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

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 ( 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.