We report a case of Susac syndrome, initially suspected to be multiple sclerosis, and advocate diagnostic caution and high suspicion. We describe a successful therapeutic approach comprising corticosteroids, intra-venous immunoglobulin and cyclophosphamide for encephalopathic relapse of Susac syndrome.Case report
A 56 year old woman presented with headache, visual disturbance, chest wall hypoaesthesia and unsteadiness that was initially thought due to multiple sclerosis. Over the course of her disease she developed bilateral tinnitus and hyperacusis, later accompanied by hearing loss. Brain MRI showed white matter changes with a propensity for the corpus callosum. Full field retinal fluorescein angiography displayed multiple branch retinal artery occlusions with retinal vasculitis. Pure tone audiometry revealed impairment in the low to mid-range frequency bands bilaterally. Disease course was complicated by encephalopathic relapse, presenting with seizure. Repeated courses of immunotherapy (pulses of intra-venous methylprednisolone, cycles of intra-venous immunoglobulins and cyclophosphamide) have suppressed symptoms and halted disease progression.Conclusion
Susac syndrome is a key differential diagnosis of neuro-inflammatory disease. International multi-centre trials are required to establish optimal therapeutic strategies. Meanwhile, we find an aggressive, sustained regime of monthly immunoglobulin and cyclophosphamide for at least six months to maintain recovery in the encephalopathic form of Susac Syndrome.