Validation of the Center for Neurologic Study Bulbar Function Scale–Chinese Version in a Population with Amyotrophic Lateral Sclerosis

Abstract

Objective The Center for Neurologic Study Bulbar Function Scale (CNS-BFS) was specifically designed as a self-report measure of bulbar function. The purpose of this research was to validate the Chinese translation of the CNS-BFSC as an effective measurement for the Chinese ALS population. Methods A total of 111 ALS patients were included in this study. The CNS-BFSC, the three bulbar function items from the ALSFRS-R, and visual analog scales (VASs) for speech, swallowing and salivation were assessed in the study. Forty-six ALS patients were retested with the same scales 5–10 days after the first evaluation. Results CNS-BFSC sialorrhea, speech and swallowing subscores were separately correlated with VAS subscores (p < 0.001). The CNS-BFSC total, sialorrhea and speech scores were significantly correlated with the ALSFRS-R bulbar subscore (p < 0.001). The CNS-BFSC total score and ALSFRS-R bulbar subscale were highly predictive of 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-BFSC total score was selected by maximizing Youden's index; this cutoff score was 33, with 86.4% sensitivity and 93.3% specificity. The CNS-BFSC total score and the sialorrhea, speech and swallowing subscores had good–retest reliability (p > 0.05). The Cronbach’s α of the CNS-BFSC was 0.972. Conclusion The Chinese version of the CNS-BFSC has acceptable efficiency and reliability for the assessment of bulbar dysfunction in ALS patients.