Diagnosis of Vertebrobasilar Insufficiency Using Transcranial Doppler Ultrasound

1. Diagnosis of Vertebrobasilar Insufficiency Using Transcranial Doppler Ultrasound Sean Steward February 20, 2013

2. Overview • Vertebrobasilar Insufficiency • Signs and Symptoms • Risk Factors • Tests • Transcranial Doppler Ultrasound • Case Study • QA statistics of TCD • Conclusion

3. Vertebrobasilar Insufficiency • Vertebrobasilar insufficiency (VBI) is a posterior circulation transient ischemic attack (TIA) caused by intermittent vertebral artery occlusion that is induced by a head rotation or extension • VBI also may result from large vessel atherosclerotic disease, dissection, cervical compressive lesions, and subclavian steal phenomenon

4. Signs and Symptoms for VBI • Loss of vision in part or all of both eyes • Double vision • Vertigo (spinning sensation) • Numbness or tingling • Nausea and vomiting • Slurred speech • Loss of coordination, dizziness or confusion • Trouble swallowing • A drop attack — sudden generalized weakness • Ucdavis.edu

5. Risk Factors for VBI • Smoking • Hypertension • Hyperlipidemia • Older age • Gender: men have a higher risk before age 75; women have a high risk after 75 • Family history • Genetic factors • Ucdavis.edu

6. Tests • Magnetic Resonance Angiography (MRA) • Standard angiography (X-ray study using injected dye) • Both are used to identify vertebrobasilar artery disease • Digital Subtraction Cerebral Angiography (DSA) is considered the “gold standard” diagnostic test • Mild sedative is used • Electrocardiogram is attached • Catheter placed starting in the groin • Contrast material • DSA uses a computer to "subtract" or take out the bones and tissues in the area viewed, so that only the blood vessels filled with the contrast dye are seen • Ucdavis.edu • Nlm.nih.gov

7. Transcranial Doppler • Typically use a 2 MHz probe • Angle of insonation is zero degrees • (3) most common windows utilized: • Transforamenal (A) • Transtemporal (B) • Transorbital (C) • Standard method of quantifying velocity is time averaged mean velocity (TAMV) • McPharlin & Rumwell A B C

8. Transcranial Doppler • Accurate vessel identification • Appropriate sample volume and depth • Direction and velocity of blood flow • McPharlin & Rumwell

9. Case Study • 50 year old Caucasian male • Presented with one year of positional vertigo and ataxic gait when extending his neck • Positional vertigo is a sudden sensation of spinning with head movements • Ataxic gait is an unsteady, uncoordinated walk • CT and MRI were WNL • TCD performed • nlm.nih.gov • thefreedictionary.com • ncbi.nlm.nih.gov

10. Case Study • TCD monitoring of the bilateral PCA (Posterior Cerebral Artery) mean flow velocities were monitored in different head positions using a head frame to avoid any changes in the angle of insonation • ncbi.nlm.nih.gov

11. Case Study • Transforamenal window was used to image the vertebral arteries and basilar arteries • Transtemporal window was used to evaluate the posterior cerebral arteries • In an upright position the mean velocities for the right and left PCA’s were 18cm/sec and 19cm/sec • ncbi.nlm.nih.gov

12. Case Study • After the TCD imaging was performed: • An electronystagmography (ENG) was performed which was negative • Electronystagmography (ENG) is used to evaluate people with vertigo (a false sense of spinning or motion that can cause dizziness) and certain other disorders that affect hearing and vision • An MRI of his cervical spine was done to rule out myelopathy • Myelopathy is a term used to describe symptoms related to spinal cord compression • Cervical (neck) myelopathy is most common • hopkinsmedicine.org • piedmonthospital.org • ncbi.nlm.nih.gov

13. Case Study • Review: • (2) MRI’s (Both negative) • CT (Negative) • ENG (Negative) • ENT (Ear nose and throat work up – Negative) • TCD (Showed positive results…thank you very much) • Patient refused spinal surgery and is being treated conservatively • ncbi.nlm.nih.gov

14. QA Statistics • According to a series that was done in 1992 that compared TCD with DSA (Gold Standard) in 20 patients the results are as follows for TCD: • Sensitivity – 87% • Specificity – 80% • Positive Predictive Value – 93% • Negative Predictive Value – 67% • The results proved that TCD is a useful screening method in patients with VBI to detect large vessel disease of the intracranial vertebrobasilar system • ncbi.nlm.nih.gov

15. Conclusion • VBI is a very difficult disease to diagnose • TCD should be the new “Gold Standard” diagnostic test for evaluating VBI’s • It’s noninvasive • No sedative, catheter, contrast dye, ECG • Relatively inexpensive test • Can go bedside if needed • Proven QA numbers

16. References Alnami, I., Siddiqui, M. & Saqqur, M. (2012, November).Case Reports in Medicine. TheDiagnosis of Vertebrobasilar Insufficiency Using Transcranial Doppler Ultrasound.Retrievedfrom: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3509548/ Ataxic gait (n.d.) The free dictionary. Retrieved from: http://medical-dictionary.thefreedictionary.com/ataxic+gait Benign positional vertigo (n.d.).Medline Plus.Retrieved from: http://www.nlm.nih.gov/medlineplus/ency/article/001420.htm Cerebral angiography (n.d.).Medline Plus.Retrieved from: http://www.nlm.nih.gov/medlineplus/ency/article/003799.htm

17. References Electronystagmography(ENG) (n.d.) John Hopkins Medicine. Retrieved from:http://www.hopkinsmedicine.org/healthlibrary/test_procedures/neurological/electronystagmography_eng_92,P07659/ McPharlin, M., & Rumwell, C. (2009). Vascular Technology: An Illustrated Review. Pasadena, CA:Davies Publishing, Inc. Myelopathy (n.d.) Piedmont Healthcare. Retrieved from:http://www.piedmonthospital.org/SpineCenter/Myelopathyctr.aspx UCDavis Health System. Vertebrobasilar insufficiency. Retrieved from:http://www.ucdmc.ucdavis.edu/vascular/diseases/vertebrobasilar.html