Hypertensive Encephalopathy

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BACKGROUND AND CLINICAL INFORMATION: Head  

Hypertensive encephalopathy: refers to a relatively rapidly evolving syndrome of severe hypertension in association with severe headache, nausea, and vomiting, visual disturbances, convulsions, altered mental status and, in advanced cases, stupor and coma.

Ophthalmoscopic findings: typical findings include arteriolar disease, papilledema, cotton wool patches, hard exudates, and hemorrhage.

CSF opening pressure is frequently elevated.

NEUROIMAGING: Head  

Imaging: radiologic findings often suggest large areas of infarctions or demyelination but the tendency to normlize over several weeks is remarkable. The major changes on MRI is bilaterally increased T2 signal intensity consistent with edema in the white matter often in the posterior part of the hemispheres. There is no mass effect and the fluid has no tendency to track along white matter tracks such as the corpus callosum.

Reversivle posterior leukoencephalopathy (reversible occipitoparietal encephalopathy): this is reversible syndrome of headache, altered mental status, seizures, and visual loss occuring primarily in adults in the setting of hypertension, eclampsia, and immunosuppression. Abrupt increase in blood pressure is often, but not necessarily, present. The white matter is primarily affected but the gray matter is also involved. Abnormal T2-weighed MRI signal is seen most common, but not exclusively, in the occipitoparietal white matter.

GROSS PATHOLOGY: Head  

The brain is usually of normal weight. There may be focal infarction or softening.

HISTOPATHOLOGY AND IMMUNOHISTOCHEMISTRY: Head  

Brain Pathology:

Lacunar infarcts are more frequently seen in cases with malignant hypertension than non-malignant hypertension.

Vascular and parenchymal lesions of the brain: The following lesions are typically multiple and show a diffuse distribution in the cases of malignant hypertension. They are most frequently confined to the brain stem, particularly the basis pontis, but are also present, in decreasing order of frequency, in the basal ganglia and diencephalon, cerebral white matter, cerebral cortex, and spinal cord.

Petechial hemorrhage is also a frequent finding.

Ophthalmic pathology:

Retinal and choroid vascular changes: 

Optic nerve: sclerosis and hyalinization, and less often, fibrinoid necrosis are noted in the arterioles of the optic nerve.

Papilla edema: the papilla is protruded, swollen, and shows lateral extension.

REFERENCES: Head

Chester EM et al., Neurology 1978 28:928

Pavlakis SG et al., J Child Neurol 1999 14:277

Nag S et al., Lab Inv 1977 36:150

Rhonda R et al., J Child Neurol 1996 11:193

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Background    Neuroimaging    Gross Pathology    Histopathology & Immunohistochemistry   Reference