Learning objectives
- to describe the key clinical and physiopathological elements of Posterior Reversible Encephalopathy Syndrome (PRES)
- to illustrate the typical findings at imaging
Background
Posterior Reversible Encephalopathy Syndrome (PRES) is a clinicoradiological entity first described by Hinchey et al.
in 1996.
Initially it was thought that it occured with a predominantely posterior distribution,
was limited to the white matter and was always reversible.
It can extend into other regions (i.e temporal or frontal lobes,
pons,
cerebellum,
cortical grey matter),
and some reports have suggested the possibility of neurological impairment or death.
The exact incidence of PRES has not been determined.
The majority of cases reported occur in midlle-aged patients,...
Imaging findings OR Procedure details
Due to the lack of specificity of the clinical and laboratory findings,
Imaging plays a key role in the diagnosis and follow-up pf PRES.
This section describes the essential findings at Computed Tomography (CT) and Magnetic Ressonance (MR).
CT is often the first exam performed,
due to its wider availability and lesser cost.
Findings are commonly normal or unspecific.
It can be useful to rule out other pathologies (i.e hemorhagic infarction) and may provide useful information in repeated scans performed when MR is unavaiable or...
Conclusion
- Posterior Reversible Encephalopathy Syndrome is an entity with a wide spectrum of etiologies.
- Its diagnosis requires a high degree of clinical suspicion and imaging evaluation is indispensable,
with Magnetic Resonance being the modality of choice.
- Irreversible sequelae may be avoided if adequate therapy is promptly initiated,
highlighting the importance of an early accurate diagnosis.
References
-Hinchey J,
Chaves C,
Appignani B,
et al.
"A reversible posterior leukoencephalopathysyndrome" N Engl J Med 1996;334:494–500
- Legriel S,
Pico F,
Azoulay E,
"Understanding Posterior Reversible Encephalopathy Syndrome" Annual update in Intensive Care and Emergency Medicine Springer Science + Business Media 2011; 631-652
-Ishikura K,
Hamasaki Y,
Sakai T,Hataya H,
Goto T,
Miyama,
Kono T,
Honda M "Children with posterior reversible encephalopathy syndrome
associated with atypical diffusion-weighted imaging and apparent
diffusion coefficient",Clin Exp Nephrol (2011) 15:275–280
- Bartynski W.S "Posterior Reversible Encephalopathy Syndrome,
Part...