It is already one week after Wang Yuanping, 50, received deep brain stimulation (DBS) surgery in Beijing Tiantan Hospital. The procedure was the last medical option available to reduce his tremors and improve his quality of life after suffering from Parkinson's disease for almost 10 years.

The surgery is expected to inactivate the parts of the brain that cause Parkinson's as the implanted device sends electrical pulses to the target areas in the brain, blocking the impulses that cause tremors.

Wang had to quit work eight years ago due to the disease. Late last year, he was unable to look after himself and needed help when turning over in bed or getting up.

Initially, the drug he took alleviated his symptoms, but as the disease progressed, it wasn't enough. When he first started using it, one pill would work for three hours; later, it would only work for one.

"The torturous feeling after the drug's effect receded was indescribable. Whether standing, sitting or lying down, I felt restless all the time," Wang said.

In the afternoon, the doctor visited him in the ward and tried to get the stimulation turned on to see how it would relieve his symptoms.

The bandage on Wang's head and chest hadn't been removed yet. The surgery involves the insertion of a wire with two electrodes into the brain, which is connected to a small unit called an implantable pulse generator (IPG), implanted in the chest. When switched on, the IPG produces electrical signals, which are sent to the brain to reduce Parkinson's symptoms.

The doctor put a special control device near Wang's chest and input some data. Amazingly, his hands stopped trembling immediately. As required by the doctor, he tried to get up and walk between the bed and the door.

"I feel it is easier to turn around now," he told the doctor. However, after walking for a few rounds, he was unable to get used to the stimulation from the device and complained of dizziness.

The doctor turned off the stimulation and Wang's hands started to tremble again. Three weeks later, when he recovers fully from the surgery, the stimulation will be adjusted to a comfortable level.

"Parkinson's disease is a degenerative neurological disorder. At present, there is still no cure for it," said doctor Zhang Jianguo, director of Functional Neurosurgery Department of Beijing Tiantan Hospital, who conducted a few DBS surgeries around World Parkinson's Disease Day on March 11.

Parkinson's disease occurs when there is a loss of nerve cells in the part of the brain known as the substantia nigra. These cells produce a chemical known as dopamine, which allows messages to be sent to the parts of the brain that coordinate movement. When approximately 80 percent of the dopamine-producing cells are lost, the symptoms of Parkinson's appear.

According to doctor Zhang, drugs and surgery can only alleviate patients' symptoms and improve their quality of life, but the disease could not be stopped completely.

He advocated that early-stage Parkinson's patients turn to drug treatment to increase the level of dopamine that reaches the brain.

In most newly diagnosed people, considerable improvements can be achieved by the careful introduction of anti-Parkinson drugs. But as the disease progresses, the drug's effects would diminish and the improvement hours would be shortened, according to Zhang.

So, surgery would be recommended for patients who had reached the later stages of the disease and failed to respond to drugs. The implanted stimulators would generally work for five years, and the IPG replacement procedure is relatively simple. However, the surgery is unaffordable for most patients, at a cost of about 200,000 yuan (US$26,000), according to Zhang. So far, a little more than 600 patients around the country have received the surgery.

A cheaper type of surgery, called lesioning, involves inserting an electrode into the brain, purposely destroying a certain part of the brain area that produces tremors. However, the procedure is irreversible and can cause complications such as difficulties in swallowing and balance as well as a hoarse voice, Zhang warned.

The burden of Parkinson's disease has long been underestimated in China, which had been reported to have the lowest prevalence of the disease worldwide.

However, an article published by professor Zhang Zhenxin of the Department of Neurology, Peking Union Medical College Hospital, in the Lancet in 2005 shook both the academic world and the public. Zhang's research team found a higher prevalence of Parkinson's disease than in previous studies in China. The prevalence of the disease for those older than 65 was 1.7 percent much the same as in developed countries. The researchers estimated that 1.7 million people older than 55 in China have the disease.

The data from doctor Zhang's epidemiological research has become widely accepted by medical world, according to doctor Shao Ming, a Parkinson's disease expert with First Affiliated Hospital of Guangzhou Medical College.

So far, the causes of Parkinson's disease are still not very clear, he said. The possible reasons scientists suggest include aging, toxins such as exposure to pesticides or heavy metals, and genetic factors.

Though the disease is more common in older people, young people can also be affected. But so far, there are no statistics to show how many are affected.

Awareness of Parkinson's disease among the Chinese public is still very low.

According to a survey released by the Chinese Medical Association's Parkinson's Disease and Movement Disorder Department, about 78 percent of the 1,033 responding patients said they didn't realize it was Parkinson's disease before they went to a hospital. Also, 65 percent of the respondents sought medical treatment after the syndrome already affected their normal life.

Wang Yuanping is a good example. For seven years, he thought his disease was cervical spondylosis. At the early stage, he felt stiffness and aches in his right arm and his right leg trailed on the ground. He was diagnosed with Parkinson's disease three years ago when he began trembling.

Knowing that many patients do not get timely help, doctor Shao established a website (www.homefpd.com) five years ago, on which up-to-date medical information on Parkinson's disease is published and patients could also ask specific questions and exchange experiences.

Shao said he was glad to see many patients get help on his website. He felt proud that the site ranks No 1 when typing in the key words "Parkinson's Disease" on Google.

"As new drugs and therapies emerge quickly, the patients could alleviate their pains by selecting a strategy most suitable to them. Information is important to making the correct choice."

(China Daily April 23, 1007)