Although the headache could have been a result of his spinal tap, McGuire's doctor told him there was a chance he was experiencing the onset of meningitis -- even though he tested had negative the day before.
"It felt like there was a knife sticking in your head," McGuire, 51, said. "I've had sinus headaches, which are more of a dull ache. This was a very sharp pain that was constant."
And McGuire is not alone in wondering whether he is having a spinal headache or meningitis. A spinal tap is the only way to tell if a patient has meningitis, and 40 percent of spinal tap patients get spinal headaches as a result, according to the Mayo Clinic.
More than 14,000 patients nationwide were exposed to fungal meningitis if they received contaminated compounded steroid injections manufactured by New England Compounding Co. in Massachusetts. They were people who already needed pain management treatment for other conditions. Of the 212 people who were infected, 15 have died, said the Centers for Disease Control and Prevention on Monday afternoon. Another two patients developed joint infections.
McGuire spent eight hours in the hospital last Monday after he learned that he received a contaminated epidural injection for his back pain in August. He was among about 300 patients to receive a spinal tap at Saint Thomas Hospital in Nashville because of the fungal meningitis outbreak, said hospital spokeswoman Rebecca Climer.
He then had to miss two and a half days of work, lying down at home with the drapes closed because his head hurt, he said.
If McGuire had a spinal headache, it would mean that spinal fluid leaked from the puncture where doctors performed his spinal tap, offsetting the normal pressure from fluid in the spinal column, said Dr. Joshua Bederson, who chairs neurosurgery at Mount Sinai Hospital in New York.
The brain produces and absorbs four cups of spinal fluid each day, he said. When there's too little fluid, as in a spinal headache, the brain sags in the skull, pulling on veins that connect the outer surface of the brain to the inner surface of the skull. That's what causes the intense headache. (The brain itself has no nerve endings and can't feel pain.) It usually clears up on its own without major health complications.
Meningitis headaches, on the other hand, are caused by inflammation of the membranes in the brain and spine. They can result in permanent neurological damage and death.
But which is which?
If the headache is positional, it's probably a spinal headache, Bederson said. The patient should get relief from lying down, but feel more pain when he or she stands up.
If the pain is constant and not positional, it may be something else.
"The doctor instructed me to stay in bed over the weekend," McGuire wrote in an email on Friday. "If I still have a headache on Monday, I am to return to the ER for another spinal tap. The saga continues."
Since McGuire only had to wait an hour for his spinal tap results, ER doctors were probably looking at his spinal fluid under a microscope for a high number of white blood cells, rather than culturing the fluid to see whether fungus grew, said Dr. Frank Esper, a pediatric infectious disease expert at University Hospitals in Cleveland. As such, patients can still test positive later. The CDC recommends waiting to do a spinal tap until the onset of meningitis symptoms.
Esper said the CDC has developed a more advanced test for fungal meningitis, a polymerase chain reaction, but it's not clear whether all hospitals can use it yet.
"If this was a person who had an injection of known material associated with this outbreak, then I would think people would be erring on the side of caution," Esper said. Since the CDC reports a median incubation period of 15 days, he said he would watch for symptoms for about up to month and a half after the tainted injection.
McGuire said his head still aches but he was able to go to work on Monday after his doctor checked in to see how he was doing.
It seems he can get back to worrying about the condition he set out to treat in the first place: the pinched nerve that's caused him back pain for three years.