October 25, 1996

Chronic post-trauma headaches traced to common pain medications

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Dr. John Warner

Chronic post-trauma headaches traced to common pain medications

Chronic headaches following head or neck trauma are often caused by continued use of analgesic pain medication, not by the injury itself, Vanderbilt University Medical Center neurologists have found.

Observations of patients who visited the Vanderbilt Headache Clinic over the course of one year showed that the vast majority complaining of post-traumatic chronic headaches improved dramatically when taken off analgesic pain medications.

Previous studies have shown that this "analgesic rebound" is common in patients with chronic daily headaches not resulting from trauma. This, however, is the first time the effect has been studied in patients complaining of post-traumatic headaches of long duration, said Dr. John S. Warner, professor of Neurology.

"Many people out there have been having unnecessary headaches for years and years," he said.

During 1995, 25 new patients were seen at the Vanderbilt Headache Clinic complaining of post-traumatic chronic daily headaches lasting at least six months. On average, these patients had been suffering daily headaches for two years. The longest had dealt with daily pain for 25 years.

For 17 of these patients, the headaches ceased once they stopped taking analgesic pain medication, Warner said.

"It took an average of about one month for the headaches to go away. That was 17 out of 25 patients, and four of those 25 flat refused to stop taking their medications and, to this day, aren't doing any better," he said.

The results of these observations by Warner and Dr. Gerald M. Fenichel, professor and chair of Neurology, were recently published in Neurology, the Journal of the Academy of Neurology.

In their report they warn that analgesic rebound must be eliminated as a cause of post-traumatic daily headache in order to properly treat a patient's pain.

"We suspect that the diagnosis of post-traumatic headache is often made when the actual cause was daily, or almost daily, use of analgesics or opiates. This can lead to an erroneous therapeutic approach," they write.

Warner has seen numerous patients who have suffered through daily headache pain for decades. For these people, the pain medication they are taking ‹ whether it's aspirin, acetomenephin or ibuprofen ‹ is actually causing their pain.

"There are suspicions about what the mechanism is that causes this, but it is not known for certain," he said. "What we know is that for some people the occasional analgesic pain medication is no problem. But if they take it for many days, they get into the headaches.

"About three weeks after starting analgesics, the headaches start setting in. Then they switch to another analgesic to get rid of the headache and end up flipping back and forth between pain medications. And all the while, the headache persists, so it doesn't matter what they're taking.

"The problem is, for these people, the medication they are taking today causes tomorrow's headache. Medication may dull the headache they're having today, but it doesn't terminate it," he said.

Once taken off of analgesic pain medication, must chronic headache sufferers report improvement within a month, but it can take up to six months for a patient to return to baseline, Warner said. Length of suffering appears not to play a role in speed of recovery for patients, some of whom have been on analgesics and suffering chronic daily headaches for decades.

"The effect of the analgesics has no correlation to what kind of analgesics were taken, how long they were taken and what caused the headache in the first place," Warner said.

"We recently had one patient who started having headaches every day when she was 11. She is now 57. We took her off the analgesics and she responded dramatically. She has now had only three hours of headache in the past month as opposed to severe headaches every day for 46 years."

Headache-free does not, however, equate to pain-free, Warner said. The injuries for which analgesic pain medications were prescribed in the first place may still cause discomfort. But after years of chronic headache, most patients ‹ once they get past their disbelief at the seemingly incongruous cause of their suffering ‹ are quite happy to put the pain medication bottle back up on the shelf, Warner said.

"The patients usually don't believe you at first. It takes time explaining these observations to them. Some don't take the message and keep taking their medications. Others say, 'I've tried everything else, I might as well try this.' These people end up happily surprised.

"It's not easy getting people to accept this, but it's true. Pain medicines can cause headaches," Warner said.