Six years after he was mugged while walking home one night - left for dead with his skull crushed - a man regained the ability to talk, chew and swallow thanks to slender electrodes implanted deep in his brain.

The patient, whose unprecedented recovery took place at a rehabilitation hospital in central New Jersey, lived in a "minimally conscious state" for years. He usually kept his eyes closed, occasionally responding to questions with slight finger movements or a faint shake of the head. He was fed through a tube.

Now 38, he is alert, and can brush his hair and drink on his own - the apparent result of what his doctors called a pacemaker for the brain. Recently, he recited the first 16 words of the Pledge of Allegiance.

"He can cry and he can laugh," his mother said tearfully yesterday, joining in a teleconference with her son's physicians. "He can say 'I love you, Mommy.' "

The doctors cautioned that their results, reported in today's issue of the journal Nature, would not apply to patients such as Terri Schiavo, the former Montgomery County resident whose life became a sociopolitical flash point.

She was in a persistent vegetative state, whereas the male patient - whose name was withheld - had clung to consciousness and had large regions of his brain intact. Indeed, Schiavo was given a similar implant that had no effect.

But the operation described in the new study - the first in a minimally conscious patient - could offer hope for thousands with similar injuries.

The patient's mother hopes this could someday help wounded soldiers. Traumatic brain injury has been called the signature injury of the war in Iraq.

The researchers warned that their study had involved just one patient, though 11 more will receive the implant. The candidates are being chosen from the "upper end" of minimally conscious patients; the procedure likely would not help many on the lower end, said Nicholas D. Schiff, the study's lead author and a neuroscientist at Weill Cornell Medical College in New York.

Still, the results are encouraging, said Ashwini Sharan, a neurosurgeon at Thomas Jefferson University Hospital who was not involved with the study. Doctors have long told families there is no good treatment for severe brain injuries.

"We have to go think about all these people we forgot," Sharan said. "We said that nothing could be done for them."

Although they are still a thing of the future for those with brain injuries, 40,000 such devices already have been implanted in people with various illnesses, most of them with Parkinson's.

The brain-injury patient has electrodes implanted in a walnut-size area of the brain called the thalamus. They appear to jump-start the thalamus, renewing its critical role of sending signals to the cortex, said study co-lead author Joseph T. Giacino, a neuropsychologist at the JFK Johnson Rehabilitation Institute in Edison, N.J.

The current is delivered from battery-operated, pacemaker-like devices implanted in the chest.

The surgery on the brain-injured man was done at the Cleveland Clinic. The follow-up testing and rehab were done at JFK Johnson. The concept was developed at Weill Cornell.

The work took the scientists into a realm that was once exclusively the province of philosophers; they now have a better idea of the neuronal hardware involved in regulating consciousness - the very essence of being.

Because the patient was unable to consent, the researchers got approval from three review boards and his family. They also set up a mechanism to involve him in future decisions, should he become able.

He's getting there, said Joseph J. Fins, a Weill Cornell physician-ethicist and coauthor of the paper. The patient has joined discussions about treatment, though his short-term memory remains impaired and he has to be reminded of events that took place the day before.

During the teleconference, the patient's mother told how when her son first went to the hospital, a doctor warned that if he survived, he would be "a vegetable the rest of his life."

He lived for nearly five years in a nursing home, where she visited him daily.

"On my way home," she said, weeping, "I would cry. It is so hard for a mother to see her child like that, and I prayed for a miracle."

Her emotional account left the researchers in silence.

"Let me just catch my breath," lead author Schiff said eventually, after the mother finished.

Initially, the patient was in a coma but became somewhat responsive three months after the attack, sometimes able to obey verbal commands by moving his head.

That improvement, along with brain scans showing that his cortex was largely preserved, led his doctors to consider him for the implant.

The 10-hour surgery involved drilling dime-size holes in his skull, after which doctors slowly inserted hairlike probes to pinpoint the exact part of the thalamus they wanted. The probes had tiny microphones attached, so the doctors could listen to the electrical activity of various neurons as they went from region to region.

Jefferson's Sharan said neuronal activity sounds like a whoosh followed by pops; the pops sound different in each brain region.

Once they found the right area, in went the electrodes.

The doctors saw improvement almost immediately after turning on the current in 2005. But to be sure, they then conducted a six-month study in which the electrodes were turned on and off in one-month alternating periods.

Since then, the current has been kept on for 12 hours a day, and the patient has continued to improve. Lately he also has been given a drug, amantadine, which the researchers said might also be helping.

They said they did not know if he would be able to walk again; his brain can give the necessary instructions, but his body cannot yet follow them.

The patient's mother, meanwhile, is watching her son rediscover simple pleasures. He is a comic-book collector and adores superhero movies, but after his injury he could not stay awake long enough to watch one. Now, he can.

"I still cry every time I see my son," she said. "But it's tears of joy."

For an animated graphic and audio clip of the patient's mother, go to http://go.philly.com/health

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