Postinfectious autoimmune encephalitis with opsoclonus-myoclonus syndrome

Opsoclonus is irregular chaotic eye movements, accompanied by impaired gaze fixation, oscillopsia and associated visual impairment. It is combined with myoclonus of the extremities, trunk, change in gait. It occurs in many pathological conditions, most often in oncological and post-infectious diseases. The rarity and uncommonness of the clinical manifestations of the opsoclonus-myoclonus syndrome, as well as the poor awareness of doctors about this pathology, cause diagnostic difficulties and errors. This report presents the case of a 49-year-old patient, who developed unsteadiness when walking, opsoclonus, myoclonus, startle syndrome, exaggerated startle response 3 weeks after an acute intestinal infection. The diagnostic errors made were analyzed. The diagnosis “Post-infection autoimmune encephalitis” was proposed and substantiated. Paraneoplastic opsoclonus-myoclonus syndrome was excluded by prospective observation of the patient for 6 years. High efficiency of glucocorticoid treatment was noted.