Magnetoencephalography (MEG) for Objective Diagnosis and Assessment of PTSD and mTBI

To generate evidence-based observations by conducting a clinical study to demonstrate the validity of MEG as a non-invasive, objective tool for the diagnosis and assessment of PTSD and mTBI.

Based on a 5-year post-Afghanistan deployment study of returning CF members commissioned by the Canadian Forces Surgeon General, about 8% were diagnosed with Post Traumatic Stress Disorder (PTSD), and 5% with mild Traumatic Brain Injury (mTBI).

For patients with PTSD and mTBI, no visible structural damages to the brain are detectable by conventional neuroimaging techniques, such as computer-aided tomography (CT) and magnetic resonance imaging (MRI). Current practice for diagnosing and managing these mental conditions relies primarily on subjective clinical assessments. An independent, objective tool for directly assessing abnormal brain function is not available, but much needed to facilitate relevant brain disorder diagnosis and management for the CF.

Magnetoencephalography (MEG) is a non-invasive biomedical tool for detecting activities in the brain by recording micromagnetic fields (biomagnetism), generated by electrical currents naturally occurring in the brain. MEG directly detects brain activity by measuring resting and evoked neuronal magnetic fields in real time (msec).

By examining the magnetic fields emitted from the brain using MEG, Defence Research and Development Canada (DRDC) is studying functional neuroimages of active regions in the brain both when a subject is resting and asked to perform mental tasks in a real or virtual environment.

Comparing the differences of functional neurobiomarkers recorded by MEG, we can determine how the brain processes various types of stimuli and how these processes may be affected in PTSD and mTBI patients.

The successful validation of MEG as a reliable non-invasive technology for assessing PTSD and mTBI will enable, for the first time, the objective detection of altered functions of the brain, where structural abnormalities are not detectable (i.e. invisible wounds).

This two-year pilot study is co-sponsored by DRDC and Canadian Forces Health Services (CFHS). The study is being done in collaboration with the United States Veterans Affairs Medical Center (USVAMC), where a parallel study is being conducted.