Beyond early motor response: Longitudinal cognitive and gait assessments after extended lumbar drainage in normal pressure hydrocephalus

Background: Idiopathic normal pressure hydrocephalus (iNPH) is a multifactorial progressive disease affecting cognition, gait, and urinary continence, potentially reversible, or at least improvable, by a prompt surgical intervention. Given its potential surgical improvement, it is crucial to determine who will benefit of a ventriculo-peritoneal shunt. To date, although several procedures are considered useful to diagnose iNPH, there is no agreement concerning the best timing of the clinical assessment or the role played by formal cognitive testing. Methods: Thirty participants with suspected iNPH were assessed at baseline, 2, and 15 days after 24-h extended lumbar drainage (ELD). Timed Up and Go test (TUG), Mini Mental State Examination (MMSE), Montreal Cognitive Assessment (MoCA), and Frontal Assessment Battery (FAB) were administered in order to quantify motor and cognitive performances. The TUG was used to assess clinical response to ELD. Results: Our sample showed significant differences between baseline assessment and follow-ups in the majority of tests. Although some enhancements in performances appeared in the first post-ELD assessment, both treatment responders and non-responders showed better performances in the delayed assessment. Post hoc comparison found significant differences in each time point between the two groups. Conclusions: These results emphasize the key role of performing multiple assessments post CSF drainage, as response can be more prominent in a delayed rather than an early phase.