A 21-year-old female patient with systemic lupus erythematosus (SLE) on steroids presented with generalized tonic-clonic seizures and altered sensorium. The top differential diagnoses included posterior reversible encephalopathy syndrome (PRES), posterior circulation ischemia/infarction, vasculitis, hypoglycemia, sinovenous thrombosis, thrombotic microangiopathies, status epilepticus, and reversible cerebral vasoconstriction syndrome. The document discusses PRES in more detail, describing its typical parieto-occipital involvement on imaging, various atypical manifestations, pathogenesis related to hypertension and endothelial dysfunction, and common causes like preeclampsia/eclampsia, infection

1. Dr. Sethu Sadanadnan
Registrar
Radiology

2.  21yr old female patient
 k/c/o SLE on steroids
 Presented with GTCS and Altered sensorium

8. DD
1.PRES/RPLS
2.Posterior circulation ischemia/infarction
3.Vasulitis
4.Hypoglycemia
5.Sinovenous thrombosis
6.Thrombotic microangiopathies
7.Status epilepticus
8.Reversible cerebral vasoconstriction syndrome

9. DD
1.P R E S / R P L S
2.Posterior circulation ischemia/infarction
3.Vasulitis
4.Hypoglycemia
5.Sinovenous thrombosis
6.Thrombotic microangiopathies
7.Status epilepticus
8.Reversible cerebral vasoconstriction syndrome

10. Posterior Reversible
Encephalopathy Syndrome:
 Posterior reversible encephalopathy syndrome (PRES)
is a clinicoradiological entity
 Posterior reversible encephalopathy syndrome (PRES)
is well recognized because of its typical imaging
appearance, that is involvement of the parieto-
occipital regions
 Other brain regions may also be affected and unusual
imaging manifestations are observed frequently

11. Classic PRES Atypical PRES
B/L symmetrical parieto
occipital cortical and
subcortical regions
Frontal lobes
Cortical watershed zones
Basal ganglia
Brainstem
Cerebellum
Spinal cord

14. PATHOGENESIS

15. CAUSES
 Preeclampsia/ eclampsia
 Infection /Sepsis / Shock
 Autoimmune Disease- SLE, WG, PAN , systemic
sclerosis
 Cancer chemotherapy, immunosuppressive drugs
 Renal failure
 Tumor lysis syndrome
 Thrombotic microangiopathies ( HUS/TTP)

16.  Enhancement (up to 37%) : cortical, leptomeningeal,
parenchymal or pachymeningeal
 Restricted diffusion (11-26%)
 Hemorrhage (10.5-17.1%) : parenchymal or
subarachnoid
 Altered brain perfusion : regional decreased or
increased, depends on disease time course
 Unilateral hemispheric involvement (2.6%)