Diagnostic spectrum and clinical outcomes of chronic inflammatory demyelinating polyneuropathy: a multicenter cohort

Abstract

Background Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is the most common immune-mediated demyelinating polyneuropathy, yet data from Arab populations are scarce. We present the first multicenter retrospective Arab cohort describing demographic, clinical, electrophysiological features, and treatment outcomes of CIDP. Methods Electronic records from five hospitals in Saudi Arabia were searched between January 2014 and January 2025 for patients diagnosed with CIDP. Patients meeting 2021 EAN/PNS criteria, aged 3 to 80 years, with a minimum follow-up of 3 months were included. Outcome at initial and last visit assessed using MRCSS and INCAT disability scores, with minimal clinically important differences defined as a 4-point and 1-point change in each score, respectively. Results Thirty-six (18 male, 18 female) met criteria (33 CIDP,3 possible CIDP). Onset age averaged 33 years (40 years in adult-onset cases). Typical CIDP was predominant (72%), with distal, motor-predominant, and multifocal variants representing 8% each. All motor demyelinating features were upper limb predominant. Maintenance monotherapy, mainly IVIG (42%) or oral steroids (33%), was used to treat 75% of patients. Over 55 months, meaningful improvement was achieved in 89% (INCAT) and 83% (MRCSS) with 3.7- and 11.9-point changes, respectively (p < 0.001). Relapses occurred in 42% at a mean of 11 months, mostly due to suboptimal response or non-compliance. Conclusion This is the first Arab multicenter CIDP study, which shows earlier disease onset than North American and European cohorts, with a similar clinical phenotype. Despite a 42% relapse rate, most patients showed meaningful improvement. These findings provide a regional benchmark for future prospective studies.