Magnetic Resonance Imaging of Vascular Encephalopathy Related to Pregnancy

Abstract

Brain lesions related to pregnancy are not frequent, but are potentially lethal. About half of the cases are intracerebral hemorrhage, subarachnoid hemorrhage, infarction, and venous thrombosis. Their imaging characteristics are not much different from those caused by other reasons than pregnancy, and can be relatively easily recognized. The other half of cases are encephalopathy related to pregnancy-induced hypertension, eclampsia, and other factors. Such pregnancy-related vascular encephalopathy can be grossly sorted into 3 categories: posterior reversible encephalopathy syndrome, HELLP (hemolysis-elevated liver enzymes-low platelets) syndrome, and reversible cerebral vasoconstriction syndrome. These conditions are rare, but neurosurgeons must be able to recognize them.

Brain MRI findings of a 24-week pregnant woman with HELLP syndrome

“…and headache (%), resolving after a mean of 5.3 days. 1 The most common causes are diverse and include hypertension, eclampsia/pre-eclampsia, sepsis, immunosuppressive agents, chemotherapy, collagen vascular disease and renal failure. 3 The exact pathogenesis of PRES remains controversial but the most probable mechanism is vasogenic edema secondary to an acute increase in arterial blood pressure, which overwhelms the autoregulatory capacity of the cerebral vasculature, causing arteriolar vasodilatation and endothelial dysfunction.…”

“…In addition to the PRES syndrome, the HELLP syndrome frequently involves the cerebellum, brainstem, thalamus and basal ganglia, where less collateral circulation exists. 1 It was demonstrated that the involvement of the brain stem is not influential in the prognosis, and the influential factor in prognosis is the reversibility of lesions and hemorrhage. 7 Typical imaging findings are demonstrated as hyperintense areas on FLAIR images in the parietooccipital, posterior frontal cortical and subcortical white matter, while less commonly the brainstem, basal ganglia and cerebellum are involved.…”

“…1 Nearly half of the neurological events related to pregnancy consist of intracerebral hemorrhage, venous thrombosis, subarachnoid hemorrhage and infarction, and the remainder are pregnancy related encephalopathy. 2 Here, we describe a patient with posterior reversible encephalopathy syndrome (PRES) and intracerebral hemorrhage that had occurred secondary to HELLP syndrome.…”

Metabolic Derangements as Indicators of Partial Hellp Syndrome

“…One of those syndromes is a conglomeration of haemolysis, elevated liver enzymes and decreased platelet counts known as HELLP that become clinically evident at a later stage of pregnancy after 37 weeks. [1] The major complications of this syndrome are due to macroangiopathy and coagulopathy evolving most commonly from hypertension. Several vital organs bear the brunt of this syndrome resulting in cortical blindness, cerebral oedema, haemorrhagic stroke, liver rupture and subarachnoid haemorrhage.…”

“…At its full expression, this syndrome consists of all of its characteristic features which have albeit a rare prevalence of 0.1%. [1] Rather, many women with low platelet count or isolated elevated hepatic enzymes without the complete HELLP syndrome are identified with prevalence as much as 21 to 24%. [8] These patients are depicted as partial HELLP syndrome having any one or two of the symptoms of fully developed HELLP syndrome.…”