Primary neurolymphomatosis initially manifesting as cubital tunnel syndrome: a case report

Myelin oligodendrocyte glycoprotein-immunoglobulin G associated disease (MOGAD) is an autoimmune demyelinating disorder of the central nervous system (CNS) which usually occurs with recurrent optic neuritis, transverse myelitis, acute disseminating encephalomyelitis, or brainstem encephalitis. To date, the anti-CD 20 drug rituximab (RTX) is employed in MOGAD although some authors reported the efficacy of Tocilizumab (TCZ) in refractory patients. We present the case of a woman affected by refractory MOGAD who was treated with TCZ after therapy with RTX had failed to prevent relapses. We also conducted a current literature review on TCZ use in MOGAD. A 57-year-old Caucasian woman affected by MOGAD with severe motor impairment and cognitive dysfunction was treated from 2020 to February 2022 with RTX. However, she experienced progressive clinical and cognitive worsening associated with white matter lesions mimicking leukodystrophy. In February 2022, the patient started therapy with TCZ administered with improvement of cognitive performance, walking ability, and brainstem functions. During TCZ, our patient reached the condition of NEDA-3 (no relapse, no increase in disability, no MRI activity on neuroimaging follow-up performed in September 2023). Moreover, the patient experienced paucisymptomatic SARS-CoV-2 infection that did not modify TCZ schedule. To date, there are few evidence on the efficacy and safety of TCZ in MOGAD. However, all the reviewed cases showed that TCZ represents an effective therapy in drug-resistant MOGAD. Our case highlights the efficacy of TCZ in drug resistant MOGAD and strengthens previous reports of TCZ safety and efficacy in MOGAD.