Hydrocephalus Flashcards
What are the three different ways of classifying hydrocephalus?
Infantile or childhood/adult, acute or chronic, obstructive or communicating
What are the three causes of hydrocephalus?
Something obstructing the flow of CSF, a problem absorbing CSF, too much production of CSF
Describe obstructive hydrocephalus?
Hydrocephalus caused by something obstructing the flow of CSF e.g. a blockage in the ventricular system or outflow from the ventricular system
Describe communicating hydrocephalus?
Hydrocephalus caused by impaired CSF absorption by the arachnoid granulations
What can obstructive hydrocephalus also be known as? Why is this?
Non-communicating hydrocephalus, the CSF in the ventricles does not communicate with the CSF in the subarachnoid space
Hydrocephalus leads to intracranial accumulation of CSF which causes what?
Increased ventricular size and raised ICP
How does acute hydrocephalus present?
With features of raised ICP: patients develop acute headache with N+V as well as a deterioration in conscious level
What are some extra features of acute hydrocephalus?
Irritability in young children and ‘sunsetting’ eyes
What causes a sunsetting gaze?
Impairment of upward gaze caused by pressure on the midbrain vertical gaze centres
How does chronic hydrocephalus usually present?
Progressive deterioration in higher neurological functions and persistent pressure headache
What are some examples of deterioration in higher neurological function seen in chronic hydrocephalus that may be seen in children?
Failure to thrive, developmental delay, worsening school performance
Occasionally, congenital hydrocephalus can be picked up before birth on what investigation?
US scan
How may congenital hydrocephalus present?
Large head, thin and shiny scalp with visible veins, bulging or tense fontanelle, downward looking eyes
Why does congenital hydrocephalus cause an increase in head circumference?
Children < 18 months have skull bones that are still unfused to increased ICP causes the skull to enlarge
As well as the signs on the head, what are some more behavioural features that may be seen in congenital hydrocephalus?
Poor feeding, irritability, sleepiness, vomiting, muscle stiffness and spasms in the lower limbs
Some babies have a large head but do not have congenital hydrocephalus. When should you be concerned about this?
When the head circumference starts increasing centiles
Does congenital hydrocephalus go away?
No, it is usually a lifelong condition
Give an example of a vascular cause of hydrocephalus which is a) obstructive? b) communicating?
a) intracerebral haemorrhage b) subarachnoid haemorrhage
Give an example of an infective cause of hydrocephalus which is a) obstructive? b) communicating?
a) infective space occupying lesion e.g. abscess b) meningitis
Give an example of a tumour cause of hydrocephalus which is a) obstructive? b) communicating?
a) any tumour within or outside the ventricular system b) carcinomatous infiltration of the meninges
Congenital hydrocephalus is usually caused by what? Is this obstructive or communicating?
Stenosis of a part of the ventricular system, this is obstructive
What is the first line investigation for hydrocephalus?
CT
What will a CT show in obstructive hydrocephalus?
Dilation of the ventricle proximal to the site of obstruction
What will a CT show in communicating hydrocephalus?
Generalised dilatation of all ventricles
