Stratified screening-based cognitive measures reveals temporal patterns of recovery after the CSF tap test in idiopathic normal pressure hydrocephalus (iNPH): A single-centre retrospective study
Wenqinyi Yang, Xudong Ma, Sitong Li, Jiaming Gao, Guanghui Zhu, Chunyan Liu, Zhijun Song, Kai Yu, Ning Nannan Zhang, Peng Zhao, Xiuyun Liu, Tao Zhu, Yan Xing, Huijie YuBackground
Idiopathic normal pressure hydrocephalus (iNPH) is a reversible disorder characterized by cognitive, gait, and urinary dysfunction. While the cerebrospinal fluid (CSF) tap test can predict surgical response, screening-based cognitive assessment protocols remain undefined, limiting prognostic accuracy.
Objectives
To delineate temporal patterns of recovery for individual cognitive subdomains after the CSF tap test in patients with iNPH, and to establish high-sensitivity, time-stratified cognitive subdomains to improve preoperative prognostication and surgical decision-making.
Design
Single-centre retrospective observational study with rigorous inclusion/exclusion criteria. All patients underwent a full series of multidimensional cognitive assessments before and at 24, 48, and 72 hours after the CSF tap test. Cognitive functions were stratified into six standardized subdomains using validated weighted composite scores. All enrolled patients underwent ventriculoperitoneal (VP) shunt surgery and completed 3-month postoperative cognitive follow-up. Longitudinal changes were analysed using repeated-measures ANOVA, linear mixed models, and receiver operating characteristic curve analysis.
Methods
In this study, 53 patients with iNPH were included. Cognitive assessments were performed consistently across all time points using the Mini-Mental State Examination (MMSE), Animal Fluency Test (AFT), Trail Making Test (TMT and TMT-A), and Clock Drawing Test (CDT). Quantitative composite scores for each cognitive subdomain were computed and analysed longitudinally.
Results
Stratified analyses showed that language ability at 24 hours (P < 0.01), orientation ability at 48 hours (P < 0.01), and recall combined with attention and calculation at 72 hours (recall: P < 0.001; attention and calculation: P < 0.01) were the most sensitive and predictive for assessing the effects of the CSF tap test across time points. All enrolled patients underwent VP shunt surgery after multi-index assessment. These improvements correlated with 3-month postoperative cognitive benefits.
Conclusions
A time-stratified, subdomain-specific cognitive assessment protocol enhances tap test sensitivity, reduces misclassification, and supports personalized surgical decision-making for patients with iNPH.