DALLAS – A 30-minute cold-water head bath shows promise as a nonpharmacologic treatment for acute migraine or tension headache.
The key to this approach is that the water starts out lukewarm, cooling slowly to cold over the course of the first 15 minutes. It makes for a very different experience than abrupt immersion in an ice bath or placement of an ice pack against the head, which can actually worsen pain; indeed, many pain studies use a cold-water bath as the standardized pain stimulus, Dr. James R. Miner noted at the annual meeting of the Society for Academic Emergency Medicine.
He presented a prospective, observational, proof-of-concept study involving 18 adults who presented to an emergency department with a primary headache – that is, either migraine, migrainous headache not meeting full diagnostic criteria for migraine, or tension headache. Their mean age was 29 years, and all were free from known vascular disease. These were patients whose headaches were sufficiently severe that ED physicians had slated them for treatment with opioids, triptans, antiemetics, or other medications widely used to treat acute primary headache in the ED.
Instead, participants were placed in what Dr. Miner termed his migraine head box for 60 minutes. The jury-rigged box looks much like the sort of porcelain sink used for hair washing in salons. An icepack is placed at the bottom of the sink of lukewarm water, and the patient then lies back and submerges his or her head in the gradually chilling water to a level just below the ears.
The subjects’ median baseline self-rated pain score on a 0- to 100-mm visual analog scale was 78 mm. Ten patients described their head pain as severe and eight as moderate.
After 30 minutes in the migraine head box, patients reported a median 19.5-mm drop in their pain score, and nine patients now rated their headache as mild. And 60 minutes in the head box brought a modest additional median 2-mm reduction in pain scores, and one additional patient who rated the pain as mild, according to Dr. Miner of Hennepin County Medical Center, Minneapolis.
Seven of the 18 patients received rescue medications. In a follow-up phone call at 72 hours, one-third of subjects reported experiencing a rebound headache after leaving the ED, a rate Dr. Miner found surprisingly high.
He stressed that these are early days for the migraine head box. Planned future studies will include controls given a sham intervention, as well as measurement of water temperatures to learn if outcomes are optimized at a certain temperature. Efforts will also be made to identify the mechanism of benefit.
"I don’t think the cold water therapy has anything to do with an anti-inflammatory effect," Dr. Miner speculated. "Most likely, the low-level innocuous stimulation is causing an afferent decrease in pain at the thalamic level."
He noted that the etiology of primary headaches remains elusive.
"You can go to a lot of different meetings and hear a lot of different theories. I can say that over the course of my career the leading contender for what causes these headaches has changed almost every 3 or 4 years. But I think there’s pretty good agreement that a lot of the pain is thalamically mediated hyperesthesia, although whether this is a result of vasospasm or spreading cortical depression immediately prior to the headache is a subject of conjecture," Dr. Miner commented.
"I think one of the reasons that we struggle with so many different drug classes that are all similarly effective for these headaches is that we don’t know what’s truly causing the headache," he added.
Audience members applauded his effort to develop a fast-acting nonpharmacologic treatment for what is a very common diagnosis in the ED. As one physician noted, "I suspect ED physicians, because of the greatly increased concern about prescribing opiates, are going to be told they need to be using other forms of treatment."
Dr. Miner reported receiving grants for acute pain research from the National Institute of Justice and Taser International.