Pseudobulbar affect (PBA) in an incident ALS cohort: results from the Apulia registry (SLAP)

The aim of this study is to investigate the frequency and the clinical correlations of pseudobulbar affect (PBA) in a population-based incident cohort of ALS patients. Incident ALS cases, diagnosed in 2011 and 2012, according to El Escorial criteria were enrolled from a prospective population-based registry in Apulia, Southern Italy. Neurological status was assessed using a standard neurological examination and the revised ALS Functional Rating Scale (ALSFRSr). The Center for Neurologic Study-Lability Scale (CNS-LS), a self-administered questionnaire, was used to evaluate the presence and severity of PBA. Total scores range from 7 to 35. A score ≥13 was used to identify the presence of PBA. One-hundred thirty-two sporadic incident ALS cases were enrolled. Median disease duration was 20 months (range 2-143), median onset-diagnosis interval (ODI) 12 months (range 2-131), median ALSFRSr at baseline 36/48 (range 2-47) and median ALSFRSr bulbar sub-score 10/12 (range 0-12). Neurological examination revealed presence of PBA in 34/132 patients (26%). Pathological CNS-LS score was found in 45/132 patients (34%). Median total CNS-LS score was 9/35 (range 7-29). The subgroup with pathological CNS-LS was characterized by a short disease duration from symptom onset, ODI, time to diffusion to a second region, time to generalization and ALSFRSr bulbar sub-score, bulbar onset, "definite" diagnostic category, bulbar upper motor-neuron involvement and presence of PBA at neurological examination. In population-based setting, one-third of ALS patients present PBA at diagnosis. The presence of PBA is associated with bulbar UMN involvement and markers of a more severe phenotype.