If you’re having difficulty identifying the right word to express yourself clearly or remembering a story correctly, you may blame menopause. A study by researchers at the University of Illinois, University of Pittsburgh, Johns Hopkins University, Rush University School of Medicine, University of Calgary, Northwestern University Feinberg School of Medicine, University of Texas Health Sciences Institute at Houston, and University of Oklahoma, suggests that physiologic hot flashes are associated with decreased verbal memory and with alterations in brain function during encoding and retrieval of memory, especially in the hippocampus and prefrontal cortex.
Previous studies have already shown that women experience a decline in memory for verbal material, such as words and stories, as they transition through menopause. In this new study, functional magnetic resonance imaging (MRI) was used to document the occurrence of physiologic hot flashes and their specific effect on hippocampal and prefrontal cortex function during encoding and recognition conditions of a memory task.
The strengths of this study are in the use of physiologic hot flash monitoring to confirm the hot flash versus relying on patient recall and the use of functional MRI to specifically evaluate real-time changes occurring within the brain during the memory testing.
Although larger studies are needed to fully evaluate the reliability of the relationship between hot flashes and altered brain function, this study provides new insights into specific areas in the brain involved in memory that appear to be adversely affected by hot flashes.
“The findings of this preliminary study, although small, support an association between objectively monitored hot flashes and adverse functional changes in the brain that affect memory. Further study is needed to determine whether hot flashes actually cause these brain changes and whether treatment of hot flashes will prevent or normalise them,” says Dr Stephanie Faubion, NAMS medical director.
Objective: Vasomotor symptoms (VMS) are associated with decreased memory performance and alterations in brain function. We conducted a preliminary examination of VMS and patterns of brain activity during a verbal memory task to provide insights into the VMS-related brain mechanisms that can contribute to memory problems in midlife women.
Methods: Fourteen postmenopausal women (mean age 53.5, 64% African-American) with moderate-to-severe VMS (>35/wk) and not taking hormone therapy completed functional magnetic resonance imaging (fMRI) assessments during word encoding and recognition, 24-hour physiologic VMS monitoring, symptom questionnaires, and two verbal memory tests.
Results: In regression analyses, a higher number of physiologic VMS, but not reported VMS, was associated with worse verbal memory on immediate and delayed logical memory (r = 0.53 and r = 0.72, P < 0.05). On fMRI assessments, a higher number of physiologic VMS, but not subjective VMS, was associated with greater activation in the left orbitofrontal cortex, left medial and superior frontal gyrus, right superior frontal gyrus, and right parahippocampal gyrus during the encoding task (P < 0.005). During the recognition task, physiologic VMS were associated with greater activation in the left medial and superior frontal gyrus, left parahippocampal gyrus and hippocampus, right medial and superior frontal gyrus, right parahippocampal gyrus and hippocampus (P < 0.005), and with decreased activation in the ventral medial prefrontal cortex (P < 0.005). Those associations were independent of symptoms and hormone levels.
Conclusions: Preliminary data suggest that VMS may contribute to memory performance through effects on the hippocampus and prefrontal cortex. Larger studies are warranted to determine the robustness of these initial observations
Maki PM, Wu M, Rubin LH, Fornelli D, Drogos LL, Geller S, Shulman LP, Banuvar S, Little DM, Conant RJ