WALNUT CREEK, Calif. — Thanks to charismatic rocker James Durbin, “American Idol” nights have become an excuse to play dress-up in the Brentwood, Calif., home of Brandon DeVincenzi.

Before every show, Brandon, 12, styles his hair into a spiky mohawk like the one Durbin often sports. He also tapes his ears slightly forward, slips on several wristbands and hangs a shirt from the back of his pants to mimic the cloth “tail” favored by the singer from Santa Cruz, Calif.

Before this year, Brandon had never watched “American Idol.” However, he considers Durbin to be “so awesome and cool” that his parents happily let him stay up past his bedtime to check it out.

Why the sudden fascination? Like Durbin, Brandon has Tourette’s syndrome, the mysterious neurological disorder that triggers involuntary movements and/or vocal outbursts called tics. The “Idol” contestant is the first person the 12-year-old has come across with the condition.

“It’s been like a coming-out party for Brandon,” said his mother, Malinda. “Before this, he found it really difficult to accept his Tourette’s, or even talk about it. James has put a face on Tourette’s and is showing Brandon that he can be comfortable with himself.”

Durbin’s powerful voice and flashy showmanship have made him one of “Idol’s” main attractions. However, he also has won over many fans by speaking frankly about his lifelong struggles with Tourette’s and Asperger’s syndromes.

“I have Tourette’s and Asperger’s, but Tourette’s and Asperger’s don’t have me,” Durbin, 22, said in an “Idol” interview earlier this season. “I’m doing what I can to suppress it. It’s not who I am.”

Although awareness of Asperger’s — a high-functioning form of autism — has increased in recent years, Tourette’s remains a highly misunderstood disorder that spawns many misconceptions.

“In the rare cases where you see Tourette’s in the movies and on TV, they tend to have fun with it,” said Cynthia Sandoval, a 27-year-old Pleasant Hill, Calif., resident who was diagnosed with the disorder in middle school. “It’s usually some person shouting out curse words all over the place. It’s a very tired image.”

Coprolalia, the form of the syndrome characterized by involuntary swearing, is quite rare, occurring in “only about 10 percent of Tourette’s patients,” said Dr. Elizabeth Lyster, of Foster City, Calif., who treats patients with Tourette’s.

Much more common are symptoms that can range from mild tics such as blinking and facial twitches, to more complex movements that include head and shoulder jerking, repetitive throat clearing, hopping and grunting. The symptoms tend to wax and wane, and they often worsen during stressful situations.

“It’s very annoying and embarrassing at times,” Sandoval said. “It can totally take over your life.”

The disorder, in severe form, affects an estimated 200,000 people in the United States, according to the Tourette Syndrome Association. It becomes evident in childhood or adolescence — a time when sufferers often experience teasing and ridicule.

“It can be really difficult for a child to have it out in the public,” said Malinda DeVincenzi, adding that son Brandon was once the target of a schoolyard bully.

Most patients do not need medication, but drugs could be prescribed if the tics are extreme enough to interfere with daily activities. There is no cure.

“Some people mistakenly believe that it’s a mental illness,” Lyster said. “But Tourette’s does not adversely affect intelligence and brain function.”

Nor does it seem to affect one’s ability to rock the “American Idol” stage. Durbin might display signs of his Tourette’s during on-camera interviews when he repeatedly squints and scrunches up his face. But as he told “Idol” viewers, when he sings, “it all just goes away, like I don’t have a care in the world.”