In “ALS-specific cognitive and behavior changes associated with advancing disease stage in ALS,” Crockford et al. presented data that show that patients with ALS have impaired cognition and behavior and that these deficits worsen with increasing severity of disease. Raaphorst et al. question whether these changes are the result of frontotemporal dementia or nocturnal hypoventilation due to ALS-associated respiratory muscle weakness. They suggest that it would be helpful to have data on the number of stage 4 patients (patients with respiratory or nutritional insufficiency requiring intervention) who required noninvasive ventilation (NIV) and the extent of each subject’s respiratory dysfunction. Abrahams and Crockford reply that 27.78% of stage 4 patients required NIV, but that there was no significant difference in cognition or behavior and requirement for NIV or lack thereof. However, they agree with Raaphorst et al. that given that respiratory dysfunction is a feature of late-stage ALS and memory impairment is associated with advanced-stage ALS, ventilatory support could potentially improve memory deficits in this population. They emphasize that further research on the relationship between respiratory dysfunction and cognition/behavior in ALS is required, as the current data on this topic come from a single small study.