Can anybody tell me what would needed to be done to fix the following complications of shunting of NPH? And also which ones would result in not being able to be shunted again? My family member is getting one and I’ve reading up on it, but I really want to know what happens if there was a complication.

Shunt Obstruction
Shunt Overdrainage
Shunt Malfunction
Shunt Infection
Intracerebral Hematoma
Subdural Hematoma
Seizures

Doctor Joshua’s Answer:

Thanks for your question. A shunt is a mechanical device in a biological entity, so the risk of having some shunt problems is real. The most common is shunt obstruction. This is dealt with by an operation in which the obstucted part of the shunt system is changed (usually the valve behind the ear). Overdrainage is rare in normal pressure hydrocephalus patients, but if that should occur, a new valve with a higher pressure setting can be installed. Shunt infection occurs in about 5% of cases, the treatment being removal of the whole system, a course of antibiotics, and then a new shunt system can be installed later.

Intracerebral hematoma (bleeding inside the brain) occurs in about 2-5% of cases, usually it is actually so small that it does not cause severe symptoms and needs no treatment. In about 2% of cases, the hematoma causes severe symptoms such as paralysis. In these cases, the hematoma may need to be surgically removed. Subdural hematoma (bleeding inside the skull -between the bone and the brain) may be related to shunt overdrainage and sometimes needs to be surgically treated.

Seizures have been reported to occur in about 5% of cases, but in my experience this is less common. Seizures can be treated with medication, and usually resolve over time.

The overall complication rate (complications requiring shunt revision) is 20-30 %. Usually the complications are not severe. These figures may vary from one center to another.

In summary, the shunt is a problematic device that often causes minor complications requiring shunt revision surgery. The risk of severe complications is low, but it exists. >95% of complications can be successfully treated and normal shunt function restored.

On the other hand, if the diagnosis is accurate, and the normal pressure hydrocephalus is causing severe symptoms, the risk of not shunting becomes greater than the risk of shunting, in which case the shunt operation is indicated.