Ver el código de «Vertebrobasilar insufficiency»

==Background==
*Characterized by diminished blood flow through the vertebral or basilar arteries
*The two vertebral arteries originally branch proximally from subclavian, travel through vertebrae, and distally join to become basilar artery
*Symptoms result from diminished circulation to the posterior brain, brainstem and cerebellum.
*Head-turning can cause ipsilateral vertebral artery to temporarily occlude
**If contralateral vertebral artery is stenotic, may lead to [[syncope]] (known as Bow hunter's syndrome<ref>#Go G, Hwang S-H, Park IS, Park H. Rotational Vertebral Artery Compression : Bow Hunter’s Syndrome. Journal of Korean Neurosurgical Society. 2013;54(3):243-245. doi:10.3340/jkns.2013.54.3.243.</ref>)
*Head extension may also provoke symptoms
*Neurologic symptoms tend to not present when one vertebral artery remains patent<ref>Ibrahim Alnaami, Muzaffer Siddiqui, and Maher Saqqur, “The Diagnosis of Vertebrobasilar Insufficiency Using Transcranial Doppler Ultrasound,” Case Reports in Medicine, vol. 2012, Article ID 894913, 3 pages, 2012. doi:10.1155/2012/894913.</ref>  
*Symptoms may result secondary to arterial plaques, arterial dissection, compressive lesions, or subclavian steal (see below).  *Posterior strokes encompass 20-30% of all strokes<ref>Ibrahim Alnaami, Muzaffer Siddiqui, and Maher Saqqur, “The Diagnosis of Vertebrobasilar Insufficiency Using Transcranial Doppler Ultrasound,” Case Reports in Medicine, vol. 2012, Article ID 894913, 3 pages, 2012. doi:10.1155/2012/894913.</ref>  
*Cervical osteophytes can also directly compress vertebral arteries and cause VBI symptoms<ref>Tintinalli</ref>.

===Bow hunter's syndrome (Rotational vertebral artery compression)===
*Head turning causes temporary occlusion of the ipsilateral vertebral artery.  VBI results if the contralateral vertebral artery has a fixed occlusion<ref>#Go G, Hwang S-H, Park IS, Park H. Rotational Vertebral Artery Compression : Bow Hunter’s Syndrome. Journal of Korean Neurosurgical Society. 2013;54(3):243-245. doi:10.3340/jkns.2013.54.3.243.</ref>.  Improvement of symptoms in neutral position is considered pathognomonic<ref>#Go G, Hwang S-H, Park IS, Park H. Rotational Vertebral Artery Compression : Bow Hunter’s Syndrome. Journal of Korean Neurosurgical Society. 2013;54(3):243-245. doi:10.3340/jkns.2013.54.3.243.</ref>
 
===[[Subclavian steal]] phenomenon===
*Stenotic lesion in the subclavian, located proximal to the vertebral artery--> reversed flow of blood in the vertebral artery when superimposed with increased arm activity(4).

==Clinical Features==
===Symptoms===
*[[Numbness]]/tingling
*[[Vertigo]]/dizziness
*[[visual disturbances|Changes in vision]]
*[[Nausea/vomiting]]
*[[Weakness]]
*[[Dysphagia]]
*[[Dysarthria]]
*[[Syncope]]

==Differential Diagnosis==
{{Vertigo DDX}}

==Evaluation==
{{Vertigo workup}}

===[[EBQ: HINTS Exam|HINTS Exam]]===
*Proposed as method of distinguishing peripheral cause from cerebellar/brain stem CVA in the Emergency Department population <ref>http://ec.libsyn.com/p/a/d/d/add761f2a2847ea5/hints-exam.pdf?d13a76d516d9dec20c3d276ce028ed5089ab1ce3dae902ea1d01c0873ed8cc5fe910&c_id=2502227</ref><ref>http://www.ncbi.nlm.nih.gov/pubmed/18541870</ref><ref>http://hwcdn.libsyn.com/p/1/c/d/1cd6b38a89c178a1/diff-of-vertigo.pdf?c_id=2502226&expiration=1380995436&hwt=0a8bc67ea910e018a1543ebea192f668</ref>

{{HINTS Exam Procedure}}

{{HINTS Exam Primary Outcome}}

*''If any of the above 3 tests are consistent with CVA obtain full work-up (including MRI)''

==Management==

===Medical management===
*Lower cholesterol
*Control [[hypertension]]
*Smoking cessation
*[[Antiplatelet]]s

===Surgical management===

*Endarterectomy
*Bypass grafting
*Stenting

==Disposition==
*Admit 

==See Also==
*[[Vertigo]]

==External Links==

==References==
<references/>

[[Category:Neurology]]