Mayo Clinic researchers have found a novel way to monitor real-time chemical changes in the brains of patients undergoing deep brain stimulation (DBS). The groundbreaking insight will help physicians more effectively use DBS to treat brain disorders such as Parkinson’s disease, depression and Tourette syndrome.
Researchers hope to use the discovery to create a DBS system that can instantly respond to chemical changes in the brain. Parkinson’s, Tourette syndrome and depression all involve a surplus or deficiency of neurochemicals in the brain. The idea is to monitor those neurochemicals and adjust them to appropriate levels.
　
‘We can learn what neurochemicals can be released by DBS, neurochemical stimulation, or other stimulation. We can basically learn how the brain works,’ says author Su-Youne Chang, Ph.D., of the Mayo Clinic Neurosurgery Department. As researchers better understand how the brain works, they can predict changes, and respond before those changes disrupt brain functioning.
Researchers 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.
The team 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 the 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.
Researchers also hope to learn more about conditions without such external manifestations.
‘We can’t watch pain as we do tremors,’ says Kendall Lee, M.D., Ph.D., 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.’
DBS has been used successfully worldwide to treat patients with tremors. However, 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. Mayo Clinic

Psychological factors can have as much-or more-impact on pediatric chest pain as physical ones, a University of Georgia study found recently. UGA psychologists discovered pediatric patients diagnosed with non-cardiac chest pain have higher levels of anxiety and depression than patients diagnosed with innocent heart murmurs-the noise of normal turbulent blood flow in a structurally normal heart.
The UGA research was done in collaboration with Children’s Healthcare of Atlanta and Emory University.
‘The fact that these psychological symptoms are higher in non-cardiac chest pain patients suggests the psychological symptoms may be playing a role in the presentation of chest pain,’ said Jennifer Lee, a doctoral candidate in the UGA Franklin College of Arts and Sciences and the study’s lead author.
The results of the study show a statistically significant increase in anxiety and depression among patients who are later diagnosed with non-cardiac chest pain when compared to patients diagnosed with innocent heart murmurs. Lee said it is not clear if the anxiety is a cause of the pain or if pain caused the anxiety in the sample group.
‘The higher levels weren’t so high as to cause a clinical diagnosis on their own, but when you contrast the two groups, there were statistically significant differences,’ said study co-author Ronald Blount, a psychology professor in the Franklin College.
The study included 129 patients ages 8 to 18. The group completed surveys prior to diagnosis. All patients were essentially in the same situation-sitting in a cardiology office awaiting their unknown medical diagnosis.
‘We are highlighting that psychology has a part in these symptoms,’ Blount said, ‘and screening for psychological, as well as medical factors, is one implication we foresee coming from this investigation.’
Chest pain can indicate serious medical conditions that require a doctor’s evaluation. In adults, pain in the chest is often linked to a cardiac problem. In children, however, less than 2 percent of patients receive a cardiac diagnosis for their pain.
The Sibley Heart Center at Children’s Healthcare of Atlanta is one of the largest pediatric heart centres in the world, seeing an average of 2,500 new patients with acute chest pain each year.
‘We know up front that 99 percent of these patients will not have a heart complication at all. The trick is, it is not zero, and I cannot miss the one patient with heart disease because the consequences could be catastrophic,’ said Dr. Robert Campbell, chief of the Sibley Heart Center and division director of the department of pediatrics at the Emory University School of Medicine.
The study also observed that non-cardiac chest pain patients have a higher level of functional disability-or the inability to participate in everyday activities like running across a football field or making it through a day without a nap. They also spent less time at school and were less involved in extra-curricular activities.
‘These kids also report greater levels of physical symptoms with unclear causes, like joint pain, stomach aches, head aches,’ Lee said. ‘These symptoms are believed to be psychological manifestations of stress. Sometimes your brain doesn’t tell you that you are stressed out, but your body does, so you will experience symptoms like these.’
Pediatric patients with non-cardiac chest pain also reported higher levels of anxiety sensitivity, a fear of experiencing physical symptoms and additionally fearing that those symptoms are related to a catastrophic health issue.
‘Psychological functioning is heavily related to pain,’ Blount said. ‘Pain is a sensory experience, but your attention to one thing or another and your emotions can impact your experience of pain. And how debilitating the pain is for you can be determined by psychological and social factors. That is what we were interested in looking at.’
Previous studies have shown reducing emotional symptoms can lead to better coping ability with pain, Lee said. ‘A goal with these patients would be to create a clearer, more comprehensive picture of what is going on and determine a better way to help these kids and adolescents.’
Campbell said the UGA research helps him serve the majority of his patients who leave his office with a clean bill of health but unexplained chest pain.
‘Most importantly what we’ve learned is that after a physical evaluation of the patient, we take the time to sit down with the family and find out what they are most worried about so we can address their psychological issues,’ Campbell said. ‘We’ve learned to pay attention and to be confident and reassuring. I need to make it clear to my patients and their parents that I’m not saying you are not having pain, but that the pain is not caused by your heart.’ University of Georgia

Scientists at Queen

Scientists at Washington University School of Medicine in St. Louis have found new clues to why some urinary tract infections recur persistently after multiple rounds of treatment.
Their research, conducted in mice, suggests that the bacteria that cause urinary tract infections take advantage of a cellular waste disposal system that normally helps fight invaders. In a counterintuitive finding, they learned that when the disposal system was disabled, the mice cleared urinary tract infections much more quickly and thoroughly.
‘This could be the beginning of a paradigm shift in how we think about the relationship between this waste disposal system, known as autophagy, and disease-causing organisms,’ says senior author Indira Mysorekar, PhD, assistant professor of obstetrics and gynaecology and of pathology and immunology. ‘There may be other persistent pathogens that have found ways to exploit autophagy, and that information will be very useful for identifying new treatments.’
Urinary tract infections are very common, particularly in women. In the United States alone, annual treatment costs are estimated to run as high as $1.6 billion. Scientists believe 80 percent to 90 percent of these infections are caused by the bacterium Escherichia coli (E. coli).
Data from the new study and earlier results have led Mysorekar and her colleagues to speculate that E. coli that cause recurrent urinary tract infections may hide in garbage-bin-like compartments within the cells that line the urinary tract.
These compartments, found in nearly all cells, are called autophagosomes. They sweep up debris within the cell, including harmful bacteria and worn-out cell parts. Then, they merge with other compartments in the cell that are filled with enzymes that break down the contents of autophagosomes.
‘We think, but can