Sex

Sex After Traumatic Brain Injury

How frontal lobe damage can change your sex drive.

Posted Oct 16, 2019

Sex is typically not the first thing that comes to mind when you think of life after a traumatic brain injury, but in some cases, such injuries can cause dramatic changes to a person’s sex drive and life. Doctors rarely discuss this topic, and patients may hesitate to bring it up when changes in the brain mean that so many other things need medical attention. But wanting too little or too much sex can have a devastating impact on relationships.

It’s not part of my routine practice as a clinical neuropsychologist to ask about people’s sex lives, but sometimes patients or their partners will spontaneously raise the subject. And sometimes, as in the case of Jack and Tessa, it is the most memorable feature of their presentation.

Jack had a traumatic brain injury and sustained right frontal lobe damage in a fall off a roof. I met him when he was in the hospital only a few weeks after his injury, and he immediately asked me for sex. I attempted to do a neuropsychological assessment with him, to check his memory and other thinking skills, but his sexual requests were relentless. 

His mind was fixated on one thing only: sex. I gave up after half an hour. I wondered how his wife was handling this unexpected outcome of his fall.

Tessa was an 18-year-old woman who had a traumatic brain injury in a road accident. She had been in the front passenger seat of a car driven by her boyfriend; he had been drunk and speeding after a night out celebrating the end of high school.

Tessa had suffered only minor physical injuries, but her mother explained that this was both a blessing and a curse: Everyone thought that since Tessa looked the same, she was the same. The invisibility of her brain injury made it difficult for her friends to understand the changes in her behavior. 

Tessa told me that ever since her accident, she was consumed by sexual thoughts and wanted to have sex "with every guy she met." 

Andrew Baird. Used with permission.
Source: Andrew Baird. Used with permission.

Jack and Tessa both had traumatic brain injuries and experienced a dramatic increase in their sex drives, or hypersexuality. Why? In both cases, it was a result of where their injuries had damaged their brains. 

Traumatic brain injuries typically occur in motor vehicle accidents. People hit their heads on the windscreen or, even worse, are flung through it headfirst. The frontal lobes of their brains are very vulnerable, given their position in the brain.

Increased sex drive and disinhibited sexual behavior tend to occur if a specific region of the frontal lobe is injured, namely the orbitofrontal region. It is often considered a by-product of general behavioral disinhibition that can occur after orbitofrontal damage, but we don’t know why some people express this in a sexual way, and others don’t.

At the other end of the spectrum of sexual outcome after traumatic brain injury is hyposexuality, or an absence or markedly reduced interest in sex. This tends to occur if the prefrontal region is injured and is considered part of the general tendency of apathy and indifference that can occur after such injuries. 

This was the case for Rita’s husband of more than 30 years. He had enjoyed a few too many beers one evening and tumbled headfirst down the stairs at the pub. When Rita arrived at the hospital, she was expecting to see a broken leg and was shocked to find her husband unconscious

The doctors asked her to sit down and looked serious as they pointed to dark patches on his brain scan that glowed on the computer screen. The only words she heard and remembered were "frontal lobes" and "severe." She couldn’t comprehend how a fall down some stairs could be so dramatic and cause so much damage. 

When I met them several years later, Rita had gotten used to her new husband, who exploded over minor irritations, repeated himself in conversation, and couldn’t stand her talking to him if he was doing something else.

She spontaneously referred to their sex life and said, "I’ve tried, and there’s nothing. He’s not interested since his fall. That’s OK. It doesn’t bother me. At least he’s not aggressive." Then she shrugged and changed the subject. 

The frontal lobes are often referred to as the "executive" or "conductor" of the brain, as they control many social, behavioral, emotional, and cognitive functions that are considered to be the very "essence" of what makes us human. To name a few of these frontal lobe or executive functions, they enable us to plan, organize, make decisions, and act on things. They help us regulate and control our emotions, are involved in motivation and reward processes, and control an array of cognitive functions, including attention, memory, problem-solving, and language. 

Our frontal lobes make us who we are in that they play a role in personalities and complex social and emotional behaviors, such as empathy, humor, deception, and creativity. Entire books and Ph.D. theses have been written on frontal lobe function, so it would be impossible to cover it all here. For our purposes, the frontal lobe’s critical role in human sexual behaviors is most relevant. 

Everything sexual that humans do involves a complex interplay of motor, social, cognitive, and emotional functions, so it makes sense that the frontal lobes play a critical role in the sexual neural network. For example, in the broadest sense, our frontal lobes (specifically the regions that mediate motor function) control the movements we need to make to have sex, inhibit us from having or seeking sexual responses at socially inappropriate times, and are involved in the myriad of social and emotional functions that accompany sex, such as the ability to empathize with a partner. 

Adjusting to life after an acquired brain injury includes the challenge of navigating intimate relationships. A change in sex drive can be an unexpected surprise for both the person with brain injury and their partner. It is only by acknowledging that this can occur and discussing it that we can increase awareness and understanding of the effects of traumatic brain injury on this fundamental aspect of people’s lives.

This is an adapted excerpt from Sex in the Brain: How Your Brain Controls Your Sex Life.

Facebook image: Federico Marsicano/Shutterstock

References

Baird, A.D., Wilson, S.J., Bladin, P.B., Saling, M.M., & Reutens, D.C. (2007). Neurological control of human sexual behaviour: insights from lesion studies. Journal of Neurology, Neurosurgery and Psychiatry, 78, 1042-1049. 

Henri-Bhargava, A., Stuss, D. & Freedman, M.  (2018). Clinical assessment of prefrontal lobe functions. Behavioural Neurology and Psychiatry, 24(3), 704-726.