VERTIBROBASILAR INSUFFICIENCY.pptx

A PowerPoint presentation about vertebrobasilar insufficiency/syndrome created by Naeem Rahbar, a budding physiotherapist from Calicut

1. VERTIBROBASILAR INSUFFICIENCY Naeem Rahbar

2. VERTIBROBASILAR 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.

3. PATHOPHYSIOLOGY Usually, VBI is caused by 2 processes of ischemia: H emodynamic insufficiency E mbolism. Unlike the carotid arteries, embolism via the vertebral arteries is not common. Donor sites for embolism may include the aortic arch, the origin of the vertebral artery or the proximal subclavian arteries. Most cases, however, are due to atherosclerotic disease.

4. HEMODYNAMIC Decreased perfusion causes most VBI. Hemodynamic ischemia occurs due to inadequate blood flow through the basilar artery, especially in the elderly and diabetic populations with poor sympathetic control. Symptoms tend to be reproducible and short, rarely causing infarction. For hemodynamic ischemia to occur, there must be occlusion in  both vertebral arteries or within the basilar artery . Also, there must be an incomplete contribution by the carotid circulation via the posterior communicating artery in the circle of Willis.

5. Cont … Other causes for a decrease in perfusion include antihypertensive medications, cardiac arrhythmia, pacemaker malfunction, and vasculitis. Thus, it is imperative that a complete workup, including ECG, be done to rule out cardiogenic causes. Occlusions in other blood vessels such as in Subclavian Steal syndrome may also cause VBI by “stealing” blood flow from the brainstem as blood flows down the path of least resistance via the vertebral artery in the presence of proximal stenosis/occlusion of the subclavian artery.

6. EMBOLISM VBI may also originate from atherosclerotic plaques that later break off to form emboli. However, emboli may also develop as a result of intimal defects secondary to trauma, compression, and in a minority of cases from fibromuscular dysplasia, aneurysm or dissection. Possibly up to one-third of cases occur intracranially, as distal emboli form from lesions within the subclavian, vertebral, or basilar artery. Most lesions that form extracranially arise from an atherosclerotic build-up in one of the vertebral arteries, and rarely the innominate or subclavian. In a very small number of cases, thrombi can arise from an ectatic ( distension) or fusiform basilar artery aneurysm which may then embolize to more distal branches.

7. SIGNS AND SYMPTOMS Loss of vision in part or all of both eyes Double vision Numbness or tingling Vertigo (Spinning Sensation) Nausea and vomiting Slurred speech Loss of coordination, dizziness or confusion Trouble swallowing Drop attack – Patient feels suddenly weak in the knees and fall Paraesthesia Ataxia

8. RISK FACTORS 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

9. INVESTIGATIONS MRI/ MRA Duplex CT/ CTA Digital Subtraction Cerebral Angiography (DSA) is considered the “gold standard” diagnostic test Mild sedative is used ECG 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

10. MANAGEMENT Endartectomy Vertebral Trans-subclavian Bypass Carotid-subclavian Subclavian-vertebral Vertebral-Carotid Transposition Angioplasty/Stenting

11. DIFFERENTIAL DIAGNOSIS Benign positional vertigo in emergency medicine Labyrinthitis MELAS (mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes) Multiple sclerosis Posterior fossa tumour Subclavian steal syndrome Stroke haemorrhage Stroke ischemic Transient ischemic attack Transtentorial herniation Vertebral artery dissection Vasculitis Vestibular neuronitis

12. REFERENCES Pirau L, Lui F. Vertebrobasilar Insufficiency. [Updated 2022 Jul 18]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Lima Neto AC, Bittar R, Gattas GS, Bor -Seng-Shu E, Oliveira ML, Monsanto RDC, Bittar LF. Pathophysiology and Diagnosis of Vertebrobasilar Insufficiency: A Review of the Literature. Int Arch Otorhinolaryngol . 2017 Jul;21(3):302-307. Najafi MR, Toghianifar N, Abdar Esfahani M, Najafi MA, Mollakouchakian MJ. Dolichoectasia in vertebrobasilar arteries presented as transient ischemic attacks: A case report. ARYA Atheroscler . 2016 Jan;12(1):55-8 Yuh SJ, Alkherayf F, Lesiuk H. Dolichoectasia of the vertebral basilar and internal carotid arteries: A case report and literature review.  Surg Neurol Int. 2013;4:153. Lou M, Caplan LR. Vertebrobasilar dilatative arteriopathy (dolichoectasia). Ann N Y Acad Sci. 2010 Jan;1184:121-33. Caplan LR. Atherosclerotic Vertebral Artery Disease in the Neck.  Curr Treat Options Cardiovasc Med. 2003 Jul;5(3):251-256.