Emotional responding in amyotrophic lateral sclerosis

Amyotrophic lateral sclerosis (ALS) is a fatal disease, leaving the patient in a partially or completely deafferented state. In an explorative study, we investigated responses to visual socio-emotional stimuli in ALS patients. Pictures from the International Affective Picture System (IAPS) were verbally judged by 12 moderately affected ALS patients with a spinal onset and a slow progression and 18 age-matched controls, and data were compared with psychophysiological responses. Verbal emotional judgments of patients were more positive than ratings of controls. Regarding arousal, patients neutralized extreme pictures, in that they rated calm pictures as more exciting than controls and exciting pictures as more calm. These changes of emotional processing were unrelated to depression or frontal lobe dysfunction. There were no major differences between patients and controls concerning physiological responses to emotional stimuli. We conclude that emotional responses of ALS patients tend to be altered towards positive valence and towards a more balanced arousal state in early stages of the disease. These findings contradict assumptions of a generally negative impact of the disease on the emotional disposition and may indicate compensatory cognitive or neuroplastic changes.