BDNF and amyotrophic lateral sclerosis: A number of potential agents that are approved for other indications, such as riluzole [29] for amyotrophic lateral sclerosis (based on its potential action to augment brain-derived neurotrophic factor (BDNF)) and memantine [30] for dementia (based on modulation of neuroinflammation), are potential approved medications that could be useful to repurpose for CRCI after thorough investigation.