Abstract
INTRODUCTION: Pseudobulbar palsy is a common symptom in patients with amyotrophic lateral sclerosis (ALS), but it is often underdiagnosed or misdiagnosed as other diseases. The Center for Neurologic Study Lability Scale (CNS-LS) is a self-report scale consisting of seven questions designed for evaluating pseudobulbar affect (PBA). The current study aimed to validate a Chinese version of the CNS-LS. METHODS: The Chinese version of the CNS-LS was obtained through a standardized forward-backward translation and cultural adaptation. A total of 105 patients with ALS were recruited from the ALS database of Peking University Third Hospital in Beijing, China, to complete the CNS-LS. The reliability of the Chinese version was determined by the test-retest method, and receiver operating characteristic (ROC) analysis was performed for criterion validity. RESULTS: Of 105 patients with ALS, 37 had symptoms of PBA and were diagnosed with that condition by neurologists. Forty-two patients completed the CNS-LS twice, and there was no statistically significant difference between the scores (Z = -0.896, p = 0.37). The Spearman correlation coefficient between the test and retest scores was 0.940 (p < 0.0005), and the Cronbach alpha coefficient was high (α = 0.905, n = 105). Scores of 12 or higher on the CNS-LS identified PBA with sensitivity of 0.919 and specificity of 0.882. The area under the ROC curve was 0.924. CONCLUSION: The Chinese version of the CNS-LS demonstrated good sensitivity and specificity in the group of patients with ALS enrolled in this study. The CNS-LS should be a useful instrument for clinical and research purposes for patients in this language group.