A Focused Neuromuscular Ultrasound Approach for the Diagnosis of Chronic Inflammatory Demyelinating Polyneuropathy

ABSTRACT

Background: Peripheral nerve ultrasonography in individuals with chronic inflammatory demyelinating polyneuropathy (CIDP) have been studied using a variety of approaches over the past decade. Several scales have been proposed to quantify upper and lower extremity nerve enlargement, with some scales being more comprehensive than others. Based on previous studies, it appears that the median and ulnar nerves are typically involved in CIDP. While these comprehensive scales are informative, they may not be feasible in busy neurodiagnostic laboratories on a routine basis. This prospective study compares only the bilateral median and ulnar nerves of individuals with CIDP to reference values in order to determine the clinical usefulness of this focused approach as a diagnostic tool.

Hypothesis:Measuring the cross-sectional area of the bilateral median and ulnar nerves with ultrasound is a targeted approach that can help diagnose CIDP in clinical practice.

Methods: The cross-sectional area (CSA), echogenicity, and vascularity of the bilateral median and ulnar

nerves of twenty-five volunteers with CIDP were measured using ultrasound. Nineteen had definite CIDP based on EFNS/PNS guidelines, whereas six had probable/possible CIDP and were diagnosed based on clinical impression.

Results: Focal nerve enlargement was found in at least one segment in all subjects. The sensitivity of this approach was therefore 100%. Twenty-three of the twenty-five subjects had ≥ 4 enlarged nerve segments, and subjects with definite CIDP had larger CSAs compared to subjects with probable/possible CIDP. Definite CIDP subjects were also twice as likely to have at least one nerve segment that exceeded 1.5 times the upper limit of normal.

Conclusions: A focused ultrasound study, involving only the median and ulnar nerves, is sensitive for the detection of nerve enlargement in CIDP. Measuring the CSA of the median and ulnar nerves is clinically feasible and may help establish the diagnosis of CIDP.

Source of mentor’s funding or other support that funded this research: 

No financial disclosures.