Multiple plasmacytoma with multiple neurological presentations: A difficult case

Multiple myeloma is a haematological malignancy with clonal plasma cell proliferation and production of monoclonal immunoglobulins. Its neurological complications are relatively common, caused by both the disease and the treatment. Neurologists should therefore be familiar with its neurological manifestations and complications. We describe a 40-year-old woman who presented with lower cranial neuropathies mimicking variant Guillain-Barré syndrome, with normal brain and spinal cord imaging and cerebrospinal fluid (CSF) albuminocytological dissociation, and subsequently diagnosed with IgD myeloma. She relapsed repeatedly with differing neurological presentations: numb chin syndrome and twice with impaired vision, first from cerebral venous sinus thrombosis and later from leptomeningeal infiltration of the optic chiasm. We discuss the neurological complications of myeloma, emphasising the need to consider it in a wide variety of neurological presentations and repeatedly to reassess its associated neurological diagnoses. We also highlight the complexity of myeloma treatment.