What Causes Normal Pressure Hydrocephalus (NPH)?

Causes of NPH can be divided into two categories:

1. Primary NPH: The cause is unclear, but it is believed to be due to reduced absorption of cerebrospinal fluid (CSF) and impaired drainage from the brain’s ventricles. This leads to an abnormal buildup of CSF. It’s most common in the elderly.
2. Secondary NPH: Caused by other conditions, including:

• Bleeding into the brain’s coverings
• Infections such as meningitis
• Brain tumors
• Head injuries
• Complications from brain surgery

What Are the Symptoms of Normal Pressure Hydrocephalus?

Patients with NPH typically have three main symptoms:

1. Gait disturbances: slow walking, short steps, difficulty lifting feet, wide gait, and balance issues. This is usually the first noticeable symptom.
2. Memory issues: short-term memory loss, confusion, poor concentration, and slow thinking. Though milder than Alzheimer’s, untreated cases can lead to dementia.
3. Urinary problems: frequent urination, urgency, or loss of bladder control.

How Is NPH Diagnosed?

• Medical history and neurological exam, including gait, balance, memory, and urinary control evaluation.
• Brain imaging (CT or MRI) may show enlarged ventricles without brain atrophy, distinguishing it from typical dementia.
• Diagnostic tests to confirm:
• Lumbar puncture (tap test): removal of 30–50 mL of CSF followed by symptom assessment within 24–48 hours. Improvement suggests NPH.
• Lumbar drainage test: continuous CSF drainage for 3–5 days with symptom monitoring.

How Is NPH Treated?

• Ventriculoperitoneal (VP) shunt surgery: the main treatment involves placing a tube from the brain’s ventricles to the abdomen to allow CSF absorption. 50–80% of patients show improvement, especially in gait.
• Supportive care and rehabilitation
• Physical therapy and gait training
• Bladder management
• Memory support therapy

Early treatment of Normal Pressure Hydrocephalus (NPH) can lead to significant symptom improvement. Gait symptoms respond best to treatment, followed by urinary symptoms. Memory issues may improve gradually. Delayed treatment may result in irreversible dementia.