foramen of luschka or single foramen of magendie. It is reabsorbed by arachnoid granulations along the venous sinuses.
What are the two types of hydrocephalus and what is the difference between them?
Communicating Hydrocephalus (Non-obstructive) Non-communicating Hydrocephalus (Obstructive) If the CSF can move freely from the choroid plexuses to arachnoid granulations then it is described as communicating. If it cannot move from start to finish and there is an obstruction then it is non communicating.
What are two causes of communicating hydrocephalus?
Commonly there is a reduced resorption of CSF compared to production. This causes dilatation of the ventricular system and raises ICP.
If there is an overproduction of CSF from choroid plexus papilloma then can get CoH.
How does a raised ICP present?
Headache Papilloedema Nausea/vomiting Gait disturbance Sixth nerve palsy Upgaze difficulty
Name some causes of NCoH
Aqueductal Stenosis Tumours/masses Cysts Infection Haemorrhage/haematoma Congenital malformations
What will be shown on a radiograph if hydrocephalus is present?
The earliest evidence will be dilatation of the temporal horns of the lateral ventricles (usually absent in younger and healthier patients)
Then get ballooned 3rd ventricle and lateral ventricles increase in size. Peripheral sulci get effaced.
Need an Evans ratio equal or more than 0.3 to diagnose ventriculomegaly.
What does an EVD do?
External Ventricular Device
goes through scalp and skull to lateral ventricle to drain CSF to outside collection system kept beside patient.
Infection risk is high.
What are some surgical treatments for hydrocephalus?
Removal of obstruction
Shunt for CoH, and NCoH if cant remove obstruction. (Ventriculo-peritoneal shunt can present with headache if malfunctions)
3rd ventriculostomy for NCoH by putting a hole in 3rd ventricle to bypass cerebral aqueduct.
Why is Normal Pressure Hydrocephalus important to diagnose?
As can be mistaken for dementia so patient never seeks or receives treatment.
What does NPH present as and how is it treated?
Hakim Adams Triad Gait Disturbance is usually the first to present (wide stance, short, shuffling steps) Urinary Incontinence Quickly progressive dementia Communicating Hydrocephalus on CT/MRI LP has normal opening pressure Treated with a VP shunt
