番茄社区

An experimental therapy that taught chronic spinal pain patients about neurophysiology and targeted movement may be superior to usual care at reducing pain and improving function, researchers in a multicenter, randomized clinical trial in Belgium reported.

Combining pain neuroscience education with movements that patients feared or avoided, the treatment produced better outcomes than current best-evidence physiotherapy and yielded a 50% improvement in chronic back and neck pain, according to Anneleen Malfliet, MSc, of Vrije Universiteit Brussel and colleagues.

Improvements in pain and functioning were sustained for 1 year and were "likely the result of integrating the newly derived pain neuroscience understanding in specific fearful movements and activities, enabling patients to deal with pain in daily life," they wrote online in .

Based on earlier studies, the researchers also expected to find changes in gray matter morphologic features, but none were seen.

"Because of the clinically significant changes in this trial -- that is, the reduction of pain and disability -- in the absence of gray matter changes, we believe that to effectively treat patients with chronic neck or low back pain, these gray matter changes might not be as relevant as we thought before," Malfliet told 番茄社区, noting that hers was the first study to look for them in the context of physical therapy.

Recent research suggests that people with nonspecific chronic spinal pain may have hyperexcitable central nervous systems, with altered and that trend toward decreased gray matter volume. These changes appear to be in modulatory, emotional-affective, and sensory-discriminative pain processing regions and .

In this triple-blinded trial, researchers studied 120 patients with chronic nonspecific spinal pain in two outpatient hospitals in Belgium from 2014 to 2017, randomizing participants to an experimental or control intervention. Both interventions lasted 12 weeks and included three educational sessions and 15 one-on-one exercise sessions with a therapist.

The experimental intervention combined pain education with an exercise program that introduced patients gradually to movements they feared or that caused them pain. "The education specifically focused on the neurophysiology of pain, explaining to the patient that pain is an output product of the brain, rather than a sign of tissue damage," Malfliet explained. The treatment aimed to help patients move functionally and avoid what Malfliet called "safety behavior." When a patient experienced pain, the exercise was finished as agreed upon between patient and therapist.

The control intervention was based on current best-evidence physiotherapy, incorporating back and neck education and general exercises. If a control group patient experienced pain, the therapist reduced the frequency, amount, or intensity of exercise.

The average age in both groups was about 40. In both groups, 53% of patients had neck pain and 47% had low back pain. The experimental group had chronic pain for a median of 97 months at baseline; the control group for 68.75 months.

The experimental intervention improved pressure pain sensitivity, central sensitization symptoms, mental and physical functioning, kinesiophobia, and hypervigilance and reduced disability. These changes had medium to large effect sizes, including 50% improvement in pain, and were maintained a year later at follow-up.

The experimental therapy also yielded greater improvement than controls in perceived pain disability and mental and physical health (small to medium effect sizes), but showed no effect on pain catastrophizing.

Only the experimental group demonstrated an increase in pressure pain threshold that exceeded than the clinically relevant 15% mark. And while the decrease in numeric rating scale pain scores exceeded the minimal clinically important difference of 30% in both groups, the experimental group (42.79% to 52.22% reduction) showed greater improvement than the control group (23.58% to 33.13% reduction).

That functional improvements were not accompanied by objective gray matter changes may be because pain catastrophizing did not decrease in this trial, observed Beth Darnall, PhD, of the Stanford University School of Medicine, who was not involved with the study.

"Prior literature suggesting morphological brain changes was specifically linked to reductions in pain catastrophizing," Darnall told 番茄社区. "Additional research is needed to better understand whether reductions in pain catastrophizing would produce morphological changes in this population, and whether the addition of effective, targeted catastrophizing treatment would yield superior results or not."

Nonetheless, this trial highlights how psychological factors may be undermining therapy and "furthers our understanding that addressing patients' fear of pain and movement leads to enhanced control over pain with lasting results," she said.

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