Predicting response to shunting requires a large-volume lumbar puncture. The above evaluations are repeated 3 hours later. Improvement in gait may be seen in the form of reduced time to walk a fixed distance, reduced gait apraxia, or reduced freezing of gait. Reduction in bladder hyperactivity also may be a sign of good outcome from shunting. When clinical suspicion is high and the patient is a good candidate for surgery, repeated lumbar punctures are indicated over the next 1-2 days.
Some clinicians use an indwelling CSF catheter in lieu of repeated lumbar punctures.
This method carries a higher risk of meningeal infection but may allow for a more accurate prognosis. Clinical outcome after CSF drainage and shunt surgery were assessed by the change in clinical examination, with grades of none, minor, moderate, or marked change. For a more objective assessment, videotape the timed walking test before and after lumbar puncture. Patients with a good response to the above procedure are candidates for ventriculoperitoneal or ventriculoatrial shunting. Some evidence indicates that patients with gait disturbance, mild or no incontinence, and mild dementia fare best among shunt surgery patients.