To describe predisposing factors and neurological manifestations related to PRES. To elucidate the main hypothesis regarding PRES pathophysiology. To distinguish the different image patterns and atypical imagen findings described in PRES. To report clinical and neuroradiological evolution in order to test the so-called reversibility of this entity.

Posterior reversible encephalopathy syndrome (PRES) is an acute onset and usually reversible neurological disorder characterized by headache, disorders of consciousness, visual disturbance and acute arterial hypertension associated with intracranial vasogenic oedema. Etiology: There are two main theories: Hyperperfusion hypothesis: elevation of blood pressure above the upper limit of cerebrovascular autoregulation leads to vascular leakage and vasogenic oedema in brain. The lesser density of sympathetic innervation in the posterior circulation in contrast to the anterior circulation would explain the high incidence of involvement of parietal and...

Between 2007 and 2019 we revised retrospectively in our radiological report database patients who met the following diagnostic criteria: neurological manifestations of acute onset, image signs of vasogenic oedema and reversibility of clinical and/or radiological findings. Clinical, imaging data and outcome of the selected patients (n=33) were analysed (Table 1, 2, 3 and 4). The most frequent predisposing factor found was hypertension, observing high blood pressure in nearly half of cases (51%). Most of these patients showed moderate-severe hypertension (mean blood pressure values >106 mmHg)....

Image expression of PRES consists of subcortical vasogenic oedema, mainly in parieto-occipital regions with three different imaging patterns described. Involvement of basal ganglia, thalami and infratentorial structures as well findings such as haemorrhage, restricted diffusion and contrast enhancement are considered atypical findings. Academicall, PRES is still a matter of controversy as its pathogenic mechanism is unresolved and relationship between image findings and outcome is weak. In daily practise PRES is a diagnosis challenge: predisposing factors may not be identified, image features are varied and neuroradiological...

P. Elvira Ruiz; Madrid/ES - nothing to disclose M. F. Arenas García; Madrid/ES - nothing to disclose M. J. García Redondo; Madrid/ES - nothing to disclose M. M. Manrique Zegarra; Madrid/ES - nothing to disclose P. Patilla Vázquez; Madrid/ES - nothing to disclose I. Garrido Morro; Madrid/ES - nothing to disclose J. A. Guzmán de Villoria Lebiedziejewski; Madrid/ES - nothing to disclose P. Fernández García; Madrid/ES - nothing to disclose

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