These 2 Women, One Who Became a Dominatrix, Say Brain Trauma Gave Them Intense Sexual Desires

— -- Two women from different parts of the world believe a brain injury gave them an overactive sex drive.

Alissa, who was in a car accident in 2008, and Heather, who suffered massive brain bleeding in 2005, say their sexual personalities changed after they each experienced trauma to their brains.

"[I would] just constantly worry about seeking guys out, feeling like if I don’t have like a sexual or romantic partner at this period of time, then I just don’t really have much of a reason to live,” Alissa, 23, from Vancouver, Canada, told ABC News’ “20/20.”

Heather, 43, from Leeds, England, says her brain injury also left her with an intense appetite for sex. Happily and faithfully married to her husband Andy, she worked in advertising and raised their son. But one day, a subarachnoid hemorrhage left her in a coma for two weeks that almost killed her.

"I think I was doing some gardening that day, and I collapsed in the garden and I can remember a huge pressure in my head and knowing that something was really wrong,” Heather told “20/20.”

"They showed me on the picture, the white spots on the brain stem. [The doctor] said, ‘That’s all blood,’” Andy told “20/20.” “And he said, ‘It’s not good, and she’s probably not going to survive.’”

Andy said that in a way he did lose his wife that day. “The wife that I married died on May the 21st,” he said.

Heather emerged from the coma with a voracious interest in having sex right there in the hospital’s shower room, while she was still hospitalized. After she was released, Heather’s desire for sex only intensified.

“It was emotionally hard. It was physically hard. It was hard,” Andy said. “I [got sick of sex].

Heather began propositioning -- and sometimes groping -- men left and right. Andy even witnessed a construction worker, whom Heather picked up, kiss her on the mouth across the street from their home.

“She was completely and utterly out of control of whatever it was at the time for her. She had no control of her behavior at the time,” Andy recalled. “She'd meet people, and within seconds, she'd be offering sex or even sort of having sex with them.”

“It was almost like a sport, you know, going out and seeing if there was [anybody around],” Heather said.

At the time, Andy said Heather couldn’t see that she was doing anything wrong or out of the ordinary. She tried to have sex with strangers, co-workers, a teenager and even a man in a gas station bathroom, while her husband and son sat in the car. Andy estimates that Heather had sex with fewer than ten other men, but behaved inappropriately with as many as fifty. And through it all, Andy stayed with his wife.

“It’s just because I love her,” Andy said. “That was my motivation.”

“Most commonly, following a brain injury the changes in sexual behavior are manifested as a decrease in interest and a decrease in drive. However in some cases, it can be the complete opposite,” Dr. Jamie Levine, a brain injury specialist at NYU Langone Medical Center, told “20/20.”

In Vancouver, Alissa was also dealing with a compulsion to have sex that she said she could trace back to her serious car crash. As a result of the brain trauma, she also suffered from depression and chronic fatigue.

"The car flipped over three times. I hit my head, and the next time I woke up was in the morning in the hospital,” Alissa said.

Before the accident, Alissa said she had been a typical teenager who had only one sexual experience with one guy. However, she said she spent most of her day thinking about sex after the crash.

“It would kind of be like a tape playing in the back of my mind, like a certain awareness,” Alissa said.

While she couldn’t stop herself, Alissa said she couldn’t enjoy herself either. The impulse to have sex was so controlling that Alissa said she even contemplated suicide.

"Because it doesn't feel good. It doesn't feel healthy -- because it's not. It doesn't feel like I'm in control of it. It feels like the other person has something that I want, and they have all the power,” she said. “They can treat me however they want to, and they'll still have this hold over me.”

Alissa began working as a stripper, then as a dominatrix, using the name Sasha Mizaree. She even built a dungeon in her apartment, but said she doesn’t have sex with her clients. She was paid $250 an hour to dominate them. She now makes money selling videos of herself.

Her attorney Scot Stanley said her decision to become a dominatrix was a result of the brain injury. When he made that case in court and sued the driver responsible for Alissa’s car accident, the court awarded Alissa with $1.5 million.

“I think that as people we'd like to think that our personality is a bit more stable than just, you know, like having, you know, a bump on the head be able to change that fundamentally,” Alissa said.

Thanks to therapy and medication, Alissa said her sexual urges have recently diminished. What she really wants now, she said, is someone to love.

Heather also underwent therapy and used prescription drugs that dampened her sexual desire. "Some medication has a negative side effect. You’ll be aware that it lowers your libido,” said Heather.

Andy and Heather are now celebrating more than 20 years of marriage and Heather’s new found monogamy.

“I don't think I have those [sexual urges] so much at all now,” Heather said. “I also make sure that I'm not in the situation where there's only me and a bloke, you know.”