Neurologic complications of polycythemia and their impact on therapy.

Polycythemia vera, a clonal stem cell disorder, produces neurologic problems in 50-80% of patients. Some symptoms, such as headache and dizziness, are related to hyperviscosity, and respond immediately to reduction of cell counts. Others seem to result from an associated coagulopathy. Patients with polycythemia tend to develop both arterial and venous thrombosis and are prone to hemorrhages. Treatments for polycythemia include phlebotomy, chlorambucil supplemented with phlebotomy, and 32P plus phlebotomy. Whatever treatment is chosen, the aim of therapy should be to reduce the hematocrit to approximately 40-45%.