Posterior Circulation Ischemia: Then, Now, and Tomorrow

Abstract

know and appreciate where we are now and where we are going in the future, it is essential to know where we have been. We cannot afford to relive and repeat the history of stroke every several decades. Posterior circulation stroke represents a microcosm of stroke in general. In this presentation I first review the development of ideas regarding brain and posterior circulation ischemia and its recognition and treatment. I then share some recent data from a large prospective registry of patients with posterior circulation ischemia. Finally, I look ahead to reflect on what I believe should be the future directions for research and for the care of patients with posterior circulation disease.Patients who present to physicians and hospitals with symptoms that suggest posterior circulation ischemia are handled differently from patients who have symptoms that suggest anterior circulation disease in the great majority of medical facilities in the United States and in the world. A patient who has an attack of dizziness with diplopia and ataxic gait usually has a brain image but seldom has vascular or cardiac investigations. A diagnosis of "vertebrobasilar insufficiency" (VBI) is often made, and physicians then debate whether or not to treat with warfarin-type anticoagulants, and, if so, for how long and at what intensity. In contrast, a patient who has right-hand weakness and aphasia is usually evaluated and treated quite differently at the very same facilities. Brain imaging, cardiac investigations, noninvasive vascular tests of the carotid and intracranial anterior circulation with the use of extracranial and transcranial ultrasound and/or MR angiography (MRA) and CT angiography, and catheter angiography are often pursued, depending on the local technological capabilities and experience of the treating physicians. An effort is made to identify the etiology and mechanism of the ischemia. Treatment is then chosen among a variety of possibilities (including carotid artery surgery, angioplasty, anticoagulants, and antiplatelet aggregants) depending on the nature, location, and severity of the occlusive disease and the mechanism of ischemia.Why should anterior and posterior circulation ischemia be handled so differently? Does this schizophrenic approach make sense? After all, the internal carotid artery and its branches and the vertebral (VA) and basilar arteries (BA) and their branches are just a few inches apart; they are made of the same coats and look the same under the microscope except for size. These vessels carry the same blood under the same blood pressure. The diseases that affect the blood vessels in the 2 circulations are the same. Do stroke mechanisms really differ between the 2 circulations? How did this differing approach originate, and does it continue to make sense today? These are some questions that I will attempt to answer as I review the development of ideas about posterior circulation ischemia and as I report recent data. Development of IdeasHerein I review how knowledge about the posterior circulation ...

Lateral medullary syndrome: a diagnostic approach illustrated through case presentation and literature review

“…3,7,8 Vertebral artery dissection and large artery atherosclerosis are important risk factors for developing lateral medullary syndrome, accounting for the majority of cases reported in stroke registries. 2,9 Vertebral artery dissection is most common in younger patients or those with a history of trauma, whereas atherosclerosis is more likely in older patients with a history of hypertension, diabetes, smoking, and coronary artery disease. 2,10,11 Embolic stroke originating from the heart is another potential etiology that should be considered, particularly in patients with arrhythmias, cardiac dysfunction, or valvular disease.…”

Bilateral Vocal Cord Dysfunction in the Setting of Lateral Medullary Infarction: A Case Report and Review of Neuro-Anatomical Correlate

“…Even with medical and surgical management, the rate of complications in patients with bilateral vocal cord paresis is high, especially pulmonary complications. A high index of suspicion of vocal cord dysfunction is advised when patients with stroke present with wheezing and dysphonia the latter being a reliable sign of vocal cord dysfunction, and an important clinical feature in the aspiration mechanism [11,12,18,19].…”

“…However, very few cases of bilateral vocal cord dysfunction related to stroke have been described [11][12][13][14], and only two were in the setting of unilateral Wallenberg's syndrome (LMS), leading to upper airway obstruction [9,12,13,[15][16][17].…”

Prevention of Cardioembolic Stroke

“…However, reports of migratory cardioembolic events that occlude penetrating vessel ostia are reported, but their involvement is typically greater than 1 cm in parenchymal size. Cardioembolic stroke affecting the posterior circulation accounts for ≤25% of posterior circulation ischemic events in some registries [18][19][20][21][22][23][24][25][26].…”