The Diamondbacks' right-hander underwent extensive examinations at the Mayo Clinic after the incident Monday. He was having dinner with his wife at a Phoenix restaurant when he passed out.
"It's something you get through," he said. "Now we know a little bit more about it. We know kind of how we'll treated it going forward, so I guess it means it's good to get one out of the way. At least now we know what we're dealing with."
McCarthy, speaking before Arizona played San Francisco on Sunday, said he knew that after a traumatic brain injury a person can become more "seizure-prone."
"There's always a chance of happening any time you have a bruise on your brain it doesn't actually ever heal, which always kind of leaves you at least somewhat vulnerable to it," he said. "So we knew the possibility was there. We had hoped we had kind of gotten past that."
McCarthy, on the 15-day disabled list with what has become an annual problem with his shoulder, said he will be taking anti-seizure medicine for the foreseeable future. He doesn't believe the seizure will impact his return to pitching.
"It's just a new thing to deal with, I guess, but it doesn't change me as a pitcher, what I do and how I go about my business," he said. "This just might be something else I have to deal with at some point. Outside of that there's no point in really changing anything."
While pitching for Oakland last Sept. 5, McCarthy sustained what was described at the time as life-threatening injuries when he was struck in the head by a line drive off the bat of Erick Aybar of the Los Angeles Angels. He had an epidural hemorrhage, brain contusion and a skull fracture. Emergency surgery was performed that night and he was released from the hospital six days later.
McCarthy, who signed a two-year free agent contract with the Diamondbacks, was 2-4 with a 5.00 ERA in 11 starts before going on the DL on May 31. He said he expects to begin throwing off the mound in the next couple of days and that the seizure would not set back that timetable.
For a time, McCarthy said, there was a chance that the situation would be much more serious after an initial CT scan showed a spot on his brain. The spot could have indicated bleeding and would have required surgery.
"When we went to sleep that night there was a chance that we wake up in the morning and someone would confirm it and we'd have to go through that whole process again," he said.
Instead, doctors concluded it was only a normal shadow.
Manager Kirk Gibson said he didn't want to comment too much on the situation because he considered a "somewhat personal" issue.
"I don't know what to say," Gibson said. "Everything that happened to him last year, when he got hit in the head, the first thing is you have a huge fear that this going to reoccur and is he OK. They're on it. He certainly won't pitch if he's not."
McCarthy insists he's not at any added risk for a brain injury despite what's happened.
"I'm not at any more risk than anybody else," he said.
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