Can a change in sexual behavior indicate a neurological problem?


As my husband and I were interviewing Joy Milne, a retired nurse in Perth, Scotland on her ability to detect Parkinson’s Disease (PD) through smell only, she revealed to us a surprising fact about her late husband, Les, who was a physician anesthesiologist:

Chris Gilbert, MD, PhD
Source: Chris Gilbert, MD, PhD

At 37 years old, while exuding a new musky smell, Les became hypersexual with Joy and sexually disinhibited in public. Les started asking Joy to wear skimpy lingerie and he wanted to use sex toys during intercourse. (All of this was new behavior.) Formerly a quiet family man, Les became flirtatious with various women at work and at parties, wanting to kiss and cuddle with coworkers and friends. This change of behavior happened over a couple of months. Les wasn’t aware that there was anything wrong with that conduct.

Les also became more irritable, sometimes violent and aggressive, sometimes abusing Joy with a scathing diatribe he could not believe he had said afterward. Later that same year, Les became more agitated in bed at night, speaking in his sleep, moving his legs and arms violently without being aware of it or waking up during his movements. This night time agitation was associated with dreams of chasing people or being chased. One night, Joy found him sweating, kneeling on the bed in a position of having a gun and shooting blackberries off bushes while being fast asleep. All those symptoms — sexual disinhibition, scathing diatribe, agitation in bed while being fast asleep, were a change of behavior from the previous years, and at the beginning of these changes, Joy thought Les might have a brain tumor. But it later developed that these changes were the beginning of his Parkinson’s Disease, which was only diagnosed eight years later when the first resting tremors started.

At the same time the sexual disinhibition started, Les’ erections became weaker and at 41, he became impotent despite a continued sexual disinhibition. Les stopped working as an anesthesiologist at age 50 and died of PD in 2015 at age 65.

It is important to emphasize that the musky smell, sexual disinhibition, agitation in bed at night and the occasional aggression were the only symptoms for 8 years until the PD tremor and rigidity appeared.

Joy mentioned that she discretely asked other women married to PD patients if sexual disinhibition had appeared early on in their husbands’ disease, and a few women said yes. When Joy asked those same women married to PD patients if they mentioned the hypersexuality and sexual disinhibition to their doctors, the women said ‘no’ because they were too embarrassed to bring the subject up. Joy herself only went public with Les’ sexual disinhibition in 2015. Yet, probably several people currently exude a musky smell and have a new sexual disinhibition without tremor. Could those people be in the early stages of PD? Or maybe another brain disease?

Sexual disinhibition is described in the literature as a symptom of full-blown, treated PD but not as a prodromal symptom. Bronner et al describe in Handbook of Clinical Neurology (2015) how hypersexuality is one of a broad range of impulse control disorders reported in PD, attributed to anti-parkinson medications, mainly the ones called dopamine agonists. David Codling and colleagues describe in Movement Disorder (2015) how sexual disinhibition affects mostly males and younger people treated for PD.

As far as prodromal symptoms of PD, a Rotterdam study published most recently in December 2017 in JAMA Neurology, showed that cognitive dysfunction can be considered a sign of prodromal PD. But this Rotterdam study didn’t mention anything about sexual disinhibition as a prodromal sign.

On the other hand, agitation at night during REM sleep is a well-know early sign of PD with people describing how their loved one can violently kick them in bed during sleep.

As far as other neurological diseases, Gabriel Cipriani and colleagues describe in Psychogeriatrics (2015), how inappropriate sexual behavior can occur in moderate and severe stages of Alzheimer’s Dementia and also in early stages of fronto-temporal dementia.

Other studies report sexual disinhibition in some cases of traumatic brain injury, stroke, epilepsy, some cases of multiple sclerosis and encephalitis.

The authors discuss the possible reasons for sexual disinhibition associated with degenerative neurological disorders: Sexual disinhibition could be due to the fact that the neurons responsible for keeping us from acting impulsively are the ones affected by the disease.

It is likely that most researchers and physicians don’t ask the question about sexual disinhibition and, from Joy’s accounts of conversations with PD families, patients and their families are too embarrassed to mention sexual disinhibition.

The importance of talking about sex despite taboos

Not only are a lot of patients embarrassed to talk about sexual problems, but so are a lot of physicians. One reason could be that doctors aren’t trained to deal with hyper sexuality, other reasons could be religious taboos.

Michael Bauer and colleagues in a December 2016 article in the journal Health Expectations say, with respect to sexual issues, that “especially in people over the age of 65, embarrassment, dissatisfaction with treatment, negative attitudes and seeming disinterest by health professionals can all inhibit discussions.”

Yet, if a change of sexuality can reveal an early sign of brain damage, it is important for patients and their loved ones to disclose the problems to their health care provider early on and it is equally important for health care professional to listen to those sexual disclosures and take them seriously into account so that a full work-up can be done.