PP137. Posterior reversible encephalopathy syndrome (PRES) is a constant component of eclampsia

INTRODUCTION

Posterior reversible encephalopathy syndrome (PRES) has been reported to occur in patients with eclampsia. In both conditions there is evidence to suggest disordered cerebral autoregulation.

OBJECTIVES

We sought to investigate the concurrence of PRES with eclampsia and to describe the associated obstetric, radiologic and critical care correlates.

METHODS

Single center 2001-2010 retrospective cohort study of all patients with eclampsia who underwent neuroimaging via magnetic resonance imaging (MRI) or computerized tomography (CT) with or without contrast. The medical records of all patients with eclampsia during the study interval were identified, evaluated and extracted for pertinent data; a diagnosis of PRES was made by radiologists using standard criteria.

RESULTS

Forty-six of forty-seven (97.9%) patients with eclampsia revealed PRES on neuroimaging using one or more modalities: MRI without contrast=41 (87.2%), MRI with contrast=27 (57.4%), CT without contrast=16 (34%), CT with contrast=7 (14.8%) and/or MRA/MRV=2 (4.3%). PRES was identified within the parietal (36, 78.3%), occipital (35, 76.1%), frontal (29, 63%), temporal (13, 28.3%) and basal ganglia/ brainstem/cerebellum (12, 26.1%). Eclampsia occurred antepartum in 23 patients, postpartum in 24 patients with 22 vaginal/25 cesarean deliveries at a mean maternal age of 21.8 years (range 15-39) and a mean gestational age of 33.9 weeks (range 22.4-41.7 weeks). Ethnicity was African-American in 38 patients. Headache was the most common presenting symptom (87.2%) followed by altered mental status (51.1%), visual disturbances (34%) and nausea/vomiting (19.1%). Severe systolic hypertension was present in 22 (47%) of patients.Use of antihypertensives (87%), magnesium sulfate (100%), diuretics (66%) and corticosteroids (50%) facilitated maternal recovery in all cases with usually a brief hospitalization (mean 3.9 days, range 1-20 days).

CONCLUSION

The common finding of PRES in patients with eclampsia suggests that PRES may be part of the pathogenesis of eclampsia. We speculate that therapy targeted at prevention or reversal of PRES pathogenesis will prevent or facilitate recovery from eclampsia.

The effect of immune factors, tumor necrosis factor-alpha, and agonistic autoantibodies to the angiotensin II type I receptor on soluble fms-like tyrosine-1 and soluble endoglin production in response to hypertension during pregnancy

BACKGROUND

Preeclampsia is considered a disease of immunological origin associated with abnormalities in inflammatory cytokines, tumor necrosis factor-alpha (TNF-alpha), and activated lymphocytes secreting autoantibodies to the angiotensin II receptor (AT1-AA). Recent studies have also demonstrated that an imbalance of angiogenic factors, soluble fms-like tyrosine kinase (sFlt-1), and sEndoglin, exists in preeclampsia; however, the mechanisms that initiate their overproduction are unclear.

METHODS

To determine the role of immune regulation of these factors, circulating and placental sFlt-1 and/or sEndoglin was examined from pregnant rats chronically treated with TNF-alpha or AT1-AA. On day 19 of gestation blood pressure was analyzed and serum and tissues were collected. Placental villous explants were excised and cultured on matrigel coated inserts for 24 h and sFlt-1 and sEndoglin was measured from media.

RESULTS

In response to TNF-alpha-induced hypertension, sFlt-1 increased from 180 +/- 5 to 2,907 +/- 412 pg/ml. sFlt-1 was also increased from cultured placental explants of TNF-alpha induced hypertensive pregnant rats (n = 12) (2,544 +/- 1,132 pg/ml) vs. explants from normal pregnant (NP) rats (n = 12) (2,189 +/- 586 pg/ml) where as sEng was undetectable. Circulating sFlt-1 increased from 245 +/- 38 to 3,920 +/- 798 pg/ml in response to AT1-AA induced hypertension. sFlt-1 levels were higher (3,400 +/- 350 vs. 2,480 +/- 900 pg/ml) in placental explants from AT1-AA infused rats (n = 12) than NP rats (n = 7). In addition, sEndoglin increased from 30 +/- 2.7 to 44 +/- 3.3 pg/ml (P < 0.047) in AT1-AA infused rats but was undetectable in the media of the placental explants.

CONCLUSIONS

These data suggest that immune factors may serve as an important stimulus for both sFlt-1 and sEndoglin production in response to placental ischemia.

Effects of hyperhomocysteinemia on arterial pressure and nitric oxide production in pregnant rats

BACKGROUND

An elevated plasma level of homocysteine (hyperhomocysteinemia) is thought to be an important risk factor for a variety of cardiovascular diseases including preeclampsia. Although clinical studies have reported a two- to threefold elevation in plasma levels of homocysteine in women who developed preeclampsia, the importance of hyperhomocysteinemia in causing endothelial dysfunction and increases in arterial pressure during pregnancy is unknown.

METHODS

Therefore, the purpose of this study was to determine the effects of a two- to threefold elevation in plasma homocysteine levels on arterial pressure, chronic pressure-natriuresis relationship, and endothelial factors during pregnancy in the rat. Homocysteine treatment for 4 weeks increased plasma homocysteine levels in pregnant rats from 7.1 +/- 1.9 to 16.7 +/- 2.3 micromol/l.

RESULTS

Homocysteine treatment decreased urinary nitrate/nitrite levels from 53 +/- 7 vs. 39 +/- 5 (micromol/24 h/kg body weight) in pregnant rats whereas having no effect on urinary excretion of endothelin. Homocysteine treatment had no effect on mean arterial pressure (MAP) in pregnant rats (104 +/- 2 vs. 107 +/- 3 mm Hg) nor on the chronic pressure-natriuresis relationship.

CONCLUSIONS

These results suggest that although hyperhomocysteinemia decreases nitric oxide (NO) production in pregnant rats, hyperhomocysteinemia does not affect MAP, the chronic pressure-natriuresis relationship, or urinary excretion of endothelin in pregnant rats. Moreover, the reported two- to threefold elevation in plasma level of homocysteine in women with preeclampsia is unlikely to contribute to the hypertension of preeclampsia.