Advanced techniques in the early diagnosis of ALS: TMS and MScanFit MUNE
ALS is a rare deadly neurodegenerative disease, characterized by progressive degeneration of upper and lower motor neurons. The tragic progress of the disease requires an urgent initiative to develop biomarkers for early diagnosis of the disease and to understand the pathogenesis that may facilitate development of therapeutic approaches. There are several ongoing drug trials, however these include probable and definite ALS, which is the very advanced stage of the disease.
This talk will explore the theoretical background and clinical applications of two advanced techniques which may be potential biomarkers for early diagnosis of ALS.
The diagnostic utility of threshold-tracking TMS in ALS has been shown in previous studies. However, threshold-tracking TMS has only been used in a few centers, in part due to the lack of readily available software but also perhaps due to uncertainty over its relationship to conventional TMS measurements. Recently, a suite of semi-automated, single- and paired-pulse TMS recording protocols has been developed, that use either conventional amplitude measurements or threshold-tracking. In this talk, these methods will be illustrated by their utility in diagnosis of ALS.
Motor unit number estimation (MUNE) methods has long been of interest to detect motor unit loss. Several methods have been developed since McComas introduced the incremental stimulation MUNE in 1975. Unfortunately, none of these methods has yet implemented in clinical practice probably due to their limitations. The most recent method, MScanFit MUNE may overcome some of these limitations. MScanFit MUNE analyzes a detailed CMAP scan, which can be recorded using a nerve-excitability set-up or an EMG machine. This lecture will review the methodology and clinical application of MScanFit MUNE, in particular, its utility in early diagnosis of ALS.