• Exploratory Evaluation of the Utility of ShuntCheck in detection of ShuntFlow in patients admitted with potential shunt obstruction [ Time Frame: Pre and post valve adjustment ] [ Designated as safety issue: No ]
  

• To assess any adverse events that arise from conducting ShuntCheck test To asess the cost effectiveness of ShuntCheck screening upon completion of the study [ Time Frame: Pre and post Valve Adjustment and 4 weeks post adjustment ] [ Designated as safety issue: Yes ]
  

Patients will be enrolled if they present with symptoms of shunt obstruction and will need to have an adjustment to their valve to determine if flow can be restored or increased if found to be low. The study will be conducted in a clinic or a doctor's office or in an emergency room by the treating physician or by the trained health care professionals. ShuntCheck is an approved, non-invasive device which can be used as an aid to the detection of shunt flow. All patients who receive the standard of care procedure, namely, valve adjustment for suspected malfunction, will be enrolled in this study initially, in case symptoms are due to inadequate drainage by a patent shunt. These patients will be tested using ShuntCheck prior to and after adjustment of the valve to determine the presence of flow prior to and after adjustment. If needed, patients may be asked to return to the clinic after 4 weeks and assessed for clinical changes post valve adjustment. An absence of flow on ShuntCheck after adjustment and diagnosis of shunt obstruction upon follow-up visit will define the suspicion of obstruction that will necessiate further shunt patency studies. Approximately 40 patients will be enrolled.