Different Tendencies in Muscle Ultrasound Characteristic in Amyotrophic Lateral Sclerosis and Chronic Inflammatory Demyelinating Polyradiculoneuropathy.

The relationship between MUS abnormalities and CMAP amplitude showed different tendencies in ALS and chronic inflammatory demyelinating polyradiculoneuropathy. The results suggested that MUS abnormalities substantially reflect the muscle function in primary axonal degeneration, whereas a discrepancy between MUS findings and muscle function can be frequently seen in demyelination; specifically, MUS findings tend to be normal even though CMAP showed a reduction. These tendencies originating from underlying pathophysiology should be considered when MUS findings are used as biomarkers of disease severity.