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Normal pressure hydrocephalus (NPH) is a neurological condition in which cerebrospinal fluid (CSF) builds up inside the brain and causes damage to the brain tissues. This condition is fully treatable, but if it is allowed to persist without treatment, the patient can experience complications. NPH is also rather tricky to diagnose, and is sometimes missed unless a doctor is very experienced. Management of this condition is usually supervised by a neurologist, a practitioner who specializes in disorders of the brain and spinal cord.
In patients with normal pressure hydrocephalus, cerebrospinal fluid builds up inside the ventricles of the brain. Normally, more fluid is always being produced, and old fluid is drained away. These patients cannot drain away excess fluid because of a blockage, and as a result, the ventricles begin to expand, pushing on the brain tissue and causing damage.
The “normal pressure” in “normal pressure hydrocephalus” is a reference to the fact that the intercranial pressure in the patient is usually normal or not unusually high. This is one of the things which makes the condition difficult to diagnose, because hydrocephalus usually leads to an increase in intercranial pressure, and a normal pressure reading may mislead a doctor. Additionally, the patient doesn't experience symptoms like headaches, vision distortions, nausea, and dizziness which are commonly associated with hydrocephalus.
One of the classic signs of normal pressure hydrocephalus is dementia. In addition, patients also have difficulty walking and often lose bladder control. Because this condition commonly occurs in the elderly, sometimes it is left untreated because the progressive neurological symptoms are attributed to aging or another condition, like Alzheimer's disease. Younger patients who develop normal pressure hydrocephalus as a result of complications from surgery or head trauma are more likely to receive treatment because a doctor recognizes that their behavior is abnormal.
To treat this condition, a neurosurgeon can install a shunt in the brain. The shunt drains fluid to the abdomen, where it can be reabsorbed and expressed by the body. This will bring down the level of CSF in the brain, reducing the pressure on the tissues of the brain and allowing the patient to recover. Depending on how early treatment is provided, the patient may be able to avoid some permanent damage, returning to a level of neurological function comparable to that experienced before the onset of NPH. A neurologist will also usually recommend follow up visits to monitor neurological function after the shunt is installed.