EEG results correlate with tension along spine in horses

Your horse has been a little off the last season, nothing you can put your finger on but he performed better last year. Vets exam has turned up nothing definite but there is some thoughts about possible back pain. What to do next? This article puts forth the idea that you may be able to hook your horse up to an electroencephalography machine and get some amount of conformation that this is a problem. More work needs to be done but it sure is interesting.
DrO

EEG individual power profiles correlate with tension along spine in horses
PLoS One. 2020 Dec 14;15(12):e0243970.
Authors
Mathilde Stomp 1 , Serenella d’Ingeo 1 2 , Séverine Henry 1 , Clémence Lesimple 1 , Hugo Cousillas 1 , Martine Hausberger 1
Affiliations
1 Univ Rennes, Normandie Univ, CNRS, EthoS (Éthologie animale et humaine)-UMR 6552, Paimpont, France.
2 Department of Veterinary Medicine, Section of Animal Physiology and Behaviour, University of Bari “Aldo Moro”, Bari, Italy.

Abstract

Assessing chronic pain is a challenge given its subjective dimension. In humans, resting state electroencephalography (EEG) is a promising tool although the results of various studies are contradictory. Spontaneous chronic pain is understudied in animals but could be of the highest interest for a comparative study. Riding horses show a very high prevalence of back disorders thought to be associated with chronic pain. Moreover, horses with known back problems show cognitive alterations, such as a lower attentional engagement. Therefore, we hypothesized that the individual EEG power profiles resting state (i.e. quiet standing) of different horses could reflect the state of their back, that we measured using static sEMG, a tool first promoted to assess lower back pain in human patients. Results show that 1) EEG profiles are highly stable at the intra-individual level, 2) horses with elevated back tension showed resting state EEG profiles characterized by more fast (beta and gamma) and less slow (theta and alpha) waves. The proportion of theta waves was particularly negatively correlated with muscular tension along the spine. Moreover, elevated back tension was positively correlated with the frequency of stereotypic behaviours (an “addictive- like” repetitive behavior) performed by the horses in their stall. Resting state quantitative EEG appears therefore as a very promising tool that may allow to assess individual subjective chronic pain experience, beyond more objective measures of tension. These results open new lines of research for a multi-species comparative approach and might reveal very important in the context of animal welfare.