Now, chemical changes in brain can be tracked in real-time

Washington:  Scientists have developed a new tool that can track real-time chemical changes in the brains of patients undergoing deep brain stimulation (DBS), a novel system which they claim can help treat neurological disorders such as Parkinson’s disease and depression. Mayo Clinic researchers who developed the new tool said the idea behind their research is to monitor neurochemicals in the brain and adjust them to appropriate levels during DSB. “We can learn what neurochemicals can be released by DBS, neurochemical stimulation, or other stimulation. We can basically learn how the brain works,” said lead study author Su-Youne Chang of the Mayo Clinic Neurosurgery Department. [caption id=“attachment_378992” align=“alignleft” width=“380”]  As researchers better understand how the brain works, they can predict changes, and respond before those changes disrupt brain functioning[/caption] As researchers better understand how the brain works, they can predict changes, and respond before those changes disrupt brain functioning, he noted. Researchers, who detailed their study in the journal Mayo Clinic Proceedings, observed the real-time changes of the neurotransmitter adenosine in the brains of tremor patients undergoing deep brain stimulation. Neurotransmitters such as dopamine and serotonin are chemicals that transmit signals from a neuron to a target cell across a synapse. They used fast scan cyclic voltammetry (FSCV) to quantify concentrations of adenosine released in patients during deep brain stimulation. The data was recorded using Wireless Instantaneous Neurotransmitter Concentration Sensing, a small wireless neurochemical sensor implanted in patient’s brain. The sensor, combined with FSCV, scans for the neurotransmitter and translates that information onto a laptop in the operating room. The sensor has previously identified neurotransmitters serotonin and dopamine in tests in brain tissue. This was the first time researchers used this technique in patients. Tremors are a visual cue that the technique is working; researchers suspect adenosine plays a role in reducing tremors. They hoped to learn more about conditions without such external manifestations. “We can’t watch pain as we do tremors,” said Kendall Lee, a Mayo Clinic neurosurgeon. “What is exciting about this electrochemical feedback is that we can monitor the brain without external feedback. So now, we can monitor neurochemicals in the brain and learn about brain processes like pain,” Lee added. DBS has been used successfully worldwide to treat patients with tremors. But, physicians do not fully understand why DBS works in patients. They know that when DBS electrodes are inserted before electrical stimulation, there is an immediate tremor reduction. Known as the microthalamotomy effect, it is reported in up to 53 percent of patients and known to last as long as a year. Researchers hope to use the study findings to create a self-contained “smart” DBS system. “With the stimulator and detection, we can create algorithms and then raise neurotransmitters to a specified level,” said Kevin Bennet, a Mayo Clinic engineer who helped create the system. “We can raise these chemicals to appropriate levels, rising and falling with each person throughout their life. Within milliseconds, we can measure, calculate and respond. From the patient’s perspective, this would be essentially instantaneous.” PTI