Sherif M Hamdy, Maged Abdel-Naseer, Nevin M Shalaby, Alaa Elmazny, Marian Girgis, Mona A Nada, Amr Hassan, Husam S Mourad, Mohamed I Hegazy, Ahmed Abdelalim, Nirmeen A Kishk, Noha T Abokrysha, Shaimaa A Genedy, Ehab A Essawy, Hatem S Shehata

Although the frequency of pediatric-onset multiple sclerosis (POMS) has increased in recent decades, it is still highly uncommon, which creates a need for the involvement of more registries from various clinical centers. To characterize the demographic, clinical, and paraclinical features of Egyptian patients with POMS. A retrospective chart review study was undertaken on 237 Egyptian patients with demyelinating events which started before the age of 18 years who attended one of five tertiary referral centers in Cairo, Egypt. Multiple sclerosis was diagnosed in 186 patients, 47 (25.27%) patients had disease onset before the age of 12 years; "early-onset pediatric multiple sclerosis (EOPMS)". The mean age of disease onset was (14.13±2.49 years), with a female:male ratio of 1.62:1, none of the enrolled patients had a primary progressive course (PPMS), whereas 10 patients (5.38%) had a secondary progressive form. Approximately two-thirds of the patients had monofocal disease onset, and less than 10% presented with encephalopathy; most of them had EOPMS. Motor weakness was the presenting symptom in half of the patients, whereas cerebellar presentation was detected in 34.95%, mainly in EOPMS. Seizures (not related to encephalopathy) were more frequent in those with EOPMS. Initial brain magnetic resonance images were positive in all patients, with detected atypical lesions in 29.03%, enhanced lesions in 35.48%, black holes in 13.98%, and infratentorial in 34.41%. Cervical cord involvement was found in 68.28%. More than two-thirds of the patients received either immunomodulatory or immunosuppressant (IS) treatment throughout their disease course, and about half of them received their treatment within the first year from symptoms onset, with a more favorable outcome, and patients with highly active disease received natalizumab, fingolimod, or other IS. The results from this registry - the largest for MS in the Arab region to date - are comparable to other registries. Immunomodulatory therapies in POMS are well tolerated and efficacious and they can improve the long-term outcome in children.