104 Acute mononeuritis multiplex in a patient with plasma cell leukaemia

A 74 year old male with a history of plasma cell leukaemia, treated with VMP (bortezomib, melphalan, prednisolone) presented with a 2 week history of lumbar back pain and weakness of the hands and ankles. Clinical examination confirmed asymmetric weakness in the hands and ankles. Sensory examination was initially normal, reflexes preserved and plantars mute. Other than the known IgG paraproteinaemia and longstanding hyponatraemia, bloods, including a vasculitis screen, were unremarkable. MRI brain and spine were non-contributary. CSF examination revealed paired bands consistent with the presence of an IgG paraprotein, but was otherwise bland. Nerve conduction studies showed a severe sensorimotor axonal neuropathy. The patient was treated with plasma exchange followed by IV methylprednisolone but continued to progress developing more proximal weakness and sensory loss to the knees and elbows, with loss of deep tendon reflexes within 2 weeks. Sural nerve biopsy showed axonal degeneration but no vasculitis or malignant infiltration. The patient became increasingly fatigued and cachectic and the decision was made jointly with the haematologists to palliate. Plasma cell leukaemia is a rare and aggressive subtype of multiple myeloma with a poor prognosis which has been associated with malignant nerve infiltration. Bortezomib may also cause a peripheral neuropathy. o.poole@nhs.net