Outpatient cerebrospinal fluid tap testing with delayed patient and caregiver assessment in suspected normal pressure...

Delayed responses after cerebrospinal fluid (CSF) removal and changes observed in daily life may be missed by same-day clinic-based testing. We evaluated an outpatient CSF tap-test pathway combining quantitative testing with a 1-week patient and caregiver assessment in older patients with suspected normal pressure hydrocephalus (NPH).

We retrospectively reviewed all 22 consecutive patients who entered the pathway at two hospitals from January 2024 through December 2025. After removal of 30-50 mL of CSF, Timed Up and Go (TUG) and Mini-Mental State Examination (MMSE) assessments were performed when feasible approximately 1 h later and at 1 week. At the 1-week visit, patients and/or accompanying family members were interviewed face to face about changes in daily activities.

All patients completed testing without admission. Quantitative improvement occurred in 10 patients, clinician-documented improvement in 13, and patient- or caregiver-reported improvement in 13. The integrated clinical response was positive in 18 patients; 5 had improvement reported only by the patient or caregiver. One transient orthostatic headache occurred. No emergency department visit, unplanned hospitalization, or serious tap-test-related adverse event occurred through 1 week. Twelve patients underwent shunt surgery, and 11 had gait improvement at 3 months.

This outpatient pathway was feasible at the participating hospitals. Delayed patient and caregiver assessment identified changes not captured by clinician documentation in some patients and may complement quantitative testing. Prospective studies should use standardized reported-outcome measures and predefined assessment schedules.