Hi, this is Tom, and in this episode I'm going to be going through hydrocephalus.

And you can find notes at zero to finals.com slash hydrocephalus and in the zero to finals pediatrics book.

And you can find flashcards and questions at members.0.0.0.com. So let's jump straight in.

Hydrocephalus describes an excessive accumulation of cerebrospinal fluid, or CSF, within the ventricular

system of the brain. This is usually the result of impaired CSF flow or absorption.

Let's go through the normal CSF physiology. There are four ventricles in the brain, two lateral ventricles,

a third ventricle and a fourth ventricle. Each ventricles, a third ventricle, and a fourth ventricle.

Each ventricle has a corroid plexus that produces cerebrospinal fluid,

although the lateral ventricles produce the majority of the cerebrospinal fluid.

CSF flows from the lateral ventricles to the third ventricle,

then through the cerebral aqueduct to the fourth ventricle.

It exits into the subarachnoid space around the brain and the spinal cord

and is absorbed into the venous system by the

arachnoid granulations. Let's talk about the congenital causes of hydrocephalus. Aqueductal

stenosis is the most common cause of hydrocephalus. The cerebral aqueduct connects the third and the fourth ventricles.

Stenosis, or narrowing, blocks the normal flow of CSF out of the third ventricle, causing CSF to build up

in the lateral and the third ventricles. Other congenital causes of hydrocephalus include

arachnoid cysts blocking the outflow of CSF,

Chiari 2 malformations where the cerebellum herniates downwards

through the pheromone magnum,

and chromosomal abnormalities and congenital

malformations that obstruct the CSF drainage. Let's talk about the presentation. The cranial

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