Subject demographics and clinical characterization.

<p>^aFisher’s exact test refers to comparison between all ALS patients and healthy controls</p><p>^bFisher’s exact test refers to comparison between all groups (ALS patients with spinal and bulbar onset and healthy controls)</p><p>^cMann-Whitney-<i>U</i>-test refers to comparison between all ALS patients and healthy controls or between ALS patients with spinal and bulbar onset.</p><p>^dKruskal-Wallis analysis of variances on ranks between healthy controls, ALS patients with bulbar and spinal onset.</p><p>^†Post-hoc comparison for <i>p</i><0.05 using Mann-Whitney-<i>U</i>-test: <i>p</i><0.001 for ALS patients with spinal onset compared with healthy controls.</p><p>^eALSFRS-R, revised ALS Functional Rating Scale (maximum score 48, falling with increasing physical impairment) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0142546#pone.0142546.ref009" target="_blank">9</a>]</p><p>^fECAS, Edinburgh Cognitive and Behavioural Amyotrophic Lateral Sclerosis Screen (maximum score 136, falling with cognitive decline) [<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0142546#pone.0142546.ref010" target="_blank">10</a>]</p><p>NA, not applicable.</p><p>Data are shown as median (interquartile range), min-max.