For those who flinch at the sight of needles, the thought of getting pricked on the tongue - one of the body's most sensitive organs - as a form of treatment would be unthinkable.
But this form of acupuncture helps treat physical pain and illnesses - even brain damage - by stimulating acu-points on the tongue, said Sun Jieguang, head of the Hong Kong International Tongue Acupuncture Research Clinic. Sun, from Liaoning province, says he invented tongue acupuncture in the 1980s, in an attempt to treat patients whom he could not heal using Western medical practices.
A registered Western doctor in the mainland, he has used Chinese medicine in his practice for more than two decades. He formally began practicing tongue acupuncture in 1993.
"Since practitioners of Chinese medicine look at the tongue to make their diagnosis, I thought that the tongue could also be used to treat illnesses directly," he says.
Different parts of the body correspond to different acu-points on the tongue, says Sun, a theory which has roots in the Medical Classic of the Yellow Emperor, the oldest written text on Chinese medicine.
Sun claims that bodily pain, such as a stomachache, can be alleviated within three minutes after receiving tongue acupuncture.
And, according to him, the condition of people with brain-related disorders such as autism, cerebral palsy, mental retardation and those suffering from brain damage can also be improved.
The plica sublingualis, the base of a fold of membrane on the underside of the tongue, contains six acu-points corresponding to the brain.
He hypothesizes that stimulating these acu-points can activate brain cells adjacent to dead brain cells that have become dormant.
Another hypothesis is that tongue acupuncture can also stimulate reserve brain cells that the body doesn't normally use, which then direct bodily functions in the place of dead brain cells.
In April 2000, he conducted a study with Virginia Wong Chun-nei, clinical professor at Hong Kong University's department of pediatrics and adolescent medicine, and Ko Chun Hung at the pediatric rehabilitation unit, Caritas Medical Centre. After performing a series of tongue acupunctures on children with cerebral palsy, they were found to have increased muscle function, mobility and coordination.
Stroke patients are examples of other success cases. "After sessions of tongue acupuncture, some may be able to raise their hand despite being paralyzed before. It's not because their arm has healed but because some brain cells controlling the movements of the arm may have been stimulated," Sun says.
Candy Wong Pui-man, a licensed traditional Chinese medicine practitioner and acupuncturist with four years of experience, says the effectiveness of acupuncture to treat stroke patients varies on a case-by-case basis. For example, younger patients in their 40s and 50s are more likely to recover their motor functions after being treated with acupuncture compared with older patients.
"Stroke patients are actually very good patients for traditional Chinese medical practitioners. But you can't wait too long. There have been cases where the patient was taken to an acupuncturist as soon as they were stable and, after a month of receiving 10-20 sessions of acupuncture on the body, they were able to recover their mobility," Wong says.
She adds that it is not unusual for pain to subside quickly after receiving tongue acupuncture - since performing acupuncture on the foot can alleviate stomach pain in 10 minutes, for example - and the tongue is a more sensitive organ than the foot.
One session of Sun's tongue acupuncture (HK$400), consisting of a rapid succession of pricks with a needle, lasts for only around 30 seconds to a minute.
"In tongue acupuncture, it's not necessary to leave the needles in. The idea of pricking the acu-points is to generate a feeling of numbness in the patients. That is already achieved by the pricking," he says.
Sun says that tongue acupuncture has no side effects. But in rare cases, patients may experience a little pain, bleeding and swelling on the tongue, but they can usually recover within three to five days without requiring any special treatment.
Sun adds that even if a patient suddenly stops receiving tongue acupuncture, their condition will not get worse.
Wong says that traditional Chinese medicine is backed by thousands of years of collective experience of practice and anecdotal evidence.
And while some successful cases may sound like miracles, some outcomes are reasonable because traditional Chinese medicine often works by stimulating the body's ability to heal itself.
"Tongue acupuncture is a more recent development. Traditional acupuncturists rarely talk about sticking needles in the tongue. There's acupuncture on the foot, on the ears and on the scalp - the tongue is just another alternative," she says.