Evaluating Concussion in Sport: A Case for Magnetoencephalography

Objective: Determine the role of magnetoencephalography (MEG) in evaluating sports-related concussions. Subject: A professional indoor soccer player who suffered his fifth concussion. Methods: The subject underwent neuropsychological testing to assess a variety of brain functions. Brain MRI and MEG were subsequently performed at the University of California, San Diego Radiology Imaging Lab-MEG Center. Standard MRI was obtained. MEG data was obtained using a 306-channel Elektaneuromag whole-head MEG-system to detect low-frequency delta waves (1-4 Hz) generated by injured axons. He visually fixated on a cross projected on a screen for three 5-minute sessions while spontaneous activity was recorded, then for three 5-minute sessions with eyes closed. Data analysis was performed using VESTAL source imaging and was co-registered with MRI coordinate systems to generate image display. Results: Neuropsychological testing showed mild impairment in a few categories but overall did not detect significant abnormalities. Brain MRI was normal. MEG detected abnormal low-frequency delta waves in multiple areas of his brain. Conclusion: MEG detected abnormal delta waves in multiple areas of the brain despite neuropsychological testing with only mild impairment and a normal Brain MRI suggesting that MEG may be a sensitive test for evaluating sport-related concussions.