Age-related differences in myelin content of the human brainstem

Very few MR investigations have been conducted to assess age-dependent myelination differences in the brainstem, in spite of the brainstem's central role in regulating vital functions. This is likely due to the small structural scale of the brainstem, necessitating accurate high spatial resolution imaging for quantitative studies. Here, we used our recently developed approach to myelin water fraction (MWF) mapping and found a decrease in myelination with age in different brainstem regions, with several regions exhibiting a quadratic association. We believe that this study is the first investigation of MWF changes with normative aging in the brainstem.