Severe posterior reversible encephalopathy syndrome (PRES) complicated by cerebellar hemorrhage
Presentation
Seizures.
Patient Data
Right cerebellar hematoma with moderate mass effect in terms of partial effacement of the fourth ventricle. Confluent areas of vasogenic edema involving the cerebral and cerebellar hemispheres.
In the CTA, mild multifocal narrowing of the intracranial arteries, better seen in the right anterior cerebral artery. In the perfusion CT there is significantly reduced TTP, which reflects increased cerebral perfusion.
Redemonstration of right cerebellar hemorrhage with confluent areas of vasogenic edema throughout the cerebral and cerebellar hemispheres, predominantly involving the partite-occipital regions, as well as in the basal ganglia, thalamus and brainstem with cortical swelling and diffuse sulcal effacement. In addition, superimposed scattered areas of diffusion restriction and microhemorrhages in the parietal/occipital lobes, and in the thalami and cerebellum.
In the TOF angiography, multifocal narrowing of the intracranial arteries, better seen in the right anterior cerebral artery.
MRI follow up one month later
Selected MRI images demonstrating an interval resolution of the previously described confluent areas of vasogenic edema as well as the scattered foci of diffusion restriction with expected evolution of right cerebellar hemorrhage.
In MRA: Interval resolution of the previously described narrowing in the intracranial arteries.
Case Discussion
The exact pathophysiology of PRES is not yet known, but there are two main theories, one of which assumes vascular leakage due to cerebral hyperperfusion, while the second suspects endothelial dysfunction.
The diagnosis of PRES is based on the exclusion of other findings and the documentation of the reversibility in the follow-up.
This case shows the classic characteristics of PRES, including the reduced time to peak (TTP), which reflects cerebral hyperperfusion and shows the importance of MRI for making the diagnosis.