Hydrocephalus is a condition in which there is an abnormal accumulation of Cerebrospinal fluid (CSF) in the ventricles and cavities of the brain. This usually results in increased intracranial pressure. Increased intracranial pressure might result in the progressive enlargement of the head (a characteristic feature of this disease), seizures, mental disability, tunnel vision and even death.
CSF is produced by the choroid plexus, which is located within the ventricular system at a rate of about 0.25 mL/min. CSF capacity of the lateral and third ventricles in a healthy person is 20 mL. Total volume of CSF in an adult is 120 mL.
The normal route of CSF from production to clearance is the following:
1) Lateral ventricle
2) Inter ventricular foramen
3) Third ventricle
4) Cerebral aqueduct of Sylvius
5) Fourth ventricle
6 ) Lateral foramina of Luschka and medial foramen of Magendie
7) Subarachnoid space
8) Arachnoid granulations
9) Dural sinus
10) Venous drainage.
Possible causes of hydrocephalus
a. Overproduction of CSF
Intracranial pressure rises if production of CSF is more than absorption. One possible cause is that CSF may be overproduced. In this case resistance to CSF flow, or venous sinus pressure may be increased as a result. CSF production will decrease as ICP rises. The brain compensates by absorption of CSF across ventricles. Temporal horns dilate asymmetrically, resulting in elevation of the corpus callosum, stretching or perforation of the septum pellucidum, thinning of the cerebral mantle, or enlargement of the third ventricle downward into the pituitary fossa (which may cause pituitary dysfunction). A possible cause of excessive CSF production might a condition known as choroid plexus papilloma, where the increase in CSF production is caused by an abnormal growth in the choroid plexus.
b. Obstruction of CSF Pathways
Obstruction of CSF pathways (usually in the fourth ventricle) may lead to decreased CSF reabsorption...