The Application of Clinical, Electrophysiological and Nerve Ultrasound Parameters in Distinguishing Acute-onset Chronic from Acute Inflammatory Demyelinating Polyneuropathy

History-taking and nerve conduction studies are fundamental for the diagnosis and assessment of the severity of acute (AIDP) or chronic inflammatory demyelinating polyneuropathy (CIDP). The diagnostic challenge of distinguishing these two immune-mediated subacute polyradiculoneuropathies remains high, as intravenous immunoglobulin and steroids exert short-term clinical improvement in the majority of the CIDP cases, whereas steroids have no effect on AIDP patients. Accordingly, the precise classification of subacute polyradiculoneuropathies significantly affects the early application of steroids in CIDP. This review aims to give a timely update on the application of clinical, electrophysiological and nerve ultrasound parameters in distinguishing subacute CIDP from AIDP.