Hydrocephalus
Hydrocephalus is a condition in which excess cerebrospinal fluid (CSF) accumulates within the ventricles of the brain, causing them to enlarge and potentially place pressure on surrounding brain tissue. It can occur at any age and may result from blockage of CSF flow, impaired fluid absorption, or, less commonly, excess fluid production. Symptoms vary depending on age and the rate of fluid buildup, ranging from headaches and balance problems to changes in memory, vision, or behavior.
What is it?
Hydrocephalus develops when the normal balance between the production, circulation, and absorption of cerebrospinal fluid becomes disrupted. The condition is generally classified as obstructive hydrocephalus, in which a blockage limits the normal flow of CSF through the ventricles, or communicating hydrocephalus, in which CSF circulates but is not absorbed properly.
A specific subtype known as normal pressure hydrocephalus (NPH) most commonly affects older adults and is associated with gait disturbance, cognitive decline, and urinary symptoms. MRI is the preferred imaging test for evaluating hydrocephalus because it provides detailed views of the brain ventricles, surrounding tissue, and CSF pathways. In some cases, a specialized CSF flow study performed during the MRI exam may help evaluate fluid movement and support treatment planning. CT imaging may also be used, particularly in emergency settings or for follow-up evaluation.
Important to Know
Hydrocephalus often requires treatment because prolonged pressure from excess fluid may affect brain function over time. The most common treatment involves placement of a shunt system that redirects excess CSF to another part of the body for absorption. In select patients, an endoscopic third ventriculostomy may create an alternative pathway for CSF circulation without requiring a shunt.
Follow-up imaging is commonly recommended to monitor ventricular size, shunt function, or overall stability. Red flag symptoms include sudden severe headache, vomiting, rapid vision changes, confusion, worsening difficulty walking, or loss of consciousness. In infants, rapid head enlargement, persistent irritability, poor feeding, or developmental concerns warrant prompt medical evaluation.