A proposed scheme for comprehensive and systematic evaluation of normal pressure hydrocephalus

Abstract

AbstractBackgroundAs ageing population continues to rise across the globe, age‐related conditions such as normal pressure hydrocephalus (NPH) are expected to become a prevalent health problem effecting gait and cognition in the elderly. Alas, the vague definition of NPH, coupled with the absence of standardized assessment protocols, can potentially result in unnecessary surgical interventions and complications. We aim to demonstrate the feasibility of our proposed objective scheme for a comprehensive and systematic evaluation of NPH, which we anticipate will be beneficial in guiding future management of this enigmatic disorder.MethodParticipants suspected of idiopathic NPH (iNPH) selected to undergo a trial of fluid diversion (i.e. large volume spinal tap) were enrolled to receive structured assessment with various biomarkers. This assessment includes pre‐fluid diversion evaluation of the following: iNPH grading scale (Kubo et al., 2008), voxel based morphometry analysis of the MRI, tablet‐based digitalized Montreal Cognitive Assessment, International Consultation on Incontinence Questionnaires, urodynamic studies. Tests that were conducted both pre‐ and post‐fluid diversion test included actigraphy, video gait analysis using Kinovea®, in‐house tablet‐based go/no‐go test and conjunction search test. During the fluid diversion trial, participants underwent an infusion test for objective quantification of cerebrospinal fluid dynamics. Cerebrospinal fluid was collected and analyzed for levels of Alzheimer’s disease biomarkers, specifically Aβ and tau species, using ELISA, as well as an α‐synuclein seeding assay. The decision to operate was made according to subjective improvement, which is the current standard of care, and subsequent assessments were repeated at 4‐month intervals for 1, 2, and 3 years postoperativelyResultBetween May 2022 and November 2022, six participants were recruited. Each test was completed by at least three out of the six participants. The participant who completed the most tests completed all but one of the tests. It is important to note that none of the participants recruited underwent shunt surgery.ConclusionThe proposed scheme for the assessment of NPH demonstrates feasibility, however, certain optimizations are necessary. Further research should be conducted to determine the correlation between these parameters and their performance in predicting long‐term responsiveness to shunt surgery.