Ultrasound and magnetic resonance imaging-based investigation of the role of perfusion and oxygen availability in menstrual pain

BACKGROUND

The mechanisms responsible for menstrual pain are poorly understood. However, dynamic, noninvasive pelvic imaging of menstrual pain sufferers could aid in identifying therapeutic targets and testing novel treatments.

OBJECTIVE

To study the mechanisms responsible for menstrual pain, we analyzed ultrasonographic and complementary functional magnetic resonance imaging parameters in dysmenorrhea sufferers and pain-free controls under multiple conditions.

STUDY DESIGN

We performed functional magnetic resonance imaging on participants with and those without dysmenorrhea during menses and outside menses. To clarify whether regional changes in oxygen availability and perfusion occur, functional magnetic resonance imaging R2∗ measurements of the endometrium and myometrium were obtained. R2∗ measurements are calculated nuclear magnetic resonance relaxation rates sensitive to the paramagnetic properties of oxygenated and deoxygenated hemoglobin. We also compared parameters before and after an analgesic dose of naproxen sodium. In addition, we performed similar measurements with Doppler ultrasonography to identify if changes in uterine arterial velocity occurred during menstrual cramping in real time. Mixed model statistics were performed to account for within-subject effects across conditions. Corrections for multiple comparisons were made with a false discovery rate adjustment.

RESULTS

During menstruation, a notable increase in R2∗ values, indicative of tissue ischemia, was observed in both the myometrium (beta ± standard error of the mean, 15.74±2.29 s-1; P=.001; q=.002) and the endometrium (26.37±9.33 s-1; P=.005; q=.008) of participants who experienced dysmenorrhea. A similar increase was noted in the myometrium (28.89±2.85 s-1; P=.001; q=.002) and endometrium (75.50±2.57 s-1; P=.001; q=.003) of pain-free controls. Post hoc analyses revealed that the R2∗ values during menstruation were significantly higher among the pain-free controls (myometrium, P=.008; endometrium, P=.043). Although naproxen sodium increased the endometrial R2∗ values among participants with dysmenorrhea (48.29±15.78 s-1; P=.005; q=.008), it decreased myometrial R2∗ values among pain-free controls. The Doppler findings were consistent with the functional magnetic resonance imaging (-8.62±3.25 s-1; P=.008; q=.011). The pulsatility index (-0.42±0.14; P=.004; q=.004) and resistance index (-0.042±0.012; P=.001; q=.001) decreased during menses when compared with the measurements outside of menses, and the effects were significantly reversed by naproxen sodium. Naproxen sodium had the opposite effect in pain-free controls. There were no significant real-time changes in the pulsatility index, resistance index, peak systolic velocity, or minimum diastolic velocity during episodes of symptomatic menstrual cramping.

CONCLUSION

Functional magnetic resonance imaging and Doppler metrics suggest that participants with dysmenorrhea have better perfusion and oxygen availability than pain-free controls. Naproxen sodium's therapeutic mechanism is associated with relative reductions in uterine perfusion and oxygen availability. An opposite pharmacologic effect was observed in pain-free controls. During menstrual cramping, there is insufficient evidence of episodic impaired uterine perfusion. Thus, prostaglandins may have protective vasoconstrictive effects in pain-free controls and opposite effects in participants with dysmenorrhea.

Ocular manifestations in a cohort of 43 patients with KBG syndrome

Ophthalmological conditions are underreported in patients with KBG syndrome, which is classically described as presenting with dental, developmental, intellectual, skeletal, and craniofacial abnormalities. This study analyzed the prevalence of four ophthalmological conditions (strabismus, astigmatism, myopia, hyperopia) in 43 patients with KBG syndrome carrying variants in ANKRD11 or deletions in 16q24.3 and compared it to the literature. Forty-three patients were recruited via self-referral or a private Facebook group hosted by the KBG Foundation, with 40 of them having pathogenic or likely pathogenic variants. Virtual interviews were conducted to collect a comprehensive medical history verified by medical records. From these records, data analysis was performed to calculate the prevalence of ophthalmological conditions. Out of the 40 participants with pathogenic or likely pathogenic variants, strabismus was reported in 9 (22.5%) participants, while astigmatism, myopia, and hyperopia were reported in 11 (27.5%), 6 (15.0%), and 8 (20.0%) participants, respectively. Other reported conditions include anisometropia, amblyopia, and nystagmus. When compared to the literature, the prevalence of strabismus and refractive errors is higher than other studies. However, more research is needed to determine if variants in ANKRD11 play a role in abnormal development of the visual system. In patients with established KBG syndrome, screening for misalignment or refractive errors should be done, as interventions in patients with these conditions can improve functioning and quality of life.

Documentation and prevalence of prenatal and neonatal outcomes in a cohort of individuals with KBG syndrome

Ankyrin Repeat Domain 11 (ANKRD11) gene mutations are associated with KBG syndrome, a developmental disability that affects multiple organ systems. The function of ANKRD11 in human growth and development is not clear, but gene knockout or mutation are lethal in mice embryos and/or pups. In addition, it plays a vital role in chromatin regulation and transcription. Individuals with KBG syndrome are often misdiagnosed or remain undiagnosed until later in life. This is largely due to KBG syndrome's varying and nonspecific phenotypes as well as a lack of accessible genetic testing and prenatal screening. This study documents perinatal outcomes for individuals with KBG syndrome. We obtained data from 42 individuals through videoconferences, medical records, and emails. 45.2% of our cohort was born by C-section, 33.3% had a congenital heart defect, 23.8% were born prematurely, 23.8% were admitted to the NICU, 14.3% were small for gestational age, and 14.3% of the families had a history of miscarriage. These rates were higher in our cohort compared to the overall population, including non-Hispanic and Hispanic populations. Other reports included feeding difficulties (21.4%), neonatal jaundice (14.3%), decreased fetal movement (7.1%), and pleural effusions in utero (4.7%). Comprehensive perinatal studies about KBG syndrome and updated documentation of its phenotypes are important in ensuring prompt diagnosis and can facilitate correct management.