The Brain Gauge is a brain health assessment tool that tests higher cognitive function processes, such as lateral inhibition using sensory stimuli (CorticalMetrics, n.d.a). Lateral inhibition is the enhancement of a stimulated region in the brain and the inhibition of the neighbouring lateral regions (CorticalMetrics, n.d.a). This event was first introduced by Georg Von Bekesy, a Nobel prize winner, over 60 years ago (Cortical Metrics, n.d.a). The area of the brain can be stimulated via sensory input and/or other regions of the brain (CorticalMetrics, n.d.a). Lateral inhibition is a crucial component of information processing and therefore a good indicator of neural function (CorticalMetrics, n.d.a). An individual with compromised neural function will have a harder time distinguishing between two inputs that are delivered simultaneously, compared to a healthy individual (CorticalMetrics, n.d.a). Unlike medical imaging, somatosensory testing can detect interruptions in lateral inhibition and does so in a non-invasive manner (CorticalMetrics, n.d.a).
Brain Gauge created by CorticalMetrics is an objective, quantifiable method that works by probing the CNS functional mechanism through tactile stimuli, detecting changes in neural mechanisms (CorticalMetrics, n.d.). Brain Gauge resembles a computer mouse and is a plug in device operable with MacBook, PC or Chromebook (CorticalMetrics, n.d.b). It works by sending vibrational patterns to the index and middle finger through specific placements on the mouse (CorticalMetrics, n.d.b). A series of questions are then asked regarding the vibrations, e.g., “Which was stronger?”, “Which one occurred first?” (CorticalMetrics, n.d.b). The questions become increasingly more difficult as they are answered correctly (CorticalMetrics, n.d.b). Eight different measures are recorded: speed, focus, fatigue, accuracy, plasticity, sensitivity and connectivity, along with an overall score labelled as corticalmetric (CorticalMetrics, n.d.b). The results are displayed in a bar graph and chart, with green representing normal levels of performance and red, orange and yellow symbolizing different levels of cognitive function (CorticalMetrics, n.d.b).
There are many applications for BrainGauge which include concussion recovery/management, research of different neurological conditions (autism, ADHD, OCD, TBI, chronic pain, etc.), examination of efficacy of treatment interventions (PEMF, TMS, etc.) and personal curiosity (effects of caffeine, alcohol, supplements) (CorticalMetrics, n.d.b). There are three Brain Gauge products that CorticalMetrics offers: Brain Gauge Home, Brain Gauge Pro and Brain Gauge MD (CorticalMetrics, n.d.c). The first is designed for individuals to use at home to monitor the effects of exercise, supplements and diet on brain health (CorticalMetrics, n.d.c). The second is targeted for health practitioners, specifically athletic therapists, physiotherapists, chiropractors, etc. (CorticalMetrics, n.d.c). It allows for unlimited subjects and tests, designed to track brain health of athletes and patients (CorticalMetrics, n.d.c). Lastly, Brain Gauge MD is a FDA-listed cognitive assessment tool created for physician use with patients (CorticalMetrics, n.d.c). It is also the only FDA approved tool that doesn’t require a baseline and has the same features as Brain Gauge Pro plus additional resources (CorticalMetrics, n.d.c).
There is an adequate amount of peer reviewed publications using Brain Gauge in reference to concussion testing (CorticalMetrics, n.d.d). A study has shown that retired contact sport athletes experiencing chronic symptoms perform significantly lower than control groups and asymptomatic retired athletes, particularly with reaction time and reaction time variability (Pearce et al., 2021). There has also been evidence that number of concussions is linked to increased intracortical inhibition and lower somatosensory performance (Pearce et al., 2021). Brain Gauge has been assessed as a predictor of concussion recovery trajectory and a helpful tool in monitoring concussion rehabilitation (Francisco et al., 2020; King et al., 2018). Compared to imPACT, Brain Gauge has better sensitivity with reaction time measures (CorticalMetrics, n.d.d). In a study examining the difference in concussion assessment tools with 200 student athletes post-concussion, there was no statistically significant difference between baseline and post-concussion reaction times for any of the time points with imPACT testing (CorticalMetrics, n.d.d). However, Brain Gauge showed a significant difference in reaction time and reaction time variability for days 1-14 and 1-21, respectively, in comparison to controls (CorticalMetrics, n.d.d). This is attributed to Brain Gauge’s accuracy of 0.33 msec, which is around 1000 times more accurate than other visual reaction time methods (CorticalMetrics, n.d.d). Brain Gauge’s measures of lateral inhibition (sequential vs. simultaneous) demonstrated significantly poorer performance than the control group even on the last day of data collection (day 28), representing incomplete recovery (CorticalMetrics, n.d.d). More research is needed in determining when it is safe to return to play, if impairments are still being detected 3-4 weeks post-concussion. Brain Gauge should also be compared to other assessment methods, as well as in combination with them, as the most effective assessment protocols are collaborative. A more diverse set of research would be beneficial to determine the complete effectiveness of this device.
References
CorticalMetrics. (n.d.a). Why does the Brain Gauge work? https://downloads.corticalmetrics.com/factsheets/whydoesbgwork.pdf
CorticalMetrics. (n.d.b). The Brain Gauge: An overview. https://downloads.corticalmetrics.com/factsheets/BrainGaugeOverview.pdf
CorticalMetrics. (n.d.c). Products. https://www.corticalmetrics.com/braingaugepro
Cortical Metrics. (n.d.d). How does the Brain Gauge measure up to other methods? https://downloads.corticalmetrics.com/factsheets/howdoesbgwork.pdf
Francisco, E.,Favorov, O., Tommerdahl, A., Holden, J., & Tommerdahl, M. (2020). Sensory testing as a predictor of short vs. long term trajectory of recovery from concussion. The Journal of Science and Medicine, 2(4). doi: 10.37714/JOSAM.V2I4.71
Pearce, A. J.,Kidgell, D. J., Tommerdahl, M. A., Frazer, A. K., Rist, B., Mobbs, R., Batchelor, J., & Buckland, M. E. (2021). Chronic neurophysiological effects of repeated head trauma in retired Australian male sport athletes. Frontiers in Neurology, 12, 316. https://doi.org/10.3389/fneur.2021.633320
King, D. A.,Hume, P., & Tommerdahl, M. (2018). Use of the Brain-Gauge somatosensory assessment for monitoring recovery from concussion: a case study. Journal of Physiotherapy Research, 2(1), 13-13. Retrieved November 2, 2021, from http://www.imedpub.com/journal-physiotherapy-research/.