Alternative diagnoses in patients referred to specialized centers for suspected MS

Objectives The aim of this study is to explore the frequency, type, and predictors of alternative diagnoses among patients referred with a recent diagnosis of multiple sclerosis (MS) to two specialized MS centers in the Middle East. Methods This is a retrospective review of a prospectively followed cohort of MS patients at 2 University specialized MS centers. All patients referred for MS were included. The final diagnosis was recorded and demographic, clinical, laboratory, electrophysiological and radiological variables were collected. Results A total of 554 patients were included in this study of which 431 were referred for diagnostic confirmation. The final diagnosis of MS was confirmed in 300 (70%), while 114 (26%) turned out to have an alternative diagnosis and 15 (3.5%) fulfilled criteria for radiologically isolated syndrome (RIS). The most common alternative diagnoses were psychogenic (16.3%), non-specific MRI white matter lesions (14.7%), NMO (9.5%), migraine (8.6%) and systemic autoimmune disorders (8.6%). The strongest predictors of a final diagnosis of MS were: younger age, presence of oligoclonal bands in the CSF, periventricular, corpus callosum, spinal (P<0.0001), or enhancing lesions (P<0.005) on MRI. Conclusions Our study shows that 30% of patients referred for a suspicion of MS end up with a different diagnosis. The most common alternative diagnoses of MS in the Middle East are not different from what has been described in Western countries. Age, MRI and CSF findings can help with the differential diagnosis.