025 A cross-sectional study of patients with chronic inflammatory demyelinating polyneuropathy (CIDP): identifying ultrasonographic features for diagnosis and prognosis

Objectives Diagnosis and treatment monitoring in CIDP is primarily based on clinical parameters. High-frequency ultrasound of peripheral nerves can reflect CIDP pathophysiology and changes with treatment. This project investigated potential diagnostic and prognostic biomarkers utilizing neuromuscular ultrasound. Methods We conducted a standardized clinical and ultrasonographic assessment of 50 CIDP patients (25 at WFBMC, 25 at Austin), comparing to 25 healthy controls and 25 axonal neuropathy subjects. Our protocol included whole-length assessment of both median and ulnar nerves, with unilateral assessment of other nerves. Results 25 of 25 CIDP patients studied at WFBMC had an abnormality on ultrasound (as determined by focal nerve enlargement determined by increased cross-sectional area), with 23 of 25 subjects having >=4 enlarged segments. 23 of 25 Austin CIDP patients had at least one enlarged segment, and 20 of 25 had >=4 enlarged segments. 46 of 48 had at least one abnormality in either median or ulnar nerve. Mild nerve enlargements were infrequently seen in healthy and disease controls. However, CIDP patients had clear difference in extent and pattern of enlargements, particularly with proximal upper limb enlargement. Specific markers differentiating CIDP patients will be presented. We analyzed our data in line with previously published diagnostic scores. We will discuss these findings for typical vs. atypical CIDP subtypes, and clinical correlations. Conclusions This cross-sectional study of neuromuscular ultrasound in patients with CIDP suggests assessing bilateral whole-length median and ulnar nerves may be adequate for diagnosis, and differentiating potentially treatment responsive immune-mediated neuropathies from axonal neuropathies and healthy controls.