Repeated CSF removal procedures in older patients with iNPH ineligible for surgical treatment

Introduction: shunt interventions represent the key treatment of Idiopathic Normotensive Hydrocephalus (iNPH)[1], but are complicated by high costs, risk of complications[2,3], and temporary benefits[4,5], especially in frail older people. Consecutive cerebral spinal fluid removal procedures (CSF TAP test) have been used to relieve patients’ symptoms and predict surgery responsiveness. We evaluated the effect of repeated CSF TAP tests in older iNPH patients ineligible for surgery. Methods: prospective, monocentric, pilot study performed in a tertiary hospital of Milan, between 2011 and 2016. Inclusion criteria: age ≥ 75 years; positive criteria for probable iNPH[6]; ineligibility for surgery. Exclusion criteria: secondary hydrocephalus, Mini Mental State Examination (MMSE) < 20, gait disorders secondary to other causes. Pre-CSF TAP test evaluation included: Barthel index, continence, Performance-Oriented Mobility Assessment (POMA), Timed Up and Go (TUG) test, and MMSE. All the tests were periodically repeated during the follow-up. Every peri-procedural adverse event was recorded Results: Twenty-eight of the 39 enrolled patients (mean age 82.5 ±4.7 years; women 43.5%) showed an improvement in Barthel, TUG, POMA and MMSE scores after the drainage procedures, whereas continence was poorly influenced over the follow-up (median 31 months). No major adverse event was recorded from the total 83 procedures. The mean period of functional benefit between procedures was 7 months. Patients who chose to interrupt the study for subjective reasons showed a more rapid worsening of the health status over time. Key conclusions: periodic CSF TAP tests are safe, allow to control iNPH symptoms and improve functional status in geriatric patients.