A Retrospective Study of Ultrasound Accuracy for the Diagnosis of Chronic Inflammatory Demyelinating Polyneuropathy

May 2022

Abstract

Introduction:

Ultrasound is emerging as a useful tool for the evaluation of immune-mediated neuropathies because it can provide high-resolution anatomic information to complement electrodiagnostic data. Nerve enlargements are commonly found in chronic inflammatory demyelinating polyneuropathy (CIDP), and their presence likely useful in diagnosis, particularly if multifocal.

Methods:

In this study, the authors undertook a retrospective chart review to identify ultrasound findings in patients with CIDP previously studied in a single busy neurodiagnostic laboratory.

Results:

Of the 50 cases identified from 2000 to 2017, individuals with a confirmed diagnosis of CIDP (21 cases) were more likely to have multiple sites of enlargement, as well as more pronounced nerve enlargement, than patients who were subsequently found to have an alternate cause of neuropathy (22 cases). The presence of any moderately enlarged nerve segment predicted definite CIDP with sensitivity of 81% and specificity 77%.

Conclusion:

This study demonstrates that ultrasound can be of diagnostic utility in patients with suspected CIDP, even when conducted in a nonstandardized real-world setting.

What is CIDP?

Chronic inflammatory demyelinating polyneuropathy (CIDP) can be thought of as the chronic form of AIDP. It is primarily distinguished both by its time course—by definition, symptoms must persist for at least 8weeks—and its responsiveness to corticosteroid treatment (AIDP, you may recall, is not steroid responsive). It tends to be monophasic, with a relatively gradual onset and even more gradual recovery, but some patients can present with a relapsing and remitting course. Otherwise, CIDP closely resembles AIDP, with predominantly distal, symmetric, ascending motor weakness and decreased or absent reflexes. Albuminocytologic dissociation in the CSF is a hallmark finding, as with AIDP. IVIG, PLEX, or pulse high- dose corticosteroids are first- line treatment.

There are several CIDP variants, including sensory- predominant and pure motor forms, that can be harder to recognize and diagnose. CSF analysis and electrophysiologic testing are helpful.