POEMS Syndrome Neurologic Features

POEMS syndrome (Crow-Fukase syndrome) is a rare paraneoplastic disorder driven by clonal plasma cell dyscrasia. The acronym describes mandatory features (Polyneuropathy, Monoclonal protein - typically IgA or IgG with lambda light chain) plus organomegaly, endocrinopathy, skin changes, and elevated VEGF as supportive criteria. Diagnosis requires both mandatory criteria plus one major (Castleman disease, sclerotic bone lesions, or VEGF elevation) and one minor criterion.

Polyneuropathy is the dominant clinical feature and often initial presentation, characterized by chronic progressive symmetric distal weakness, sensory loss, and demyelinating features on nerve conduction studies (similar to CIDP but with axonal loss). Cranial nerves are typically spared. Other neurologic manifestations include papilledema, sensorineural hearing loss, and ischemic stroke from hyperviscosity or paraproteinemia.

Workup includes serum and urine immunofixation, free light chains, VEGF level, skeletal survey or PET-CT for sclerotic bone lesions, bone marrow biopsy, and lymph node biopsy if Castleman suspected. Management depends on extent: localized disease (1-2 sclerotic lesions) is treated with radiotherapy with neuropathy improvement in 50-70%; widespread disease requires high-dose melphalan with autologous stem cell transplant or lenalidomide-dexamethasone or bortezomib-based regimens. VEGF normalization correlates with response. Median survival is 14 years with treatment but neuropathy may persist requiring long-term rehabilitation.