Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an immune-mediated polyneuropathy characterized by segmental demyelination, sometimes accompanied by axonal loss. Nerve size and architecture are altered. Despite composite criteria, diagnosis can be challenging. Furthermore, objective measurements to follow disease activity are limited. High-resolution nerve ultrasound could potentially aid in diagnosis and disease monitoring; it is inexpensive, widely available, noninvasive, and can rapidly image long segments of multiple nerves. However, few studies have examined the relationship between nerve morphology and function in CIDP using ultrasound.(1</SUP)