Plateaus and reversals evaluated by different methods in patients with limb-onset amyotrophic lateral sclerosis

To determine the difference in frequency of amyotrophic lateral sclerosis (ALS) reversals and plateaus in limb-onset patients evaluated with different methods.One hundred and eighteen patients with limb-onset ALS were prospectively recruited. ALS Functional rating scale-revised (ALSFRS-R) score, total Medical Research Council (MRC) muscle strengthscore and clinical global impression (CGI) score were followed up every three months for at least 1 year. The changes between two follow-up points in scores were analyzed.Reversal and plateau in ALSFRS-R score were detected in 26.14% patients between initial and 3-month, 21.19% between 3-month and 6-month, 23.73% between 6-month and 9-month, 19.49% between 9-month and 12-month, respectively. For total MRC muscle score, the percentages were 28.81%, 21.19%, 16.95%, 13.56%, respectively. For CGI score, the percentages were 74.57%, 64.41%, 66.10%, 66.95%, respectively. There was significant difference in the frequency of plateau or reversal between ALSFRS-R scale and total MRC scale over 3-month interval visit (P < 0.05), while no significant difference was revealed between CGI scale and ALSFRS-R scale or total MRC scale. The frequency of reversal and plateau were 8.47% at 6-month, 4.24% at 9-month, 3.34% at the last follow-up in both ALSFRS-R score and total MRC score, respectively.Plateaus and reversals in ALSFRS-R score, total MRC score and CGI score are not uncommon in limb-onset patients during follow-up. The combination of ALSFRS-R score and total MRC score could better reflect the relentless progression of ALS. The importance of long-interval follow-up should be stressed in clinical practice.