Validation of the Center for Neurologic Study Bulbar Function Scale–Chinese version in a population with amyotrophic lateral sclerosis

The Center for Neurologic Study Bulbar Function Scale (CNS-BFS) was specifically designed as a self-reported measure of bulbar function. The purpose of this research was to validate the Chinese translation of the CNS-BFS_C as an effective measurement for the Chinese population with ALS.

A total of 111 ALS patients were included in this study. The CNS-BFS_C score, three bulbar function items from the ALSFRS-R, and visual analog scale (VAS) score for speech, swallowing and salivation were assessed in the present study. Forty-six ALS patients were retested on the same scale 5–10 days after the first evaluation.

The CNS-BFS_C sialorrhea, speech and swallowing subscores were separately correlated with the VAS subscores (p < 0.001). The CNS-BFS_C total score and sialorrhea and speech scores were significantly correlated with the ALSFRS-R bulbar subscore (p < 0.001). The CNS-BFS_C total score and ALSFRS-R bulbar subscale score were highly predictive of a clinician diagnosis of impaired bulbar function (area under the receiver operating characteristic curve, 0.947 and 0.911, respectively; p < 0.001). A cutoff value for the CNS-BFS_C total score was selected by maximizing Youden’s index; this cutoff score was 33, with 86.4% sensitivity and 93.3% specificity. The CNS-BFS_C total score and the sialorrhea, speech and swallowing subscores had good–retest reliability (p > 0.05). The Cronbach’s α of the CNS-BFS_C was 0.972.

The Chinese version of the CNS-BFS_C has acceptable efficacy and reliability for the assessment of bulbar dysfunction in ALS patients.