Síndrome de encefalopatía posterior reversible recurrente con respuesta a nimodipino

Arginine Vasopressin and Posterior Reversible Encephalopathy Syndrome Pathophysiology: the Missing Link?

Posterior reversible encephalopathy syndrome (PRES) is a clinicoradiological entity characterized by a typical brain edema. Its pathogenesis is still debated through hypoperfusion and hyperperfusion theories, which have many limitations. As PRES occurs almost exclusively in clinical situations with arginine vasopressin (AVP) hypersecretion, such as eclampsia and sepsis, we hypothesize that AVP plays a central pathophysiologic role. In this review, we discuss the genesis of PRES and its symptoms through this novel approach. We theorize that AVP axis stimulation precipitates PRES development through an increase in AVP secretion or AVP receptor density. Activation of vasopressin V_1a receptors leads to cerebral vasoconstriction, causing endothelial dysfunction and cerebral ischemia. This promotes cytotoxic edema through hydromineral transglial flux dysfunction and may increase endothelial permeability, leading to subsequent vasogenic brain edema. If our hypothesis is confirmed, it opens new perspectives for better patient monitoring and therapies targeting the AVP axis in PRES.

Reversible cerebral vasoconstriction syndrome after blood transfusion

OBJECTIVES

To report 2 cases of reversible cerebral vasoconstriction syndrome (RCVS) with posterior reversible encephalopathy syndrome (PRES) after blood transfusion for severe anemia.

BACKGROUND

RCVS is presented with recurrent thunderclap headache and reversible constriction of cerebral arteries. PRES is a known complication of RCVS. Blood transfusion for severe anemia could be a cause for PRES in few cases; however, it is seldom mentioned as an etiology for RCVS.

METHODS

We report a case series.

RESULTS

We report 2 women presented with RCVS with PRES after blood transfusion for anemia, and reviewed another 4 similar cases reported in the literature. Our 2 patients were middle-aged women, with severe chronic anemia (average hemoglobin: 1.45 g/dL), and received multiple blood transfusions (average: 3250 mL) over a period of 5-7 days. They developed thunderclap headache and other symptoms about 1 week after the last blood transfusion. Cerebral vasoconstrictions were demonstrated by magnetic resonance angiography and transcranial color-coded sonography. PRES was found in both of them using magnetic resonance imaging, and one of them also had cytotoxic edema on diffusion weighted image.

CONCLUSIONS

RCVS with PRES is one complication of blood transfusion in patients under chronic severe anemia (especially when hemoglobin level increased for more than 5 g/dL), particularly in Asian women with menorrhagia. Blood pressure surge and the occurrence of severe headaches or other neurological symptoms should be aggressively monitored within 10 days after the last blood transfusion.