Evidence map›Paper›PMID 40519138›Full record

SynthesisAnnals of neurology2025

The Scale of Neurodegeneration in Moderate-to-Severe Traumatic Brain Injury: A Systematic Review of Longitudinal Studies.

Bhanu Sharma, Leanne Monteiro, Alana Changoor, Brenda Colella, Robin Green

Abstract readSystematic Review
In one paragraph

Synthesis in Annals of neurology, 2025. 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

5 authors.

Bhanu SharmaMcMaster University, Hamilton, Ontario, Canada.
Leanne MonteiroToronto Rehabilitation Institute, University Health Network, Toronto, Ontario, Canada.
Alana ChangoorToronto Rehabilitation Institute, University Health Network, Toronto, Ontario, Canada.
Brenda ColellaToronto Rehabilitation Institute, University Health Network, Toronto, Ontario, Canada.
Robin GreenToronto Rehabilitation Institute, University Health Network, Toronto, Ontario, Canada.ORCID 0000-0001-9451-3963

Funding

Natural Sciences and Engineering Research Council of Canada RGPIN-2017-06615Physicians' Services Incorporated 12-43Saunderson Family FoundationThe Joseph & Antoinette Sorbara Foundation N/AThe Walter and Maria Schroeder Foundation
6 · The paper itself

Abstract

objectiveAlthough moderate-to-severe traumatic brain injury (msTBI) was once considered a static neural event following resolution of acute injuries, numerous studies now demonstrate progressive losses to volume and white matter integrity in the months and years postinjury, leading to a paradigm shift in our understanding. These findings have yet to be synthesized. Therefore, our objective was to assimilate longitudinal studies of chronic msTBI to better elucidate the scale and timelines of neurodegeneration, regions of vulnerability, and ongoing gaps in the literature.

methodsAs per our published systematic review protocol (see PROSPERO CRD42019117548), 6 electronic databases were searched from inception to June 2024. Included studies examined adults (> 17) with msTBI, were longitudinal with first acquisition at least 2 months postinjury, and reported whole brain and/or regional volumetrics or fractional anisotropy (FA).

resultsWe identified 21 studies, with and without controls, and computed annualized percent change for the limited studies with overlapping regions and timelines with sufficient data. Overall, widespread progressive volumetric and FA losses were observed, with no evidence of accelerated progression across time. No volumetric but some FA increases (predominantly nonsignificant) were observed. Annualized percent changes in ascending order were: total grey matter volume (-0.28%), total white matter volume (-0.65%), hippocampal volume (-1.98%, bilaterally), and corpus callosum FA (-3.15%).

interpretationGaps in our understanding include mechanisms of degeneration, whether progressive losses remain constant or attenuate with time, and how patterns vary by region. Longitudinal research with 3 timepoints, standardized reporting, and additional outcome modalities (eg, functional magnetic resonance imaging [fMRI], and blood biomarkers) would refine our understanding and inform treatment research. ANN NEUROL 2025;98:668-681.

Indexed as

BrainBrain Injuries, TraumaticNeurodegenerative DiseasesDisease ProgressionHumansLongitudinal StudiesWhite Matter

Identifiers

PMID40519138
PMCPMC12542324

What OpenQuestion holds

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LicenceCC BY-NC-ND
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Registered trials

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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.