Pelle Sandstrak, a grandson of whale-hunters, grew up dreaming that he would one day own a Chrysler and get a girl. In the remote Norwegian fishing town of his childhood, he remembers gazing out of his classroom window, mesmerised, whenever a car appeared. As it drove past, the teacher's voice would fade and a motorised noise would accumulate inside his head, intensifying as he strained to identify the car, until suddenly he'd jump up in the middle of the lesson and yell: "Fucking asshole Saab!"

Raised in a culture of restraint, Pelle would spit, swear, fire off obscene jokes and - though acutely shy - compulsively touch people and grab their things. His phobias included the letter X, which he associated with fish-hooks, blood and death. Throwing his X-infested algebra book into the river, he had to explain its disappearance. "Fucking asshole seagull took it!"

When Pelle was 16, his father read an article in an English magazine about the strange behaviour of children with Tourette's syndrome. "That's my son!" he shouted, and arranged a consultation with the nearest psychiatrist, 400km away in Trondheim. Pelle explained his odd fantasies, and the professor informed his parents that their boy had an intractable personality disorder. When Pelle's father disagreed, angrily waving his magazine, the professor responded: "Tourette's? We don't have that here."

These days, when Pelle speaks at conferences, that line always gets a laugh. He now views his early symptoms as belonging to two distinct though connected problems: an obsessive compulsive disorder that turned washing or walking through doorways into nightmarishly repetitive rituals; and then the underlying Tourette's, emerging from what the great Russian physiologist Ivan Pavlov called "the blind force of the subcortex", a disturbance of those primitive parts of the "old" brain which govern the drives.

Most sufferers experience only physical tics, but for some like Pelle there is also coprolalia: the involuntary utterance of obscenities. What's fascinating is the way this organic, neurological disorder finds highly precise social and psychological expression; so Pelle grew up feeling like the joker in the pack, the one impelled to invert accepted codes of behaviour.

In the 1980s, moving to a flat in Oslo, his compulsions began to consume him. Going to the toilet would take hours, so he began urinating and defecating into plastic bags, which he hung from his walls, until this became too much and he began sleeping rough. In a disused warehouse, he discovered to his delight the wreck of a 1950s Chrysler, and for several months this became home.

One day, ticcing and chattering away near his favourite hot-dog stand, Pelle's crazy commentary caught the attention of a producer from the local anarchist radio station, who offered him a late-night slot. And with the job came chemical back-up. In the studio there was an envelope that read: "A little something for you."

It contained speed from Poland and he found that, instead of giving him a rush, the amphetamine calmed him down. Suddenly, he got a glimpse of normal behaviour. The only problem was that the dealers who had left him this taste of salvation also returned to demand their dues. Pelle broke into a public office, stole 10,000 kroner, paid off his debts, and was jailed.

With no speed to calm him, and prison routines exacerbating his obsessions, he was thrown into solitary for refusing to walk through his cell door properly. There, on a pocket radio, he tuned into a talkshow on which a professor described a boy who compulsively ticced and joked. "That's me!" Pelle shouted. He wrote a long letter, telling the man his story. And a month later, that doctor came to find him. "You've got Tourette's," he said. "I can get you out of here, and you can get better." He was taken to Lund, in southern Sweden, and for the next 10 years worked through the routines of cognitive behaviour therapy to modify his own pathological routines.

Pelle also came to terms with his inner anarchist by telling his story publicly, first at conferences, then as a one-man theatre show. Always, he would describe how he had emerged from the wreck of an old car.

And then the call came. He was invited to open a huge neuroscientific conference in Chicago. Thanks to a senior executive, whose own son had Tourette's, the conference was sponsored by Chrysler. They had heard the story of Pelle's "home" and offered him $15,000 for his talk. Instead of a fee, he asked for something else.

Now, at the age of 42, Pelle lives with his girlfriend in a cottage in Sweden, where he is putting the finishing touches to his book, Mr Tourette And I. Outside in the drive stands a shiny, blood-red Chrysler.