Brain activation differs in women with HSDD and those with normal sexual function

Studies of hypoactive sexual desire disorder (HSDD) traditionally have focused on behavioral and biologic components of the disease. A new multicenter study, however, sheds light on brain activation patterns during sexual arousal in women with the condition.

Conducted by Woodard et al.¹ and published in Fertility and Sterility, the report is based on results from use of functional magnetic resonance imaging (fMRI) to compared oxygen metabolism and blood flow throughout the brain in women with and without HSDD, and their correlation with neuronal activity produced by cognitive and mental processes.

For the study, the researchers recruited 16 healthy premenopausal women, 10 of whom had symptoms consistent with HSDD that were confirmed by clinical interview and validated questionnaires. The sexually normal women were younger (mean age 29 versus 37 in the group with HSDD) and had higher Sexual Function Questionnaire scores in relation to desire and lower levels of distress as assessed by the Female Sexual Distress Scale. Brain activity was measured in all of the women for 32 minutes while they watched a sexually explicit video featuring male and female heterosexual intercourse and other sexual activity, interspersed with control images of nonsexual interactions and blue screens.

Different fMRI Patterns Noted Between Groups

Among women with normal sexual function, brain activation was most prominent in the lingual gyrus, inferior parietal lobule, thalamus, superior temporal gyrus, and the insula on the right, and at the culmen of the vermis, parahippocampal gyrus, claustrum, hippocampus, and precentral gyrus on the left. The control group also demonstrated bilateral activation of the insula and clastrum. 

In contrast, women with HSDD had greater activation on the right at the middle temporal and fusiform gyri and on the left at the caudate body, declive, precuneus, anterior cingulate gyrus, amygdala, and middle occipital gyrus. Bilateral activation of the thalamus, medial frontal gyrus, and culmen was also observed in the women with HSDD.

The authors said that activation of the medial frontal gyrus, which is involved in attention and reflection of emotions and emotional states, might play a role in making women with HSDD more prone to self-monitoring during sexual activity, which can inhibit their response. In addition, the anterior cingulate gyrus has been shown to be associated with depression, obsessive-compulsive disorder, apathy, and post-traumatic stress disorder, all of which can negatively impact sexual function. Likewise, activation of the amygdala in women with HSDD may suggest that women with HSDD have higher levels of anxiety, fear, or other negative emotional responses during sexual situations. And activation of the precuneus, which is associated with recall of episodic memories and past episodes related to the self, suggests that women with HSDD may be putting out more effort than women with normal sexual functioning in trying to retrieve past memories related to sexual encounters.

In addition to confirming previous fMRI research², the authors said the results also “support the possible role of memory encoding/retrieval and self-monitoring in women’s sexual response and suggest that women with HSDD may have alterations in activation of structures that are responsible for these tasks.”

Limitations of the study include the small sample size and lack of controls for menstrual phase, hormonal contraceptive use, and male faces.

In concluding, Drs. Woodward et al. said that identification of the activation patterns in the brain and their correlation to memory encoding and retrieval as well as self-monitoring may lead to new therapeutic targets for the treatment of HSDD.

REFERENCE

1. Woodard TL, Nowak NT, Balon R, Diamond MP. Brain activation patterns in women with acquired hypoactive sexual desire disorder and women with normal sexual function: A cross-sectional pilot study. Fertil Sterol. 2013;100(4):1068-1076. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3828051/

2. Arnow BA, Millheiser L, Garrett A, et al. Women with hypoactive sexual desire disorder compared to normal females: A functional magnetic resonance imaging study. Neuroscience. 2009;158:484-502.