WHAT IS IT LIKE to raise a severely handicapped child? Two mothers describe their very different experiences.

Alice Mendenhall (not her real name) wonders how the old saying about the punishment fitting the crime ever got started. As far as she can tell, the only thing she ever did wrong was to bring a baby into the world.

Lori, her daughter, was born in 1966 with an abnormally small head. She has an IQ of no more than 20. She also throws sceaming fits that last entire days and nights. She is confined to a wheelchair because of severe curvature of the spine. Alice attends to Lori's every need. In Alice's words, her daughter has "made an old woman out of me."

The Mendenhalls, who also have a normal 16-year-old son, live near the Ohio- Indiana border. Alice's husband Jack squeezes a small income out of their tiny farm, but he must supplement the family finances by working as a machinist. He is a good and gentle man, with an appetite for work, but he doesn't have much time or patience to help his wife with Lori. Any decisions about the child's care he leaves to Alice.

Lori was a handful right from the start. "She came home from the hospital demanding attention," her mother recalls. "She was a miserable little person, crying all the time. And she would abuse herself. She'd lie in her crib at night and bang her head. It was all we could do to keep her from cracking her skull."

Because of a malfunctioning stomach valve, Lori suffered from projectile vomiting. She had to be fed almost hourly to get enough food in her stomach to keep her alive. Between the head banging and the feedings, Alice did not get more than three hours sleep a night for the first four years of Lori's life. When Alice came close to a breakdown from taking care of both Lori and Dwayne and helping with the farm chores, the Mendenhalls placed the child in a state institution. But they became so distressed by conditions there that they brought Lori home after a year.

Lori's tantrums and head banging have grown worse with age, and Alice must frequently wrestle her into submission. "She's 65 pounds and she's strong." sighs Alice. Lori is not toilet-trained and must wear special diapers; moreover, the digestive problems of her infancy have taken the adult form of extreme constipation. Alice must manage the girl's bowels with enemas and by manual stimulation. "It's no fun for either of us."

In the past 12 years the Mendenhalls have had but one vacation -- five years ago, when Alice's parents agreed to baby-sit for a week so that Alice and Jack could go to Florida. "We knew it would be the last vacation we would ever take," says Alice. "My folks are both in their late 70s now. They could never handle Lori again."

Lori developed curvature of the spine when she was 13. Doctors gave the Mendenhalls a choic whether or not to have corrective surgery performed. They said the operation was exceedingly risky, and might require Lori to be strapped down motionless on her back for months. But without it, Lori was almost certain to die in her early 20s of compression of the heart.

Alice and Jack walked around in the rain for an hour, crying. At last they decided against the surgery. "We told each other that we'd given her 13 years of a good life." Now, as Lori approaches 19, it appears the doctors were wrong. Her heart is in perfect condition. "She could live forever," Alice says.

Alice describes what she feels for her daughter as "ambivalence in its extreme form. I had a night recently when I got very little sleep. She kept getting me up hour after hour. Then, in the morning, I didn't hear from her for ever so long, and I found myself thinking it would be nice if one morning she just slipped away. Just died. And then, of course, my next thought was, 'How would I cope with that?' I probably love Lori in a way that isn't healthy. When a person is this dependent on you, you don't know where they begin and you leave off. I feel like I've wasted my life, though. I can't help it. I am tired and bitter, and my back hurts from lifting her day and night."

Alice likes to think that if there had been life-or-death decisions to make when Lori was an infant, she would have been "brave enough" to let her daughter die. As for those parents who do face this choice, Alice believes they should be able to exercise it. "I feel very strongly about that. I think the judge who says, 'This child will be taken away and treated' should have to change the diapers when the child is a teen-ager and walk the kid all night long while she's screaming. I hear some people with a retarded child say that everybody should have one of these kids, that it's the best thing that ever happened to them. That's cuckoo. How can anyone think the best thing that could happen is to have a child who's less than whole?"

Monica Sullivan and her husband Terrence, of suburban Chicago, are the parents of a 17-year-old boy named John. He has brought an extraordinary light into their lives, although he has never uttered a word and never will. John was born with brain and motor damage, webbed fingers and toes and four heart defects. One of his eyelids was locked shut and he had a hernia and an undescended testicle. At birth, however, no life-or-death decisions had to be made about him.

Physicians didn't expect John ever to sit up, walk, talk, or even recognize anyone on sight. They advised that he be institutionalized. "But we just couldn't do it," Terrence recalls. Today John is a happy but severely limited adolescent whose IQ is too low to measure. He stands just three feet tall and weighs only 50 pounds. He is not toilet-trained, nor can he speak, but he has mastered several hand signals. For example, he claps his hands to indicate he wants a cookie. He touches his head for something to drink and his lips for something to eat.

When John turned 9, the Sullivans faced their first crisis. His cardiac malformations had to be repaired or he would die. "We decided to get John the operation, just as if he were a normal kid," says his father. "I just couldn't let him die," says Monica. "Despite all his handicaps, I have learned a great deal from him. Having a child like John has matured me emotionally, made me more of a fighter. I found I couldn't live my life through my child. I had to find other ways to be fulfilled -- something besides my son getting As in school and being on the baseball team."

Terrence thinks that John has had a more positive effect on them than a normal child would have. "John teaches you the simple pleasures, the things that are fundamentally important. He doesn't know or care what car payments are. And he is forgiving of everything. You get nothing but hugs and smiles from John."

Monica says that John has seldom been a real burden. "He causes us no more inconvenience than a normal child. Yes, inconvenience in the sense of all these years of diapers. It's not pleasant to change a diaper on a 17-year-old. But not an inconvenience in any real sense. We've always been able to find baby-sitters who get to know John and understand his signs. He's no trouble."

Does Monica have any regrets? "Well, you regret it when you wonder what he might have been. But I don't regret it in the sense that I wouldn't have had him all over again the way he is. Neither of us says, 'Gee, I wish he'd never been born.' But if I had one wish in the world, I'd wish that he were healthy. You hate to see someone you love suffer."

Monica confesses that occasionally when visiting women friends, it occurs to her that their children are in high school now. And then it hits her that that is where John would be if he had been normal. "John's kind of ageless, I guess," she remarks wistfully. "He's Peter Pan."