Late onset multiple sclerosis.

Abstract Introduction Late onset multiple sclerosis (LOMS) is an unusual entity, poorly characterized and difficult to diagnose. Objective To study a series of patients with LOMS (presentation of the first symptom of disease after the age of 50 years). Patients and methods In this retrospective study we review demographic characteristics, first onset symptom, diagnostic delay, disability at the time of diagnosis (EDSS), disease course and findings in CSF, VEP and MRI studies. Results We included 18 patients (12 F and 6 M) with LOMS (4.8% of the total). The most frequent first symptoms were motor deficits (33%), multisystem deficits (33%) and cerebellum disorder (16%). Clinical course (all the cases with a minimal follow-up of 5 years after the diagnosis): primary progressive-MS (62%), secondary progressive MS (22%), relapsing-remitting MS (16%). The initial EDSS score was higher than 4 points in one third of patients and diagnosis delay was over 5 years in two thirds of cases. The cerebral MRI study was abnormal and compatible with MS in all patients and fulfilled the Barkhof criteria in 12 cases (67%). IgG oligoclonal bands were positive in 64% of patients in the CSF study and VEP were abnormal in 73%. The most frequent wrong diagnoses were cerebrovascular disorders and spondyloarthritic cervical myelopathy. Conclusions LOMS course is often primary, progressive and motor and multisystem symptoms are the most frequent. The diagnosis is usually delayed and when it is made patients have a high disability score. The findings of cerebral and spinal MRI, CSF and VEP studies are of high diagnostic yield. Cerebrovascular disorders and spondyloarthritic cervical myelopathy are the most important entities in the differential diagnosis of LOMS.