Heterogeneity of Root and Nerve Ultrasound Pattern in CIDP Patients

Objective: The few published ultrasound (US) studies on chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) report diffusely increased cross-sectional area (CSA) of nerves. The data are, however, heterogeneous and correlations with clinical history or disease severity are lacking.

Methods: Thirty-four patients with CIDP underwent US nerve evaluation by two neurologists blinded to clinical data. US nerve pattern for each patient was defined by a third neurologist blinded to clinical data. Three US classes were identified based on CSA and echogenicity: large nerves with hypoechoic nerves/fascicles (class 1); large nerves with heterogeneous hypo- and hyperechoic fascicles (class 2); normal size nerve but abnormal hyperechoic array (class 3).

Results: In all patients, US nerve changes were observed: in most of the cases, enlarged nerves or nerve segments were observed. The three 'classes' of US nerve changes significantly correlated (R: 0.68, p<0.001) with disease duration, but not with age or Inflammatory Neuropathy Cause and Treatment (INCAT) disability score.

Conclusions: US may be of adjunctive diagnostic value in CIDP assessment. Nerve morphological changes may mirror the underlying pathophysiological mechanisms and seem to correlate with disease duration.

Significance: These results offer the possibility of exploring the use of US to assess CIDP disease activity and treatment.