EEG-based sensory testing reveals altered nociceptive processing in elite endurance athletes

Abstract

Increased exercise loads, as observed in elite athletes, seem to modulate the subjective pain perception in healthy subjects. The combination of electroencephalography (EEG) and standardized noxious stimulation can contribute to an objective assessment of the somatosensory stimulus processing. We assessed the subjective pain ratings and the electroencephalogram (EEG)-based response after standardized noxious mechanical and thermal stimuli as well as during conditioned pain modulation (CPM) in 26 elite endurance athletes and compared them to 26 recreationally active controls. Elite endurance athletes had consistently stronger somatosensory responses in the EEG to both mechanical and thermal noxious stimuli than the control group. We observed no significant group differences in the subjective pain ratings, which may have been influenced by our statistics and choice of stimuli. The CPM testing revealed that our conditioning stimulus modulated the subjective pain perception only in the control group, whereas the EEG indicated a modulatory effect of the conditioning stimulus on the spectral response only in the athletes group. We conclude that a higher activation in the cortical regions that process nociceptive information may either be an indicator for central sensitization or an altered stimulus salience in the elite endurance athletes’ group. Our findings from our CPM testing were limited by our methodology. Further longitudinal studies are needed to examine if exercise-induced changes in the somatosensory system might have a critical impact on the long-term health of athletes.

Nociception in chicken embryos, Part II: Embryonal development of electroencephalic neuronal activityin ovoas a prerequisite for nociception

“…The situation is much clearer in the adult bird. Physiological responses including spectral changes in the EEG to nociceptive stimuli have been described for awake birds [62][63][64] , being consistent with those observed in awake mammals 13,39,40,43,64 . The neuroanatomical prerequisites such as cutaneous mechanical, thermal, chemical and polymodal nociceptors are present and respond to external stimulation similar to mammalian nociceptors 3,65,66 .…”

“…EEG signals from EEG1 were analyzed with a wavelet transform portion of the newtimeffunction with 3 cycles at the lowest frequency of 3Hz and 20 cycles at the highest frequency of 100Hz. In the ERSP results, any deactivation or activation below a threshold of -2dB or above a threshold of +2dB was considered as a response to the stimulus 39,40,43 . For the analysis of all baseline EEG recordings and stimuli-locked EEGs, 6 randomly selected datasets from each development stage (ED07-ED19)…”

“…The phase-locked response in the EEG after electrical stimulation was expected rather immediately after the onset of the stimulus (below 100ms). The EEG response after thermal stimulation was expected well after the onset of the stimuli due to ∆Theating of the Peltier-element (between 100ms and 800ms) 39,40,43 .…”

Nociceptive Processing of Elite Athletes Varies Between Sport-Specific Loads: An EEG-based Study Approach

“…The presented manuscript is a subanalysis of our previously published results, from which the described methodology and research question was derived (17). This publication is also part of a series of publications on the establishment of the applied methodology (15,(17)(18)(19). The research questions were designed to identify whether there are differences in pain perception and the noxious processing of standardized, painful stimuli using EEG and HPT in sports with the same modality, i.e., endurance.…”

“…Therefore, EEG could also potentially assist in the detection of alteration caused by different types of sport that are not presented or masked in subjective ratings of pain intensity. Because chronic pain is also a common phenom among elite athletes, using the EEG might help identifying early patterns of chronic pain and identify athletes at risk (17).…”