CINCINNATI-Two patients, each with the same debilitating nerve pain, walk into a clinic for a sympathetic block. After the injection, one patient gets relief and goes on to live their life pain free for weeks or months. The other patient experiences no relief and the pain may continue for a lifetime.
"Ideally, we want to know up front whether we should give them the block or not; basically, will this patient get better or not," says pain researcher Jun-Ming Zhang, MD, the principal investigator of a $1.95 million federal grant to study the interacting roles of the sympathetic nervous system, sensory nervous system, and immune system in several different preclinical models of back pain and neuropathic pain.
The pre-clinical study is funded by the National Institute of Neurological Disorders and Stroke within the National Institutes of Health (NIH).
"This research represents a major new direction for our laboratory," says Zhang, Vice Chair for Research in the Department of Anesthesiology at the University of Cincinnati College of Medicine.
He says in previous studies, his and the work of others, the focus has been primarily on abnormal interactions between the sympathetic system and the sensory nervous system, but this study will investigate the role of the sympathetic nervous system in directly affecting local inflammation and how the timing of a nerve block treatment might play a large role in resolving chronic pain.
"There are many factors that can influence pain, like mood such as with depression...we also think pain relief depends on the stage of the disease or trauma. Almost everyone who gets treatment early responds, but beyond three to six months you get a very poor response (to the sympathetic block)."
According to the NIH, at least 100 million American adults have common chronic pain conditions; a conservative estimate because it does not include acute pain, and back pain is the leading cause of disability in Americans under 45 years old. The most recent NIH data shows that in the U.S. adults who reported pain said causes include: low back pain (28.1 %), knee pain (19.5 %), severe headache or migraine (16.1%), neck pain (15.1%), shoulder pain (9.0 %), finger pain (7.6 %), and hip pain (7.1 %).
Zhang says the study of chronic pain, whether it be from trauma or disease states such as diabetes, is receiving attention and funding, due to the U.S. Food and Drug Administration's (FDA) directive to find ways to decrease the abuse of prescription opioid painkillers.
"Pain is very complex...we need to find ways to understand the nerve block treatments and hope to identify the responders to those treatments."
This grant is a continuation of a grant that Zhang received in 2004. The research team for this funding period includes Ian Lewkowich, PhD, an assistant professor of pediatrics at the UC College of Medicine and an immunologist at Cincinnati Children's Hospital Medical Center.