A condition where an excessive amount of cerebrospinal fluid accumulates within the skull, hydrocephalus was, in older times, referred to as “water on the brain.”

A clear fluid that surrounds and protects both the brain and spinal cord from impacts and jarring, cerebrospinal fluid also acts as a transporter of nutrients down the spinal cord and well as a remover of waste and regulator of pressure on the brain—too much pressure, as in those suffering from hydrocephalus, can lead to permanent brain damage and death.

Occurring in all age and gender groups, hydrocephalus is classified into specific types: the “congenital” form is present at birth and arises from abnormal fetal development; “acquired” presents after birth and is the result of injury or disease; “communicating” occurs when cerebrospinal fluid is blocked after leaving the ventricles of the brain; “obstructive” means the cerebrospinal fluid can’t flow between ventricles; “normal pressure” (common with elderly patients) arises from trauma and hemorrhages, infections or tumors; and “ex-vacuo” is the result of a stroke or other trauma to the brain. And in terms of causes of hydrocephalus, genetic defects, traumas, strokes, hemorrhages, infections of the central nervous system and tumors of the brain and spinal cord can all lead to the condition.

Depending on how much cerebrospinal fluid is building up and what is causing the condition, symptoms can vary widely but often include nausea and vomiting; changes in mood or behavior; problems with memory and cognitive functions; balance and coordination issues; vision problems; headaches; and irritability.

A diagnosis of hydrocephalus is attained through an examination of a patient’s medical history (which may include previous head traumas, surgeries and diseases affecting the brain) as well as an assessment of cognitive and movement abilities (walking and balance). Imaging tests such as CT scans and MRIs to determine the extent of the condition and what areas of the brain and spinal cord are being affected will likely be necessary and, in certain cases, a procedure to drain an amount of cerebrospinal fluid (a lumbar puncture or spinal tap) will be performed to see if it alleviates symptoms.

Left untreated, hydrocephalus can worsen quickly and become life threatening. However if, during the lumbar puncture, symptoms improve, surgery will likely be highly successful and recommended. These procedures will concentrate on removing whatever obstruction is leading to the accumulation of cerebrospinal fluid; using a shunt to force any excess cerebrospinal fluid to flow away from the brain and into another part of the both where it can absorbed; and creating a new pathway out of a ventricle for the cerebrospinal fluid to flow.