Wolf remembered what might have been her earliest symptoms back in the summer of 1996: The pain that pierced through her left calf after a routine run and her left foot's refusal to flex during dance class. She switched to swimming to give her leg a chance to heal. The following winter, perplexed doctors treated her for nerve damage, but her symptoms only worsened.
"I knew ALS was a possibility, but I pushed it to the back of my mind in favor of treatable conditions," she recalled.
But the diagnosis evolved until there were no other prospects. By the fall of 1998, Wolf accepted the devastating consensus from three independent ALS specialists.
Despite major advances in ALS research over the past decade -- including the discovery of new genetic mutations and faulty proteins now known contribute to the demise of afflicted motor neurons -- the cause of ALS, and a cure, remain elusive. Although one in 10 patients has an inherited form of the disease, the majority of cases are sporadic and thought to stem from a cruel, complex interaction of genetic and environmental risk factors.
"It is hard to accept that ALS randomly struck you," said Wolf.
Most people with ALS first experience weakness in a limb. But as the disease progresses, more limbs are affected and the ability to speak, swallow and breathe is lost, it seems less plausible that a focal injury was involved, she said.
"That said, the human mind wants reasons," Wolf said. "I sometimes wonder if my moderate running -- 15 miles per week for about 10 years prior to ALS -- interacted with some genetic susceptibility."
Although the disease started in her legs, Wolf already was slurring words six months after her diagnosis. Planning for the unthinkable, she recorded phrases in her own voice, like 'thank you' and 'goodbye,' the names of family, and a few third-grade jokes like, 'What's green and hangs from trees? Giraffe snot.' She wishes she had recorded more.
Researchers long have suspected there was a link between ALS and injuries sustained during sport or combat.
In a 2007 study published in the American Journal of Epidemiology, individuals who reported having sustained repeated head injuries were three times more likely to have ALS than those who said they were injury-free.
In other studies, the incidence of ALS among professional soccer players in Italy and professional football players in North America was higher than normal. War veterans also are thought to have a heightened risk.
"It's very possible that physical injury may be some kind of trigger, but it's absolutely not the cause," said Lucie Bruijn, ALS researcher and senior vice president of research and development for the ALS Association.
While nerve injury might exacerbate the disease, Bruijn stressed that there's clearly an underlying genetic predisposition.
"The impact of the article was a real confusion among patients," Bruijn said. "I think there was concern over what this might mean for their diagnosis and their disease."
Wolf understands how patients like her could experience this kind of confusion.
"The [New York] Times is a reputable source, and despite the ALS Association's cautionary statement, many people might have believed their disease was a result of preventable behavior," she said.
McKee was sorry to hear that clinicians felt her study had upset their patients, she said. But her reaction from patients has been very different.