Misfolded alpha-synuclein in amyotrophic lateral sclerosis: Implications for diagnosis and treatment.

BACKGROUND: Alpha-synuclein (α-Syn) oligomers and fibrils have been shown to augment the aggregation of TAR DNA-binding Protein 43 (TDP-43) monomers in vitro, supporting the idea that TDP-43 proteinopathies such as ALS may be modulated by the presence of toxic forms of α-Syn. Recently, parkinsonian features were reported in a study of European patients and Lewy bodies have been demonstrated pathologically in a similar series of patients. Based on these and other considerations, we sought to determine whether seed-competent α-Syn can be identified in spinal fluid of patients with ALS including familial, sporadic, and Guamanian forms of the disease. METHODS: Based on the finding that α-Syn has been found to be a prion-like protein, we have utilized a validated α-Synuclein seed amplification assay to determine if seed-competent α-Syn could be detected in the spinal fluid of patients with ALS. RESULTS: Toxic species of α-Syn were detected in CSF in 18 of 127 ALS patients, 5 of whom were from Guam. Two out of twenty six samples from patients with C9orf72 variant ALS had positive seed-amplification assays (SAAs). No positive tests were noted in superoxide dismutase type 1 ALS subjects (n = 14). The SAA was negative in 31 control subjects. CONCLUSIONS: Our findings suggest that a sub-group of ALS occurs in which self-replicating α-Syn is detectable and likely contributes to its pathogenesis. This finding may have implications for the diagnosis and treatment of this disorder.

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

OBJECTIVE: 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-BFSC as an effective measurement for the Chinese population with ALS. METHODS: A total of 111 ALS patients were included in this study. The CNS-BFSC 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. RESULTS: The CNS-BFSC sialorrhea, speech and swallowing subscores were separately correlated with the VAS subscores (p < 0.001). The CNS-BFSC total score and 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 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-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 efficacy and reliability for the assessment of bulbar dysfunction in ALS patients.

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

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.