BEIJING — They're paralyzed from diving accidents and car crashes, disabled by Parkinson's, or blind. With few options available at home in America, they search the Internet for experimental treatments — and often land on Web sites promoting stem cell treatments in China.

They mortgage their houses and their hometowns hold fundraisers as they scrape together the tens of thousands of dollars needed for travel and the hope for a miracle cure.

A number of these medical tourists claim some success when they return home:

Jim Savage, a Houston man with paralysis from a spinal cord injury, says he can move his right arm. Penny Thomas of Hawai'i says her Parkinson's tremors are mostly gone.

But documentation is mostly lacking, and Western doctors warn that patients are serving as guinea pigs in a country that isn't doing the rigorous lab and human tests that are needed to prove a treatment is safe and effective.

Noting the lack of evidence, three Western doctors undertook their own limited study. It involved seven patients with spinal cord injuries who chose to get fetal brain tissue injections at one hospital in China. The study reported "no clinically useful improvements" — even though most patients believed they were better. Five developed complications such as meningitis.

PLACEBO EFFECT?

Experts in the West have theories about why some people think they've improved when the evidence is thin. Some are often getting intensive physical therapy, along with the mysterious injections; the placebo effect may also be a factor.

John Steeves, a professor at the University of British Columbia who heads an international group that monitors spinal cord treatments, has another theory. Some patients may be influenced by the amount of money they paid and the help they got from those who donated or helped raise money.

"Needless to say, when they come back, what are they going to report to their friends and neighbors? That it didn't work?" said Steeves. "Nobody wants to hear that."

Western doctors discourage their patients from seeking such treatments. They say it's impossible to gauge the safety and effectiveness of the treatments, or even know what's in the brain and spinal cord injections.

Patients and their families say they accept those risks. They simply don't have time to wait for more conclusive evidence. "It's one of the only games in town," said Savage, 44, a lawyer who suffered severe spinal cord injuries after a canoe trip 25 years ago.

Savage spent 2 1/2 months in late 2006 and early 2007 at a hospital in the southern China city of Shenzhen to get what he was told were stem cell injections in his spine from umbilical cord blood. He made the arrangements through Beike Biotechnology Co., which offers the treatments at a number of hospitals in China.

Afterward, Savage said he was able to move his right arm for the first time since his diving accident; a video made at the hospital appears to show slight movement. He also said he noticed greater strength in his abdomen and more sensation on his skin.

Just how many foreigners like Savage are coming to China for treatment isn't known, and China is only one of several countries where such techniques are being offered.

Many Chinese doctors don't wait for results of rigorous testing before treating patients and they offer what they say are stem cell or other cell treatments to those willing to pay.

What is known about the procedures being performed comes from material on their Web sites or from patients who give detailed accounts of their visits. Little has been published in scientific journals for other doctors to scrutinize.

For decades, doctors around the world have been using adult stem cells from blood and bone marrow — and more recently from umbilical cord blood — to treat cancers of the blood like leukemia and blood diseases like sickle cell anemia.

Scientists have been exploring whether such adult stem cells and other cells such as those from the retina or fetal brain tissue could be used to replace cells lost because of injury or disease. And they are trying to figure out if there's a way to stimulate the body's own stem cells to make repairs.

But those strategies are still being investigated in the lab in animals; there have been very limited tests in people.

Whether any clinics in China are using the more controversial embryonic stem cells — doctors in some other countries claim to be — isn't clear. These stem cells are taken from days-old embryos. They can develop into all types of cells, but research into their usefulness is in early stages.

Patients seek out these unproven treatments after hearing about them from other patients, patient groups or Web sites for the medical companies. The patients' stories posted on the Internet usually tell of some kind of improvement from the treatments — slight movements in arms or legs, fewer spasms or tremors, a feeling of sensation, an ability to sweat.

WORTH $20,000?

Chris Hrabik, 21, has been disabled since a 2004 car crash left him with limited use of his hands and legs. His father took out a second mortgage on their Oak Ridge, Mo., home to help pay for $20,000 worth of stem cell injections at a Beike facility in China.

More than a year after returning home, Hrabik says he has nearly complete use of his left hand, with improvement in the right. He said he was able to move his left fingers within days of that first injection of umbilical cord stem cells into his spinal cord. There's been little progress since he left China, but he called the incremental changes significant.

"I just wanted something back, no matter what it was," he said.

Beike founder Sean Hu, who returned from abroad in 1999 with a doctorate in biochemistry, said the company has treated more than 1,000 patients, including 300 foreigners. The only side effects have been slight fevers and headaches among a small percentage of patients, Hu says.

He said patients with trauma injuries experience the most dramatic improvements; those with degenerative diseases such as amyotrophic lateral sclerosis, also known as Lou Gehrig's disease, tend to improve initially but then slide back to their former condition within months.

"Patients shouldn't have their expectations too high," Hu said. He's now seeking venture capital to expand his web of treatment centers, labs and doctors and adapt proprietary techniques from researchers overseas.

"There is real potential here for China to take the lead in stem cells," Hu said.

Western experts point to the lack of documented evidence that cell treatments have any benefit for spinal cord injuries or degenerative diseases like Parkinson's.

"All of us in the so-called Western world, if there was something valid, we'd be the first to be offering it," said Steeves, the Canadian professor and director of the International Collaboration on Repair Discoveries, known as ICORD.

Three other experts were involved in the study that found no improvement in the seven spinal cord injury patients who went for fetal brain tissue injections in China. The patients were evaluated before and after their surgery.

The doctors stressed their observations were no substitute for a larger, more strict investigation.

Dr. Michael Okun, medical director of the National Parkinson Foundation, said his group discourages patients from seeking out experimental treatments unless they're being done under the most rigorous research protocols.

"Stem cell therapy ... is a really interesting area that has a lot of promise for therapeutic approaches. But we're just not ready to be putting stem cells into people's brains at this point in time," said Okun.

But such warnings don't dissuade people like Penny Thomas of Captain Cook, Hawai'i. She sought treatment for Parkinson's disease at Tiantan, where doctors drilled into her skull and injected what she was told were cells from a donor's retina. One year later, she said her tremors are almost gone and her medication has been cut to one-half of a single pill.

"I have no regrets and would do it all over again if need be," said Thomas, 53.