A national survey of pseudobulbar affect and symptomatic treatment in Amyotrophic Lateral Sclerosis

We aimed to determine diagnostic prevalence and symptom burden of pseudobulbar affect (PBA) in patients with Amyotrophic Lateral Sclerosis (ALS) in Denmark and differences in ongoing symptomatic treatment.

In this national cross-sectional survey study, participants with ALS completed an online survey regarding PBA and PBA symptoms, which were quantified through the Center for Neurologic Study Lability Scale (CNS-LS). A CNS-LS score ≥ 13 served as a threshold indicative of PBA.

157 participants with ALS were recruited. 12.1% were diagnosed with PBA and were more likely to receive antidepressant medication compared to those not diagnosed with PBA (47.4% compared to 15.2%, p = 0.002). 30.6% scored ≥13 in the CNS-LS; however, the proportion of participants treated with antidepressants was similar compared to those scoring below the ≥13 threshold (25% compared to 16.5%, p = 0.27). Of those not diagnosed with PBA, 23.2% scored ≥13 in the CNS-LS. This PBA symptomatic, but undiagnosed group was less likely to receive symptomatic treatment compared to patients with diagnosed PBA (12.5% compared to 47.4%, p = 0.009). No differences were seen in CNS-LS score between these groups.

The proportion of diagnosed PBA among the study population was low compared to previous studies; however, the proportion of patients with symptoms of possible PBA was markedly higher. Patients with known PBA were more likely to receive recommended symptomatic treatment compared to patients not diagnosed with PBA, despite symptoms indicative of PBA. These findings highlight the potential underrecognition of PBA in ALS and concurrent absence of symptomatic treatment.