Zeydan B, et al. - In women who had bilateral salpingo-oophorectomy (BSO) before age 50 years and before reaching natural menopause, researchers examined medial temporal lobe structure, white matter lesion load, and β-amyloid deposition. The results from this nested case-control study indicate that medial temporal lobe structural abnormalities later in life could be due to abrupt hormonal changes due to BSO in premenopausal women.

Methods

• This investigation using the population-based Mayo Clinic Cohort Study of Oophorectomy and Aging-2 (MOA-2) and in the Mayo Clinic Study of Aging (MCSA) in Olmsted County, MN, involved women who had BSO from 1988 through 2007 and a control group from the intersection of the two cohorts.
• Women who had BSO and control participants who had a neuropsychological evaluation, magnetic resonance imaging (MRI), and Pittsburgh compound B positron emission tomography (PiB-PET) were recruited.
• From November 2017 to August 2018, data analysis was performed.
• Using the standard uptake value ratio, cortical β-amyloid deposition on PiB-PET scan was calculated.
• For this investigation, they measured white matter hyperintensity volume and biomarkers for medial temporal lobe neurodegeneration (eg, amygdala volume, hippocampal volume, and parahippocampal-entorhinal cortical thickness) on structural MRI and entorhinal white matter fractional anisotropy on diffusion tensor MRI.

Results

• Ultimately 41 women who had BSO and 49 control participants were enrolled; following a diagnosis of an ovarian malignant condition, one woman was excluded from the BSO group, and six women were excluded from the control group after undergoing BSO after enrollment.
• Data reported that 20 control participants and 23 women who had undergone BSO completed all examinations.
• In the BSO group, the median (interquartile range [IQR]) age at imaging was 65 (62-68) years and 63 (60-66) years in the control group.
• It was noted that amygdala volume was smaller in the BSO group (median [IQR], 1.74 [1.59-1.91] cm³) vs the control group (2.15 [2.05-2.37] cm³; P < .001).
• It was observed that the parahippocampal-entorhinal cortex was thinner in the BSO group (median [IQR], 3.91 [3.64-4.00] mm) vs the control group (3.97 [3.89-4.28] mm; P=.046).
• Findings revealed that entorhinal white matter fractional anisotropy was lower in the BSO group (median [IQR], 0.19 [0.18-0.22]) vs the control group (0.22 [0.20-0.23]; P=.03).
• In both groups (BSO, n = 22 of 23 [96%]; control, n = 10 of 19 [53%]), women were treated with estrogen.
• Between the groups, global cognitive status test results did not differ.