DANTE AUTULLO WAS sure he’d merely cut himself with a nail gun while building a shed, and thought doctors were joking when they told him what an x-ray revealed: a 3 1/4-inch nail was lodged in the middle of his brain.

Autullo was recovering yesterday after undergoing surgery at Advocate Christ Medical Center in Illinois, where doctors removed the nail that came within millimeters of the part of the brain controlling motor function.

“When they brought in the picture, I said to the doctor ‘Is this a joke? Did you get that out of the doctors joke file?’” the 32-year-old recalled. “The doctor said ‘No man, that’s in your head.’”

As he was rushed by ambulance to another hospital for surgery, he posted a picture of the x-ray on Facebook.

Autullo said he was building a shed on Tuesday and using the nail gun above his head when he fired it. With nothing to indicate that a nail hadn’t simply whizzed by his head, his long-time companion, Gail Glaenzer, cleaned the wound with peroxide.

“It really felt like I got punched on the side of the head,” he said, adding that he continued working. “I thought it went past my ear.”

While there are pain-sensitive nerves on a person’s skull, there aren’t any within the brain itself. That’s why he would have felt the nail strike the skull, but he wouldn’t have felt it penetrate the brain.

Neither he nor Glaenzer thought much about it and Autullo went on with his day, even plowing a bit of snow. But the next day when he awoke from a nap, feeling nauseated, Glaenzer sensed something was wrong and suggested they go to the hospital.

At first Autullo refused, but he relented after the two picked up their son at school on Wednesday evening.

An x-ray was taken a couple hours later. And there, seeming to float in the middle of his head, was a nail.

Doctors told Autullo and Glaenzer that the nail came within millimeters from the part of the brain that controls motor function, and he was rushed by ambulance to the other hospital for more specialized care.

“He feels good. He moved all his limbs, he’s talking normal, he remembers everything,” Glaenzer said earlier Friday. “It’s amazing, a miracle.”

Neurosurgeon Leslie Schaffer acknowledged that Autullo’s case was unusual, but not extremely rare. Schaffer said having a nail penetrate the skull is not like being shot in the head, noting that a bullet would break into multiple pieces.

“This (the nail) is thinner, with a small trajectory, and pointed at the end,” he said. “The bone doesn’t fracture much because the nail has a small tip.”

Schaffer said the man’s skull stopped the nail from going farther into his brain. He said he removed the nail by putting two holes in Autullo’s skull, on either side of the nail, then pulled the nail out along with a piece of the skull.

The surgery took two hours, and the part of the skull that was removed for surgery was replaced with a titanium mesh, hospital spokesman Mike Maggio said.

Glaenzer said Autullo hasn’t really talked about how scared he was about what might have happened, but he did express a recognition about coming close to death.

“He was joking with me (after surgery), ‘We need to get the Discovery Channel up here to tape this,’” she recalled him saying. “‘I’m one of those medical miracles.’”