Acute Embolic Cerebral Ischemia in Polycythemia Vera
Acute Embolic Cerebral Ischemia in Polycythemia Vera
Introduction Patients with polycythemia vera are at high risk for vaso-occlusive events including cerebral ischemia. Although unusual, acute ischemic stroke may be an initial presentation of polycythemia vera. It had been previously assumed that cerebral ischemic events were due to increased blood viscosity and platelet activation within the central nervous system arterial vessels. However, there are now a few isolated case reports of probable micro-embolic events originating from outside of the brain. This suggests unique management issues for these patients.
Case presentation We present the case of a 57-year-old right-handed Caucasian male in excellent health who presented to the Emergency Department with acute right-handed clumsiness. Hematologic investigations revealed a hyperviscous state and magnetic resonance imaging was consistent with cerebral emboli. Symptoms rapidly improved with phlebotomy and hydration.
Conclusion The etiology of stroke in polycythemic patients is likely to be multifactorial. While hemodilution has been generally discredited for general stroke management, it is potentially beneficial for patients with polycythemia vera and euvolemic hemodilution should be considered for the polycythemic patient with acute cerebral ischemia.
Acute stroke is the number three cause of death within the United States, and a leading cause of long-term disability. There are many populations with an increased incidence of stroke, however patients with polycythemia vera (PV) are a unique subset, both for the pathophysiology and for management. Ischemic stroke may be the first presenting symptom of PV in 15% or more of those affected. One study followed 265 patients with PV for a mean of 3 years, with a 5% incidence of stroke. Even among those patient undergoing treatment, the incidence of ischemic stroke is approximately 14.3 per 1000 patient years versus 5.3 per 1000 patient years in the general, over 55 population.
Historically, assumptions had been previously made that cerebral ischemia in polycythemic patients was due to the increased viscosity of the blood leading to poor cerebral blood flow, along with platelet (PLT) activation creating an environment for thrombus formation in local cerebral arteries and arterioles. While this may be the cause in some patients, recent case reports have suggested another possibility involving formation of emboli.
National efforts have been made to optimize care for all stroke patients, with formation specialized stroke centers adhering to published guidelines for the management of acute ischemic stroke include blood pressure control, anti-PLT agents, and, in appropriate cases thrombolysis. Hemodilution has been considered in multiple past studies, with conflicting results. A meta-analysis has concluded there is a lack of proven efficacy, although this was for patients with acute ischemic stroke and did not specifically include patients with hematologic conditions but did state that '[h]aemodilution for acute ischaemic stroke should not be used outside of clinical trials with the possible exception of patients with severe polycythemia'.
Abstract and Introduction
Abstract
Introduction Patients with polycythemia vera are at high risk for vaso-occlusive events including cerebral ischemia. Although unusual, acute ischemic stroke may be an initial presentation of polycythemia vera. It had been previously assumed that cerebral ischemic events were due to increased blood viscosity and platelet activation within the central nervous system arterial vessels. However, there are now a few isolated case reports of probable micro-embolic events originating from outside of the brain. This suggests unique management issues for these patients.
Case presentation We present the case of a 57-year-old right-handed Caucasian male in excellent health who presented to the Emergency Department with acute right-handed clumsiness. Hematologic investigations revealed a hyperviscous state and magnetic resonance imaging was consistent with cerebral emboli. Symptoms rapidly improved with phlebotomy and hydration.
Conclusion The etiology of stroke in polycythemic patients is likely to be multifactorial. While hemodilution has been generally discredited for general stroke management, it is potentially beneficial for patients with polycythemia vera and euvolemic hemodilution should be considered for the polycythemic patient with acute cerebral ischemia.
Introduction
Acute stroke is the number three cause of death within the United States, and a leading cause of long-term disability. There are many populations with an increased incidence of stroke, however patients with polycythemia vera (PV) are a unique subset, both for the pathophysiology and for management. Ischemic stroke may be the first presenting symptom of PV in 15% or more of those affected. One study followed 265 patients with PV for a mean of 3 years, with a 5% incidence of stroke. Even among those patient undergoing treatment, the incidence of ischemic stroke is approximately 14.3 per 1000 patient years versus 5.3 per 1000 patient years in the general, over 55 population.
Historically, assumptions had been previously made that cerebral ischemia in polycythemic patients was due to the increased viscosity of the blood leading to poor cerebral blood flow, along with platelet (PLT) activation creating an environment for thrombus formation in local cerebral arteries and arterioles. While this may be the cause in some patients, recent case reports have suggested another possibility involving formation of emboli.
National efforts have been made to optimize care for all stroke patients, with formation specialized stroke centers adhering to published guidelines for the management of acute ischemic stroke include blood pressure control, anti-PLT agents, and, in appropriate cases thrombolysis. Hemodilution has been considered in multiple past studies, with conflicting results. A meta-analysis has concluded there is a lack of proven efficacy, although this was for patients with acute ischemic stroke and did not specifically include patients with hematologic conditions but did state that '[h]aemodilution for acute ischaemic stroke should not be used outside of clinical trials with the possible exception of patients with severe polycythemia'.