U-M, Brazilian Dental Schools Collaborate

Ann Arbor, MI — December 8, 2011 — Although chronic daily headaches affect about three percent of the word’s population, a new study provides revealing insights in how improper treatment of headaches negatively influences their prevalence and frequency in tribal natives living in northeast Brazil. 

The study was part of research collaboration by investigators from the University of Michigan School of Dentistry and the University of Sao Paulo, Brazil.  One of the U-M investigators, Dr. Thiago Nascimento, presented the research results at the third annual Student Global Health Day on the U-M campus last month.

Nascimento, a research fellow with the School’s Headache and Orofacial Pain Effort (HOPE) in the Department of Biologic and Materials Sciences, spent six weeks in remote and restricted areas of Brazil collecting epidemiologic data on headaches and orofacial pain among indigenous populations.  This tribe was chosen because of its history of collaboration with other departments at the University of Sao Paulo.  In addition, frequent headaches had been identified as a significant health complaint for this population.  However, there were never any studies about the prevalence or treatment of headaches or other orofacial pain.

This study was different because the majority of data reported from other headache studies has been conducted among urban populations, making it difficult to compare findings with other cultures or even verify if it is present in other societies with different lifestyles.

Surprising Results

From an investigation of more than 200 adults of Pataxo ethnicity in Bahia State in northeastern Brazil, Nascimento and other team members discovered a common reason chronic migraine headaches may be a problem in that remote part of the world — overmedication.

“The Brazilian government, as a part of its health policy, provides indigenous populations with unlimited access to pain killers that can also be used to briefly minimize the effects of migraine headaches,” he said.  “With this group, unsupervised drug dispensing has been the main reason for the high prevalence of primary headaches, such as migraines and tension-type headaches."

Nascimento said about three percent of the world’s population experiences chronic daily headaches, but the prevalence in the Pataxo population is well above that number, and the use of pain killers may be the primary cause.  The incidents of medication overuse to treat headaches and chronic daily headaches were also higher than for urban populations.

“Our research shows that about 15 percent of the Pataxo population reported headache symptoms that fit the international criteria for medication overuse to treat migraines,” Nascimento said.  “That the rate is nearly five times higher with that specific tribe in Brazil compared to urban society, and is probably due to taking too many pain killers without receiving proper instruction on how to use them.”

Oral health care providers, Nascimento said, “can play an important role in managing this condition by working with government agencies to develop better educational and treatment policies that help those suffering from migraine headaches, regardless of where and how they live.”

Because of the remote and restricted location of the tribes, the Brazilian government conducted a rigorous review of this research initiative.  Once the study was approved and Nascimento was allowed to communicate with the tribe, he worked carefully to build confidence among Pataxo children and adults. 

Nascimento said the study, conducted in 2006, was presented by the HOPE group in June during the annual meeting of the American Headache Society in Washington, D.C.  The research was regularly updated as Nascimento finished work on his master’s degree at the University of Minnesota.  In 2010, he came to Michigan and began working with his mentor, Dr. Alexandre DaSilva, director of HOPE and assistant professor who is a headache and orofacial pain research specialist at the School of Dentistry.

DaSilva and Nascimento continue collaborating with a multidisciplinary team of neurologists at the University of Sao Paulo including Drs. Jose Speciali and Marcelo Bigal.  The group is investigating new ways to possibly expand the study to include other tribes in Brazil and other parts of the world.  The researchers are also attempting to collect genetic and behavioral information to gain new insights about other factors that may also contribute to the prevalence of migraine headaches.