Magnetic Resonance Imaging of Nerve Roots in the Diagnosis of Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) - A Systematic Review and Meta-Analysis.

BACKGROUND

Chronic inflammatory demyelinating polyneuropathy (CIDP) is a relevant differential diagnosis for progressive polyneuropathy, with effective treatment options available. In case of an ambiguous diagnosis, supportive tests like nerve imaging are recommended. However, MRI is considered of limited use by the current guidelines. This meta-analysis provides an analysis of current data on morphological MRI features in CIDP.

METHODS

We searched databases in PubMed, Scopus, Web of Science, and Google Scholar and reported findings following PRISMA guidelines. We included prospective and retrospective case-control and cohort studies on qualitative or quantitative assessment of cervical and lumbar nerve roots in CIDP. The size and morphological appearance of nerve roots were compared between affected vs. non-affected subjects.

RESULTS

We included 11 studies with qualitative and 15 with quantitative outcome measures. Odds ratios indicated hypertrophy, hyperintensity, and gadolinium enhancement in CIDP patients. Quantitative analysis confirmed larger nerve root diameters averaging at 5 mm in the cervical and 7 mm in the lumbosacral area. Few studies investigated the cross-sectional area and volume of nerve roots, confirming larger values in CIDP patients.

CONCLUSIONS

Plexus imaging provides valuable adjunctive support in the diagnosis of CIDP and our analysis revealed greater diagnostic significance for lumbar nerve roots. Yet its utility must be interpreted with nuance because of data heterogeneity and potential imaging mimics simulating CIDP features on MRI. Future advancements should focus on refining imaging techniques and developing quantitative metrics to enhance diagnostic specificity. The integration of imaging modalities with clinical and electrophysiological findings remains essential in diagnosis of CIDP.