London, Dec 9 (IANS) Fifteen minutes of treatment with high flow oxygen significantly eased cluster headaches, according to a new study.
Cluster headache attacks, characterised by bouts of excruciating pain usually near the eye or temple, typically last for 15 minutes to three hours if untreated and have a frequency of up to eight attacks a day on alternate days.

High flow oxygen is given at a rate of six to seven litres per minute for 10 to 20 minutes at the start of a cluster headache.

Attacks usually occur in bouts, or clusters, lasting for weeks or months, separated by remissions lasting months or years, according to the study.

The current treatment for acute attacks of cluster headache is injection with the drug sumatriptan, but frequent dosing is not recommended because of adverse effects.

Another treatment option is the inhalation of high-dose, high-flow oxygen, but its use may be limited because of the lack of a good quality controlled trial.

Anna S. Cohen, of the National Hospital for Neurology and Neurosurgery, and colleagues conducted a randomised, placebo-controlled trial of high-flow oxygen for the treatment of acute attacks of cluster headache.

The study included 109 adults (aged 18-70 years). Patients treated four cluster headache episodes alternately with high-flow oxygen (inhaled oxygen at 100 percent, or 12 litres per minute, delivered by face mask, for 15 minutes at the start of an attack) or placebo (high-flow air).

Patients were recruited and followed up between 2002 and 2007. The final analysis included 57 patients with episodic cluster headache and 19 with chronic cluster headache.

The researchers found that 78 percent of the patients who received oxygen reported being pain-free or to have adequate relief within 15 minutes of treatment, compared to 20 percent of patients who received air.

For other outcomes, such as being pain-free at 30 minutes or a reduction in pain up to 60 minutes, treatment with oxygen was superior to air. There were no serious adverse events related to the treatments, says a National Hospital release.

“To our knowledge, this is the first adequately powered trial of high-flow oxygen compared with placebo, and it confirms clinical experience and current guidelines that inhaled oxygen can be used as an acute attack therapy for episodic and chronic cluster headache,” the authors write.

The study appeared in the Wednesday issue of JAMA.