She had been battling mental illness for almost a decade, but this was new.
He told her his name, and she eyed him incredulously.
"No, Sheldon's a good guy," she told him. "You're hateful. You're a terrible person."
Ms. Waxman, 55, suffers from Capgras delusion, which can accompany schizophrenia and causes individuals to believe their loved ones have been replaced by imposters.
In Canada, doctors see only about 50 to 100 cases a year, but the disorder has entered the public consciousness of late with the trial of Tony Rosato, a former SCTV cast member who is facing charges of criminal harassment against his wife. According to his lawyers, Mr. Rosato suffers from Capgras and believes his wife and daughter have been substituted by mysterious twins.
It is the stuff of science fiction, a bizarre affliction that has formed the plot of CSI episodes and the 2006 novel The Echo Maker. It is even referenced in the new film The Invasion, a remake of Invasion of the Body Snatchers that will be released tomorrow.
But for the family members of those who suffer from Capgras, the strange delusion is all too real.
They must struggle to deal with wives, husbands and children who suddenly look at them as strangers, and often perceive them as a threat.
"It's hard on the families," said Joel Jeffries, a psychiatrist at the Centre for Addiction and Mental Health in Toronto who has seen several cases of Capgras. "You explain that it's part of the illness and not to take it too personally, but it is personal because they're seen as the imposters."
Mr. Waxman said it has been torture to slowly lose his wife of 31 years, but he has grown immune to her accusations."I'm numb to it now," said the 66-year-old lawyer who lives in Grand Rapids, Mich. "I've developed a thick skin."
He met Ms. Waxman when she was working as an intensive care nurse. She was so full of energy that he used to call her "the butterfly" because she was constantly flitting from one place to the next.
"I left my first wife to marry her," he recalled this week. "She was the woman of my dreams."
But 15 years into their marriage, she began to change.
She became despondent and suffered what doctors classified as a "psychotic break," usually the first episode of a decline into schizophrenia. She was given tranquillizers, hospitalized repeatedly and eventually diagnosed with schizoaffective disorder, which combines the psychotic symptoms of a thought disorder with the manic components of a mood disorder.
She heard voices, carried on conversations with invisible characters and paced the yard of their home screaming to the sky.
"It was horrible," her husband said.
The Capgras delusion came later, he added, and was always directed solely at him.
Some sufferers, perhaps including Mr. Rosato, believe that several people in their lives have been replaced by strangers. Others suffer "mirror self-misidentification" in which they believe their own reflection is an imposter.
In his book Phantoms in the Brain, California psychiatrist V.S. Ramachandran describes a Capgras patient who thought his poodle had been replaced, and another who woke up each morning believing his shoes had been switched in the night.
Ms. Waxman recognizes her children, who are 30 and 26, but is constantly suspicious of her husband.
"If I'm not Sheldon, how come your children accept me as being Sheldon?" Mr. Waxman used to ask his wife. "She would tell me I had them brainwashed."
Capgras delusion was named in 1923 for a French psychiatrist who described the case of Madam M, a woman who insisted her family had been switched with doubles. According to a 2005 article about the affliction in Scientific American Mind, she believed the imposters were rapidly replaced and claimed to have had more than 80 strangers in the role of her husband.
Dr. Jeffries says most Capgras suffers regard their doubles as benign, and are treated with anti-psychotic medication. Mr. Rosato's case has raised alarms within the mental health community because he has been held in custody for two years without receiving treatment.
But Mr. Waxman's wife stopped taking anti-psychotic medication years ago after developing painful side effects, and refuses to begin again.
The couple's son wanted to have her committed, so she would be cared for professionally, but Mr. Waxman, who works as a criminal lawyer, could not bring himself to see her liberties restrained.
"The idea of incarceration doesn't sit well with me," he said.
Now, Mr. Waxman lives in one end of his ranch house with his wife in the other.
He has given her a cellphone in case she gets lost or confused in public, and often receives calls from store clerks asking him to pick her up. Once, he had to bail her out of jail.
"She has a life," he said. "I don't think it's one that you or I would like to have, but she's functional in a lot of ways."
While he doesn't spend much time analyzing her delusions now, he does still wonder what triggered this change in his wife.
When she was young, she was hit in the left side of the head with a baseball bat, he said.
Some studies of the Capgras phenomenon have linked the delusion to head injuries, suggesting a neurological malfunction, but no definitive cause is known.
It cannot be a simple case of the brain misreading visual cues, because blind people have been known to have Capgras.
In some rare cases, Capgras patients become violent.
A psychiatrist at a Veterans Affairs medical centre in California compiled 80 cases in which Capgras patients attacked a presumed double either verbally or physically, two of which involved fatalities.
In 2005, Andrew Crago of Mississauga was found not criminally responsible for killing his parents, Robert and Cecella. The 29-year-old suffered from Capgras and during his trial the court heard that he believed his real parents had been killed or were being held against their will.
Mr. Rosato's wife, Leah, is reportedly so afraid of her husband that she has agreed to testify only from behind a screen in the courtroom, so that he can't see her.
Mr. Waxman said his wife has never been violent toward him, but her illness has taken other tolls.
He takes occasional comfort in her describing the good qualities of the real Sheldon, but says he has come to see Ms. Waxman as just as much of a stranger as she regards him.
"Do I still love her? I love who she used to be, but she's not that any more," he said. "So, no, I guess not."