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Hypertensive Encephalopathy

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Hypertensive Encephalopathy, Posterior Reversible Encephalopathy Syndrome, Posterior Leukoencephalopathy Syndrome, PRES, RPLS

  • Pathophysiology
  1. Cerebral perfusion is autoregulated via arteriole constriction and dilation
    1. Blood Pressure may exceed autoregulation and allow fluid and blood to leak across the blood brain barrier
    2. Results in Hypertension-induced cerebral edema and micro-Hemorrhages
  2. Blood Pressure thresholds vary based on chronicity of Severe Hypertension
    1. Chronic Severe Hypertension is compensated and encephalopathy occurs at a higher Blood Pressure
    2. Acute Severe Hypertension is more likely to cause encephalopathy at a lower Blood Pressure (esp children)
  • Symptoms
  1. Headache
  2. Visual changes
  3. Vomiting
  4. Dizziness
  • Signs
  • Imaging
  1. MRI Brain
    1. Abnormal in Reversible Posterior Leukoencephalopathy Syndrome (RPLS, PRES)
    2. Symmetric white matter edema in posterior Cerebral Hemispheres
  • Diagnosis
  1. Clinical diagnosis of exclusion (although RPLS or PRES may be diagnosed on MRI)
  2. Hypertensive Encephalopathy typically improves with Blood Pressure lowering (even 10-20%)
    1. Other causes of Altered Level of Consciousness and Hypertension (e.g. CVA) do not improve as readily
  • Differential Diagnosis
  • Management
  1. See Hypertensive Emergency for agents to emergently lower Blood Pressure
  2. Lower Blood Pressure by 10-20% within first hour of presentation
    1. Further lowering as needed
  • Prognosis
  1. Fully reversible in most cases within days to weeks
  2. In one study, nearly 25% died and another subset had permanent neurologic dysfunction
    1. Covarrubias (2002) Am J Neuroradiol 23(6): 1038-48 +PMID:12063238 [PubMed]
  • References
  1. Elliott and Varon (2016) Evaluation and Treatment of Hypertensive Emergencies, UpToDate, accessed 12/28/2016
  2. Neill (2016) Reversible Posterior Leukoencephalopathy Syndrome, UpToDate, accessed 12/28/2016
  3. Staykov (2012) J Intensive Care Med 27(1): 11-24 +PMID:21257628 [PubMed]