00:01
What about a non-communicating hydrocephalus?
This can behave like a mass effect.
00:08
Mass such as a tumor
or an extrinsic obstruction of
the normal CSF drainage pathway.
00:14
Recall a few slides back,
the choroid plexus,
all the way to the subarachnoid space,
is a defined pathway.
00:21
Any obstruction along that pathway
can cause a non-communicating hydrocephalus.
00:26
Remember, the brain has had
less time to compensate
and more likely to develop intracranial hypertension.
00:34
Besides our physical and history,
imaging diagnosis can be helpful.
00:39
Generally speaking, we get a CAT scan.
00:41
The arrow is pointing to you
a very decreased amount
of lateral ventricle space.
00:47
In this MRI image,
you notice quite dilated ventricles.
00:52
This probably represents a CSF accumulation
due to the lack of absorption
rather than an obstruction.
00:58
Now, you’ve diagnosed hydrocephalus.
01:02
When do we need to treat it?
Well, indications for treatment,
which includes a ventricular peritoneal shunt,
is when the patient becomes symptomatic.
01:11
In this shunt procedure,
a catheter is placed between the ventricles,
tunneled under the skin
and introduced into the abdomen.
01:19
Although a fairly routine procedure,
it does contain some complications.
01:23
Mostly, as you can imagine,
if the catheter is in the abdomen,
intestines can loop around it.
01:28
This catheter can be clogged
and becomes dysfunctional.
01:32
It may need to be replaced.
01:34
Additionally, also remember,
sometimes the ventricular peritoneal
shunt is actually a ventricular plural shunt.
01:41
That's when the ventricular drainage
catheter is placed into thoracic –
into the thoracic space
as opposed into the abdomen.
01:49
Some reasons that neurosurgeons may
choose to place it into the thoracic space
as opposed to the abdominal space is
because of prior surgeries in the abdomen.
01:58
As we previously described,
this catheter sits in the ventricle,
is tunneled, as you can see in this schematic,
either into the thoracic space
or into the abdomen.
02:08
Now, it’s time to remind you of
some clinical pearls and high-yield
information on hydrocephalus.
02:14
Remember the classic findings of
normal pressure hydrocephalus?
Although rare, it's a popular test question.
02:21
It requires a high index of suspicion,
so you as a clinician should think
about normal pressure hydrocephalus.
02:28
If the clinical scenario
presents with classic findings,
you have your answer.
02:34
And remember, Arnold-Chiari syndrome.
02:37
This syndrome is a skull malformation
that can cause cerebellar
tonsils to displace inferiorly.
02:44
This actually causes an obstruction.
02:46
So, this would not be an example
of normal pressure hydrocephalus.
02:50
This is so-called non-communicating hydrocephalus.
02:54
This is high-yield information.
02:56
I’d encourage you to commit it to memory.
02:59
Thank you very much for joining me
on this discussion of hydrocephalus.