All eyes were on Perry Cohen when he froze at the microphone. His voice failed him. He couldn’t read his notes. Eventually, the once-powerful Parkinson’s disease speaker had to be helped off the stage halfway through his speech.

That was in February 2012, but the memory of that day is emblazoned in his mind. “It was the adrenaline and the pressure of speaking — it drained all the dopamine out,” Cohen says, referring to the brain chemical that is found lacking in the neurodegenerative disorder. “That’s why my symptoms got worse.” When Cohen learned he had Parkinson’s disease 17 years ago his symptoms were subtle. In the past couple years, however, the deterioration of his nervous system has become increasingly obvious, ultimately threatening to silence one of the most prominent voices in the Parkinson’s patient community.

Cohen is now first in line to try a novel treatment he hopes will halt or even reverse the symptoms of his Parkinson’s disease. Two months ago he became the inaugural patient to undergo a gene therapy treatment led by the National Institutes of Health.

The trial attempts to devise an intervention for Parkinson’s disease at the root of the problem: protecting dopamine in the brain. Researchers in this trial are attempting to surgically deliver a gene into the body that will make a natural protein to protect dopaminergic neurons, the brain cells attacked by the disease. To date no Parkinson’s treatment is geared toward reversing the progression of Parkinson’s disease.

For patients in the Parkinson’s community Cohen has become a squeaky wheel that cannot be ignored, helping researchers understand more about the patient experience and how to utilize their input in procedures and patient care. A scientist with a PhD from Massachusetts Institute of Technology in organization studies, Cohen says his background helped fuel his ability to bring people together to take action to advocate for people with Parkinson’s disease. His persistency also helped keep him on researchers’ radars when they were hunting for eligible patients for the trial.

As a savvy medical consumer, Cohen knew to be choosy about volunteering for a research trial, “Patients have one ticket to get on an experimental treatment train. Once you have used your ticket you’re used up and we have to be careful how we choose it,” Cohen says, pointing to the requirements of the current NIH clinical trial.

Since his diagnosis in 1996 Cohen’s whole life morphed until his disease became the center of his universe. The 67-year-old former healthcare consultant spoke before the Institute of Medicine on protecting human research participants and he testified before Congress. He founded a new Parkinson’s disease support group in the D.C.-area for individuals like him who were relatively young and mobile when they received their diagnosis. His friendships grew out of his relationships at the support group and through the scientific meetings he would attend where he often spoke about the role of patients in research.

Early on he decided that he wanted to be part of a gene therapy experiment and waited patiently until the right investigation came along. He volunteered for more than 15 clinical or observational studies — though none involved brain surgery. He also turned down deep brain stimulation, an increasingly common treatment for Parkinson’s disease, because he knew it would disqualify him from any attempt to insert genes into the brain.

Essentially deep brain stimulation involves implanting a “pacemaker for the brain,” that will regulate neural activity and block the abnormal nerve signals that cause tremor and other Parkinson’s symptoms. The procedure does not slow the progression of the disease; it just helps facilitate communication among the nerve cells in the brain.

The gene therapy trial had three main requirements, which Cohen made sure he fulfilled. To be eligible, a patient would have to be in the advanced stages of the disease —check. He would have had to avoid any other brain surgery and cleared other exclusionary factors —check. And he would have to be told that the procedure was part of a Phase I trial — meaning it was geared toward testing for safety and that there was no guarantee it would help him — check. But Cohen had done his homework on the trial and his hopes were high. He had followed the evolution of the science on this type of gene therapy through its early animal trials and he eagerly anticipated when the human trials would finally wind their way through the reviews process, allowing him to sign up. He also personally spoke with almost all the investigators involved in this area of research. And, it goes without saying, he had his fingers crossed that this treatment would work.

In May of 2013, Cohen went under the knife. A team of surgeons made an incision across the top of his head and drilled two holes in his skull. They inserted needles on both sides of his brain and used an MRI scan to monitor their work while they pumped in a virus solution containing the genes they hope will serve as an elixir to save dopaminergic cells. Now, Cohen has returned to his daily life and is anxiously awaiting signs that might indicate whether the procedure worked—something NIH investigators say may not be detectable until this autumn.

When Cohen was diagnosed with Parkinson’s disease, a stranger passing him on the street would not have known anything was wrong, but as his disease progressed, the tremors often associated with the disease began to show up along with the insomnia and the “Parkinson’s mask” that caused his muscles to droop and look rigid. Now, “I take short steps, I can’t even walk half a mile anymore,” he says. He has what are commonly called “shuffles” in Parkinson’s disease — referring to his difficulty maintaining balance and the appearance that he is lurching forward when he stops walking. Now he is often short of breath and speaks in a raspy, halting voice. He had to abruptly end interviews with Scientific American on two separate occasions when his symptoms acted up. His five daily medications may help improve his symptoms and combat his lethargy, but there is no treatment that changes the arc of the disease.

Today his energies are focused on his own health; he is waiting for any clues that the genes were successfully integrated into his system — anything from his involuntary movements becoming less prominent after he takes his usual medication to indications that he can walk and move faster between his medication doses than before the procedure. One thing the disease certainly teaches is patience.