Normal pressure hydrocephalus (NPH) is a particularly important form of hydrocephalus because it mainly affects older adults and its symptoms — trouble walking, memory problems, and bladder issues — are easily mistaken for "just aging," Alzheimer's disease, or Parkinson's disease. What makes NPH so important is that, unlike most causes of dementia, its symptoms can sometimes improve with treatment.
What NPH is NPH is a type of communicating hydrocephalus in which the ventricles enlarge, but the pressure inside the skull is often normal or only intermittently elevated when measured — which is why it's called "normal pressure." Despite the normal pressure readings, the enlarged ventricles appear to affect nearby brain regions that control walking, thinking, and bladder function. Most cases are idiopathic (no clear cause), though some follow events like bleeding, infection, or injury.
The classic three symptoms (the triad) NPH is known for a characteristic trio, sometimes remembered informally as "wet, wobbly, and wacky":
- Walking difficulty (gait disturbance). Often the earliest and most prominent symptom — a slow, broad-based, shuffling, or "magnetic" gait where the feet seem stuck to the floor. Balance problems and falls are common.
- Cognitive changes. Slowed thinking, forgetfulness, difficulty with attention and planning — which can resemble other dementias.
- Bladder symptoms. Urinary urgency and, later, incontinence.
Not everyone has all three, and the walking problem is usually the symptom most likely to improve with treatment.
Why it's often missed Because each symptom is common in older adults and overlaps with other conditions, NPH is frequently misdiagnosed or overlooked. Yet recognizing it matters enormously, because it's one of the few causes of these symptoms that may be reversible.
How it's diagnosed Diagnosis combines the clinical picture with brain imaging (CT or MRI showing enlarged ventricles out of proportion to any brain shrinkage) and, crucially, tests that predict whether treatment will help — most importantly a large-volume spinal tap (the "tap test") or a few days of spinal fluid drainage, watching to see if walking and thinking temporarily improve. These tests are covered in detail in their own article.
How it's treated The main treatment is a shunt (usually a ventriculoperitoneal shunt), which drains excess CSF and can relieve symptoms — especially gait — in appropriately selected patients. Modern adjustable (programmable) valves are often used so the drainage can be fine-tuned. Not everyone benefits, which is why careful selection with the tap test matters.
A message of cautious hope NPH is worth knowing about because it offers something rare in this area of medicine: the possibility of meaningful improvement. If an older adult develops the combination of walking, memory, and bladder problems, it's worth asking a doctor specifically about NPH. Even partial improvement — particularly in mobility — can significantly improve quality of life and independence.