Evidence map›Paper›PMID 41654915›Full record

ArticleFluids and barriers of the CNS2026

Targeted CSF metabolomics and conformal prediction improve diagnostic accuracy of normal pressure hydrocephalus.

Ulrika Hofling, Jenny Jakobsson, Ida Erngren, Oskar Ekman, Eva Freyhult, Akshai Parakkal Sreenivasan, Jakob Siljebo, Sylwia Libard, Lena Kilander, Malin Löwenmark and 3 more

Abstract read
In one paragraph

Article in Fluids and barriers of the CNS, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

0numbers the graph read from it
0cells of the map it votes in
0citing papers in PubMed
–field-weighted citation impact
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

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

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

13 authors.

Ulrika HoflingDepartment of Medical Sciences, Neurology, Uppsala University, Akademiska Sjukhuset, Ing 85, Uppsala, 751 85, Sweden.
Jenny JakobssonDepartment of Medical Sciences, Clinical Chemistry, Uppsala University, Uppsala, Sweden.
Ida ErngrenDepartment of Medical Sciences, Clinical Chemistry, Uppsala University, Uppsala, Sweden.
Oskar EkmanDepartment of Medical Sciences, Neurology, Uppsala University, Akademiska Sjukhuset, Ing 85, Uppsala, 751 85, Sweden.
Eva FreyhultDepartment of Cell and Molecular Biology, National Bioinformatics Infrastructure Sweden, Science for Life Laboratory, Uppsala University, Uppsala, Sweden.
Akshai Parakkal SreenivasanDepartment of Medical Sciences, Clinical Chemistry, Uppsala University, Uppsala, Sweden.
Jakob SiljeboDepartment of Medical Sciences, Clinical Chemistry, Uppsala University, Uppsala, Sweden.
Sylwia LibardDepartment of Pathology, Uppsala University Hospital, Uppsala, Sweden.
Lena KilanderDepartment of Public Health and Caring Sciences, Clinical Geriatrics, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden.
Malin LöwenmarkDepartment of Public Health and Caring Sciences, Clinical Geriatrics, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden.
Martin IngelssonKrembil Brain Institute, University Health Network, Toronto, Ontario, Canada.
Kim Kultima *Department of Medical Sciences, Clinical Chemistry, Uppsala University, Uppsala, Sweden.
Johan Virhammar *Department of Medical Sciences, Neurology, Uppsala University, Akademiska Sjukhuset, Ing 85, Uppsala, 751 85, Sweden. johan.virhammar@uu.se.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

BACKGROUND AND

objectivesIdiopathic normal pressure hydrocephalus (iNPH) is a progressive but treatable neurological disorder. Yet, diagnosis is often confounded by overlapping symptoms and biomarker profiles with Alzheimer’s disease (AD), mild cognitive impairment (MCI), and frontotemporal dementia (FTD). We aimed to determine whether cerebrospinal fluid (CSF) metabolomic profiling, combined with uncertainty-aware machine learning using conformal prediction (CP), could improve diagnostic differentiation of iNPH.

methodsCSF samples were collected from 120 patients with iNPH, 44 healthy controls, and 152 individuals with AD, MCI, or FTD. Targeted metabolomics of 59 metabolites was performed using liquid chromatography–high-resolution mass spectrometry. Group differences were assessed using age- and sex-adjusted regression models. Multivariate classification with partial least squares discriminant analysis (PLS-DA) incorporated metabolites, demographics, and conventional biomarkers (amyloid-β42, tau, phosphorylated tau). CP was applied to address individual-level diagnostic uncertainty.

resultsEight metabolites (proline, threonine, histidine, tyrosine, tryptophan, isobutyrylcarnitine, citric acid, and dehydroascorbic acid) were consistently reduced in iNPH (q < 0.05), independent of ventricular volume and cortical tau or amyloid-β pathology. An integrated PLS-DA model combining metabolomic, demographic, and AD-biomarker data achieved excellent discrimination (AUC = 0.97). CP provided calibrated case-level confidence, identifying clear-cut and uncertain cases while maintaining high accuracy (94% for iNPH, 97% for not-iNPH). DISCUSSION: iNPH exhibits a distinct CSF metabolomic signature reflecting altered amino acid metabolism, mitochondrial function, and oxidative stress. Integrating metabolomic data with established biomarkers enhances diagnostic accuracy, while CP adds individualized uncertainty estimates to improve diagnostic confidence and guide treatment decisions.

Indexed as

Hydrocephalus, Normal PressureMetabolomicsAgedAged, 80 and overAlzheimer DiseaseBiomarkersCognitive DysfunctionFemaleFrontotemporal DementiaHumansMachine LearningMaleBiomarkersBiomarkersCSFGlymphatic systemiNPHLC-MSMetabolomicsNeurodegenerationOxidative stress

Identifiers

PMID41654915
PMCPMC12930833

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

None linked

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.