Completing the Differential: A Comprehensive Discussion of Multiple Sclerosis Mimics

This review will examine the MR imaging findings, symptoms, pathophysiology, laboratory, and treatment differences of multiple sclerosis and its many clinical and radiologic mimics to educate the reader about the broad differential that should be considered by radiologists. The cases used for this article were identified and selected from an institutional review board approved data base of patients with MS-like symptoms. A review of MR images and clinic notes showed that patients presented with a wide variety of medical conditions, such as chronic inflammatory demyelinating polyneuropathy, dilatative arteriopathy, and human T-lymphotropic virus type 1. Despite the clinical criteria, laboratory tests, and specific brain and/or spine MR imaging findings that aid in pinpointing the correct diagnosis, MS remains a diagnosis of exclusion due to the many disorders that mimic this autoimmune disease. MS variants Balos concentric sclerosis and neuromyelitis optica express positive complement, which results in a more aggressive course. Inflammatory conditions that mimic MS include acute disseminated encephalomyelitis, progressive multifocal leukoencephalopathy, HIV encephalopathy, Lyme disease, toxoplasmosis, and human T-lymphotropic virus type 1. Small vessel disease‐dilatative arteriopathy, CADASIL, chronic inflammatory demyelinating polyneuropathy, Behçet disease, Susac syndrome, sarcoidosis, systemic lupus erythematosus, Sjögren syndrome, and neoplasms can also be misdiagnosed as MS.

Learning Objectives: Understanding the WM pattern differences in MS and its mimics, with the knowledge that certain mimics and variants of MS will require different therapies (such as Balos concentric sclerosis and neuromyelitis optica), and understanding how different laboratory tests will help differentiate among the different disease processes that mimic MS.