Evidence map›Paper›PMID 40496131›Full record

ArticleFrontiers in neurology2025

Assessment of the brain impact of soccer heading using pupillary light reflex.

Junzo Nakao, Ai Muroi, Aiki Marushima, Kuniharu Tasaki, Yoshiaki Inoue, Yuji Matsumaru, Eiichi Ishikawa

Abstract read
In one paragraph

Article in Frontiers in neurology, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing 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

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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

1 citing paper in PubMed.

  1. Observational
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

7 authors.

Junzo NakaoDepartment of Neurosurgery, Institute of Medicine, University of Tsukuba, Tsukuba, Japan.
Ai MuroiDepartment of Neurosurgery, Institute of Medicine, University of Tsukuba, Tsukuba, Japan.
Aiki MarushimaDepartment of Neurosurgery, Institute of Medicine, University of Tsukuba, Tsukuba, Japan.
Kuniharu TasakiDepartment of Ophthalmology, Institute of Medicine, University of Tsukuba, Tsukuba, Japan.
Yoshiaki InoueDepartment of Emergency and Critical Care Medicine, Institute of Medicine, University of Tsukuba, Tsukuba, Japan.
Yuji MatsumaruDepartment of Neurosurgery, Institute of Medicine, University of Tsukuba, Tsukuba, Japan.
Eiichi IshikawaDepartment of Neurosurgery, Institute of Medicine, University of Tsukuba, Tsukuba, Japan.

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

Background: Soccer heading is linked to adverse cognitive effects and changes similar to traumatic brain injury (TBI). In recent years, pupil light reflex (PLR) analysis via pupillometry offers a practical, reliable and objective neurological assessment for TBI. This is the first study to evaluate brain impact from soccer heading by evaluating PLR. We aimed to evaluate changes in PLR from heading and investigate if rubber balls reduce brain impacts compared with regular soccer balls. Methods: Our study involved 30 male healthy volunteer participants aged 18-29 years with >5 years of soccer experience. PLR was measured using the NPi-200 pupillometer system before and after performing every 10 headings, up to 30 headings with regular (session 1) and rubber soccer balls (session 2) in separate sessions. The parameters included neurological pupil index (NPi), constriction rate (CH), constriction velocity (CV), and maximum constriction velocity (MCV). Results: In session 1, CH and MCV significantly decreased compared with the baseline after 30 headings. In session 2, only CH significantly decreased compared with the baseline. CH significantly decreases from the 20th heading onwards in session 1 compared with session 2 (both at 20 and 30 headings; Conclusion: Heading affects PLR, with regular soccer balls causing more significant changes than rubber balls. The use of rubber balls during training may mitigate brain impacts, offering a safer alternative for players.

Indexed as

brain impactheadingpupillary light reflexsoccertraumatic brain injury

Identifiers

PMID40496131
PMCPMC12148879

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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.