The stories were hard to believe at first -- tales of autistic children coming down with fevers and suddenly acting like a normal child.
Youngsters who routinely told their parents to go away instead said, "Play with me." Children who usually shunned physical contact cuddled up to mom on the couch.
Many parents were sure their doctors would think those stories were sheer fantasy.
But Dr. Andrew W. Zimmerman, a pediatric neurologist at Kennedy Krieger Institute in Baltimore, heard so many of these accounts over the course of his 40-year career that he decided to see if science would back them up.
In a surprising finding published in this month's issue of the journal Pediatrics, Zimmerman and his colleagues determined that fever-induced improvements did, in fact, occur in more than 80 percent of the 30 autistic children they studied.
But the positive changes in behavior and language use were fleeting. And scientists still don't know what brought them on -- or why they occurred in some children and not others.
But researchers say the observations offer new insight into what is malfunctioning in the autistic brain -- and how it might one day be treated.
"If we could understand what's going on with this, we might be able to understand autism better and be in a better position to treat it," said Zimmerman, director of medical research at Kennedy Krieger's Center for Autism & Related Disorders.
Autism is a spectrum of disorders marked by impaired social development and communication as well as repetitive behavior such as flapping arms or jumping up and down. Autistic children usually are slow to learn to speak and often find it hard to read basic social cues in the faces of others or to relate to people in general.
Rene Craft's son Jackson was diagnosed as autistic when he was 3 1/2 years old. But doctors determined much earlier that he had a sensory integration disorder.
Craft says her son, now 6, is highly sensitive and "not in a good way." He feels assaulted by the background music in department stores, the feel of denim, the bright lights and constant sounds that others accept as part of their world.
One day, when he was 3 and did not yet speak more than a word here or there, Jackson came down with a fever.
"He was lying in our bed and ... out of the blue, he said, 'I like the sheets, Daddy. They're very comfortable.' We had never heard our son's voice in anything but a scream. I don't think he'd ever addressed us," recalled Craft, who lives in Austin, Texas. "Then he looked out the window and said, 'It's raining.' He never noticed the weather before. He never noticed anything.
"When he had a fever, it was almost like a fog was lifted."
She and her son watched a video together that day. He watched to see whether she was laughing at the funny parts and then he would laugh.
Two days later, when Jackson was feeling better, she put the same video in.
"He ran screaming from the room," she said. "The fever was gone, and he was gone again. He didn't speak for another year."
Researchers do not know what causes autism, whose various symptoms affect up to one in 150 children. But they say they believe it has a genetic component that might be triggered by something in the environment.
Autism stole her child, Craft said. But when Jackson had a fever, he seemed to be telling her that he was in there somewhere. She said she was glad that her husband was there to see it, because she doubts that her pediatrician believed her when she told him.
It wasn't in the literature, she was told.
But now it is.
While Zimmerman's study was small, Dr. Martha R. Herbert, a brain researcher at Harvard Medical School, said it points the way toward new avenues of research. Though the world generally regards autism as a behavioral disorder, she is convinced that it has biological underpinnings.
"We should be thinking of this as a condition that isn't necessarily inevitable or fixed in every respect," she said.
Unfortunately, she added, this is not where current research is focused. Instead, scientists approach autism more as broken wiring in the brain. But if a fever can change the way an autistic child's mind operates, what else might have a similar impact?
Although the Kennedy Krieger study is an early finding, "it breaks out of the box -- and it's a good box to break out of," she said.
Zimmerman said one possible explanation is that fever generates proteins called cytokines from the immune system -- proteins that play a role in the development of brain synapses and enhance their function.
Another possibility is that a fever's internally generated heat -- a visit to a sauna won't do the job -- could change the physical properties of cell membranes and, in turn, make synapses connect better.
"They're not cured. It doesn't make them normal. It makes them so much more normal," he said. "We're realizing the children were very much more aware of things than people gave them credit for."
The children in the study, ages 2 to 18, all had fevers of more than 100.4 degrees Fahrenheit, mostly from colds and other viruses. When confronting an infection, the human body will often raise its temperature in order to fight whatever is making it sick.
The researchers gathered a group of volunteers with autistic children and then waited until the kids developed fevers -- a process that took years in some cases.
Parents answered questions about the children's behavior within the first 24 hours of discovering the fever, after three days, and then a week after that. Researchers found that the febrile children were more lethargic but improved on other scales, including irritability, hyperactivity and language.
Researchers dismissed one possible explanation -- that fever simply made the youngsters too tired to misbehave -- since youngsters in both high and low lethargy groups showed improvements.
But Dr. Deborah Fein, a psychology professor at the University of Connecticut, said lethargy could account for more of the effect than the study indicates.
For example, while researchers noted and measured declines in inappropriate speech, such as the repetition of words, they did not inquire about increases in positive behavior.
"The more crucial thing will be to verify that social and language interaction increase with the fever," she said. "That would be a very important piece of data."
Though no one suggests that doctors should induce fevers in autistic children, other researchers have documented the positive effects of fevers on disorders such as epilepsy.
In the 1920s, doctors used injections of a fever-inducing malaria parasite to treat neurosyphilis, a practice that continued until the advent of the antibiotic penicillin during World War II. Seizures and other cognitive conditions associated with a rare form of encephalitis related to measles also seem to decrease during a fever, Zimmerman said.
In the tight community of parents with autistic children, fever has been discussed for years. Sarah Lurz of Glen Arm had heard the reports but didn't give them much thought until her son started talking to her about something he was watching on television.
She was confused. Sam, now 5, didn't just strike up conversations like that. So, she reached over and felt his forehead. Her son was running a fever.
"He tries to interact with you more socially when he's not feeling well," Lurz said. "He'll even talk to you about what he's thinking, which is something that he never does.
"He's almost typical, to some degree, when he has a fever."
stephanie.desmon@baltsun.com