Deep brain stimulation (DBS) is a form of surgery that is used to treat some of the symptoms of advanced Parkinson's disease. It involves the implantation of wires, with 4 electrodes at their tip to deep brain structures, most commonly an area called ‘the subthalamic nucleus’ (STN) in the two sides of the brain. Following the surgery for a short period of time the other end of the wire implanted in the brain is accessible for recording. For brain researchers this offers a unique opportunity to record invasively the activity of the areas in the human brain not easily accessible to non-invasive methods.
Our team was the first in the world to combine invasive recordings from wires implanted in the brain with non-invasive recordings using a state-of-the-art method called magnetoencephalography (MEG). This method is based on picking up very weak changes in magnetic field around the head caused by synchronized activity of neurons in the brain. By using a MEG scanner we can record the activity of many brain areas at the same time, critically without even touching the patient’s head. This is especially important as the patients in our studies have fresh surgical wounds. The MEG scanner also makes it possible to determine in which brain area a particular signal originates.
We would like to understand how subcortical areas from which we record directly via implanted electrodes communicate with the rest of the brain seen by the MEG. In particular, we are looking at oscillatory neural activity and how it is affected by task performance and medication state.