Impact of neurologic signs and symptoms on functional status in peripheralneuropathies

Objective: To determine whether the Neurologic Disability Score (NDS), the Neuropathic Symptom Score (NSS), and the Medical Research Council (MRC) "su mscore" are reliable, and to determine whether they provide information reg arding the functional status of patients with peripheral neuropathies. Meth ods: The authors analyzed homogeneity of the frequently used outcome measur es in 97 patients using Cronbach's alpha coefficient and corrected item-tot al correlations. Their association with functional status (sickness impact profile and modified Rankin score) was analyzed univariately with Pearson's and Spearman's correlation coefficients, and multivariately with linear re gression analysis. Results: The NDS and MRC scales were homogeneous (range of Cronbach's alpha, 0.81 to 0.97) compared with the NSS scales (range, 0.2 0 to 0.63). The correlation patterns between neurologic signs and symptoms and functional status ranged from 0.13 to 0.65. Multivariate linear regress ion analyses showed that 40% or less of patients' functional status could b e explained by the three tested outcome measures. Conclusion: The NDS and M RC are reliable measures, but these measures do not correlate with measures of functional status.