MRI Doesn’t Show Sciatica and Lumbar-Disk Herniation Link

April 2, 2013

Physicians are using MRI to assess the association between sciatica symptoms and lumbar-disk herniation, despite controversy over its validity.

MRI is not a useful tool to determine the effectiveness of treatment for sciatica related to lumbar-disk herniation, according to a study published online in the New England Journal of Medicine.

Dutch researchers studied 283 patients who participated in a randomized trial comparing surgery for lumbar-disk herniation and sciatica with prolonged conservative treatment. The goal was to determine if the MRI could distinguish between patients with favorable and unfavorable outcomes.

The patients underwent MRI at baseline and again at one year. Disk herniation was rated on a scale of one to four, with one as “definitely present” and four as “definitely absent.” According to the authors, “A favorable clinical outcome was defined as complete or nearly complete disappearance of symptoms at one year.”

Upon comparing proportions of patients with favorable outcomes among those with definite absence of disk herniation, and those with definite, probable, or possible herniation, the researchers found that among the 84 percent of patients who reported having favorable outcomes, 35 percent had visible disk herniation. Thirty-three percent of patients with unfavorable outcomes also had disk herniations seen by MRI.

“A favorable outcome was reported in 85 percent of patients with disk herniation and 83 percent without disk herniation,” the authors wrote.

The researchers concluded that MRIs at one-year follow-up for lumbar-disk herniation did not distinguish between patients.