To the Editor We read with interest the study by Montero-Odasso et al1 that shows that low dual-task gait speed is a sensitive marker of imminent dementia onset among patients with mild cognitive impairment (MCI). The study has important implications for dementia risk stratification among patients with MCI, which may help to select patients with MCI for putative neuroprotective clinical trials that aim to delay the clinical onset of dementia. However, 3 important gaps in knowledge remain......Please contact the library to request a copy of this article - http://bit.ly/1Xyazai