Evidence map›Paper›PMID 36810827›Full record

SynthesisJournal of neurology2023

Is dementia more likely following traumatic brain injury? A systematic review.

John Gerrard Hanrahan, Charlotte Burford, Palani Nagappan, Gideon Adegboyega, Shivani Rajkumar, Angelos Kolias, Adel Helmy, Peter John Hutchinson

Abstract readSystematic Review
PubMed Publisher
In one paragraph

Synthesis in Journal of neurology, 2023. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 10 papers, 1 of them a synthesis that pooled it.

0numbers the graph read from it
0cells of the map it votes in
10citing papers in PubMed, 1 pooled it
–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

10 citing papers in PubMed, 1 synthesis or guideline pooled it.

  1. Pooled it
  2. Review
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  4. Observational
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  7. Article
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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

8 authors.

John Gerrard Hanrahan *Department of Clinical Neurosciences, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.
Charlotte Burford *Department of General Surgery, East Kent University Hospitals NHS Foundation Trust, Ashford, UK. charlotte.burford1@nhs.net.ORCID http://orcid.org/0000-0002-4554-8761
Palani NagappanDepartment of Clinical Neurosciences, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.
Gideon AdegboyegaBart's and the London Medical School, Queen Mary University of London, London, UK.
Shivani RajkumarDepartment of Clinical Neurosciences, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.
Angelos KoliasDepartment of Clinical Neurosciences, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.
Adel HelmyDepartment of Clinical Neurosciences, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.
Peter John HutchinsonDepartment of Clinical Neurosciences, University of Cambridge, Addenbrooke's Hospital, Cambridge, UK.

Funding

Medical Research Council G0802251
6 · The paper itself

Abstract

backgroundThe association between traumatic brain injury (TBI) and dementia is controversial, and of growing importance considering the ageing demography of TBI.

objectiveTo review the scope and quality of the existing literature investigating the relationship between TBI and dementia.

methodsWe conducted a systematic review following PRISMA guidelines. Studies that compared TBI exposure and dementia risk were included. Studies were formally assessed for quality with a validated quality-assessment tool.

results44 studies were included in the final analysis. 75% (n = 33) were cohort studies and data collection was predominantly retrospective (n = 30, 66.7%). 25 studies (56.8%) found a positive relationship between TBI and dementia. Clearly defined and valid measures of assessing TBI history were lacking (case-control studies-88.9%, cohort studies-52.9%). Most studies failed to justify a sample size (case-control studies-77.8%, cohort studies-91.2%), blind assessors to exposure (case-control-66.7%) or blind assessors to exposure status (cohort-3.00%). Studies that identified a relationship between TBI and dementia had a longer median follow-up time (120 months vs 48 months, p = 0.022) and were more likely to use validated TBI definitions (p = 0.01). Studies which clearly defined TBI exposure (p = 0.013) and accounted for TBI severity (p = 0.036) were also more likely to identify an association between TBI and dementia. There was no consensus method by which studies diagnosed dementia and neuropathological confirmation was only available in 15.5% of studies.

conclusionsOur review suggests a relationship between TBI and dementia, but we are unable to predict the risk of dementia for an individual following TBI. Our conclusions are limited by heterogeneity in both exposure and outcome reporting and by poor study quality. Future studies should; (a) use validated methods to define TBI, accounting for TBI severity; (b) follow consensus agreement on criteria for dementia diagnosis; and (c) undertake follow-up that is both longitudinal, to determine if there is a progressive neurodegenerative change or static post-traumatic deficit, and of sufficient duration.

Indexed as

Brain Injuries, TraumaticDementiaCase-Control StudiesCohort StudiesHumansRetrospective StudiesCritical appraisalDementiaHead injuryNeurotraumaTraumatic brain injury

Identifiers

PMID36810827

What OpenQuestion holds

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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.