Summary
Posterior reversible encephalopathy syndrome (PRES) is a neurological condition characterized by vasogenic edema predominantly involving the subcortical white matter of the posterior cerebral hemispheres. Causes include acute severe hypertension (e.g., pregnancy-induced hypertension), autoimmune diseases, and certain immunosuppressant or antineoplastic agents. Clinical features typically include altered mental status (AMS), seizures, headache, and/or visual disturbances. Diagnosis relies on neuroimaging (e.g., MRI brain), which typically shows bilateral edema in the parieto-occipital regions. Lumbar puncture may be performed to exclude infectious or inflammatory mimics. Management involves addressing the underlying cause and providing symptomatic support. With early recognition and treatment, most patients achieve complete clinical and radiological recovery.
Epidemiology
-
Incidence in the general population is unknown and differs in certain patient cohorts, e.g.: [1][2]
- End-stage renal disease and systemic lupus erythematosus (SLE): ∼ 1%
- Bone marrow transplantation: 2.7–25%
- Preeclampsia or eclampsia: 20–98%
- Most commonly affects young to middle-aged adults
- ♀ > ♂ [2]
Epidemiological data refers to the US, unless otherwise specified.
Etiology
- Acute severe hypertension (e.g., hypertensive emergency, preeclampsia, eclampsia)
- Renal failure
- Sepsis
- Autoimmune diseases (e.g., SLE)
- Antineoplastic drugs and immunosuppressant drugs (e.g., cyclosporine A, cisplatin, cyclophosphamide)
Pathophysiology
The exact pathophysiology of PRES is not fully understood, but the following theories have been proposed. [2]
- ↑ Blood pressure → loss of cerebrovascular autoregulation → hyperperfusion with endothelial damage and vasogenic edema
- Presence of endogenous or exogenous toxins → endothelial dysfunction
Clinical features
Severity of symptoms may vary. [1][2]
- Altered mental status
- Seizures
- Headache (typically moderate to severe and generalized)
- Visual disturbances
- Nausea, vomiting
Diagnosis
Diagnosis is based on characteristic clinical features, neuroimaging findings, and risk factors.
Neuroimaging [1][2]
-
MRI brain (preferred modality)
- Characteristic finding: bilateral vasogenic edema predominantly in parieto-occipital regions
- Crucial for differentiating PRES from mimics (e.g., acute ischemic stroke)
- CT brain: less sensitive than MRI for vasogenic edema
Evaluation for the underlying cause [1][3]
- Blood pressure monitoring
- Blood tests, e.g.:
- Urine tests
Additional studies [2]
Consider the following to exclude alternative diagnoses:
-
Lumbar puncture
- Use: to assess for CNS infection or inflammation
- Findings in PRES: normal or mildly elevated protein concentration
- Electroencephalography: to evaluate encephalopathy and exclude nonconvulsive status epilepticus
Differential diagnoses
Differential diagnoses include: [1][2]
- Vascular
- Infectious: infectious encephalitis
- Inflammatory
- Demyelinating
- Neoplastic: primary or secondary brain tumors
-
Metabolic and toxic encephalopathies
- Substance-induced encephalopathy
- Mitochondrial encephalopathy (see “Mitochondrial myopathies”)
- Hepatic encephalopathy
The differential diagnoses listed here are not exhaustive.
Management
Management is focused on treating the underlying cause and providing supportive care. [1][2][3]
- Provide immediate initial management of AMS or coma.
- Consider admission to ICU. [1]
- Identify and manage the underlying cause, which may include:
- Management of hypertensive emergencies
- Management of urgent hypertensive pregnancy disorders
- Reduction or discontinuation of causative medications (e.g., immunosuppressants), under specialist supervision
- Renal replacement therapy for renal failure
- Management of acute seizures and status epilepticus