Results of brain surgery on a small group of type 2 diabetes patients point the way to a possible new approach for treating the disease.
Physicians at Allegheny General Hospital in Pittsburgh used a form of surgery called microvascular decompression on ten type 2 patients to relieve stress on the medulla oblongata. The medulla oblongata, located in the lower part of the brain stem, controls such functions as respiration, blood pressure, and heart beat.
The medulla is also known to control pancreatic function. The Pittsburgh group, led by neurosurgeon Peter Jannetta, wondered if repositioning arteries pressing on the medulla would have an effect on pancreatic function. The surgery consisted of moving a pressing artery away from the medulla and then placing a protective pad between them.
Dr. Jannetta’s curiosity was an outgrowth of his earlier work with 15 patients who had cranial nerve disease as well as type 2 diabetes. He noted that after undergoing decompression surgery, nine of them showed improved glucose control-a possible indicator of lessened insulin resistance due to the surgery’s beneficial effects on the pancreas.
He recruited a second group of patients for a follow-up study. All ten had type 2 diabetes and a diagnosis of compression of the medulla, revealed by magnetic resonance imaging. Members of the group underwent decompression surgery over a two-year period, followed by a one-year period during which they were forbidden to make any changes in their diets, weight, or level of physical activity.
By the end of the year, Dr. Jannetta’s team noted that seven of the ten had lower blood glucose levels and were able to decrease the dosages of their medications. One patient was able to cease taking medications entirely.
The three patients who did not respond favorably to the surgery all had extremely high body mass indexes and were considered obese. (The other seven fell into the overweight category.
Although the results of Dr. Jannetta’s study are intriguing, the sample of patients involved was too small to assert a definite link between microvascular decompression surgery and an improvement in type 2 symptoms. His team is now undertaking a larger study, working with the University of Toronto and the University of Minnesota.
The study has been published in the journal Surgical Neurology International.