There is little evidence that spinal manipulation is an effective treatment for headaches, according to the authors of a new study.
Millions of Americans suffer from chronic headaches, and many see chiropractors to treat their headaches with spinal manipulation, whose goal is to properly align the vertebrae. But the treatment "does not demonstrably generate more good than harm," study co-author Dr. Edzard Ernst, of Peninsula Medical School in the UK, told Reuters Health by email.
Ernst and co-author Dr. Paul Posadzki reviewed studies in which patients with a particular type of headache, known as cervicogenic headache, caused by neck strain, had spinal manipulation. Of those 9 trials, 6 suggested that spinal manipulation was better at reducing pain than other treatments, physical therapy, massage, medication, or no treatment, while 3 suggested that spinal manipulation was no better than the alternatives.
While the majority of the studies favored spinal manipulation, the authors argue in the journal Headache that there is not enough evidence to prove that spinal manipulation is an effective treatment for headaches.
The only study in the review that compared spinal manipulation to a sham treatment found that the technique was no more effective than the sham treatment.
The authors are concerned about the potential complications associated with spinal manipulation. A 1996 RAND study found that the rate of severe complications, including strokes, was just 3 for every 2 million neck manipulations. However, in another study Ernst found more than 700 unreported severe complications, suggesting that the rate is potentially much higher.
"It follows that there is a problem, we don't know how large it is, and we should, as always, err on the safe side," Ernst said.
But adverse events are "very rare," argues Dr. William Lauretti of New York Chiropractic College in Rochester, New York. Lauretti said it is possible that spinal manipulation may not be the cause of the strokes, noting that the rate is not higher than in the general population.
Lauretti said that the evidence supports spinal manipulation for headaches more strongly than alternative treatments, many of which have their own risks. The most recent review of studies by the Cochrane Collaboration, an international organization that evaluates medical research, found that spinal manipulation "was no more or less effective than medication for pain, physical therapy, exercises, back school or the care given by a general practitioner."
Still, given the lack of quality evidence supporting spinal manipulation for headaches due to neck strain, "patients should be advised to use other therapies," Ernst said.