Hydro­cephalus in Adults

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The term Hydro­cephalus refers to a con­di­tion where the fluid filled spaces (ven­tri­cles) in the brain become enlarged due to an abnor­mal build up of cere­brospinal fluid (CSF). This can be caused by either abnor­mal­i­ties in how the CSF is pro­duced, cir­cu­lated, or reab­sorbed. As the CSF builds up, it causes the ven­tri­cles to enlarge and the pres­sure inside the head to increase. This increased pres­sure effects brain func­tion, caus­ing symptoms.

Cere­brospinal fluid (CSF) is a clear, water-​like fluid, which bathes the brain. The fluid cir­cu­lates into the space around the brain and spinal cord, where it func­tions as shock absorber, or as a pro­tec­tive cush­ion. Under nor­mal con­di­tions, you have about 125ml (a half cup) of CSF. CSF con­tains dis­solved sugar (glu­cose), pro­teins, salts, and some white blood cells.


Symp­toms of hydro­cephalus may include:

  • Headache
  • Nau­sea or vomiting
  • Irri­tabil­ity or exces­sive sleepiness
  • Vision prob­lems (ie. blurred or dou­ble vision)
  • Per­son­al­ity changes
  • Weak­ness, bal­ance or coor­di­na­tion problems


Hydro­cephalus is a con­di­tion, not a dis­ease, and can develop for a vari­ety of rea­sons, such as a brain tumour or cyst, menin­gi­tis, encephali­tis, hem­or­rhage, or a head injury.


CT scan, Lum­bar Punc­ture (LP), and Mag­netic Res­o­nance Imag­ing (MRI) are the main diag­nos­tic tests used to find out whether or not you have hydrocephalus.



The place­ment of a Ven­tricu­loperi­toneal (VP) or Lum­boperi­toneal (LP) shunt is the most com­mon treat­ment. In a shunt sys­tem, a flex­i­ble sil­i­con tube is used to drain the excess fluid (CSF) from the brain or the space around the spinal cord to another part of the body (usu­ally the abdom­i­nal cav­ity). The surgery for the place­ment of a VP shunt is explained in more detail in the patient guide, VP Shunt for Hydrocephalus.


The ven­tri­cles con­tain a spe­cialised tis­sue called choroid plexus, which pro­duces CSF. In hydro­cephalus, a build up of fluid in the brain causes the ven­tri­cles to enlarge. Since in adults the skull is set (like a rigid box), pres­sure builds up inside the skull as the ven­tri­cles expand in size.The result is increased intracra­nial pres­sure, or increased ICP, and the com­pres­sion of the sur­round­ing brain tis­sue. These in turn lead to clin­i­cal symp­toms asso­ci­ated with hydrocephalus.

Infor­ma­tion about InfoNEURO
Neuro-​Patient Resource Cen­tre
Mon­treal Neu­ro­log­i­cal Hosp­tial Room 354
Tel: (514) 3985358
E-​mail: infoneuro@​muhc.​mcgill.​ca
Web site: http://​infoneuro​.mcgill​.ca/

This infor­ma­tion is pro­duced by the Neuro-​Patient Resource Cen­tre and Mon­treal Neu­ro­log­i­cal Hos­pi­tal staff. This infor­ma­tion is for edu­ca­tional pur­poses only, and is not intended to replace the advice of a pro­fes­sional health­care prac­ti­tioner, or to sub­sti­tute for med­ical care.

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Con­trib­u­tors: Carole-​Ann Miller MSc(A), Nurse Man­ager and Andrew Stein­metz, Med­ical Librar­ian.
Series Edi­tor: Dr. David Sin­clair (Neu­ro­surgery).
Orig­i­nal Illus­tra­tion: Neu­ropho­tog­ra­phy.
Mon­treal Nuro­log­i­cal Hos­pi­tal.


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