Anti-IgLON5 Disease with intriguing MRI findings respond dramatically to immunotherapy

Background: We present the first case of Anti-IgLON5 disease with unremarkable or unspecific brain magnetic resonance imagings, and poor responsiveness to immunotherapy.Case presentation A 37-year-old man presented with 4-day history of gait instability, dysarthria, and oculomotor abnormalities. The initial neurologic examination revealed mild unsteady gait, subtle dysarthria, and left abducent paralysis. The brain MRI imaging showed multiple, scattered diffusion restriction in the bilateral cerebral hemispheres involving left tegmentum of the midbrain, and occipital horn of right lateral ventricle, without contrast enhancement. The Anti-IgLON5 antibodies were detected in the serum (titer 1:32). Furthermore, the human leukocyte antigen (HLA) genotyping confirmed HLA-DRB1*11:01 and HLA-DRB1*15:01, HLA-DQB1*03:01 and HLA-DQB1*06:02 alleles. The symptoms of patient rapid improvement after high-dose intravenous methylprednisolone and immunoglobulins.Conclusions In this paper, we report a new case of anti-IgLON5 disease with major symptoms of gait instability, dysarthria, and oculomotor abnormalities, with distinctive brain magnetic resonance findings, and responsive to immunotherapy.