Cognitive and upper limb symptom changes from a tap test in Idiopathic Normal Pressure Hydrocephalus.

OBJECTIVES

To determine which cognitive and upper limb assessments can identify change in patients undergoing a Cerebrospinal fluid (CSF) tap test (TT) diagnosed with idiopathic Normal Pressure Hydrocephalus (iNPH).

PATIENTS AND METHODS

Prospective observational study of 74 iNPH patients undergoing a CSF TT for consideration of a ventricular peritoneal shunt. Patients who were offered surgical intervention were classified as responders. Patients were assessed with a battery of cognitive and upper limb assessments prior to and following a CSF TT. The Timed up and go cognition (TUG-C), Montreal Cognitive assessment (MoCA) and 9-hole peg test were utilised.

RESULTS

40 patients were classified responders. Significant differences were identified for responders for the MoCA (0.62 points) and TUG-C (-6.02 s). Only the executive function and orientation sub scores of the MoCA showed significant changes for responders. The 9 hole peg test mean change of 4.33 s for responders was not significant. Non-responder change scores for the MoCA (0.22 points), TUG-C (0.3 s) and 9 hole peg test (2.58 s) were not significant.

CONCLUSION

The TUG-C has the potential to identify change in patients resulting from a CSF TT. While statistically significant change was found for the MoCA, a mean change of less than 1 point on this scale is unlikely to be clinically relevant. Similarly, the 9 hole peg test cannot be endorsed as an assessment tool for identifying changed performance in iNPH.