How Does Deep Brain Stimulation Affect Magnetoencephalography Data?

Deep Brain Stimulation (DBS) is an established and effective neuromodulation technique preferred in treating several neurological and neuropsychiatric disorders such as Parkinson’s Disease(PD), epilepsy, obsessive compulsive disorder, depression and several such disorders. Magnetoencephalography (MEG) is a widely used neuroimaging strategy to understand the pathology and the therapeutic effects of DBS in clinical cohorts. One of the significant limitations is the inability to differentiate the DBS stimulation artefact from actual neuronal excitations, especially in lower frequency bands of interest where sub-harmonics of DBS artefacts may obscure the biological response and is a confounder. The primary objective of this study is to understand how DBS stimulation artefacts affect MEG signals and to this end, we employ a phantom based on a water melon. Using this phantom, we record the spectral signature of the DBS stimulation artefact at various DBS frequencies and stimulation voltages, the effect of standard artefact rejection approaches like spatiotemporal signal space separation (tSSS). We present in this paper the results of the initial analysis.