Vascular Neurology Board Review: An Essential Study Guide

This book provides a concise review for practitioners in preparation for the Vascular Neurology Boards including the Maintenance of Certification exam. This valuable second edition is expertly written and supplemented with new treatment paradigms as well as new and updated trial results.. 

Beginning with a general overview on how to prepare for the exam, this practical guide emphasizes clinically relevant scientific principles that must be mastered by the stroke clinician. Subsequent chapters review acute management of ischemic and hemorrhagic stroke, specific epidemiological risk factors, stroke pathophysiology, stroke classification, and vascular neuroanatomy. This edition also reviews cardiac and hematological considerations in stroke patients, genetic stroke syndromes, vascular malformations, cognitive disorders, stroke rehabilitation, and peri-operative stroke management. 

Vascular Neurology Board Review, Second Edition, is not only written to act as a guide for the neurology resident and fellow, but also as a useful framework for non-neurologists.

• Language: English
• Publisher: Springer
• Release date: Sep 29, 2020
• ISBN: 9783030525521

Book preview

© Springer Nature Switzerland AG 2020

H. P. Amin, J. L. Schindler (eds.)Vascular Neurology Board Reviewhttps://doi.org/10.1007/978-3-030-52552-1_1

1. How to Prepare for the Exam

Hardik P. Amin¹  and Joseph L. Schindler²

(1)

Medical Stroke Director, Assistant Professor of Neurology, Yale University School of Medicine Yale-New Haven Hospital, St. Raphael Campus, New Haven, CT, USA

(2)

Clinical Chief Division of Vascular Neurology, Director of Yale New Haven Comprehensive Stroke Center, Associate Professor of Neurology and Neurosurgery, Yale University School of Medicine, Yale-New Haven Hospital, New Haven, CT, USA

Introduction

Hello, and welcome to Vascular Neurology Board review. The Vascular Neurology Boards are offered every 2 years (2016, 2018, 2020, etc). It is highly recommended that you take them the first year they are offered after you complete your fellowship. Before we get into review material, we have broken down the key elements of the exam itself. In this chapter, we offer an outlined plan that covers registration, preparation, and day of exam tips. We hope you find it useful!

Registering for the Exam

Visit the American Board of Psychiatry and Neurology (ABPN) website at http://​www.​abpn.​com/​ as information may change. Follow the links for board certification and take a subspecialty exam. Under vascular neurology, you will find key information about examination dates, application fees, and deadlines. Do this at the start of your fellowship to avoid late surprises!

Activate an ABPN account.

You must have passed certified by the board in neurology or neurology with special qualification in child neurology by December 31 of the year prior to sitting for the Vascular Neurology boards.

You must have completed all training and licensing requirements in an ACGME-accredited fellowship by July 31st of the year of your examination.

Get your medical license.

Application and registration:

Application fee ($700 for 2018) is separate from the examination fee ($1200 for 2018).

Applications are usually available towards the beginning of the year.

Submit the application early (typically by March of the year you plan to take the exam) to get your first choice of testing centers and to avoid a late application fee ($500 in 2018!).

The examination is offered every 2 years (2016, 2018, 2020, etc.), and is typically in the late summer or fall.

You must choose one out of 5 days provided to sit for the exam.

If you must withdraw from the examination, you must notify the ABPN at least 2 months prior to the first examination date to get your examination fee refunded (application fees are not refunded).

If you cannot sit for the exam on the scheduled day, you must contact Pearson VUE at least 24 hours prior to your scheduled day to reschedule. You may be required to pay a $200 seating fee.

If you cannot sit for the exam due to an unforeseen medical or other emergency, submit a personal statement and supporting documentation to the Board office no later than 30 days after the date of examination.

Day of Exam

Get plenty of sleep the night before!

Bring two forms of ID, including one form of government-issued photo ID (driver’s license, military ID, passport, state ID).

Bring water and snacks for your breaks (no gum!)

Exam Format

The exam consists of 200 multiple-choice questions, broken up into four sections.

The total time allotted is 4 hours, which includes 10 minutes for the non-disclosure agreement, instructions, and end of exam survey (rounds out to about 69 seconds per question, not including breaks).

Breaks: optional breaks are offered between each section, but the examination time will continue to run. Manage your breaks carefully!

Scoring is based on total percent correct, and there is no penalty for guessing. Don’t leave any question blank!

Recent test composition was as follows (Table 1-1) (refer to the ABPN website for more detailed breakdown):

Table 1-1

2020 Content blueprint

Preparing for the Test

Believe it or not, you will absorb a significant amount of information during your fellowship! During fellowship, become well versed in the treatment guidelines for acute treatment as well as primary and secondary prevention for both ischemic and hemorrhagic stroke.

Know the clinical evaluation (history and physical) and how the findings affect management.

While the exam may not test you on specific trial data, we have included Notable Trials in this book to enrich the study material.

Be prepared to interpret MRI , MRA, CT, CTA, perfusion, basic carotid ultrasound and transcranial doppler, and diagnostic angiography images.

Additional books that may help in preparation (not required or sufficient in isolation):

Futrell, Vascular Neurology: Questions and Answers

Victor and Adams, Textbook of Neurology

Continuum Reviews

Caplan, Uncommon Causes of Stroke

Adams, Handbook of Cerebrovascular Diseases

Maintenance of Certification (MOC) Fellowship Waiver

A 3-year block of C-MOC requirements (CME, SA, and PIP) will be waived for diplomates who graduated from an ACGME-accredited subspecialty fellowship training program in 2011 or later and who pass the corresponding ABPN subspecialty exam.

You still have to pay the annual fees.

Contact [e-mail] for more details.

MOC Examination

Refer to Table 1-2 for exam breakdown

10-Year MOC Program: For diplomates who passed a certification or MOC exam prior to 2012, and are due for recertification in 2019–2021

Maintain full unrestricted license.

Complete 300 Self-Assessment (SA) CME credits prior to applying for exam.

One Improvement in Medical Practice (PIP) Unit.

Pass an MOC exam every 10 years.

C-MOC Program: For diplomates who passed a certification or MOC exam in 2012 or later.

Maintain full unrestricted license.

Complete the following MOC activities for each 3-year block in the ABPN Folios account.

90 Category 1 CME credits (includes SA CME)

24 Self-Assessment (SA) CME credits

One Patient Safety Activity (required for first C-MOC block)

One Improvement in Medical Practice (PIP) Unit.

Pay the annual fee.

Pass an MOC exam every 10 years.

Refer to the ABPN website for further details: https://​www.​abpn.​com/​maintain-certification/​

Table 1‑2

2020 MOC exam content blueprint

© Springer Nature Switzerland AG 2020

H. P. Amin, J. L. Schindler (eds.)Vascular Neurology Board Reviewhttps://doi.org/10.1007/978-3-030-52552-1_2

2. Initial Stroke Evaluation

Hardik P. Amin¹  and Joseph L. Schindler²

(1)

Medical Stroke Director, Assistant Professor of Neurology, Yale University School of Medicine Yale-New Haven Hospital, St. Raphael Campus, New Haven, CT, USA

(2)

Clinical Chief Division of Vascular Neurology, Director of Yale New Haven Comprehensive Stroke Center, Associate Professor of Neurology and Neurosurgery, Yale University School of Medicine, Yale-New Haven Hospital, New Haven, CT, USA

Abbreviations

AF

Atrial fibrillation

BP

Blood pressure

CAD

Coronary artery disease

CT

Computed tomography

DM

Diabetes mellitus

EKG

Electrocardiogram

EMS

Emergency medical services

HTN

Hypertension

INR

International normalized ratio

MI

Myocardial infarction

MRI

Magnetic resonance imaging

OSA

Obstructive sleep apnea

PT

Prothrombin time

PTT

Partial thromboplastin time

PVD

Peripheral vascular disease

tPA

Tissue plasminogen activator

Introduction

The acute stroke evaluation can be stressful. When a patient arrives at an Emergency Department, they will be surrounded by EMS, nurses, techs, emergency physicians, and students. As a stroke neurologist, it is your job to phase out the noise and focus on the patient. It is important to remember that your job is to perform a very systematic evaluation requiring only an abbreviated history and physical examination. Your next task is to rule out intra-cerebral hemorrhage with CT scan and, if suspected, to determine if the patient has a large vessel occlusion. You will ultimately determine if the patient is a candidate for intravenous thrombolysis and/or thrombectomy. Your evaluation must be done efficiently to provide timely assessment and treatment.

Expedited History and Physical (in the Emergency Department)

Chief Complaint (Obtained from the Patient, Family, or EMS)

Common focal neurological symptoms: acute onset of face/arm/leg weakness, slurred speech, word finding difficulty, non-sensical speech, transient monocular vision loss, homonymous hemianopia, diplopia, gaze palsy, hemi-sensory loss, dysmetria, or ataxia

Non-focal symptoms: headache, vertigo, sleepiness, lethargy, nausea, vomiting

History of Presenting Illness

Exact time of symptom onset.

If time of symptom onset unknown, try to obtain the time the patient was last known to be at their neurological baseline.

If a patient has symptoms when they wake from sleep, their last seen normal time, is considered to be the time they went to sleep.

Description of symptom onset (sudden and maximal at onset versus gradual and progressive), static or fluctuating, singular event versus multiple events.

Past Medical History

Known risk factors for stroke: HTN , DM , AF , smoking , prior ischemic or hemorrhagic stroke, CAD, MI , PVD, obesity , OSA

Other risk factors: drug use, trauma, recent surgery, malignancy

Baseline level of function: cognition, ambulation, level of independence

Dominant hand

Medications

Anticoagulants

Anti-platelet agents: aspirin and clopidogrel (do not affect decision to administer tPA).

Other relevant medications: anti-hypertensives , statins , anti-seizure drugs.

Family History

Family history of stroke is particularly important if patient is young.

History of heart disease, DM , malignancy.

Social History

Smoking , alcohol , drug use (cocaine and amphetamines in particular)

Job, family situation

Driving status

Allergies

Specifically to gadolinium or iodinated contrast dye, shellfish

Review of Systems

Neurologic, cardiac, hematologic, immunologic, musculoskeletal, psychiatric, pulmonary, gastrointestinal

Physical Examination

Temperature, blood pressure, heart rate

Elevated BP is common in both ischemic and hemorrhagic stroke.

Low BP + focal deficits should raise concern for aortic dissection , MI , cardiogenic, or septic shock

Irregular heart rate should raise suspicion for atrial fibrillation

Initial neurological examination is the National Institutes of Health Stroke Scale (NIHSS) (Fig. 2-1).

Initially developed as a research tool.

Cortical symptoms such as gaze palsy and aphasia , or score >7 have a higher likelihood of large vessel occlusion.

Left hemispheric strokes tend to score higher than strokes in the right hemisphere of same size, or in the posterior circulation (due to weight of aphasia on score).

Patients with impaired mental status with abnormal speech may be encephalopathic, whereas alert patients with abnormal speech are more likely to have stroke.

HINTS exam: bedside maneuver to help distinguish central versus peripheral causes of vertigo. Highly sensitive for posterior circulation stroke.

Head impulse test: positive/abnormal test (presence of corrective saccades) suggests a peripheral process, whereas a negative/normal test (no corrective saccades) should raise suspicion for a central lesion.

Nystagmus: bidirectional nystagmus suggests central lesion.

Skew deviation: presence suggests central lesion.

Cardiac and pulmonary auscultation.

EKG.

Weight in kilograms (needed to determine dose of IV tPA).

../images/330798_2_En_2_Chapter/330798_2_En_2_Fig1_HTML.png

Figure 2-1

National Institutes of Health Stroke Scale (NIHSS )

Laboratory Studies

Guidelines suggest the only laboratory test absolutely required before treatment with IV recombinant tissue plasminogen activator is a finger-stick blood glucose, unless the patient is on anticoagulation or has known hematologic abnormalities.

Complete blood count (hematocrit, hemoglobin, platelets, white blood cell count).

Basic metabolic panel (including creatinine).

Cardiac enzymes (troponin, CK-MB).

Coagulation panel (PT, PTT, INR).

Critical if patient is prescribed anticoagulants

Imaging

Non-contrast head CT : rule out intracerebral hemorrhage, mass lesion, or subacute stroke (i.e., signs of ischemia to suggest stroke is >4.5 hours old), identify hyperdense vessel. The only mandatory imaging needed for treatment with tPA. A hyperdense vessel can also confirm large vessel occlusion if CTA not available.

CT angiogram of the head and neck: iodinated contrast study to evaluate vasculature for critical stenosis, occlusion, dissection

CTPerfusion : may be performed in cases of suspected/confirmed large vessel occlusions to identify the presence of penumbra , determine suitability of thrombectomy

MRI brain: may be performed acutely for diagnostic uncertainty

Likely to introduce significant delay in treatment

MRI not required to give IV tPA

Chest X-ray

Management

Discussed in greater depth later in the book

Circulation, airway, breathing

Ischemic Stroke: decision to treat

IV tPA : inclusion/exclusion criteria discussed later

Thrombectomy in select patients

Hemorrhagic stroke

BP control

Reversal of coagulopathy

Consider admission to Intensive Care Unit

Neurosurgical consultation

Hyperosmotic therapy

Admission to Neurological Intensive Care Unit or Telemetry unit with frequent neuro-check capability for further workup and management

Situations that may require ICU monitoring:

Post tPA and/or endovascular therapy

Fixed occlusion with increased risk of neurological decline

Massive infarct

Intracerebral hemorrhage

Fluctuating exam, progressive, or worsening symptoms

© Springer Nature Switzerland AG 2020

H. P. Amin, J. L. Schindler (eds.)Vascular Neurology Board Reviewhttps://doi.org/10.1007/978-3-030-52552-1_3

3. Vascular Neuroanatomy

Hardik P. Amin¹  and Joseph L. Schindler²

(1)

Medical Stroke Director, Assistant Professor of Neurology, Yale University School of Medicine, Yale-New Haven Hospital, St. Raphael Campus, New Haven, CT, USA

(2)

Clinical Chief Division of Vascular Neurology, Director of Yale New Haven Comprehensive Stroke Center, Associate Professor of Neurology and Neurosurgery, Yale University School of Medicine, Yale-New Haven Hospital, New Haven, CT, USA

Abbreviations

ACA

Anterior cerebral artery

ACOMM

Anterior communicating artery

AICA

Anterior inferior cerebellar artery

ATP

Adenosine triphosphate

BBB

Blood-brain barrier

cAMP

Cyclic adenosine monophosphate

CCA

Common carotid artery

CNS

Central nervous system

CO2

Carbon dioxide

CSF

Cerebrospinal fluid

DWI

Diffusion-weighted imaging

ECA

External carotid artery

HIF

Hypoxia inducible factor

ICA

Internal carotid artery

ILGF

Insulin-like growth factor

LDL

Low density lipoprotein

LGN

Lateral geniculate nucleus

MCA

Middle cerebral artery

MRA

Magnetic resonance angiography

NO

Nitric oxide

NOS

Nitric oxide synthetase

PCA

Posterior cerebral artery

PCOMM

Posterior communicating artery

PICA

Posterior inferior cerebellar artery

RAH

Recurrent artery of Heubner

SAH

Subarachnoid hemorrhage

SCI

Spinal cord infarct

tPA

Tissue plasminogen activator

VEGF

Vascular endothelial growth factor

VEGF-A

Vascular endothelial growth factor A

Introduction

Knowledge of neuroanatomy is crucial for any neurologist, but it is particularly beneficial to the stroke neurologist for rapid localization. Predicting where the lesion is will help you hone in on specific areas on the head CT , which can help identify subtle findings. This chapter reviews the basics of neuroanatomy and the essential tools for the practitioner to effectively localize a patient’s symptoms and begin the diagnostic evaluation.

Blood-Brain Barrier

Blood-brain barrier : Diffusion barrier that regulates movement of nutrients and waste products between the CNS and peripheral circulatory system (Fig. 3-1).

Absent in the area postrema, hypophysis, pineal gland (circumventricular organs)— i.e., all organs that require significant amounts of cross-talk between the brain and peripheral blood to release molecules and hormones.

Disrupted with ischemic stroke and with vasogenic edema . This can be seen in contrast enhanced T1 imaging.

Structures

Endothelium .

Closest layer to the vessel lumen.

Single layer of cells without fenestrations, connected by tight junctions and adherens junctions .

Expand and contract in response to environmental conditions via actin stress fibers in cytoskeleton.

cAMP promotes relaxation of fibers.

Relaxation of actin stress fibers leads to endothelial cell expansion and tight junction compression, leading to reduced permeability through tight junctions .

Aggrenox causes increase in intracellular cAMP , i.e., vasodilation, which is the main reason for headaches.

VEGF and protein kinase C promote contraction of fibers.

Contraction of fibers leads to endothelial cell contraction and tight junction expansion, leading to increased permeability through tight junctions .

Produces anti-thrombotic and pro-thrombotic substances:

Anti-thrombotic substances: prostacyclin, nitric oxide, antithrombin III, endogenous tPA, and heparin -like molecules.

Nitric oxide: vasodilator produced by endothelium via nitric oxide synthetase (NOS) that can counteract factors that raise blood pressure

L-Arginine + NOS ➔ citrulline + NO

Pro-thrombotic substances: factor Va, factor VIII, tissue factor, plasminogen activation inhibitor.

Expressed when cells are exposed to injury, inflammation.

Atherosclerotic plaques overexpress plasminogen activator inhibitor-1 (main inhibitor of in vivo tPA ) and tissue factor.

Basement membrane.

Structural support for capillary and certain proteins

Tight junctions .

Specialized junctions between endothelial cells that limit passive diffusion (transcellular and paracellular movement) of blood solutes (oxygen, CO2, small lipophilic substances) across BBB

Confer high electrical resistance in BBB , facilitating retention of ions within the vascular lumen

Three integral membrane proteins: claudin, occludin, junction adhesion molecules

Zona occludens , cingulin: accessory proteins that link membrane proteins with cytoskeleton of endothelial cell

Multiple sclerosis, Alzheimer’s disease, stroke, seizures all associated with dysregulation of tight junction proteins

Adherens junctions .

Transmembrane proteins called cadherins

Catenin proteins: accessory proteins that link cadherins to actin cytoskeleton

Astrocytes .

Play a role in BBB development

Regulate water and ionic homeostasis in brain, may inactivate neurotransmitters, scavenge reactive oxygen species, uptake excess potassium

High number of K+ channels

Astrocyte end feet contain Aquaporin −4 water channels, affected in cytotoxic edema

Aquaporin-4 channels found in astrocyte endfeet facilitate water movement, and are the first cellular structures to promote swelling in cytotoxic edema

Molecular transport across BBB .

BBB allows free passage of oxygen, CO2, small lipophilic substances (i.e., no need for special transport receptors).

BBB is impermeable to glucose, amino acids (hydrophilic molecules), or larger molecules.

These must cross through transporters on apical or basolateral endothelial membrane.

Facilitated diffusion (carrier mediated transport): glucose, galactose, amino acids, nucleosides, purines, vitamins.

Substances move down a concentration gradient from blood to brain.

Receptor-mediated transport: for neuroactive proteins and peptides, chemokines, cytokines, and large proteins like transferring, LDL , insulin, ILGF

Active efflux transporters: apical and basolateral endothelium for removal of waste products

Ex ATP binding cassette transporter superfamily: use ATP

Endocytosis: for passage of lipophobic molecules

P-Glycoproteins: ATP-dependent proteins that limit BBB permeability to hydrophobic compounds (i.e., protect from drugs and neuro-toxins)

Neurovascular unit: A network of microstructures (neurons, astrocytes , pericytes) that interact with the cerebral vasculature and regulate of blood flow (Fig. 3-1)

../images/330798_2_En_3_Chapter/330798_2_En_3_Fig1_HTML.png

Figure 3-1

Blood-brain barrier and neurovascular unit

Vessel Formation and Structure

Vasculogenesis : de novo differentiation of mesodermal precursors into endothelial cells in a developing embryo that go on to form primitive vascular networks

Angiogenesis

Formation of new microvessels from existing primitive vascular networks or vessels through branching and budding

Neovascularization: induction of angiogenesis seen in tumor growth and metastasis

Occurs during tissue growth and repair

Controlled via positive and negative growth factors

Positive (stimulatory) growth factors

Vascular endothelial growth factor (VEGF):

VEGF-A: dominant growth factor in angiogenesis , stimulates endothelial mitogenesis, vascular permeability in normal and abnormal conditions (tumor)

Expression highly regulated by hypoxia via hypoxia-inducible transcription factors (HIFs)

HIFs: increase transcription of VEGF gene

Fibroblast growth factor: promotes endothelial cells proliferation and differentiation

Hepatocyte growth factors: regulate cell growth, motility, and morphogenesis

Insulin-like growth factors: mediate cell growth and differentiation

Negative (inhibitory) growth factors

Angiostatin: angiogenesis inhibitor

Endostatin: angiogenesis inhibitor

Vascular smooth muscle

Hypertrophy: increase in size of smooth muscle cells, promoted by angiotensin II, thrombin, and hypertension

Hyperplasia: cellular proliferation, promoted by vascular mechanical injury (i.e., restenosis after carotid endarterectomy ), inflammatory cytokines, platelet-derived growth factor, fibroblast growth factor

Arterial Structure (Fig. 3-2)

Endothelium

Single layer of cells lining the inner wall of arteries forming an interface between blood and tissue

Modulates tone, growth, hemostasis, and inflammation

Tunica Intima .

Endothelial cells, and lower concentration of smooth muscle cells

Frequently the site of arterial dissection origin

Tunica media

Mostly comprised of smooth muscle cells

Medial hyperplasia is the most common type of fibromuscular dysplasia

Tunica adventitia

Collagen, elastin, fibrinous tissue

Dysfunctional in scurvy (vitamin C is essential in collagen formation)

Tunica media and adventitia are much thinner in intracranial vessels than extracranial vessels, hence intracranial dissections may have higher risk of SAH .

../images/330798_2_En_3_Chapter/330798_2_En_3_Fig2_HTML.png

Figure 3-2

Arterial anatomy

Anterior Circulation Anatomy

Refer to Fig. 3-3 for anatomy and Fig. 3-5 for vascular supply.

Aorta

Main source of cerebral blood supply

Brachiocephalic (innominate) artery: most proximal branch off aortic arch

Bifurcates into right common carotid and right subclavian arteries

Right vertebral artery originates from right subclavian artery

Left common carotid artery : usually the second main vessel off aortic arch

Subclavian artery : Proximally to distally, give rise to vertebral artery , internal thoracic artery (travels inferiorly), thyrocervical trunk (travels superiorly), dorsal scapular artery, then becomes axillary artery

Variants

Bovine aortic arch: normal variant with shared origin of brachiocephalic artery and left CCA (occurs in about 20% of cases). Clinically asymptomatic but L CCA can be difficult to selectively catheterize in this setting

Direct left vertebral artery origin from the aortic arch (typically arising just proximal to the left subclavian), incidence 4%

Common carotid artery (CCA)

Travels within carotid sheath with internal jugular

Reviews for Vascular Neurology Board Review

[Robert Hamilton · Rating: 4 out of 5 stars]

This is a nice review of vascular neurology material. Overall, it encompasses much of the material that a fellow was likely exposed to during training but does not dive deep into the mechanisms or pathophysiology of disease/treatments. I found that this was a decent book for stimulating questions for review and I found myself looking up material in many journals to answer questions that arose. Typos run rampant through the text and are usually in regards to improper bullet point position that makes reading confusing at times when moving to related subjects.

For the boards, this book does fairly well in material prep but for clinical application and retention of data, it should not be used alone. I am pairing this with the vascular board review question & answer book.