O24 A novel method to follow disease progression in ALS: MScanFit MUNE

Abstract

Objectives To evaluate the potential of a novel motor unit number estimation (MUNE) method MScanFit MUNE (MScan) as a measure of disease progression in ALS compared to two traditional MUNE methods; Multiple point stimulation MUNE (MPS) and Motor Unit Number Index (MUNIX). Methods Twenty-seven ALS patients were included. MPS, MScan and MUNIX were performed in the abductor pollicis brevis (APB) muscle in all subjects and repeated after 4 months (23 patients) and 8 months (16 patients). Patients were evaluated clinically by the ALS functional rating scale (ALSFRS-R). Changes in MUNE values were assessed with Wilcoxon signed rank test. Results There was a decrease in MUNE value with MScan from baseline to the 4 months recording (10%) and to the 8 months recording (29%). MScan registered a significantly larger decrease in MUNE value than MPS (increase of 2%) and MUNIX (decrease of 1%) from baseline to 8 months. No significant difference was found in MUNE decrease between the methods from 4 to 8 months. Discussion MScan registered a decrease in MUNE value in an earlier phase of the disease than MPS and MUNIX. This emphasizes the potential of MScan as a more sensitive follow-up tool in detecting motor unit loss in ALS. Conclusion The results suggest that MScan may be an important and sensitive measure of disease progression in ALS. Significance MScan may be a useful method in which the ability to quantify motor unit loss can be helpful in assessment of treatments aiming to reduce or prevent motor neurone degeneration.