Susac syndrome misdiagnosed as multiple sclerosis with exacerbation by interferon beta therapy

Abstract

Susac syndrome is a rare autoimmune disorder characterised by the clinical triad of encephalopathy, retinopathy (branch retinal artery occlusions) and hearing loss. The diagnosis of Susac syndrome may be difficult initially, and it is not uncommon for patients with Susac syndrome to be misdiagnosed with multiple sclerosis. In this case report, we describe a patient who was diagnosed as having multiple sclerosis for three years, with further deterioration after starting treatment with interferon beta-1a. The patient had the triad of encephalopathy, branch retinal artery occlusions and sensorineural hearing loss. She had the classic magnetic resonance imaging appearance, with normal magnetic resonance imaging of the spinal cord and absence of oligoclonal bands in the cerebrospinal fluid. Our patient responded well to treatment with a combination therapy and discontinuation of interferon beta-1a. Our observations raise awareness about the importance of the early and correct diagnosis of Susac syndrome, which usually affects young patients, with an excellent prognosis if treated aggressively at an early stage of the disease. Susac syndrome is underdiagnosed and is not uncommonly misdiagnosed as multiple sclerosis. Susac syndrome is a great mimicker of multiple sclerosis, and establishing diagnostic criteria for this syndrome is very useful. In any patient presenting with a progressive disabling neurological disorder associated with callosal lesions and/or hearing loss, and/or visual loss especially in women, Susac syndrome should be suspected.

Classification of neurological diseases using multi-dimensional CSF analysis

“… 48 Misdiagnosis as multiple sclerosis can be detrimental, since some therapeutics such as interferon-β, dimethyl fumarate, fingolimod, natalizumab and alemtuzumab in NMOSD (reviewed in Jarius et al . 49 ) and interferon-β in Susac syndrome 50 have adverse effects. We were able to demonstrate that established parameters including the occurrence of intrathecal plasma cells and IgG synthesis are sufficient to differentiate patients with multiple sclerosis from those suffering from NMOSD, Susac syndrome and AIE with prediction accuracy values of of 92%, 91% and 83%, respectively.…”

Manifestation of Susac syndrome during interferon beta-1a and glatiramer acetate treatment for misdiagnosed multiple sclerosis: a case report

“…Misdiagnosis of SS as MS can cause serious complications. Drugs such as interferon beta-1a or natalizumab have been reported to worsen the course of SS [ 5 – 7 ]. However, there are reports that natalizumab may be effective for the treatment of SS [ 3 ].…”

“…Misdiagnosing SS as MS may not only leads to the delayed diagnosis that can worsen the prognosis but may also cause serious complications because MS drugs can worsen the course of SS [ 5 – 7 ]. This case report confirms previous reports that the use of interferon beta-1a in the course of misdiagnosed MS may lead to exacerbation of SS [ 5 , 6 ]. Moreover, our case report shows that glatiramer acetate may also exacerbate the course of SS.…”

Susac’s syndrome diagnostic difficulties — the neurological point of view

“…A proper distinction between multiple sclerosis and Susac's syndrome is crucial because treatment with interferon beta (commonly used in treating MS) can exacerbate SuS [38].…”