Quantitative magnetic resonance neurography in chronic inflammatory demyelinating polyradiculoneuropathy: A longitudinal study over 6 years

Abstract

ObjectiveTo evaluate magnetic resonance neurography (MRN) for the longitudinal assessment of patients with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP).MethodsProspective examination of twelve CIDP patients by neurological assessment, MRN, and nerve conduction studies in 2016 and 6 years later in 2022. Imaging parameters were compared with matched healthy controls and correlated with clinical and electrophysiological markers. The MRN protocol included T2‐weighted imaging, diffusion tensor imaging (DTI), T2 relaxometry, and magnetization transfer imaging (MTI).ResultsNerve cross‐sectional area (CSA) was increased in CIDP patients compared to controls (plexus: p = 0.003; sciatic nerve: p < 0.001). Over 6 years, nerve CSA decreased in CIDP patients, most pronounced at the lumbosacral plexus (p = 0.015). Longitudinally, changes in CSA correlated with changes in the inflammatory neuropathy cause and treatment validated overall disability sum score (INCAT/ODSS) (p = 0.006). High initial nerve CSA was inversely correlated with changes in the INCAT/ODSS over 6 years (p < 0.05). The DTI parameter fractional anisotropy (FA) showed robust correlations with electrodiagnostic testing both cross‐sectionally and longitudinally (p < 0.05). MTI as a newly added imaging technique revealed a significantly reduced magnetization transfer ratio (MTR) in CIDP patients (p < 0.01), suggesting underlying changes in macromolecular tissue composition, and correlated significantly with electrophysiological parameters of demyelination (p < 0.05).InterpretationThis study provides evidence that changes in nerve CSA and FA reflect the clinical and electrophysiological course of CIDP patients. Initial nerve hypertrophy might predict a rather benign course or better therapy response.

A rare presentation of acute-onset chronic inflammatory demyelinating polyneuropathy with the detection of anti-GM3 and anti-sulfatides antibodies: a case report

“…A UPSS of <3 had a negative predictive value of almost 100% for the exclusion of CIDP. The current study suggests that quantification of the extent of neuro enlargement using the utility of ultrasound pattern sub-score A (UPSA) is superior to CSA values alone in supporting CIDP, in particular a UPSA score of ≥7 ( 6 , 7 ). In one study, a diagnostic pathway was developed to increase the specificity and sensitivity of the diagnosis of CIDP using a newly developed aBUS.…”

“…In one study, a diagnostic pathway was developed to increase the specificity and sensitivity of the diagnosis of CIDP using a newly developed aBUS. If EFNS/PNS criteria are possible or probable and aBUS is at least 2, CIDP is suspected ( 7 ). As well as nerve cross-sectional area and distribution pattern, other ultrasound parameters such as nerve echogenicity play an important role and are prognostic.…”

“…As well as nerve cross-sectional area and distribution pattern, other ultrasound parameters such as nerve echogenicity play an important role and are prognostic. Even in short disease courses, increased echo intensity (class 2) appears to be a specific feature of CIDP (specificity 100%) ( 7 ). In CIDP, a hypoechogenic nerve is associated with edema and demyelination and clinical signs may remain stable or even improve with time, while a hyperechogenic nerve is associated with axonal damage with fibrous scarring and inflammatory infiltration and is more likely to show clinical deterioration.…”