[Severe bortezomib-induced peripheral neuropathy in a patient with multiple myeloma].

A 59-year-old man was diagnosed with IgA-kappa multiple myeloma in October 2005. He was treated with 4 courses of VAD and autologous peripheral blood stem cell transplantation (auto-PBSCT) after 200 mg/m(2) melphalan in September 2006, followed by a second auto-PBSCT after 200 mg/m(2) melphalan in February 2007. However, he did not achieve a very good partial response (VGPR). Laboratory examinations showed increased serum IgA level and renal dysfunction gradually progressed. Bortezomib was then started at a dose of 1.3 mg/m(2) in November 2008. After three cycles of bortezomib, the patient developed numbness, pain and weakness of his upper and lower extremities. The sensation of position and vibration was diminished in the fingers and toes. He developed left foot drop and gait disturbance due to left peroneal nerve palsy. Autonomic dysfunction such as orthostatic hypotension and urinary retention also occurred. Nerve conduction studies showed severe sensorimotor polyneuropathy particularly in the lower extremities. He developed grade 4 motor neuropathy and severe painful neuralgia. Six months after the cessation of bortezomib, these symptoms gradually improved and he was able to walk with support and discharged. Close monitoring of neurological symptoms and prompt dose-reduction or cessation of bortezomib are important to prevent the progression of irreversible peripheral neuropathy.