Hydrocephalus

Hydrocephalus is a buildup of cerebrospinal fluid (CSF) deep inside the brain. CSF normally flows through hollow spaces called ventricles, delivering nutrients, clearing waste, and cushioning the brain from injury. When this fluid can’t flow or drain properly, the ventricles widen and put pressure on the brain. Because the body produces CSF continuously, pressure can build up quicky. Hydrocephalus can occur at any age and can be serious, making early diagnosis and treatment important.

Hydrocephalus is treated by specialists in neurosurgery and neurology. At Penn Medicine, care is tailored to your age, symptoms, and overall health. For children with hydrocephalus, we work closely with Children’s Hospital of Philadelphia (CHOP) Neuroscience Center through a long-standing pediatric alliance. This collaboration brings together world-class pediatric experts and local care teams, helping families access coordinated care, advanced treatments, and the latest research close to home.

Types of hydrocephalus

Hydrocephalus varies based on where the blockage occurs and whether it causes increased pressure in the skull:

• Communicating hydrocephalus: The buildup of CSF occurs due to a blockage in flow outside the ventricles or due to reduced reabsorption. Increased CSF creates elevated pressure inside the ventricles.
• Noncommunicating hydrocephalus: A passage between the ventricles becomes blocked, leading to a buildup of CSF and increased pressure.
• Normal pressure hydrocephalus: There is a slow increase in fluid, which allows the tissues around the ventricles to expand. But pressure in the brain does not increase.

Hydrocephalus can be present at birth (congenital) or develop later in life due to an illness or injury. In some cases, including normal pressure hydrocephalus, the exact cause isn’t known.

Common causes include:

• Birth factors: Premature birth or infections during pregnancy
• Head injuries: Serious accidents or trauma to the brain
• Illness: Brain infections like meningitis, or a stroke
• Tumors: Growths in the brain or spinal cord that block fluid flow
• Pressure changes: Conditions like idiopathic intracranial hypertension