Pediatric multiple sclerosis with primary progressive course--report of a retrospective cohort study in Iran.

The aims of this study were to suggest the rate of primary progressive (PP) subtype of pediatric onset multiple sclerosis (MS) in Isfahan, Iran, and describe its clinical and paraclinical features. The data of patients were retrieved from Isfahan MS Society (IMSS) database from April 2003 to August 2011. Among 3,843 MS patients of Isfahan who have been registered in IMSS, 260 patients had onset symptom when younger than the age of 18 years, of whom, 11 patients had a PP course (4.23%). The mean age at onset in pediatric primary progressive multiple sclerosis (PPMS) was 16 years (range: 13 to 17) with female preponderance (2.66:1) and disease duration of 4.73 ± 3.03 years. Ataxia was the most frequent initial symptom (7/11). Additionally, the mean Expanded Disability Status Scale and progression index was 4.31 ± 0.60 and 1.50 ± 1.21, respectively. Cerebrospinal fluid analysis showed oligoclonal immunoglobulin G bands in seven patients. Magnetic resonance imaging (MRI) demonstrated periventricular lesions in all 11 patients and spinal lesions in 9 patients. Exposure to parental smoking was recorded in seven individuals. In conclusion, PPMS is an uncommon subtype of pediatric onset MS. Cerebral lesions are more common MRI findings in pediatric PPMS patients than that in adults. The course of PPMS seems to be more progressive in the pediatric population than in adults.