Continuous Spinal Fluid Drainage

The treatment for a patient felt to have normal pressure hydrocephalus (NPH) is placement of a shunt from the fluid cavities in the brain to another location. Knowing who has NPH and who may benefit from a shunt is very challenging. There is not test that conclusively tells us that a patient has NPH. However, some tests are very helpful. In addition to MRI and CT scanning, it has been shown that continuous drainage of spinal fluid, over a few days, can be helpful in predicting if a patient may benefit from placement of a shunt.

A catheter, similar to the one used to epidural anesthesia during delivery, is placed in the spine. The catheter is placed under sterile conditions, in the hospital. The tubing is connected to a drainage tube, and then to a collecting bag. The entire procedure is very much like a spinal tap, and usually takes about 30 minutes. You are free to get up and walk around, but this may cause headache. So, for your comfort, we ask use not to get up unless absolutely necessary.

I generally ask the nurses to let fluid drain into the bag for 3-4 hours out of each 8 hr shift. If there is a great deal of headache, the drainage will be less. I want to be able to get a good test, but not cause unnecessary distress.

During this time period and the following 1-2 weeks, it is necessary for everyone that knows the patient well, to observe them for any signs of improvement. You should watch for improvement in balance, walking ability, bladder control, and short-term memory. Are periods of confusion less and sleepiness less? Is their gait more rapid and confident?

If the patient shows no signs of improvement, they are less likely to improve after a shunt is placed. If they do show signs of improvement, they are likely to show improvement with shunt placement. The idea of this test is to avoid operating upon patients that are not likely to improve afterwards. On the other hand, a favorable response makes placement of a shunt a reasonable option. A positive response to drainage does not mean that the patient will absolutely get improvement after a shunt is placed. If the CT/MRI, history and physical exam are also suggestive of NPH, the patient is likely to benefit from a shunt.

Complications

Likely - headache, transient worsening of the patients impairment

Unlikely -blood clot or infection

Also, putting an elderly patient to bed rest makes pneumonia a little more likely, as well as blood clots in the legs. The general health of the patient often dictates the possible complications, so that possibilities have to be individualized.