A Randomized Cross-over Study for Normal Pressure Hydrocephalus

Efficacy of Shunt Surgery in Normal Pressure Hydrocephalus: a Randomized Cross-over Study

The goal of our study is to verify the effectiveness of the shunt and to identify the most sensitive criteria to select patients for surgery. The study is designed to assess improvement in walking and balance (gait), urinary function and memory after shunting. In addition, the study aims to identify the most accurate and sensitive tools to measure improvement for our patients.

Normal Pressure Hydrocephalus (NPH) causes memory loss, walking, and urinary difficulties. If NPH goes unidentified and untreated it can cause severe disability. The cause of this disease is poorly understood. It may involve damage caused by impaired blood flow in the brain.

The standard methods by which we diagnose patients who have symptoms of NPH are less accurate than desired. Many times patients remain undiagnosed or untreated while others receive treatment due to a false-positive diagnosis.

To treat NPH, a small tube called a 'shunt' can be surgically placed in the brain to drain cerebrospinal fluid (CSF) and help relieve symptoms. Currently, the reported response rates to shunting vary from 31% to 89%. Follow-up studies have shown that the shunts may not work long-term. This could be due to the natural history of the disease, development of other diseases, or due to a short term 'placebo effect' following the shunt placement surgery.

Our group is doing a study of patients with NPH. All participants in this study will have a shunt placed. These shunts are programmable and, once placed, may be opened or closed by the doctor. Programming the shunt does not require an additional surgical procedure. All study participants will be divided into two groups. One group will have their shunts open and draining. The other group will have their shunts closed (not draining). After 6 weeks, the groups will be switched. Those with open shunts will have them closed, and the group with closed, non-draining shunts, will have theirs opened. Participants will not know if their shunts are open (draining) or if they are closed (not draining). Study participants will be followed for two years. Any participants who develop recurrent, new or worsening symptoms will be taken off study and treated according to good medical practice.

The purpose of this study is to (a) look for symptom improvement in response to the draining shunt compared to the non-draining shunt (placebo affect), (b) find 'predictors' that will help doctors identify patients who will respond well to shunt placement, (c) monitor the long-term effects of these shunts, and (d) assess current diagnostic testing to see which methods are most accurate.

Eligibility Criteria:

Inclusion Criteria

1. Age of Patients ( between 60 to 85 years old).
2. Clinically suspected Idiopathic Normal Pressure Hydrocephalus (iNPH) with at least gait impairment.
3. Informed consent from patient.

Exclusion Criteria

1. Etiology for hydrocephalus other than iNPH.
2. Patients not capable of providing an informed consent.
3. History of intra-cerebral hemorrhage.
4. Cardiac Pacemaker.

Inclusion Criteria:

• Age of Patients ( between 60 to 85 years old)
• Clinically suspected Normal Pressure Hydrocephalus (NPH) with at least gait impairment
• Informed consent from patient

Exclusion Criteria:

• Etiology for hydrocephalus other than idiopathic normal pressure hydrocephalus
• Patients not capable of providing an informed consent.
• History of intra-cerebral hemorrhage
• Cardiac Pacemaker