Abstract Details

MEGAbIT, an MRC funded study (Clinical Trials reference: NCT03867513), combined magnetoencephalography (MEG) with ultrahigh-field MRI, to detect functional and structural neuroimaging abnormalities within two weeks of mTBI.

Can measuring brain wave activity differentiate those with mild traumatic brain injury (mTBI) from orthopaedic trauma controls (with no head injury), and healthy controls.

We recruited 41 participants within two weeks of an emergency department visit and assessed resting state and task specific MEG, followed by ultrahigh-field MRI including structural, susceptibility, and diffusion sequences. Participant reported symptom scales were completed at baseline, three, and six months. Two prospectively selected analyses of resting state MEG data were conducted: excess delta band activity, the most commonly reported MEG abnormality in the literature, and reduced beta band burst coincidence connectivity, as this has previously demonstrated abnormalities in sub-acute mTBI.

No significant difference was found in global mean delta power between the mTBI cohort and either control cohort. However, a reduction in beta band burst coincidence connectivity was observed in the mTBI cohort compared to the healthy control cohort (Z=-2.612, p = 0.009). This gave a sensitivity of 86% and a modest specificity of 51%. Half our mTBI cohort had persistent self-reported disability, consistent with large prospective registry studies. Susceptibility weighted imaging revealed only two mTBI participants with microhaemorrhages, their clinical course did not differentiate them from others in the mTBI cohort.

Given the global prevalence of mTBI and the high levels of persistent disability it causes, there is an urgent need for neuroimaging tools that link to both the underlying neuropathology and reported symptoms. Our results suggest that mTBI impairs the dynamic coordination of neural network activity. This finding was more sensitive than structural ultrahigh-field MRI and requires further exploration.