Accuracy of CSF tap test and lumbar infusion test in predicting shunt response in idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis
11 affiliations
- 1Department of Neurology, All India Institute of Medical Sciences
- 2Department of Clinical Neurologic Sciences, University of Western Ontario
- 3Department of Biomedical Sciences, Humanitas University, Pieve Emanuele
- 4IRCCS Humanitas Research Hospital, Rozzano
- 5Center for Community Medicine, All India Institute of Medical Sciences
- 6Center for Evidence for Guidelines, Department of Health Research, MoHFW, Govt of India
- 7Department of Neurology, Fixel Institute for Neurological Diseases, University of Florida, Gainesville
- 8Clinical Research Unit, All India Institute of Medical Sciences
- 9Department of Neurology, Pramukhswami Medical College
- 10Department of Medicine, All India Institute of Medical Sciences
- 11Department of Neurology, National Institute of Mental Health and Neurosciences
Abstract
Background: Idiopathic normal pressure hydrocephalus (iNPH) presents with gait disturbance, cognitive impairment, and urinary incontinence. The cerebrospinal fluid tap test (CSF-TT) and lumbar infusion test (LIT) are commonly used to predict postoperative improvement after shunt surgery; however, their validity remains debated.
Methods: We performed a systematic review and meta-analysis to assess the sensitivity and specificity of CSF-TT and LIT. The protocol was registered in PROSPERO (CRD42023454502). Reporting followed the PRISMA-DTA guidelines, and the certainty of evidence was assessed using the GRADE approach.
Results: Of 1,955 studies, 15 were included, reporting on 721 CSF-TT and 393 LIT patients, with shunt surgery as the reference standard. Nine CSF-TT studies ( n = 700) and five LIT studies ( n = 368) contributed to the primary meta-analysis. Considerable heterogeneity existed in test protocols, timing of assessment, and outcome measures. Several studies were retrospective with a high risk of bias. The pooled estimates were derived from a limited number of heterogeneous studies. Using a bivariate random-effects model, pooled sensitivity and specificity of CSF-TT were 64.1% (95% CI 49.2–76.6%, I ² 81.3%) and 54.8% (95% CI 41.8–67.2%, I ² 59.7%), respectively. The certainty of evidence was very low for sensitivity due to bias, inconsistency, and imprecision, and low for poor specificity due to bias and inconsistency. LIT showed a pooled sensitivity of 77.5% (95% CI 70.2–83.4%, I ² 14.7%) and a specificity of 28.3% (95% CI 19.0–39.9%, I ² 4.6%), with moderate certainty for sensitivity and moderate certainty for poor specificity.
Conclusion: Both CSF-TT and LIT show poor specificity for predicting shunt responsiveness in iNPH, with low-certainty evidence for CSF-TT and moderate-certainty evidence for LIT. A positive result from either test should not be used in isolation to guide surgical decisions. Standardized prospective studies with clearly defined patient selection criteria and outcome measures are needed to establish the true diagnostic value of these tests.
Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD42023454502 .
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BibTeX
@article{aliyar2026accuracy,
title = {{Accuracy of CSF tap test and lumbar infusion test in predicting shunt response in idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis}},
author = {Aminu Aliyar and Deepa Dash and Alfonso Fasano and Manya Prasad and Vikas Dhikav and Aparna Wagle Shukla and Ashish Datt Upadhyay and Soaham Desai and Sagar Poudel and Pramod Kumar Pal and Arunmozhimaran Elavarasi},
journal = {Frontiers in Neurology},
year = {2026},
month = oct,
doi = {10.3389/fneur.2026.1908328},
url = {https://www.frontiersin.org/articles/10.3389/fneur.2026.1908328/full},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Accuracy of CSF tap test and lumbar infusion test in predicting shunt response in idiopathic normal pressure hydrocephalus: a systematic review and meta-analysis
AU - Aminu Aliyar
AU - Deepa Dash
AU - Alfonso Fasano
AU - Manya Prasad
AU - Vikas Dhikav
AU - Aparna Wagle Shukla
AU - Ashish Datt Upadhyay
AU - Soaham Desai
AU - Sagar Poudel
AU - Pramod Kumar Pal
AU - Arunmozhimaran Elavarasi
PY - 2026
DA - 2026/10/12
JO - Frontiers in Neurology
DO - 10.3389/fneur.2026.1908328
UR - https://www.frontiersin.org/articles/10.3389/fneur.2026.1908328/full
AB - Background: Idiopathic normal pressure hydrocephalus (iNPH) presents with gait disturbance, cognitive impairment, and urinary incontinence. The cerebrospinal fluid tap test (CSF-TT) and lumbar infusion test (LIT) are commonly used to predict postoperative improvement after shunt surgery; however, their validity remains debated. Methods: We performed a systematic review and meta-analysis to assess the sensitivity and specificity of CSF-TT and LIT. The protocol was registered in PROSPERO (CRD42023454502). Reporting followed the PRISMA-DTA guidelines, and the certainty of evidence was assessed using the GRADE approach. Results: Of 1,955 studies, 15 were included, reporting on 721 CSF-TT and 393 LIT patients, with shunt surgery as the reference standard. Nine CSF-TT studies ( n = 700) and five LIT studies ( n = 368) contributed to the primary meta-analysis. Considerable heterogeneity existed in test protocols, timing of assessment, and outcome measures. Several studies were retrospective with a high risk of bias. The pooled estimates were derived from a limited number of heterogeneous studies. Using a bivariate random-effects model, pooled sensitivity and specificity of CSF-TT were 64.1% (95% CI 49.2–76.6%, I ² 81.3%) and 54.8% (95% CI 41.8–67.2%, I ² 59.7%), respectively. The certainty of evidence was very low for sensitivity due to bias, inconsistency, and imprecision, and low for poor specificity due to bias and inconsistency. LIT showed a pooled sensitivity of 77.5% (95% CI 70.2–83.4%, I ² 14.7%) and a specificity of 28.3% (95% CI 19.0–39.9%, I ² 4.6%), with moderate certainty for sensitivity and moderate certainty for poor specificity. Conclusion: Both CSF-TT and LIT show poor specificity for predicting shunt responsiveness in iNPH, with low-certainty evidence for CSF-TT and moderate-certainty evidence for LIT. A positive result from either test should not be used in isolation to guide surgical decisions. Standardized prospective studies with clearly defined patient selection criteria and outcome measures are needed to establish the true diagnostic value of these tests. Systematic review registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD42023454502 .
SN - 1664-2295
ER -