To review communicating hydrocephalus, see Hydrocephalus:Communicating Type by clicking here or from selecting the topic from the home page. The CT Scan to the left shows an enlarging ventricular system. The blood results in decreased absorption of the CSF (cerebral spinal fluid). The production of CSF continues so a net increase of CSF occurs. Thus, the ventricles begin to enlarge. About 10% of people who suffer SAH (subarachnoid hemorrhage) develop hydrocephalus.

DELAYED COMMUNICATING HYDROCEPHALUS FROM SAH

Sometimes hydrocephalus is not apparent during the acute treatment of an aneurysm rupture. It may present itself several months later. Follow-up CT scans are important to diagnose delayed hydrocephalus if clinically indicated.

UNDERSTANDING WHAT SUBARACHNOID MEANS: WHERE IS THE HEMORRHAGE?

On top of the surface of the brain tissue is a layer called the arachnoid. It looks like cellophane. It is clear in young individuals, can become a little opaque as we all get older. Between this layer and the brain is cerebrospinal fluid which is circulating around the brain tissue. Blood vessels are also along the surface of the brain. These are the blood vessels which can form into an aneurysm and bleed. When they bleed, the blood will mix and spread with the cerebral spinal fluid along the surfaces of the brain. Since it is below the arachnoid, it is called a subarachnoid hemorrhage. Other relatively common causes of subarachnoid hemorrhage include trauma and arterial venous malformations.