Weinshenker, BG

Background: Optic neuritis (ON) is often associated with multiple sclerosis (MS). Early diagnosis is critical to optimal patient management. Objective: To estimate the incidence of acute ON and the rates of conversion to MS and antibody-mediated ON. Method: Population-based prospective study was performed in patients with ON from three ophthalmological departments and 44 practicing ophthalmologists from 2014 to 2016. Ophthalmological and neurological examination, magnetic resonance imaging (MRI), determination of aquaporin-4(AQP4)-IgG and myelin-oligodendrocyte glycoprotein (MOG)-IgG were investigated blindly. Results: In all, 63 patients were evaluated and 51 fulfilled the criteria for ON. All were Caucasian, with female:male ratio of 2.2:1 and a median age of 38 years (16–66); 44 (86%) had a single episode of ON (four bilateral), while 7/51 (14%) had recurrent ON. The overall age-specific incidence was 3.28 (2.44–4.31) per 100,000 person years, 2.02 for men and 4.57 for women. At follow-up, 20 patients met the diagnostic criteria for MS, MRI lesions disseminated in space and time in 17/20 patients. AQP4-IgG was detected in none, MOG-IgG was detected in two patients. Conclusion: The prospective incidence of ON was estimated. MRI enabled a diagnosis of MS in a subgroup of patients. Antibody-mediated ON with specificity for MOG was detected in 4% of cases.

Background and objectives Diagnosis of multiple sclerosis (MS) requires exclusion of diseases that could better explain the clinical and paraclinical findings. A systematic process for exclusion of alternative diagnoses has not been defined. An International Panel of MS experts developed consensus perspectives on MS differential diagnosis. Methods Using available literature and consensus, we developed guidelines for MS differential diagnosis, focusing on exclusion of potential MS mimics, diagnosis of common initial isolated clinical syndromes, and differentiating between MS and non-MS idiopathic inflammatory demyelinating diseases. Results We present recommendations for 1) clinical and paraclinical red flags suggesting alternative diagnoses to MS; 2) more precise definition of “clinically isolated syndromes” (CIS), often the first presentations of MS or its alternatives; 3) algorithms for diagnosis of three common CISs related to MS in the optic nerves, brainstem, and spinal cord; and 4) a classification scheme and diagnosis criteria for idiopathic inflammatory demyelinating disorders of the central nervous system. Conclusions Differential diagnosis leading to MS or alternatives is complex and a strong evidence base is lacking. Consensus-determined guidelines provide a practical path for diagnosis and will be useful for the non-MS specialist neurologist. Recommendations are made for future research to validate and support these guidelines. Guidance on the differential diagnosis process when MS is under consideration will enhance diagnostic accuracy and precision.