Chinese Translation and Validation of the Center for Neurologic Study Lability Scale

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.

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.

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.

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.