Until last year, Alan Felzer was an energetic engineering professor who took the stairs to his classes two steps at a time. Now the 64-year-old grandfather sits strapped to a wheelchair, able to move little but his left hand, his voice a near-whisper.

Felzer suffers from ALS, also known as Lou Gehrig's disease. The fatal neurological disorder steals the body's ability to move, speak and ultimately to breathe. But rather than succumb to despair along with his illness, Felzer turned to the Web to become his own medical researcher -- and his own guinea pig.

Dozens of ALS patients are testing treatments on their own without waiting on the slow pace of medical research. They are part of an emerging group of patients willing to share intimate health details on the Web in hopes of making their own medical discoveries.

Some doctors caution that such patient-led research lacks rigor and may lead to unreliable results, false hopes and harm to patients.

"The Internet is a wonderful tool, but you know, it's buyer beware," said Dr. Edward Langston, immediate past chairman of the American Medical Association's board.

In Felzer's case, the experiment's results illustrate the obstacles that stand between patients and self-discovered breakthroughs. The drug he tried did no good. But he and his family felt they had little time and little to lose in trying.

"ALS is such a short illness," said Felzer's wife, Laura. She helps her husband communicate using sign language with his one good hand when his slow, halting words become difficult to understand. "You want to do what you can as fast as you can."

The U.S. Food and Drug Administration has approved only one drug to treat ALS symptoms. It only works for some patients, and its effects are limited. As a result, Internet forums for ALS patients brim with links to the latest research offering any hint of promise. After Alan Felzer was diagnosed last year, his 33-year-old daughter, Karen, dived into the forums and found new hope.

In a recent small study, Italian scientists reported that every ALS patient given the drug lithium, commonly used to treat bipolar disorder, saw the disease's progress slow substantially.

Many ALS patients began trying lithium on their own. They persuaded their doctors to prescribe it "off-label" -- a use not approved by federal drug regulators. Off-label prescribing is a common practice, researchers say, when patients are facing a terminal illness.

Despite the risks, Langston of the AMA pointed out that doctors often stumble upon treatments, and patients could possibly do the same. "If patients are willing to share their experiences, that may in fact occur," he said.

Felzer began taking lithium in January, and his scientifically minded family reached out to other ALS patients. "All those people are taking it anyway," said Alan Felzer, whose smile remains bright and his gaze sharp even as the rest of his body fails him. "So it only made sense to keep track of what was happening."

The task of leading the ALS-lithium project fell to Felzer's daughter, Karen, a U.S. Geological Survey earthquake researcher. Her partner in the effort was Humberto Macedo, a 42-year-old computer systems analyst, father of six and ALS patient in Brasilia, Brazil.

The study grew naturally out of the strong reliance of ALS patients on one another for information, Macedo said.

Working online, Karen Felzer and Macedo recruited nearly 200 patients worldwide to take a specific lithium dosage and answer standard surveys to gauge their symptoms. They began running their study through a Web site called PatientsLikeMe.com, using it to attract volunteers and track their progress.

On the site, patients share detailed information about their symptoms and the drugs they are taking. The site focuses on conditions that have stubbornly resisted medical science, such as ALS, Parkinson's and multiple sclerosis.

The site's founders hope professional and amateur researchers alike will dip into the resulting pool of data and emerge with insights that lead to better treatments.

"My ultimate frustration that drove this site into existence was an overall feeling that there was a lack of transparency and speed or urgency" by the medical system, said Jamie Heywood, who co-founded PatientsLikeMe months before his own brother died of ALS.

Heywood too hoped that lithium was the breakthrough he and others had been seeking.

But after six months, none of the 87 people who stuck with the study showed any letup in the disease's progress, said Karen Felzer. She now doubts the Italian study's results.

"It's obvious to everyone it's not the miracle drug we thought at first," she said. She also thinks other tests of lithium for ALS should be halted to spare patients the drug's possible side effects, such as tremors, weakness and difficulty breathing. Her father stopped taking the drug, though Macedo is continuing.

However, other reseachers say professional lithium studies should go forward. Dr. Merit Cudkowicz, a Harvard Medical School professor, is set to begin one in December with 84 patients. Her study will stick to the so-called gold standard of research, in which each patient will be randomly chosen to take the drug in question or a placebo. Neither patients or researchers will know who got the drug to avoid introducing bias.

Because the patient-led lithium study lacked those tight controls, it is unreliable as a measure of safety and effectiveness, Cudkowicz said. With an incurable disease, she said, "You don't want to be throwing something away that works because of a bad study."