Dorsal Column Degeneration after Bortezomib Therapy in a Patient with Multiple Myeloma

We present here a case of dorsal column degeneration in a female patient with multiple myeloma following exposure to bortezomib. Two days after intravenous administration of a first course of bortezomib 1 mg/m(2), the patient developed rapidly-progressive numbness, pain and muscle weakness in the bilateral upper and lower limbs. Following gancyclovir treatment of subsequent cytomegalovirus viremia, the patient went on to receive a course of EPOCH (etoposide 50 mg/m(2)/day on days 1-4, vincristine 0.4 mg/m(2)/day on days 1-4, doxorubicin 10 mg/m(2)/day on days 1-4, cyclophosphamide 750 mg/m(2)/day on day 6, and prednisolone 60 mg/m(2)/day on days 1-6). Shortly thereafter, the patient developed bilateral Aspergillus pneumonia. Despite treatment with appropriate antifungal agents, the patient died from respiratory failure due to bilateral diffuse alveolar damage of the lungs and without recovery of severe sensory and motor neuropathy prior to her death. Post mortem examination revealed spongy degeneration of the dorsal column from the medulla oblongata to the cervical spinal cord. Bortezomib-associated peripheral neuropathy in patients with multiple myeloma has been commonly reported but appears to resolve in a majority of these patients after dose reduction or discontinuation. We believe this to be the first report of spinal cord abnormalities in a patient with multiple myeloma treated with bortezomib. Further investigation is required to ascertain the exact mechanism of this central neurotoxic effect and to identify appropriate neuroprotective strategies.