Evidence map›Paper›PMID 42919198›Full record

ArticleBMC neurology2026

Diagnostic accuracy of CSF tap-test parameters in predicting shunt responsiveness in normal pressure hydrocephalus: a cohort study.

Sagar Poudel, Deepa Dash, Alfonso Fasano, Aparna Wagle Shukla, Ajay Garg, Ashish Datt Upadhyay, Naveet Wig, Roopa Rajan, Animesh Das, Divya M Radhakrishnan and 15 more

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Article in BMC neurology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

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4 · The record

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5 · Who and what money

Authors and funding

25 authors.

Sagar PoudelDepartment of Medicine, All India Institute of Medical Sciences, New Delhi, India.
Deepa DashDepartment of Clinical Neurological Sciences, University of Western Ontario, London, Canada.
Alfonso FasanoDepartment of Biomedical Sciences, Humanitas University, Milan, Italy.
Aparna Wagle ShuklaDepartment of Neurology, Fixel Institute for Neurological Diseases, University of Florida, Gainesville, FL, USA.
Ajay GargDepartment of Neuroimaging and Interventional Neuroradiology, All India Institute of Medical Sciences, New Delhi, India.
Ashish Datt UpadhyayClinical Research Unit, All India Institute of Medical Sciences, New Delhi, India.
Naveet WigDepartment of Medicine, All India Institute of Medical Sciences, New Delhi, India.
Roopa RajanDepartment of Neurology, All India Institute of Medical Sciences, New Delhi, India.
Animesh DasDepartment of Neurology, All India Institute of Medical Sciences, New Delhi, India.
Divya M RadhakrishnanDepartment of Neurology, All India Institute of Medical Sciences, New Delhi, India.
Manjari TripathiDepartment of Neurology, All India Institute of Medical Sciences, New Delhi, India.
Achal K SrivastavaDepartment of Neurology, All India Institute of Medical Sciences, New Delhi, India.
S S KaleDepartment of Neurosurgery, All India Institute of Medical Sciences, New Delhi, India.
P Sarat ChandraDepartment of Neurosurgery, All India Institute of Medical Sciences, New Delhi, India.
Ashish SuriDepartment of Neurosurgery, All India Institute of Medical Sciences, New Delhi, India.
Pramod K PalDepartment of Neurology, National Institute of Mental Health and Neurosciences, Bengaluru, India.
Hrishikesh KumarMovement Disorders Program, Institute of Neurosciences, Kolkata, India.
Sakoon SagguDepartment of Neurology, All India Institute of Medical Sciences, New Delhi, India.
Deepti VibhaDepartment of Neurology, All India Institute of Medical Sciences, New Delhi, India.
Rajesh Kumar SinghDepartment of Neurology, All India Institute of Medical Sciences, New Delhi, India.
Jasmine PariharDepartment of Neurology, All India Institute of Medical Sciences, New Delhi, India.
Ranveer Singh JadonDepartment of Medicine, All India Institute of Medical Sciences, New Delhi, India.
Ved Prakash MeenaDepartment of Medicine, All India Institute of Medical Sciences, New Delhi, India.
Bindu PrakashDepartment of Medicine, All India Institute of Medical Sciences, New Delhi, India.
Arunmozhimaran ElavarasiDepartment of Neurology, All India Institute of Medical Sciences, New Delhi, India. arun_ela@yahoo.com.ORCID http://orcid.org/0000-0002-0128-7037

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundThe cerebrospinal fluid tap test (CSF-TT) is widely used as an ancillary test to select patients with idiopathic normal pressure hydrocephalus (iNPH) for ventriculoperitoneal (VP) shunt surgery; however, its diagnostic utility remains unclear.

objectivesTo evaluate the diagnostic utility of CSF-TT in predicting outcomes following VP shunts.

methodsPatients with probable iNPH underwent assessments of gait, urinary, and cognitive function using the Dutch gait scale, timed up and go (TUG) gait score, iNPH grading scale, and modified Rankin Scale (mRS) at baseline and 24 h after CSF-TT. They were offered VP shunt surgery based on the clinico-radiological profile, regardless of CSF-TT outcome. Postoperative outcomes were evaluated at 24 weeks, and patients who showed ≥ 1-point improvement in mRS were classified as shunt responders. We also assessed the diagnostic accuracy of the tap test for predicting ≥ 1-point improvement in iNPH at 24 weeks. The diagnostic performance of various baseline tests was assessed using the area under receiver operating characteristic curves (AUROCs).

results24 patients underwent VP shunting, 15 (62.5%) were classified as shunt responders. A one-point reduction in the mRS at 24 h post-CSF-TT had a sensitivity of 53.3% (95% CI: 26.6-78.7) and specificity of 66.7% (95% CI: 29.9-92.5) in predicting shunt responsiveness based on mRS as outcome. A one-point reduction in the iNPH scale at 24 h post CSF-TT had a sensitivity of 64.3% (95%CI 35.1-87.2) and a specificity of 66.7% (95% CI 22.3-95.7) to predict a one-point improvement in the iNPH scale at 24 weeks post VP shunt. Changes in mRS, Dutch gait score, TUG test score, and iNPH score were not valid predictors, as the confidence intervals of the AUROCs crossed 0.5.

conclusionCSF-TT parameters show limited accuracy in predicting shunt responsiveness in patients with iNPH. Our results suggest that about one-third of positive tap tests were false positives, and the test has poor diagnostic performance as a standalone predictor of postoperative shunt outcomes.

Indexed as

Hydrocephalus, Normal PressureSpinal PunctureVentriculoperitoneal ShuntAgedAged, 80 and overCohort StudiesFemaleHumansMalePredictive Value of TestsTreatment OutcomeCSF Tap testDiagnostic accuracyGaitiNPHNormal Pressure HydrocephalusNPHShunt responsivenessVentriculoperitoneal shunt

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.