Investigators suspect inflammation as the cause of some post-surgical neuropathies

A recently published Mayo Clinic study found that orthopedic, abdominal, chest or dental surgeries that lead to neuropathy may be caused by nerve inflammation rather than nerve compression or stretching during surgery.

The investigators of the study, led by neurologist P. James Dyck, MD, have identified immunotherapy as a potential treatment for the loss of sensation, pain and muscle weaknesses that individuals with neuropathy may experience. The research appears in the September issue of Brain.

“It is important that a person with postsurgical inflammatory neuropathy receive a diagnosis and treatment quickly,” Dyck stated in a Mayo Clinic press release. “Understanding the role of inflammation in these patients’ neuropathy can lead to appropriate immunotherapy and improvement of neurological symptoms and impairments.”

For their study, Dyck and his colleagues focused on 23 patients who developed neuropathy within 30 postoperative days. According to Dyck, the patients’ neuropathy did not seem to be caused by nerve stretching or compression since their damaged nerves tended to be at a site other than the surgical one or the neuropathy occurred at least a few days after the surgery.

The investigators biopsied all the nerves. They found that 21 patients showed increased inflammation and treated 17 of the patients with immunotherapy for a 3-month period. At follow-up, they discovered that all cases of impairment from the neuropathy improved.

“This is exciting for patients because it allows for appropriate identification and accurate treatment of post-surgical neuropathy,” Nathan P. Staff, MD, PhD, a Mayo Clinic neurologist and investigator for the study, stated in the release. “Without showing inflammation on the nerve biopsies, we would have been unable to know the cause of neuropathy.”

Reference:
Staff N, Englestad J, Klein CJ, et al. Post-surgical inflammatory neuropathy.Brain. Published online Sept. 18, 2010. doi:10.1093/brain/awq252.

This is truly remarkable data. To have histological and MRI data is extremely informative and seems to consistently identify inflammation. Nonetheless, questions remain. Given that they felt the pathological findings were consistent with vascular insult, the inflammatory changes could be reparative or reactive rather than causative. The role of and treatment with immunomodulation, in particular, remains speculative without a controlled study.

In spite of these shortcomings, these data make a compelling case that many, if not most, post-operative neuropathies are not related to positioning or compression.

— David C. Ring, MD, PhD
Orthopedics Today Editorial Board member
Boston

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