High−flow oxygen appears to help ease the pain of cluster headaches according to a recent research study. The study's authors hope their findings will lead to a more widespread use of oxygen as a treatment for cluster headaches.

Over three−quarters (78%) of the patients who received oxygen when a headache had just begun reported being pain−free or having adequate pain relief within 15 minutes of treatment.

Cluster headaches are extremely painful headaches, more painful than migraines. They have been described as more painful than childbirth. Attacks usually last from 15 minutes to three hours and may occur several times in a day. They are called cluster headaches because they often occur in cyclical patterns, with periods of frequent attacks lasting for weeks or months followed by periods of remission when no attacks occur. Pain is usually on a single side of the head, generally in or around the eye.

The most common treatment for a cluster headache is an immediate injection of the drug sumatriptan. Frequent dosing is not recommended because the drug has many side effects, some of them serious. Some studies have suggested that oxygen may be helpful in treating cluster headaches but these studies have been limited, as has the overall use of oxygen to treat cluster headaches.

The study recruited and followed 109 adults between 2002 and 2007, 76 of whom completed the study. The study was randomized and placebo controlled. Each patient treated four episodes of cluster headache separately with air or oxygen (12 liters/minute), delivered by face mask for 15 minutes at the start of an attack. The treatments were alternated from one episode to the next. After receiving oxygen, 78% of the patients reported being pain−free or having adequate pain relief within 15 minutes of treatment, while only 20% of the patients reported this after receiving air. There were no serious adverse effects from the treatment.

The researchers feel that this study offers an evidence−based treatment alternative for those who cannot take sumatriptan or similar medications.

It is not currently known what causes or triggers cluster headaches. Cluster headaches often occur at the same time of day during an individual's frequent attack cycle and the cycles often follow the seasons. This suggests that the body's biological clock is involved, control of which is thought to reside in the hypothalamus.

Both sumatriptan and oxygen are believed to relieve the pain of cluster headaches by narrowing blood vessels in the brain which have become dilated.

The results of the study were published in the December 9, 2009 issue of the Journal of the American Medical Association (JAMA).