-Apart from the known risk factors,
such as hypertension,
immunosuppressants,
and renal failure of various etiologies may be the precipitants of PRES.
- Early recognition of PRES is important for early therapy start.
The patients must have clinical history of acute neurologic symptoms,
such as headache,
visual disturbance,
seizures or neurological deficit; brain imaging findings such as focal vasogenic edema and clinical or radiologic proof of reversibility.
-A large proportion of our patients with PRES present with atypical neuroimaging findings.
In accordance to recent articles published in the literature.
Thus it is important for radiologists to be familiar with both the typical and atypical imaging features of PRES.
-The appearance of severe cases of PRES is not uncommon in clinical practice,
being difficult to confirm the diagnosis in these situations,
because these patients have complex medical histories,
with more than one possible cause of the imaging findings.
-The diagnosis is not always straightforward and typical imaging features require correlation with clinical and laboratory data for accurate assessment.
We found that it may not be easy to find a clear clinical-radiological association even in typical reversible cases.
-Thalamus,
midbrain,
and pons affection was significantly less frequent in preeclampsia-eclampsia associated PRES (P=0.01).
Preeclampsia-eclampsia patients had significantly less severe edema,
less cytotoxic edema,
hemorrhage and contrast enhancement,
while more frequent complete resolution of edema and less frequent residual structural lesions were seen on follow-up imaging.
-We found an involvement of the basal ganglia,
brainstem,
or cerebellum in aboutone-third of cases studied.
But,
such an occurrence never appeared isolated (Fig 1).
The main MRI lesions are located particularly in the parieto-occipital regions (90-95%).
-All our patients showed a bilateral affection,
frequently asymmetrically.
This suggests that PRES shows a typical MRI pattern on fluid-attenuated inversion recovery (FLAIR)-weighted imaging in PRES patients that makes the following diagnoses more likely:
- The predominant affected region is parieto-occipital.
- Both hemispheres are affected,
sometimes asymmetrically.
- The subcortical white matter is always affected,
but an involvement of cortex is also very common.
– Differential diagnosis considered in the most challenging cases and couldn't be confimed,
were ichemic lesions either in vasculitis,
or emboli in vertebrobasilar system or emboli in border zones.