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Information about a piece of news titled Stian Bahr Sandmo defended his thesis on the 17th of December 2020

Stian Bahr Sandmo defended his thesis on the 17th of December 2020

Intoduction

MD Stian Bahr Sandmo defended his thesis "Repetitive head impacts in football – quantifying exposure and assessing outcomes" at the Norwegian School of Sports Sciences/ The University of Oslo.

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Disputas

  • Date: Thursday 17th of December
  • Place: Bacause of Covid-19, the events will streamed. 

  

Committee

  • Committee chair: Professor II Eirik Helseth, Institutt for klinisk medisin, Universitetet i Oslo.
  • 1. Opponent: Professor Niklas Marklund, Lunds universitet, Sverige
  • 2. Opponent: Professor Margo Mountjoy, McMaster University Medical School, Ontario, Canada.

 

To further our understanding of the link between repetitive head impacts in football and potential neurological consequences

Football involves voluntary heading and an inherent risk of concussions. The question is: What are the effects on the brain from such exposure?

The aim of the the thesis has been to further our understanding of the link between repetitive head impacts in football and potential neurological consequences.

Prospective studies are on the way, aiming to answer the question above. Central to this thesis is the study RepImpact, exploring potential neurological effects of repetitive head impacts in youth football. Importantly, however, such studies encounter several challenges when quantifying exposure and assessing outcomes. 

First, accurate exposure data is key to assess risk. Thus, we quantified heading exposure in youth football, observing thousands of male and female players across several age groups. Heading rates were influenced by both sex and age, and heading was a rare event in the age groups currently targeted by injury prevention measures. 

Then, we evaluated the validity of different methods for quantifying heading exposure in RepImpact. First, we evaluated in-ear sensors. Despite inaccurate readings in the laboratory, the sensors could discriminate heading from non-heading events during on-field testing. Still, there was a need for secondary verification (e.g. using video analysis) of headers in real-life settings, making their use highly labor intensive. Consequently, we also evaluated a self-report questionnaire. Substantial measurement errors rendered self-report unable to quantify individual heading exposures. However, it could still identify players belonging to high and low-exposure groups, supporting its potential use in RepImpact.

Last, we explored if headers or accidental head impacts cause structural damage to the brain, detected as an increase in NfL or tau proteins in the blood. There was no evidence of structural brain injury; however, we identified an increase in tau levels in response to high-intensity exercise, highlighting an important limitation for its use.

Ultimately, findings from this thesis pave the way for future studies to settle the question on whether repetitive head impacts in football are harmful for the brain.

Conclusions

Central conclusions from this work are as follows: (1) Heading is a rare event in the youngest age groups in youth football, thereby questioning the effects of current prevention measures; (2) self-report seems the most adequate method for quantifying heading in large studies in youth football, despite inherent limitations; and (3) there is no evidence of structural brain injury by repetitive headers and accidental head impacts in football, as detected by tau and NfL proteins in the blood. 

Implications

This thesis can help guide future injury prevention measures. Moreover, it has paved the way for future studies to settle the question on whether repetitive head impacts in football are harmful for the brain.

Supervisors 

  • Professor Roald Bahr, Oslo Sports Trauma Research Center
  • Professor Inga K. Koerte, Ludwig-Maximilians-Universität, Münich, Germany 
  • Professor Lars Engebretsen, Oslo Sports Trauma Research Center/University of Oslo/Orthopedic Division, Oslo University Hospital  

The thesis is based on the following articles:

1. Sandmo SB, Andersen TE, Koerte IK, Bahr R. Head impact exposure in youth football – Are current interventions hitting the target? Scand J Med Sci Sports. 2020 Jan;30(1):193-198.

2. Sandmo SB, McIntosh AS, Andersen TE, Koerte IK, Bahr R. Evaluation of an in-ear sensor for quantifying head impacts in youth soccer. Am J Sports Med. 2019 Mar; 47(4):974-981.

3. Sandmo SB, Goiijers J, Seer C, Kaufmann D, Bahr R, Pasternak O, Lipton ML, Tripodis Y, Koerte IK. Evaluating the validity of self-report as a method for quantifying heading exposure in male youth soccer. Accepted in Res Sports Med 29 Sep 2020.

4. Sandmo SB, Filipcik P, Cente M, Hanes J, Andersen TE, Straume-Naesheim TM, Bahr R. Neurofilament light and tau in serum after head-impact exposure in soccer. Brain Inj. 2020 Apr 15:34(5):602-609.


Read more about Stian and his projects here.