1. eEdE-46

2. NO DISCLOSURE

3. The various presentations of posterior reversible encephalopathy syndrome
M. Ollivier, S. Gerber, D. Galanaud, S. Deltour, D. Ben Salem, D. Dormont, D. Leclercq

4. Posterior Reversible Encephalopathy Syndrome (PRES)
INTRODUCTION
Posterior Reversible Encephalopathy Syndrome (PRES)
RADIOCLINICAL
ENTITY
Vasogenic edema Predominate in the posterior white matter
Headache
Seizures
Altered mental status
Visual disturbances

5. INTRODUCTION Posterior Reversible Encephalopathy Syndrome (PRES) +
RADIOCLINICAL ENTITY +
PREDISPOSING FACTORS
Immunosuppressor agents
Hypertension
Eclampsia
Lupus

6. INTRODUCTION The aim of this pictorial review is to:
Define an MRI adapted protocol
Describe oedema patterns of distribution
Identify the different types of haemorrhage
Discuss the relevance of the DWI
Approach the physiopathology: perfusion, ARM
Monitor changes over time

7. MRI AND PRES MRI is the method of choice Adapted protocol: - FLAIR
- Diffusion
- Susceptibility-weighted imaging
(SWI > T2* to detect microhemorrhage)*
- ASL perfusion
- 3D TOF angio-MR
- T1-WI pre and post-contrast
At the acute phase and follow-up
*R.N.K. Nandigam et al. AJNR Am J Neuroradiol. Feb 2009

8. EDEMA DISTRIBUTION TYPICALLY Vasogenic edema Bilateral ± symmetric
Focal or confluent
Parieto-occipital regions
98%*
Additional involvement:
Frontal lobes (68%) typically linear along the superior frontal sulcus
Inferior temporal lobes (40%)
Cerebellar hemispheres (30-53%)
Variable involvement:
Cortex
Deep and sub-cortical white matter
*W.S. Bartynski et al. AJNR Am J Neuroradiol. Aug 2007

9. EDEMA DISTRIBUTION 3 major patterns of PRES (according to Bartynski*)
SUPERIOR FRONTAL SULCAL
HOLOHEMISPHERIC WATERSHED
DOMINANT PARIETAL-OCCIPITAL
*W.S. Bartynski et al. AJNR Am J Neuroradiol. Aug 2007

10. EDEMA DISTRIBUTION 3 major patterns of PRES SUPERIOR FRONTAL SULCAL
Superior frontal sulcal involvement
No frontal pole extension
Varying degrees of parietal and occipital abnormality

11. EDEMA DISTRIBUTION
3 major patterns of PRES
SUPERIOR FRONTAL SULCAL

12. EDEMA DISTRIBUTION 3 major patterns of PRES HOLOHEMISPHERIC WATERSHED
Linear pattern
spanning the
frontal, parietal
and occipital
lobes
± temporal lobes
- Watershed

13. EDEMA DISTRIBUTION
3 major patterns of PRES
HOLOHEMISPHERIC WATERSHED

14. EDEMA DISTRIBUTION 3 major patterns of PRES
DOMINANT PARIETAL-OCCIPITAL
The typical
“posterior” pattern
Parietal and
occipital
involvement

15. EDEMA DISTRIBUTION 3 major patterns of PRES
DOMINANT PARIETAL-OCCIPITAL

16. EDEMA DISTRIBUTION Cerebellar hemispheres involvement (30-53%)*
Extensive involvement of the cerebellum with obstructive hydrocephalus and tonsillar herniation
Associated with the supra tentoriel lesions
Isolated cerebellar involvement : 1 case reported**
*W.S. Bartynski et al. AJNR. 2007
J.E. Fugate et al. Mayo Clin Proc. 2009
**MH LIM et al. Intern Med. 2008

17. EDEMA DISTRIBUTION
ATYPICAL LOCATIONS
Asymmetric

18. EDEMA DISTRIBUTION ATYPICAL LOCATIONS Deep white matter
- corona radiata
- corpus callosum
- internal capsule

19. EDEMA DISTRIBUTION
ATYPICAL LOCATIONS
Basal ganglia
Thalamus

20. EDEMA DISTRIBUTION ATYPICAL LOCATIONS Brain stem (12,5%)* - midbrain
- pons
- medulla
*W.S. Bartynski et al. AJNR. 2007

21. HAEMORRHAGE IN PRES ≈ 15% * 3 types: Hematoma Sulcal subarachnoid
Minute haemorrhage
(<5mm)
± combined
*H.M. Hefzy et al. AJNR Am J Neuroradiol. Aug 2009
AM McKinney et al. AJR Am J Roentgenol 2007

22. HAEMORRHAGE IN PRES ETIOLOGIC FACTORS May occur secondarily
Controversial and unproven
Alteration of the blood-brain barrier
Rupture of pial vessels
Post-ischemic reperfusion injury
May occur secondarily

23. HAEMORRHAGE IN PRES
20 D

24. HAEMORRHAGE IN PRES ETIOLOGIC FACTORS
Controversial and unproven
Alteration of the blood-brain barrier
Rupture of pial vessels
Post- ischemic reperfusion injury
Rate of haemorrhage much greater in patients after allo-BMT (compared with those with solid-organ transplantation)*
Blood pressure does not appear to affect the incidence or the type of haemorrhage in PRES*
*H.M. Hefzy et al. AJNR Am J Neuroradiol. Aug 2009

25. DIFFUSION IN PRES TYPICAL VASOGENIC EDEMA
Hyperintense, hypointense, or isointense on DIFFUSION-WEIGHTED IMAGING*
Increased ADC values
*C. Lamy et al. J Neuroimaging. 2004

26. DIFFUSION IN PRES CYTOTOXIC EDEMA POSSIBLE (11-26 %*)
Decreased ADC values
May lead to local INFARCTION★
Must be regarded WITH CAUTION:
COMPLETE REVERSIBILITY possible**
**O. Kastrup et al. Clin Neuroradiol. 2014
A. Benziada-Boudour et al. Journal of Neuroradiology. 2009
*★Covarrubias DJ et al. AJNR Am J Neuroradiol 2002
* Koch S et al. AJNR Am J Neuroradiol 2001

27. DIFFUSION IN PRES
No infarction
D 0
D 10
D 90

28. sous cortical infraction
DIFFUSION IN PRES
Cortico-
sous cortical infraction
CORTICAL HYPERSIGNAL
ADC
D 90

29. PERFUSION IN PRES PATHOPHYSIOLOGICAL approach
Disordered cerebral autoregulation and endothelial damage
Two main hypotheses:
Severe arterial hypertension  failed autoregulation  hyperperfusion  edema
W.S. Bartynski. AJNR Am J Neuroradiol, Jun-Jul 2008

30. PERFUSION IN PRES
Cerebral blood flow (ASL)
HYPERPERFUSION

31. PERFUSION IN PRES
D 0
D 10
D 40
FLAIR
CBF (ASL)

32. PERFUSION IN PRES PATHOPHYSIOLOGICAL approach
Failed cerebral autoregulation and endothelial damage
Two main hypotheses:
Vasoconstriction  hypoperfusion  ischemia  edema
W.S. Bartynski. AJNR Am J Neuroradiol, Jun-Jul 2008

33. PERFUSION IN PRES
Cerebral Blood Volume
HYPOPERFUSION

34. PERFUSION IN PRES Cerebral artery VASOCONSTRICTION
In the second and third-order branches
Diffuse and focal vasoconstriction
Focal vasodilatation
Reversible
W.S. Bartynski et al. AJNR Am J Neuroradiol. Mar 2008

35. PERFUSION IN PRES

36. PERFUSION IN PRES Vasocontriction / vasodilatation Courtesy
Dr F.Clarençon

37. ENHANCEMENT IN PRES 23 % cases*
Breakdown of the blood-brain barrier **
Endothelial injury or dysfunction
LEPTOMENINGEAL enhancement
same location as edema
or distant from the site of parenchymal involvement★
*O. Kastrup et al. Clin Neuroradiol. 2014
**JG Smirniotopoulos et al. Radiogaphics, 2007
★R.T. Fitzgerald et al. Pediatric Neurology.2013

38. ENHANCEMENT IN PRES LEPTOMENINGEAL ENHANCEMENT D O D 8
EVOLUTIVE LEPTOMENINGEAL ENHANCEMENT

39. ENHANCEMENT IN PRES INTRAPARENCHYMAL enhancement CORO
Leptomeningeal and intraparenchymal enhancement

40. PRES FOLLOW-UP Typically reversible > 2/3 cases* How quickly?
Complete resolution possible in 1 or 2 weeks
Sometimes in up to 1 month
*O. Kastrup et al. Clin Neuroradiol. 2014

41. PRES FOLLOW-UP
D 0
D 15
D 25
Non uniform evolution : - development of new oedematous lesions
- then complete resolution

42. PRES FOLLOW-UP
D 0
D 8
D 30
D 90
Slow and retarded regression of edema

43. RECURRENT PRES Anecdotally reported Recurrent PRES: 3,8% * 02/2015
07/2014
Anecdotally reported
Recurrent PRES: 3,8% *
*J M. Sweany et al. J Comput Assist Tomogr., 2007

44. CONCLUSION The spectrum of imaging findings in PRES is wide
Bilateral parietal and occipital subcortical vasogenic oedema is almost constant (98%)
Typically edema is reversible
Haemorrhage is common (15%) and does not exclude the diagnosis
Lesion with decreased ADC values ≠ conversion to infarction
Perfusion and Angio-MR reflect cerebral vasculopathy