IntroductionThe prefrontal cortex plays a crucial role in cognition, particularly in executive functions. Cortical reactivity measured with Transcranial Magnetic Stimulation combined with Electroencephalography is altered in pathological conditions, and it may also be a marker of cognitive status in middle-aged adults. In this study, we investigated the associations between cognitive measures and TMS evoked EEG reactivity and explored whether the effects of this relationship were related to neurofilament light chain levels, a marker of neuroaxonal damage.MethodsFifty two healthy middle-aged adults from (...) the Barcelona Brain Health Initiative cohort underwent TMS-EEG, a comprehensive neuropsychological assessment, and a blood test for NfL levels. Global and Local Mean-Field Power, two measures of cortical reactivity, were quantified after left prefrontal cortex stimulation, and cognition was set as the outcome of the regression analysis. The left inferior parietal lobe was used as a control stimulation condition.ResultsLocal reactivity was significantly associated with working memory and reasoning only after L-PFC stimulation. No associations were found between NfL and cognition. These specific associations were independent of the status of neuroaxonal damage indexed by the NfL biomarker and remained after adjusting for age, biological sex, and education.ConclusionOur results demonstrate that TMS evoked EEG reactivity at the L-PFC, but not the L-IPL, is related to the cognitive status of middle-aged individuals and independent of NfL levels, and may become a valuable biomarker of frontal lobe-associated cognitive function. (shrink)

Idiscovered Martha C. Nussbaum and Saul Levmore's Aging Thoughtfully: Conversations about Retirement, Romance, Wrinkles, and Regret at the same time I was rereading the ancient Roman philosopher Cicero on living and dying well, a text I often used in teaching prior to my retirement. Nussbaum and Levmore's book addresses a series of concerns about aging, and these concerns are presented by the two authors as alternative personal and professional perspectives. The authors acknowledge at the outset that their focus is not (...) end-of-life matters, and they also concede that they are making their observations from a relatively privileged point of view. They both like their work, and personal health matters are not... (shrink)