Excessive emotional reactivity in a case of behavioral variant frontotemporal dementia with amyotrophic lateral sclerosis

Although amyotrophic lateral sclerosis (ALS) is defined as a neuromuscular disease, cognitive and/or behavioral symptoms are relatively common, and a portion of ALS patients will meet criteria for behavioral variant frontotemporal dementia (bvFTD). In this report, we describe the case of a man with ALS with bvFTD (ALS-FTD) presenting with excessive emotional reactivity, including severe anger, aggression, and obsessive thoughts. We contrast this case with the decreased emotional reactivity that is usually observed in patients with bvFTD without ALS. We discuss possible explanations including that: 1) the behavioral symptoms of bvFTD and ALS-FTD are the same, but the motor dysfunction influences the clinical manifestations of the behavioral symptoms in ALS-FTD; 2) the emotional and behavioral symptoms of bvFTD and ALS-FTD are the same, but ALS-FTD patients come to clinical attention earlier in the course of their FTD than bvFTD patients without ALS; and 3) the emotional and behavioral symptoms of bvFTD and ALS-FTD could differ.