The Sometimes Son.

I don't think Kevin's mother and father ever experienced any of the joys of parenthood. Their son didn't like to be held when he was an infant, and his first developmental milestone was violently banging his head against the side of his crib.

Then, around the age of three, Kevin retreated into his own private world and ignored everyone around him. If anyone tried to speak to him, he covered his ears with his hands and ran away. The social isolation, sensory and speech problems, and self-injurious behavior were more than enough to label Kevin autistic.

Kevin and his parents had been coming to my Saturday clinic for three months. Behavioral interventions had decreased the frequency of Kevin's head-banging, and there was a small improvement in his isolate behavior, but he still wouldn't talk.

I thought Kevin was going to be another one of my slower-progressing autistic kids until his mother called to tell my secretary they would not be coming back. No need, she said. Thanks to my clinic, Kevin no longer had autism.

Like all neuropsychological disorders, autism ranges in its severity, and while there continues to be disagreement and confusion among the experts regarding the prevalence and etiology of autism, everyone agrees that autism is usually a lifelong disorder.

Denial often occurs in parents overwhelmed by the task of caring for a child with a neuropsychological disorder. I felt certain denial had prompted the call from Kevin's mother. So, I called her back and asked if I could drop by.

"I'd like to check on Kevin," I told his mother, after she had opened the door to her home. She smiled and motioned me inside. "He's stopped banging his head and he's talking to us," she bragged. "We can't thank you enough."

I faked a smile and followed her into the living room. Kevin was nestled on the couch beside his father, quietly watching TV. This wasn't the Kevin I knew from my clinic. This Kevin appeared attentive and sociable.

I walked over and extended my hand. "How are you doing?" I asked, as I racked my brain for an explanation of this extraordinary change in his behavior. Kevin looked straight at me and shook my hand. "Okay," he answered in a clear voice.

I leaned over and examined Kevin's head. His mother was right; there were no fresh bruises. "Are you feeling any different now than you have in the past?" I inquired. "Yes," Kevin answered, again looking at me. "Me see and hear better now."

"Oh, so you had problems seeing and hearing," I confirmed as I stood in front of him. "Yes, problems seeing and hearing," Kevin said, nodding his head. "Couldn't hear sounds or sounds too loud."

"And what about your visual problems, Kevin?" I asked, noting his pronoun confusion, which is typical of many higher-functioning autistic children who are verbal. "Things fuzzy at times and me couldn't see," Kevin said, looking back toward the TV.

I understood how chaotic sensory distortions could have sent Kevin into his own private world. Some deaf children act and have even been misdiagnosed as autistic. What I couldn't understand, at the moment, was Kevin's remarkable recovery.

I sat down on the couch beside Kevin. Several minutes passed before he covered his mouth with his hand and coughed several times. "Kevin may have a bit of a cold," his father informed me, as he put his arm around his son. "He doesn't appear to be very sick," I said. When I felt his forehead, however; I realized Kevin had a high fever.

I've never seen an estimate of the percentage, but some autistic children, as well as children with certain other neuropsychological disorders, become almost normal when they have a fever. Of course, all children quiet down when they are sick. But the changes that occur in these autistic children are more dramatic--more like a metamorphosis in which the autistic child suddenly becomes almost normal.

These children experience increased alertness, a decrease in social isolation and self-injurious behavior, an increase in verbal behavior, and an attempt to reach out and communicate with adults. Not only parents but entire institutions report improvements in autistic children with high fever.

In 1980, a viral epidemic causing high fever hit Bellevue Psychiatric Hospital in New York City. All of the staff noticed an improvement in the autistic children they worked with. Sadly, after a few days, the fever dissipated and all of the children became autistic again.

According to anecdotal reports, stress can have a similar short-lived effect. Autistic children undergoing stressful medical procedures become verbal after years of being mute. (Patients with catatonic schizophrenia have been known to give up their unusual postures and walk normally out of burning buildings. Once they are safely away from the building, they resume their catatonic poses.)

Various theories in the area of brain chemistry try to explain why high fever and stress improve the behavior of some autistic children. But there's nothing on the horizon in the way of a potential cure I could mention to Kevin's parents. Sooner or later, I'd have to tell them that the boy sitting on the couch would leave soon and he'd only return when he was sick and running a high fever again.

I decided the bad news could wait until morning. Tonight, I'd sit and watch Kevin's parents enjoy a few precious moments with the son they'd never had. I thought they deserved as much time with him as the fever would give them.

It seems like every time I go to the mall now, I bump into Kevin and his parents. They smile, wave innocently, and hurry on. But I think I know what they're up to. In the crowded mall, Kevin has a better chance of catching a stray virus. And sometime, they'd like to have their son come home for another visit.

Gary Brown is a practicing psychologist affiliated with the University of Tennessee. He frequently contributes to professional journals and popular media publications and is the author of two academic survival books for college students.