Cervical dystonia is a rare disease affecting the neck muscles. Worldwide, only about 90 people out of every million get it.

Its effect, while gradual, is dramatic. The neck can, for instance, twist sideways or the head can slump downwards.

It may be incurable unless treatment is effective in getting the patient back to his normal posture.

Now, a research company is looking for people here with the condition for its clinical trial using the botulinum toxin, commonly known as Botox.

As a general condition, dystonia is described by the Dystonia Australia website as a "neurological movement disorder that causes muscles in the body to contract involuntarily".

Most commonly, the head is rotated to one side. In other instances, it tilts sideways and down to the shoulder, or forward, or backwards.

Dr June Tan, consultant neurologist at the National University Hospital, said: "The long-standing abnormal neck postures can cause neck pain and degenerative changes in the spine."

Dr Lim Li Ling, medical director and consultant neurologist at the Singapore Neurology and Sleep Centre, said cervical dystonia is fairly uncommon. It affects women twice as much as men, and typically hits people when they are in the 50s.

While dystonia can be inherited, the cause is unknown in most cases.

There are possible non-genetic causes too. DrAu Wing Lok, consultant neurologist at the National Neuroscience Institute, suggested previous exposure to psychiatric medication and neck injury as two possibilities.

Although cervical dystonia is a lifelong disorder in most cases, Dr Au said medication, injections of the botulinum toxin or surgery can help to control the effects.

"Where suitable, botulinum toxin can be injected directly into the affected areas to relax the muscles," he explained.

They are then less likely to contract involuntarily and the head may then gradually regain its upright position. The abnormal posture could recur though, when the drug’s effect wears off.

Repeat injections, about once every three to six months, are needed, said Dr Charles Siow, consultant neurologist at Siow Neurology Headache and Pain Centre.

He gets a patient with the disorder about once every two months. Since he went into private practice two years ago, he has had about 10 patients with the disorder.

Most doctors MYB spoke to said that complete recovery from the condition is rare. No figures are available on the disorder here.

Dr Au explained: "It’s probably under-diagnosed in Singapore because the symptoms can be mistaken for other neck problems."

Dr Lim agreed: "A doctor needs to examine the patient to differentiate cervical dystonia from other causes of neck pain and abnormal posture."

goyshiyi@sph.com.sg