With the aid of electrodes implanted in his brain, a man paralyzed from the neck down was able to perform certain everyday activities — move a computer cursor, open e-mail, turn on a TV set — merely by imagining them.

The patient, whose spinal cord was injured when an attacker stabbed him in the neck, was even able to open and close a prosthetic hand, his thoughts translated into action by a custom-built computer.

For now, the patient must be tethered to a cart loaded with electronics. The system was developed by scientists at Brown University, who say it is just a few years away from commercial use.

The results, reported in today’s issue of the journal Nature, offer hope that thousands of people with injured spinal cords could someday regain significant function by simply bypassing the injury. Eventually the team expects patients will have a wireless device implanted in the brain that sends signals not just to computers, but to parts of their own bodies.

Coincidentally Wednesday, a team that includes Drexel University scientists reported progress toward a similar goal in lab rats, albeit by different means. The researchers removed a nerve from each animal’s leg and transplanted it across the injured spinal cord, restoring some mobility to paralyzed forelimbs.

Researchers at the University of Arkansas for Medical Sciences have developed a couple of simpler devices to help spinal cord injury patients regain mobility.

Ozark Systems Manufacturing, of Siloam Springs, Ark., has licensed the use of a Motorized Bicycle Exercise Trainer to restore muscle mass to patients who have lost the use of their legs and to eliminate the excessive reflexivity found in such patients.

The other is an epidural implant that triggers the legs to walk, said Dr. Edgar Garcia-Rill, director of UAMS’ Center for Translational Neuroscience.

Meanwhile the efforts of the Brown University team, which included researchers in Chicago and Massachusetts, seem like something out of science fiction.

After implanting electrodes in the brain of Matthew Nagle, the 25-year-old stabbing victim, scientists discovered that the neurons associated with moving his arms and hands could still generate electrical signals — a surprising find, three years after the attack.

They ran wires through his skull to BrainGate, an electronic device that filtered out the noise and learned to interpret the signals. When connected to a computer, Nagle was able to play the video game “Pong” and also drew a circle using a computer drawing program.

“I just imagined moving the cursor,” he said via phone from a Massachusetts hospital room.

University of Pittsburgh neurobiologist Andrew Schwartz, who was not part of this study but has done similar work in monkeys, said the success in human patients was a good start.

It is “still far from being a useful device,” he wrote in an e-mail from Europe.

John Donoghue, the article’s senior author and chief scientific officer Cyberkinetics Neurotechnology Systems Inc., which makes BrainGate, acknowledged room for improvement.

But the technology has gotten even better since his team wrote the Nature article, he said.

Nagle sometimes moved the cursor wobbly and overshot his target on the screen. Later patients have done better because researchers refined the computer algorithm, Donoghue said.

Translating is hard, as millions of neurons help move an arm, while the hair-thin electrodes only get signals from dozens.

The goal is to make a wireless device that could be fully implanted so the patient would not have to be wired to a computer.

One hitch: the electrodes in Nagle’s brain seems to have suffered a short-circuit near the end of the 14-month experiment. But this was not caused by an adverse reaction in the brain itself, Donoghue said.

“The barriers to this seem more technological, but surmountable, rather than anything biological,” he said. “I’m very encouraged.”

While current work involves moving computer cursors and prosthetic devices, the researchers hope someday to transmit electrical signals from the brain to a patient’s real hands and arms.

Nagle’s parents worried about the brain implant, but he was determined to press forward.

The electrodes were removed after the experiment, so he no longer can bypass his crippling injury. But Nagle’s participation was not just about bettering his own condition, he said, his voice a hoarse because he breathes with a ventilator.

“I knew it would give a lot of people hope,” Nagle said.

By Tom Avril
Philadelphia Inquirer
July 13, 2006.