筋萎縮性側索硬化症診断基準とその問題点

抄録

Recently, the emergence of several new drugs for amyotrophic lateral sclerosis (ALS), including methylcobalamin and edaravone, has been highlightend. While clinical trials for those drugs disclosed importance of treatment in early disease stages, diagnostic criteria for ALS do not have adequate powers to diagnose such patients, because mighty diagnoscit biomarkers have not been found. As such, the establishment of strong diagnosic criteria for ALS is an urgent issue. In 1960's, Lambert EH proposed electrophysiologic criteria. The criteria were precise, but had several issues. A prior study reported that 37% ALS patients did not meet the criteria. As such, El Escorial and revised El Escorial criteria were advocated by the World Federation of Neurology (WFN) and divide ALS patients into four grades, from definite to possible, according to the number of upper and lower motor neuron signs in the four body regions. These criteria were well established, but had several problems, including low sensitivity. To overcome these issues, new diagnostic criteria were developed by the International Federation of Clinical Neurophysiology (IFCN) in the Awaji island, in 2008. The criteria were called as the Awaji criterion and defined choronic denervation with acute denervation or fasiciculation potentials, observed by EMG, as equivalent to clinical lower motor neuron sign. While several studies reported that the Awaji criteria improve diagnostic sensitivities, other studies dislosed decreasing diagnostic sensitivities. As such, IFCN reformed the Awaji criteria in Gold Cost, in 2020. The criteria were simplified and require minimum upper and lower motor neuron signs in the only one region or lower motor neuron signs in two regions, and grading was eliminated. The Gold Cost criteria are simple and may increase sensitivity but may decrease specificity.