Passive Neurofeedback Treatments for Mild Traumatic Brain Injury: Neuroimaging Changes Detected by MEG after applying Low-Intensity Pulses using Transcranial Electrical Stimulation

Mild traumatic brain injury (mTBI) is a leading cause of sustained impairments in military service members, Veterans, and the general civilian population. However, few treatments are available for mTBI, partially because the mechanism of persistent mTBI deficits is not fully understood. The present study used magnetoencephalography (MEG) to investigate neuronal changes in the brain in individuals with mTBI in response to a passive neurofeedback-based treatment program called IASIS. This program involved applying low-intensity pulses using transcranial electrical stimulation (LIP-tES) with electroencephalography (EEG) monitoring. Study participants included 6 individuals with mTBI and persistent post-concussive symptoms (PCS). IASIS treatments were applied twice weekly for a period of 6 weeks. MEG exams were performed at baseline and follow-up to evaluate the effect of the IASIS treatment on brain functioning. We focused on changes in MEG source-imaging measures of abnormal slowfrequency activity and its relationship to changes in PCS. The results showed that at the baseline MEG exam, all participants had abnormal slow-wave signals. In the MEG exam following the IASIS treatment, the participants showed significantly reduced abnormal slow-waves in approximately the same brain areas that generated abnormal slow-waves at the baseline exam. Significant reductions in abnormal MEG slow-wave generation strongly correlated with significant reductions in PCS scores after the IASIS treatment. Altogether, the present study demonstrates, for the first time, neuroimaging-based documentation of the effect of LIP-tES treatment on brain functioning in individuals with mTBI.