Hydrocephalus Flashcards
What is hydrocephalus?
An abnormal accumulation of CSF within the ventricle of the brain?
What is obstructive hydrocephalus?
This occurs when there is a block/obstruction (e.g. stenosis) proximal to the arachnoid granulations, this leads to enlargement of the ventricles proximal to the obstruction.
What is communicating hydrocephalus?
There is a defect in the reabsorption of CSF (so a problem at the arachnoid granules/villi), this means that all of the areas containing CSF will enlarge as they are all proximal to the problem.
What is normal pressure hydrocephalus?
There is an enlargement in ventricles due to increased CSF but the pressure when measured (such as in a lumbar puncture) is normal.
What is the triad of symptoms classic with hydrocephalus?
Difficulty walking
Urinary incontinence
Cognitive loss
What are some signs/symptoms that can be seen in young children with hydrocephalus?
Bulging fontenelle
Enlarged head circumference
Upward gaze palsy (setting sun sign)
6th nerve palsy
What investigations are used in suspected hydrocephalus?
Ultrasound (used in babies whose fontenelles have not yet closed as this provides a window in the bone for the probe to look through. (anterior fontenelle is the last to close between 9-18 months).
CT
MRI
Treatment for hydrocephalus?
External ventricular drain
Endoscopic third ventriculostomy (this creates a bypass for the fluid)
Ventriculo-peritoneal shunt
Can a lumbar puncture (or lumbar drain) be used?
Yes, only in communicating hydrocephalus because if used in obstructive it can lead to coning and therefore brainstem death.
What is Dandy Walker malformation?
This is a congential atresia of the foramina of Luschka and Magendie (the formina which allow CSF to pass from the 4th ventricle in to the sinuses). This causes a large build up of CSF posteriorly in the head.
What are some acquired causes of hydrocephalus?
Infection
Haemorrhage (subarachnoid)
Secondary to masses.
