Profile of Polish patients with primary progressive multiple sclerosis

•Patients with PPMS account for approximately 10% of all patients with multiple sclerosis.•The first symptoms of PPMS occur at around the age of 40 with a similar frequency in both sexes.•PPMS diagnosis takes more than twice the time for RRMS.•The dominant symptom of PPMS is spastic paresis of the lower limbs. Epidemiologic data on primary progressive multiple sclerosis (PPMS) in Poland are limited. The aim of this study was to assess selected clinical and socio-demographic factors of Polish patients with PPMS and compare this form and relapsing-remitting (RRMS) and secondary progressive (SPMS) forms. Patients who attended follow-up visits under the Registry of Patients with Multiple Sclerosis (RejSM) were enrolled in the study in the autumn of 2017. The prevalence of individual types of the disease was compared and the clinical, demographic, and social differences between RRMS, PPMS and SPMS were analyzed. Of the 8,045 registered patients, current data as on December 31, 2017 was obtained from 4,398 patients. The RRMS form was seen in 2,925 patients (66.5%); secondary progressive form, in 1.051 patients (23.9%); and PPMS, in 422 patients (9.6%). The first symptoms of PPMS appeared almost 10 years later than in patients with RRMS (39.2 ± 11.4 vs. 29.8 ± 9.8). The period from the first symptoms to diagnosis was more than twice as long in patients with PPMS (5.8 ± 3.4) than RRMS (2.4 ± 1.6). SPMS was diagnosed on average after 14 years of RRMS (46.2 ± 13.5). The RRMS form was more frequently found in women (2.4:1), while the PPMS form was almost equal in both sexes (1.2:1). The average degree of disability based on the Expanded Disability Status Scale was 3.2 ± 2.1 for RRMS, 4.6 ± 2.4 for PPMS and 5.2 ± 3.6 for SPMS. The dominant symptom in PPMS was paresis of the lower limbs (86%). Patients with PPMS had higher education and higher instance of marriage than those with RRMS or SPMS. PPMS occurs in about 10% of Polish patients with multiple sclerosis, and the first symptoms appear at around 40 years of age with the same frequency in both sexes. PPMS diagnosis takes more than twice the time for RRMS.