Patients with Neuromyelitis optica spectrum disorder (NMOSD) and Multiple sclerosis (MS) usually experience first symptoms between 20 to 40 years of age. However, the onset of these disease rarely can occur in pediatrics population. Few data are available for patients with pediatric onset of NMOSD (PO-NMOSD) and MS (POMS).
To survive the clinical characteristics, outcome, and predictive factors of disability in PO-NMOSD, and compared to patients with POMS.
This retrospective follow up study was performed evaluating 18 patients with PO-NMOSD and 144 PMS patients presenting at MS clinic, Kashani Hospital, affiliated to the Isfahan University of Medical Sciences, Isfahan, Iran. All cases were ascertained and diagnosed by a neurologist with subspecialty training in MS and NMOSD.
In PO-NMOSD group, female to male ratio was 8.0:1; the mean age of onset was 14.77±2.23; age at last visit was 21.06±5.42; and median (IQR) follow-up was 6.0 (3.0, 11.0). The mean of first and last EDSS were 2.47±1.16 and 2.11±2.01; twelve (66.6%) patients had relapsing course; the median of first inter-attack was 3.0 (1.0, 4.0); and a total of 38 attacks (2.11 attack per patient) were recorded. Up to now, five (27.8%) patients reach EDSS ≥3. Three patients received azathioprine and other were treated by rituximab. For individuals with POMS, female/male ratio was 3.5:1; the mean age of onset was 14.84±2.35; age at last visit was 24.08±7.29; and median follow-up was 8.0 (4.2, 14.0). The mean of first and last EDSS were 1.68±1.20 and 1.44±1.85; no patient had primary progressive course and 20 (13.8%) patients converted to secondary progressive course; the median of first inter-attack interval was 2.0 (1.0, 4.0); and a total of 317 attacks (2.20 attacks per patient) were recorded. Until now, 34 (23.6%) patients reach EDSS ≥3. Most patients received beta interferon (47), fingolimod (23), and rituximab (23). There was statistically significant difference between the groups in the term of first EDSS score (p=0.019). In both groups, multivariate analysis shows significant association between the age at last visit, firs EDSS, disease duration with higher EDSS score at last appointment. The survival curves showed that PO-NMOSD patients reach to EDSS ≥3 earlier than POMS, though the difference was not statistically significant.
Patients with pediatric onset NMOSD and MS show specific features and prognosis, which should be taken in consideration for the diagnosis and treatment.