History

• 73 yo M PMH HTN, prior posterior CVA with residual peripheral vision deficit, DM, hyperlipidemia, p/w change in mental status
• Wife heard pt fall, found him down
• Immediately after the fall, patient was speaking but confused.
• Per EMS, he has had declining mental status while en route to the hospital.
• Stroke alert was called in the field by EMS

Physical Exam

T 98.4, HR 117, BP 270/143, Pulse ox 92% RA, RR 16

• Laying on stretcher with eyes closed
• Pupils equal, round, reactive, no gaze deviation
• No verbal response, not following commands
• Localizes to pain with deep sternal rub 
• Cardiopulmonary exam wnl
• Abdomen soft, non-tender

Differential Diagnosis

• Stroke  vs intracranial hemorrhage vs seizure
• Hypertensive encephalopathy vs PRES given marked elevation in BP

Management 

• Stroke alert activated
• Pt brought to CT scanner from ambulance triage for CT head non contrast and CTA head and neck

Diagnostics and Case Progression

• CT head showed no ICH, CTA showed no LVO N
• On return from CT scan, repeat blood pressure again 270s/140s
• Symptoms suspected due to hypertension vs PRES, so nicardipine infusion was started
• As patient’s BP came down, his exam improved
• Over the next 2 hours, his systolic BP was lowered to about 200 systolic
• Repeat physical exam at this time showed patient tracking examiner with eyes and following commands in all four extremities

Discussion

• Hypertensive encephalopthy is thought to be due to failure of cerebral autoregulation, leading to vasogenic edema especially of the posterior circulation (i.e. PRES syndrome - Posterior Reversible Encephalopathy Syndrome)
• Diagnosis suspected with acute onset encephalopathy, markedly elevated blood pressure usually >200 systolic/120 diastolic, and lack of other diagnosis to explain symptoms
• An MRI of the brain may reveal the classic changes of PRES in the posterior circulation as seen below

• Treatment is directed at reversal of underlying cause, if any, as well as reduction of systemic blood pressure with medications such as nicardepene, a peripherally acting calcium channel blocker

Reference

Feske, Steven. Posterior Reversible Encephalopathy Syndrome: A Review. Semin Neurol 2011; 31(2): 202-215.