Cerebral CT findings in toxemia of pregnancy

Cerebrovascular disorders complicating pregnancy--beyond eclampsia

OBJECTIVE

Our purpose was to investigate the problems encountered in the diagnosis and management of cerebrovascular disorders associated with pregnancy and the puerperium.

STUDY DESIGN

Pregnancies complicated by cerebrovascular disorders were identified by retrospective chart review (1985 to 1995). Events associated with trauma, neoplasm, drug ingestion, and infection were excluded.

RESULTS

The study population comprised 24 women with a variety of cerebrovascular disorders: 14 with infarction (5 arterial, 9 venous), 6 with intracranial hemorrhage (3 anatomic malformation, 3 unknown etiology), 3 with hypertensive encephalopathy, and 1 with an unruptured aneurysm. Blood pressure reflected physical condition at presentation and did not predict diagnosis or outcome except in the 3 women with hypertensive encephalopathy. Only 4 of 14 women with infarction and 1 of 6 with intracranial hemorrhage had a diastolic blood pressure > or = 110 mm Hg. Presumption of eclampsia delayed the diagnosis in 10 women (41.7%). In addition, patient delay in seeking medical attention complicated 10 cases. After review, none of the adverse maternal outcomes were deemed preventable by earlier physician intervention. Seven maternal deaths occurred (29.2%). Neonatal outcome was related to the gestational age and the maternal condition at presentation.

CONCLUSION

Cerebrovascular disorders are an uncommon and unpredictable complication of pregnancy that are associated with substantial maternal and fetal mortality. Suspected eclampsia unresponsive to magnesium sulfate therapy warrants an immediate neuroimaging study. Interestingly, in women with intracranial hemorrhage, severe hypertension was not an associated predictive factor.

Resolution of focal CT hypodense lesions in patients with subarachnoid hemorrhage

Cerebral infarction in the setting of vasospasm due to subarachnoid hemorrhage (SAH) is a known complication of aneurysmal rupture. Computed tomography (CT) has been instrumental in making this diagnosis; however, focal hypodense lesions on CT scan do not always represent infarcted tissue. Two patients are presented here who had CT hypodense lesions in regions of cerebral vasospasm following subarachnoid hemorrhage.

Magnesium sulfate reverses experimental delayed cerebral vasospasm after subarachnoid hemorrhage in rats

We induced experimental delayed cerebral vasospasm by the intracisternal injection of greater than 0.5 ml blood in 30 rats. Seventy-two hours later the basilar artery was exposed via the transclival approach and photographed at high-power magnification through an operating microscope. We then evaluated the effect of topical (n = 30) and intravenous (n = 20) magnesium sulfate on the spastic artery by computerized image analysis. A greater than 50% reduction in baseline diameter of the basilar artery was observed in the rats subjected to subarachnoid hemorrhage compared with the 10 controls (p less than 0.0001). Intravenous magnesium sulfate dilated the spastic artery to approximately 75% of the baseline diameter in control rats (p less than 0.0001). Topical magnesium sulfate caused dramatic dilation of the basilar artery in both the control and the subarachnoid hemorrhage groups to near 150% of the baseline diameter in the controls (p less than 0.001). All rats receiving intravenous magnesium sulfate reached therapeutic plasma levels of the ion. Hemodynamic effects were mild and immediately reversible upon cessation of magnesium sulfate administration. We suggest that magnesium has a role in the treatment of subarachnoid hemorrhage-induced vasospasm in humans.

Postpartum amaurosis

Blindness is a rare but dramatic complication of pregnancy and delivery. We present the case of a patient who developed toxemia at the time of delivery that with ineffective treatment resulted in cortical blindness without seizure activity. The pathogenesis as well as the diagnostic workup and treatment of this unusual complication are discussed.

MR of uncommon congenital and vascular lesions of the intracranial visual pathways

The MR findings of two patients with rare congenital abnormalities of the optic pathways are reported and illustrated, including one case of unilateral aplasia of the optic chiasm, tract, and visual radiations and another patient with anophthalmos. In three other patients with unusual vascular causes of visual disturbance, MR was important in early establishment of an accurate diagnosis and had consequent implications for decisions regarding further patient management.

Computed tomographic changes of the brain in toxaemia of pregnancy

Four cases of toxaemia of pregnancy examined with computed tomography scans of the brain are reported. A review of the literature reveals 19 other cases with previously reported CT brain scans. The review shows intracerebral oedema as the main finding. Haemorrhage, massive or punctate was noted in four cases. The pathogenesis of the CT changes and the clinico-radiological correlation of the visual disturbances are discussed.

Action of magnesium sulfate in the treatment of preeclampsia-eclampsia

Recent evidence supports the concept that cerebral vasospasm is involved in the pathogenesis of eclampsia. Magnesium, which has a beneficial effect in eclampsia, may act by opposing calcium-dependent arterial constriction, thereby relieving vasospasm. Magnesium may also antagonize the increase in intracellular calcium concentration caused by ischemia and thus prevent cell damage and death. Magnesium might have a role in the treatment of cerebral vasospasm and ischemia, such as occurs in subarachnoid hemorrhage, ischemic stroke, and brain trauma.

Acute hypertensive crisis in pregnancy

Severe pre-eclampsia is a state of acute afterload increase where compensation may be total by use of the Frank-Starling mechanism and/or increased adrenergic drive, or may be uncompensated in a patient with limited or exhausted preload reserve. As such, we are presented with a diverse group of patients and antihypertensive therapy ideally should be individualized. In reality we are dealing with a complex situation because of the presence of the fetus raising concerns about direct effects on the fetus as well as on uteroplacental blood flow. This limits our choice of agents to those with extensive use in pregnancy except in complicated or resistant cases. For these reasons, hydralazine is the antihypertensive agent of choice for treatment of acute hypertensive emergencies in pregnancy. In the complicated case other agents such as sodium nitroprusside or nitroglycerin may be more appropriate and, in these cases, hemodynamic monitoring should be performed to allow not only greater safety, but also to tailor therapy to the individual hemodynamic profile.

Eclampsia: a pediatric neurologic problem

Eclampsia is a syndrome of hypertension, proteinuria, edema, and neurologic manifestations such as seizures, focal deficits, or blindness occurring during pregnancy, mainly in primigravidas. Although it is not seen often in the pediatric population, it occurs with greater frequency among pregnant patients under the age of 15 than in the general population. Serious sequelae can be prevented with prompt and adequate treatment, including termination of pregnancy.

Cerebral vasospasm and eclampsia

We describe a patient who experienced focal cerebral and brainstem ischemia in the setting of postpartum eclampsia. Cerebral angiography showed spasm of large- and medium-caliber arteries. This case provides rare documentation that vasospasm may account for cerebral ischemia in eclamptic women with focal signs. This observation suggests that in such patients cerebral angiography may be informative and useful.

CT and angiographic correlation of severe neurological disease in toxemia of pregnancy

Two patients with severe cerebral symptoms of toxemia of pregnancy were examined using computed tomography (CT) and angiography. CT disclosed extensive areas of low attenuation within the cerebral hemispheres. Angiography revealed constriction and narrowing of proximal and peripheral vessels suggesting vasculitis with extensive areas of impaired regional cerebral blood flow. A review of the known pathology and the theories regarding the pathophysiology of the cerebral effects of toxemia is presented.

Eclampsia. IV. Neurological findings and future outcome

Sixty-five patients with eclampsia were longitudinally evaluated regarding neurological abnormalities and maternal outcome (6 to 42 months) after eclampsia. Electroencephalograms were obtained on all patients during the subsequent 6 months. Computerized axial tomographic scans (n = 20) and cerebral arteriograms (n = 3) were obtained on patients with neurological deficits and/or those with an atypical clinical course. The electroencephalogram was abnormal in 49 patients (75%) at initial assessment but gradually returned to normal in all observed patients within 6 months. Cerebral arteriograms and computerized axial tomographic scans were normal in each patient studied. None of the patients had neurological deficits or subsequent convulsions on follow-up examination. Thirty-eight patients had one or more subsequent pregnancies without recurrent eclampsia, but 14 (37%) had pregnancy-induced hypertension. The findings suggest that neurological events of eclampsia are acute and transient and that long-term neurological deficit is rare in the properly managed patient. Computerized axial tomography and electroencephalography are rarely indicated in the management of such patients.