BY CAROL MARTIN
A clinical trial getting underway in Sault Ste. Marie could offer diabetic patients experiencing chronic, debilitating foot pain and numbness significant relief. A study designed to test surgical peripheral nerve decompression for the treatment of diabetic neuropathy in the foot is currently recruiting subjects in the city under the direction of Dr. Tim Best, assistant professor with the Northern Ontario School of Medicine.
The operation has already been performed on 15,000 to 20,000 patients, mostly in the United States but some in Canada, said Best, who became interested in the procedure when the American Association of Neurologists endorsed it as a plausible solution to the problem of foot pain in diabetics, but cited a need for more clinical trials to assess its effectiveness.
“Our obligation is to find out if the help outweighs the harm,” said Best. “From an ethical point of view, the last thing we should do is provide false hope.”
In 2009, Best applied for a grant from the Physicians’ Services Incorporated Foundation and was awarded $151,000 to undertake the study.
Best said his grant application was successful because diabetic care is very well organized in Sault Ste. Marie under the auspices of the Group Health Centre’s Algoma Diabetes Education and Care Program (ADEC) and because the Sault has a cohesive medical community open to collaboration.
It’s taken almost two years of consultations, team building and resource management to design and implement the study, Best said. Results will be available in two or three years.
Pain, numbness
He likened diabetic neuropathy of the feet to carpal tunnel syndrome. In both disorders, the nerves that supply feeling to the extremities must pass through very restricted spaces. Some of the pain and numbness afflicting diabetic patients is due to nerve damage, but some is also due to the nerves becoming inflamed and pinched in the narrow canals in the knee, ankle and an area of the foot near the big toe. Theory indicates that surgically relieving the pressure on nerves in these areas will give patients significant pain reduction, as it does in more than 90 per cent of cases of carpal tunnel syndrome.
Currently, diabetic neuropathy of the feet is treated with pain relievers and by working with patients to manage and stabilize blood sugar levels. This treatment has seen limited success, Best said, in part because controlling blood sugar levels doesn’t always alleviate diabetic neuropathy.
Neuropathy has been observed in significant numbers of patients with well controlled blood sugar levels and even in patients who haven’t developed full-blown diabetes. The specific causes of diabetic neuropathy are not well understood, Best said. He suspects research will show a combination of surgery and new medications targeting neural irritation and inflammation will yield the best results in treatment of the condition while research into its underlying causes continues.
Best said his interest in the procedure and its possible outcomes also follows from his studies of peripheral nerve research. He said he was seeing an increasing number of diabetic patients referred to him for chronic, debilitating, burning pain and numbness in the hands and feet. Neurologists like Best have been surgically relieving pain and numbness in hands for several years and Best is a specialist of preference for many Sault and area physicians with diabetic patients.
“Traditional teaching when I was in medical school in the early to mid ’80s said diabetic patients’ hands and feet will go numb,” he said. “Now, I can relieve pain and numbness in hands with surgery. I was following the same line of thinking with legs.”
Sample size
The surgical peripheral nerve decompression trial will have a sample size of 60 patients. Of those patients, 30 will receive the surgery, while the remaining 30 patients in the control arm of the single-blind study will continue on the same course of treatment they had been receiving for diabetic neuropathy. At the outset, and at the three, six, and 12-month points, patients will be tested on a number of quantitative scales, including their total neuropathy score and their tissue oxygenation. They will also be given a questionnaire designed to establish their quality of life and the levels of pain or numbness they are experiencing.
Best said the results will not be released until all the study participants have completed the study and data can be compared across the subjects. At that point, he hopes to be able to more definitively draw some conclusions about the effectiveness of surgical peripheral nerve decompression.
He’s looking for diabetic patients who meet the study criteria, including patients with consistent control of blood sugar to eliminate as many variables as possible.
For more information, or to participate in the study, contact Susan McLean, RN, at 888-779-1166 susan.mclean@saultcare.ca
The study can also be viewed at the U.S. National Institutes of Health Clinical Trials website.
http://clinicaltrials.gov/ct2/show/NCT01006915?term=diabetic+poly+neuropathy+surgery&rank=1
Carol Martin is a freelance journalist based in Sault Ste. Marie.
