The patients suffer from severe asthma who experience spasms in their vocal cords as well as their lungs.
The condition can cause severe breathlessness and wheezing, which is often mistaken for regular asthma, and affects about 250,000 Australians.
Monash Health director of respiratory and sleep medicine Phil Bardin said he and his colleagues tested the treatment in 11 patients with severe asthma who were shown to have vocal cord dysfunction on a CT scan.
By looking inside the airways and using a guide, Botox injections are administered to certain areas of the vocal cords. The effect of this is to relax the muscles and therefore the voice box, allowing the air to travel through to the lungs.
The majority of patients reported significant improvements in their asthma symptoms one month after the Botox treatment, which was also shown to improve airway size on CT scans.
Professor Bardin said the effects of Botox usually lasted two or three months, and one of its side-effects in the vocal cords was that patients reported speaking more softly than usual.
‘‘The treatment may not be suitable for all patients, but the early indicators are that it may be an option for those with severe upper airway distress, which is very exciting,’’ he said.
‘‘Many of these patients’ symptoms are extremely severe, so it has been tremendously satisfying to provide them with some relief.’’
A larger trial is required to confirm the study’s findings but early indications are good and may mean a safe treatment for patients suffering with severe vocal cord dysfunction.
One patient in the study, Lyn Dowsey, 68, found the treatment helped overcome asthma symptoms that required frequent hospital stays and left her feeling like she was being strangled.
‘‘I’m not choking up anymore, I can get up on my feet and move around without struggling to breathe,’’ she said.
Ms Dowsey said friends and family had joked that her vocal cords must be beautiful due to the Botox treatment.
‘‘I asked if I could have it elsewhere, but no,’’ she said, laughing.