**18. Follow up after shunt surgery**

Patients who have had shunt surgery should have periodic follow-up visits. The follow-up of patients with a shunt is similar to the follow-up of patients with parkinsonism or other chronic neurologic disorders. The interval history should cover all three NPH symptoms of gait impairment, incontinence, and dementia. The neurologic examination should include cognitive screening (e.g., MMSE), gait evaluation, and a general neurologic examination. Imaging may be done to rule out over-drainage, such as subdural effusion or hematoma, particularly in the first 6–12 months after shunt surgery until it is determined that the patient's condition and the appearance of the scan are stable. In most instances, a CT scan without contrast suffices. The setting of adjustable shunts should be confirmed during the follow-up visit, provided the neurologist has the device appropriate for the patient's shunt. Depending on the degree of symptomatic recovery and presence or absence of lowpressure signs and symptoms, the shunt setting can be raised or lowered in increments [25]. If there is suspicion regarding patency of the shunt radionucleotide, shunt patency test can determine the flow of radionuclide in the peritoneal cavity or the venous system (for ventriculoatrial shunts) [25].
