• Posterior reversible encephalopathy syndrome
• brainstem
• hypertension
• renal dysfunction

• Brainstem
• dialysis
• magnetic resonance image
• posterior reversible encephalopathy syndrome

• Diffusion-weighted imaging (DWI)
• apparent diffusion coefficient (ADC)
• brainstem variant of posterior reversible encephalopathy syndrome
• posterior reversible encephalopathy syndrome (PRES)

Posterior Reversible Encephalopathy Syndrome (PRES) is a clinical-radiological syndrome, usually reversible and with a favorable prognosis, which recognizes a variety of etiologies and clinical patterns and is likely due to an impairment in cerebral blood flow autoregulation. It is typically characterized by subcortical, predominantly parieto-occipital, vasogenic brain oedema in patients with acute-subacute neurological symptoms. Infratentorial oedema on neuroimaging has been mostly described in association with the typical supratentorial pattern and seldom as isolated.

We report a case of PRES with isolated pons involvement on MRI. A woman affected by Turner syndrome, epilepsy, slight mental deficiency, obesity and hypothyroidism, experienced a progressive gait and standing impairment, worsening in the last 2 weeks. At admission blood pressure was 220/110 mmHg. Brain MRI showed a wide FLAIR signal hyperintensity on T2-weighted sequences affecting the entire pons, without contrast enhancement. Clonidine, doxazosine, furosemide and telmisartan were effective in restoring normal blood pressure. Pons hyperintensity completely resolved on MRI 3 weeks later, together with return to normal neurological examination.

Though isolated infratentorial involvement in PRES recognizes several causes, hypertension, which is a common feature in Turner syndrome, would have played a key role in our case with solely pons MRI T2-hyperintensity.

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Clinical and radiological findings of PRES are heterogeneous with possible atypical presentations: in this regard an accurate differential diagnosis is mandatory in order to provide prompt intervention.

• A typical Posterior Reversible Encephalopathy Syndrome
• Clinico-radiological dissociation
• Infratentorial vasogenic oedema
• Pontine oedema

Severe hypertension is associated with multiple symptoms that reflect the end-organ damage effect of rapidly increasing blood pressure. Encephalopathy is a manifestation of the clinical spectrum of hypertensive emergencies. Hypertensive encephalopathy was initially described as part of the posterior reversible encephalopathy syndrome, which mostly involved the parieto-occipital white matter of the brain. A more detailed review of this syndrome reveals many cases where the brain abnormalities are distributed in a more random pattern. We describe a case of diffuse leukoencephalopthy in a young male who presented with altered mental status, ataxia, and blurred vision. This is the most diffuse brain involvement ever described in hypertensive statuses.

Presented here is a 36-year-old male with arterial hypertension who developed brainstem edema and intracranial hemorrhage. Magnetic resonance scan revealed diffuse brainstem hyperintensity in T2-weighted and fluid-attenuated inversion-recovery images, with an increase in apparent diffusion coefficient values. After a reduction in blood pressure, rapid resolution of the brainstem edema was observed on follow-up. The patient's condition was thus interpreted as hypertensive brainstem encephalopathy. While many consider this a vasogenic phenomenon, induced by sudden, severe hypertension, the precise mechanism remains unclear. Prompt recognition and aggressive antihypertensive treatment in such patients are essential to prevent permanent or life-threatening neurologic injury.

• Brain stem
• Edema
• Encephalopathy
• Hypertension

Hypertensive brain stem encephalopathy (HBE) is a rare, under diagnosed subtype of hypertensive encephalopathy (HE) which is usually reversible, but with a potentially fatal outcome if hypertension is not managed promptly. To the best of our knowledge, only one case of HE with brain stem hemorrhage has been reported. We report a case of HBE with pontine hemorrhage in a 36-year-old male patient. The patient developed severe arterial hypertension associated with initial computed tomography showing the left basilar part of pons hemorrhage, fluid-attenuated inversion-recovery showing hyperintense signals in the pons and bilateral periventricular, anterior part of bilateral centrum ovale. The characteristic clinical findings were walking difficulty, right leg weakness, and mild headache with nausea which corresponded to the lesions of MR imagings. The lesions improved gradually with improvements in hypertension, which suggested that edema could be the principal cause of the unusual hyperintensity on magnetic resonance images.

• Hypertensive brain stem encephalopathy
• Pontine hemorrhage

We report on a 42-year-old female patient who presented with high arterial blood pressure of 245/150 mmHg and hypertensive brainstem encephalopathy that involved the brainstem and extensive supratentorial deep gray and white matter. The lesions were nearly completely resolved several days after stabilization of the arterial blood pressure. Normal diffusion-weighted imaging findings and high apparent diffusion coefficient values suggested that the main pathomechanism was vasogenic edema owing to severe hypertension. On the basis of a literature review, the absolute value of blood pressure or whether the patient can control his/her blood pressure seems not to be associated with the degree of the lesions evident on magnetic resonance imaging. It remains to be determined if the acceleration rate and the duration of elevated arterial blood pressure might play a key role in the development of the hypertensive encephalopathy pattern.

• MR imaging.
• acceleration
• duration
• hypertension
• hypertensive encephalopathy
• vasogenic edema