A. Electrophysiological (EMG) recording of a patient with ALS demonstrating fibrillation potentials at rest, i.e. spontaneous denervation-related muscle activity.
B–D. Muscle biopsy of a patient with ALS. All the features associated with neurogenic disorders, i.e. grouping of atrophic fibers (B,C), predominance of one type of fiber (D), and presence of angulated fibers (D), are observed.
(B: semi-thin section, X 250; C: H–E staining, X 200; D: NADH-TR staining, X 100).