Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Jan;32(1):e16411.
doi: 10.1111/ene.16411. Epub 2024 Sep 14.

'Knock down the brain': a nonlinear analysis of electroencephalography to study the effects of sub-concussion in boxers

Renato De Donato  1   2 , Natale Vincenzo Maiorana  2 , Maurizio Vergari  3 , Angelica De Sandi  3 , Anisa Naci  3 , Giada Aglieco  3 , Tommaso Albizzati  2 , Matteo Guidetti  2 , Rosanna Ferrara  2 , Tommaso Bocci  2   4 , Sergio Barbieri  3 , Roberta Ferrucci  2   3   5 , Alberto Priori  2   4
Affiliations

'Knock down the brain': a nonlinear analysis of electroencephalography to study the effects of sub-concussion in boxers

Renato De Donato et al. Eur J Neurol. 2025 Jan.

Abstract

Background and purpose: Boxing is associated with a high risk of head injuries and increases the likelihood of chronic traumatic encephalopathy. This study explores the effects of sub-concussive impacts on boxers by applying both linear and nonlinear analysis methods to electroencephalogram (EEG) data.

Methods: Twenty-one boxers were selected (mean ± SD, age 28.38 ± 5.5 years; weight 67.55 ± 8.90 kg; years of activity 6.76 ± 5.45; education 14.19 ± 3.08 years) and divided into 'beginner' and 'advanced' groups. The Montreal Cognitive Assessment and the Frontal Assessment Battery were administered; EEG data were collected in both eyes-open (EO) and eyes-closed (EC) conditions during resting states. Analyses of EEG data included normalized power spectral density (nPSD), power law exponent (PLE), detrended fluctuation analysis and multiscale entropy. Statistical analyses were used to compare the groups.

Results: Significant differences in nPSD and PLE were observed between the beginner and advanced boxers, with advanced boxers showing decreased mean nPSD and PLE (nPSD 4-7 Hz, p = 0.013; 8-13 Hz, p = 0.003; PLE frontal lobe F3 EC, p = 0.010). Multiscale entropy analysis indicated increased entropy at lower frequencies and decreased entropy at higher frequencies in advanced boxers (F3 EC, p = 0.024; occipital lobe O1 EO, p = 0.029; occipital lobe O2 EO, p = 0.036). These changes are similar to those seen in Alzheimer's disease.

Conclusion: Nonlinear analysis of EEG data shows potential as a neurophysiological biomarker for detecting the asymptomatic phase of chronic traumatic encephalopathy in boxers. This methodology could help monitor athletes' health and reduce the risk of future neurological injuries in sports.

Keywords: boxing concussion; chronic traumatic encephalopathy; dementia; nonlinear EEG; sub‐concussion; traumatic brain injuries.

PubMed Disclaimer

Conflict of interest statement

The authors declare no conflict of interest.

Figures

FIGURE 1
FIGURE 1
nPSD, all channels, 4–7 Hz and 8–13 Hz (p = 0.013, p = 0.003).
FIGURE 2
FIGURE 2
nPSD, 3.5 Hz frequency band LF (p = 0.038), LFT (p = 0.023) and Z (p = 0.028).
FIGURE 3
FIGURE 3
PLE, eyes closed F3 (p = 0.010).
FIGURE 4
FIGURE 4
LRTC, F3 eyes open, 4–7 Hz (p = 0.036); 13–20 Hz (p = 0.036).
FIGURE 5
FIGURE 5
MSE low frequencies, eyes closed Fp1 (p = 0.043); F3 (p = 0.024).
FIGURE 6
FIGURE 6
MSE high frequencies, eyes open O2 (p = 0.029); O1 (p = 0.036).
See this image and copyright information in PMC

References

    1. Nagahiro S, Mizobuchi Y. Current topics in sports‐related head injuries: a review. Neurol Med Chir (Tokyo). 2014;54(11):878‐886. doi:10.2176/nmc.ra.2014-0224 - DOI - PMC - PubMed
    1. Koh JO, Cassidy JD, Watkinson EJ. Incidence of concussion in contact sports: a systematic review of the evidence. Brain Inj. 2003;17(10):901‐917. doi:10.1080/0269905031000088869 - DOI - PubMed
    1. Powell JW, Barber‐foss KD. Traumatic Brain Injury in High School Athletes. JAMA. Original Contribution. 1999;282(10):958‐963. - PubMed
    1. Rabadi MH, Jordan BD. The cumulative effect of repetitive concussion in sports. Clin J Sport Med. 2001;11(3):194‐198. doi:10.1097/00042752-200107000-00011 - DOI - PubMed
    1. Finch CF, Clapperton AJ, McCrory P. Increasing incidence of hospitalisation for sport‐related concussion in Victoria, Australia. Med J Aust. 2013;198(8):427‐430. doi:10.5694/mja12.11217 - DOI - PubMed