UPFRONT | Roundup RESEARCH Study sheds light on migraine sufferers’ preference for darkness People experiencing mi-graines often avoid light and find relief in darkness. A new study led by researchers at Beth Israel Deaconess Medi-cal Center (BIDMC) in Boston has revealed a previ-ously unknown connection between the light-sensitive nerve cells in the eye and centres in the brain that reg-ulate mood and a host of physical parameters such as heart rate, shortness of breath, fatigue, congestion and nausea. The findings, which ex-plain how light can induce the negative emotions and unpleasant physical sensa-tions that often accompany migraines, were published online in Proceedings of the National Academy of Sciences. “While studying the effects of colour on headache inten-sity, we found that some pa-tients reported finding light uncomfortable even when it didn’t make their headaches worse,” said lead author Rami Burstein, vice-chair-man of research in the De-partment of Anesthesia, Critical Care and Pain Med-icine at BIDMC, and profes-sor of anesthesia at Harvard Medical School. “We found that exposure to different colours of light could make patients experi-encing a migraine feel irrita-ble, angry, nervous, depressed and anxious. These patients also reported feeling physical discomfort, including tight-ness in the chest or throat, shortness of breath, light-headedness and nausea.” Burstein and colleagues showed different coloured lights to 81 people who frequently experienced mi-graines and 17 people who had never had a migraine and asked them to describe what they experienced. The effects of light and colour were tested three times: once for those who never experience migraines and twice for pa-tients with migraines – once during an attack and once between attacks. The researchers found that all colours of light triggered unpleasant physiological sen-sations in patients with mi-graines both during and be-tween attacks. Additionally, migraine sufferers reported intense emotional responses such as anger, nervousness, hopelessnes, sadness, depres-sion, anxiety and fear when exposed to all light colours, except green. Participants who did not suffer from mi-graines did not report a strong physiological response when exposed to any colour of light, but they did report that all colours of light evoked pleasant emotions. “These findings explained accounts from earlier work from blind migraine sufferers in a previous study,” said Burstein. “We had noticed that light exacerbated head-ache intensity in participants who perceive light but have no sight as a result of loss of rods and cones, but not in those who lack light percep-tion because of optic nerve degeneration. This suggested the nerves relaying signals from the eye to the brain played a critical role in the discomfort associated with migraine.” In a pre-clinical experi-ment with albino rats, first author Rodrigo Noseda, researcher at BIDMC and assistant professor of anes-thesia at Harvard Medical School, identified previously unknown connections be-tween nerve cells in the ret-ina – the back of the eye where light is detected – and neurons extending into re-gions of the brain that regu-late physiological, auto-nomic, endocrine and emotional responses to changes in the external envi-ronment. “We now have a physical explanation of why migraine patients have negative reac-tions to light,” said Burstein. “And now we are working on ways to use this information in hopes that soon migraine sufferers will be able to avoid not only the pain but also the negative emotions and phys-ical discomfort that light creates for them.” These findings build on research published by Burstein and colleagues last year, which reported that migraine headache intensity increases with blue, red, amber and white lights but decreases with a specific wavelength of green light. This green light, they discov-ered, activates the neurons in the retina and the brain to a lesser extent than blue, red, amber and white lights do, and is therefore less likely to trigger the physiological, autonomic, endocrine and emotional responses mi-graine sufferers often report. Beth Israel Deaconess Medical Center is a patient care, teaching and research affiliate of Harvard Medical School. -Newswise WELLNESS App that rewards healthy living gets $1.5 million from Ontario Ontarians who want to im-prove their health and person-al finance skills can get points from popular consumer re-wards programs for their ef-forts, paid for in part by the provincial government. Ontario government offi-cials have announced the province is spending $1.5 million on the Carrot Rewards smartphone app, which allows users to get reward points from programs including Aeroplan and Petro-Points for completing tasks such as walking a certain number of steps or taking quizzes on healthy living and personal finance. The app gives users advice on topics such as eating sea-sonal fruits and vegetables and following a budget. Eleanor McMahon, Ontario’s minister of sport, says the government’s investment in the app is about giving people an incentive to make good choices and showing that leading a healthier life can be fun. Toronto-based company Carrot Insights developed the app in 2015 with funding from the federal government and British Columbia. It became available to Ontarians in February and the company says it has about 200,000 active users in the province today. – The Canadian Press 8 Canadian Chiropractor September 2017 www.canadianchiropractor.ca
Chiropractic + Naturopathic Doctor September 2017: Page 8
