Written By Grace Xu
Women’s Neurology
Overview of Women’s Neurology
An interdisciplinary and developing field, Women’s Neurology focuses on gender differences in medical evaluation, diagnosis, treatment, and care of women with neurological diseases. Women’s Neurology takes a holistic approach to medicine by understanding neurology from various perspectives by taking into consideration how hormonal and reproductive changes, pregnancy, menopause, contraceptives, and assisted reproduction impact neurological health and disease (Brigham and Women’s Hospital, n.d.). These key periods in a woman’s life, whether the patient is cisgender, transgender, or nonbinary, all require different management approaches in patients with neurological disease than a man would.
The field of Women’s Neurology is a crucial field to understand as many conditions that affect the brain are more complicated to treat in women. Many hormones concerning women and reproductive factors that men do not encounter can greatly influence a woman’s neurological condition and course of treatment. For example, hormones affect seizure frequency in 30 percent of women with epilepsy and women are three times more likely than men to be diagnosed with multiple sclerosis (Northwestern Medicine, n.d.).
Neurological Concerns During Pregnancy
Additionally, neurologists who care for patients during pregnancy may face an abundance of clinical concerns including drug safety, the effects of pregnancy on neurologic disease activity, the safety of anesthetic and delivery modes, or how underlying neurologic diseases may increase the risk of pregnancy complications (LaHue et al., 2023). Furthermore, the number of pregnant patients is expected to grow along with the rate of pregnancy among older women, who have a greater risk of peripartum (the period shortly before, during, and after giving birth) neurologic complications such as eclampsia (seizures that occur in pregnant patients who experience preeclampsia) and stroke.
Women-Focused Neurology Centers and Research
Thus, research continues to be conducted to treat female patients more effectively. Despite the importance of research advancements in Women’s Neurology, only a few women-focused neurology centers exist across the country. One of those is the Brigham and Women’s Hospital located in Boston, Massachusetts. The Brigham and Women’s Hospital has made extensive contributions to gender-focused neurology research in their Clinical Neuroscience Laboratory of Sex Differences in the Brain where they address questions of why the male and female sexes are at varying risk for different psychiatric and neurologic disorders. By investigating neurology from unique standpoints such as hormonal status at various time points in a woman’s life from puberty to menopause, we can better understand the brain and expand areas of treatment.
Sex-Specific Differences in the Healthy Brain
Within the field of women’s neurology, understanding sex-specific differences in the healthy brain is a crucial initial step toward understanding which biological mechanisms are lacking in neurological and psychiatric disorders with known sex differences (Clinical Neuroscience Laboratory, n.d.). Previous research, such as work conducted by the Brigham and Women’s Hospital, reveals multiple ways in which one’s sex impacts health and disease.
Many animal and human studies have suggested normal sexual dimorphisms of the brain. Early work in this field, mostly in rats, has studied the effects of sex-specific steroid hormones on brain morphology during critical periods of early development (Goldstein et al., 2001). Furthermore, postmortem work in humans has also identified sexual dimorphisms in brain regions involved in the neural control of sexual and maternal behavior.
Magnetic Resonance Imaging (MRI) Study on Sexual Dimorphism
Recently, with the rise of magnetic resonance imaging (MRI) technology, researchers have been able to examine brain anatomy in vivo, meaning within living organisms. Utilizing in vivo imaging, studies suggest that the cerebrum is larger in men than in women by 8-10% (Goldstein et al., 2001). Meanwhile, regionally specific sex differences, relative to cerebrum size, differ as sex-specific effects differ depending on the brain region. For example, these studies have reported that, relative to cerebrum size, women have greater gray matter volume, larger volumes of regions associated with language functions (i.e. the Broca’s area), and larger volumes of the hippocampus (involved in memory, learning, and emotion) among other findings.
A potential factor involved in human sexual dimorphisms of the brain has been hypothesized to be the effects of sex steroid hormones, such as testosterone and estrogen, on brain development (Goldstein et al., 2001). In scientific literature, this has mostly only been tested in animals. Despite there being species-specific neurological mechanisms, some are shared between certain mammalian organisms and humans, allowing researchers to demonstrate how the spatial organization of estrogen receptors in human adults within particular brain regions is similar to homologous regions in other species.
Thus, a neurological mechanism that has been thoroughly studied in animals is the role of aromatization on sexual differentiation (Goldstein et al., 2001). Aromatization is a biological process that takes place during critical periods of early development when the hormone testosterone is partly converted to estradiol by the enzyme aromatase, a crucial pathway for estrogen synthesis. Aromatase activity has been found in the hypothalamus and amygdala, where there is the highest concentration of sex hormone receptors such as estrogen and androgen receptors. In animals, cortical regions (regions of the brain concerning the cerebral cortex) show high concentrations of these receptors during fetal and early postnatal development which begin to recede afterward; the drop in cortical sex hormone receptors postnatally suggests that estrogen may have a leading role in the regulation of cortical sex-specific differentiation.
A study utilizing MRI technology assessed brain volumes of human males and females from a sample group, completing analysis to compare brain regions with and without high levels of sex steroid receptors during development (Goldstein et al., 2001). The results support the linkage between sex steroid hormones and sexual dimorphisms in humans. Statistical tests showed significantly higher sexual dimorphism among brain areas with higher levels of sex steroid hormone receptors. Furthermore, the research identified specific regions of the brain where sexual dimorphism is more pronounced within each sex. For example, in cortical regions, women exhibited larger volumes in frontal and medical paralimbic areas while men had larger volumes in the front medial cortex, amygdala, and hypothalamus. This study significantly contributes to the field of women’s neurology as it advances our current understanding of sexual dimorphisms in the human brain, knowledge that is crucial for medical interventions to better tailor toward the unique characteristics of each biological gender, especially in neurological conditions that disproportionately affect women or where sex-specific treatment options can greatly improve patient outcomes. Additionally, the identification of certain brain regions where sexual dimorphism exists at greater rates can help advance future research on the specific regions’ functions and roles.
Figure 1
A transverse view of the Rostral Pons. The right photo displays brain structures from the schematic image (bottom left) outlined on the MRI (upper left), highlighting the technology utilized by Brigham and Women’s Hospital Women’s Neurology research efforts.
Rushmore et al., (2020). MRI and Schematic Image of the Rostral Pons [Image]. National
Library of Medicine. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7538715/
Future Directions in Women’s Neurology Research
Although these current contributions to the field of Women’s Neurology are helping better to understand female patients from a more holistic view, researchers are actively looking into how these changes develop over time and how these differences change during the aging process beyond early development.
Women’s Neurology Training
The Need for Specialized Training in Women’s Neurology
Despite the importance of the advancement of the field of women’s neurology as an emerging subspecialty, very few specialists exist. In 2019, a survey was sent to all US neurology residency program directors to evaluate how well their residents were educated in caring for women with neurologic disease; responses underscored the urge for additional educational programs in this field for neurology residents (LaHue et al., 2023).
Educational Gaps in Women’s Neurology
There remain clear gaps in the educational opportunities for neurology residents who want to further advance their expertise in this area. In the neurology residency survey collected, only 44% of the residency program directors felt that their residents were adequately prepared to care for pregnant women with neurologic diseases. Furthermore, 28% of the programs had no lectures focused on the care of women with neurologic illness; 56% of the residency program directors identified this as an area where residents were not properly trained.
The Importance of Women’s Neurologist Specialists
Women’s neurologist specialists help shape treatment that takes into consideration various determinants of health from social to cultural considerations of women’s health, ultimately optimizing the clinical care setting of women. Other specific intersectional subspecialties in medicine may be seen in cardio-obstetrics, reproductive psychiatry, and more. This type of nuanced training makes personalized and gender-specific care attainable.
The field of women’s neurology may be appealing to medical students or general neurologists who are interested in the intersection of obstetrics and neurology, providing a space for educational and research advancement. Not only will further research in the field of women’s neurology greatly benefit patients but also neurology departments and the field of neurology as a whole.
Current Women’s Neurology Fellowship Programs and Future Insights
As mentioned before, Massachusetts General and Brigham and Women’s Hospital has a thorough Women’s Neurology Fellowship program which is a one-year program (LaHue et al., 2023). This fellowship focuses on outpatient care and the management of sex-specific neurologic issues across a woman’s life span in the clinical setting supplemented by two months of electives in areas ranging from women’s mental health to maternal-fetal medicine.
A similar fellowship program exists in the University of Pittsburgh’s two-year women’s neurology fellowship (LaHue et al., 2023). In the Magee Women’s Hospital, trainees begin their first year in clinical neurophysiology or epilepsy in order to address the need for expertise in peripartum epilepsy management. In their second year, physicians immerse themselves in the field of obstetrics where they rotate in various subfields such as obstetrical anesthesia services and high-risk obstetrical services.
As the field of women’s neurology continues to grow, it is imperative to advance care for women with neurologic disorders to improve health outcomes and educational programs for physicians. Neurologists trained in women’s neurology have the ability to create unique interdisciplinary clinical treatments, advance research, and initiate new educational programs, ultimately making strides in healthcare for women.
References
Goldstein, J. M., Seidman, L. J., Horton, N. J., Makris, N., Kennedy, D. N., Caviness, V. S., Faraone, S. V., & Tsuang, M. T. (2001, June 1). Normal sexual dimorphism of the adult human brain assessed by in vivo magnetic resonance imaging. OUP Academic. https://academic.oup.com/cercor/article/11/6/490/370633?login=false
LaHue, S. C., Paolini, S., Waters, J. F. R., & O’Neal , M. A. (2023, January 3). Opinion and special article: The need for specialized ... - neurology.org. Neurology. https://www.neurology.org/doi/10.1212/WNL.0000000000201451
Northwestern Medicine. (n.d.). Women’s Neurology. https://www.nm.org/conditions-and-care-areas/neurosciences/womens-neurology
Sex Differences in the Healthy Brain. Clinical Neuroscience Laboratory . (n.d.). https://www.cnl-sd.mgh.harvard.edu/sex-differences-healthy-brain
Women’s Neurology Research. Women’s Neurology Research - Brigham and Women’s Hospital. (n.d.). https://www.brighamandwomens.org/neurology/womens-neurology-program/research
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