Thanks for joining me
on this discussion of hydrocephalus
in the section of neurosurgery.
Let’s start by asking you a question.
What are the causes of hydrocephalus?
I’ll give you a second to think about this.
Hydrocephalus is caused by anything
that increases the volume of the CSF.
You may recall from our discussion in the
trauma series about the Monro-Kellie doctrine.
Remember, the skull is a fixed space
containing CSF, brain and blood.
This is a little different than
traumatic brain injury patients
because CSF and hydrocephalus develops over time.
And as a result, there's some
compensatory mechanisms in play,
so that the patient does not herniate,
like a traumatic brain patient.
Now, let's review the
normal drainage of the CSF.
As you know,
CSF is produced in the choroid plexus.
It then travels to the lateral ventricle,
and eventually dumps into the subarachnoid space.
Any obstruction along this
pathway can cause CSF hydrocephalus.
What are some physical findings of hydrocephalus?
Commonly, cognitive deterioration.
This may be subtle.
It may not be a comatose patient,
somebody who's got increasing confusion.
It may, particularly in elderly patient,
present as suspicion for dementia.
Maybe the patient has some vomiting.
And frequently patients discuss
nuchal rigidity and neck pain.
Sometimes, patients are suspected
of having meningitis in these situations.
Frequently, patients also present
with imbalance and gait disturbances.
Let's discuss normal pressure hydrocephalus.
Normal pressure hydrocephalus is very high yield
and it's got a classic association syndrome.
That includes gait disturbances,
normal pressure hydrocephalus –
in other words, it doesn't
increase intracranial pressures –
are communicating in nature.
It's usually due to a decreased absorption
as opposed to an obstructing hydrocephalus.
And as we discussed previously,
they tend to be chronic and slow.