PRES

Question 1

PRES (Posterior Reversible Encephalopathy Syndrome)

Definition:

Answer 1

=>Syndrome with constellation of clinical and Radiological features:
* Acute onset
* HTN
* Headache
* Altered conscious state
* Confusion
* Seizures
* Coma
* Visual symptoms
* Blindness
* Reversibility on days to weeks

Question 2

Risk factors:

Answer 2

• Hypertension
• Pregnancy (Eclampsia/Pre-eclampsia)
• Chemo (tacrolimus, Infliximab etc.)
• Autoimmune conditions (SLE, scleroderma)
• Bone marrow transplant, solid organ transplant
  
  • GVHD, CRF

Question 2

DDx:

Answer 2

• Eclampsia
• Hypertensive encephalopathy
• Stroke
• CNS vasculitis (CVST)
• CVST
• Encephalitis
• CNS malignancy / lymphoma

Question 2

Pathophysiology:

Answer 2

• Hypertension → failed autoregulation
  → brain hyperperfusion→ Dilation of arterioles→ Permeability ↑ → migration of fluid into brain parenchyma (vasogenic oedema)→ Hypoperfusion, Ischemia

Flaws with the theory: Not all pts hypertensive
Asso. conditions- pregnancy, Immunosuppression not explained.

Question 3

Associated conditions

Answer 3

• • TTP / HUS
• • Acute renal failure
• • Porphyria

Question 4

Imaging:

Answer 4

-> Oedema → symmetrical, bilateral, posterior occipital/parietal distribution (most common)
* May involve frontal, holohemispheric

->MRI:
*	Hyperintense in affected regions
*	DWI: normal or ↑ signal
*	SWI: microhaemorrhages

Question 5

Treatment:

Answer 5

• Treat underlying cause
• Aggressive BP control
• Seizure control (antiepileptics)
• Stop causative drug
• Supportive ICU care

Question 6

Prognosis

Answer 6

Prognosis:
* Partial to complete recovery usually occurs
* Residual neurological or visual deficits may persist