Podcast #499: Posterior Circulation Ischemia

Podcast # 499: Posterior Circulation Strokes

Contributor: Neal O’Connor, MD

Educational Pearls:

• Dizziness is a very common complaint in the emergency department, but how can we find patients with a dangerous cause of their symptoms, namely a posterior circulation stroke?
• Consider a posterior circulation stroke in those with an abrupt onset of headache with neck pain, balance problem, blurred vision, or dysphagia 
• Thorough cranial nerve exam can be important to screen for posterior circulation stroke, as much of the brainstem is supplied by the posterior circulation. 
• The most common posterior circulation stroke is a lateral medullary infarct (Wallenberg Syndrome), which produces dysphagia due to cranial nerve IX and XII involvement
• Other physical exam findings include truncal ataxia, extremity ataxia, visual field cuts, and Horner syndrome (Ptosis, Miosis, Anhidrosis) 
• The HINTS exam (Head Impulse - Nystagmus - Test of Skew)can be used to differentiate between peripheral and central causes of dizziness
• Concerning exam findings for central cause may include vertical nystagmus, gaze skew, or inability to track with head impulse

References

Áine Merwick, David Werring. Posterior circulation ischaemic stroke. BMJ 2014;348:g3175 doi: 10.1136/bmj.g3175

Kattah JC, Talkad AV, Wang DZ, Hsieh YH, Newman-Toker DE. HINTS to diagnose stroke in the acute vestibular syndrome: three-step bedside oculomotor examination more sensitive than early MRI diffusion-weighted imaging. Stroke. 2009;40(11):3504–3510. doi:10.1161/STROKEAHA.109.551234

Nouh A, Remke J, Ruland S. Ischemic posterior circulation stroke: a review of anatomy, clinical presentations, diagnosis, and current management. Front Neurol. 2014;5:30. Published 2014 Apr 7. doi:10.3389/fneur.2014.00030

From CarePoint PA Academy, 2019