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10.1 Acute Ischemic Stroke: Syndromes & Reperfusion
ABIM Internal Medicine Exam
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1 Chapter 0: The ABIM Exam, Blueprint & Study Strategy
0.1 Exam Format, Question Types & the 2026 Blueprint 0.2 Eligibility, Registration, Fees & Exam-Day Logistics 0.3 Scoring, the Passing Standard & Score Reports 0.4 Building a Blueprint-Weighted Study Plan
2 Chapter 1: Cardiovascular Disease (14% of Exam)
1.1 Ischemic Heart Disease & Acute Coronary Syndromes 1.2 Antithrombotic Therapy, Secondary Prevention & Mechanical Complications of MI 1.3 Atrial Fibrillation, Atrial Flutter & Stroke Prevention 1.4 Supraventricular Tachycardias, Ventricular Arrhythmias & Bradycardias 1.5 Heart Failure: Classification, Staging & Guideline-Directed Medical Therapy 1.6 Device Therapy, HFpEF & the Cardiomyopathies 1.7 Valvular Heart Disease & Endocarditis Prophylaxis 1.8 Pericardial Disease & Acute Aortic Syndromes 1.9 Hypertension: Classification, Diagnosis & Secondary Causes 1.10 Hypertensive Crises & Dyslipidemia 1.11 Adult Congenital Heart Disease & Coarctation of the Aorta 1.12 Syncope: Reflex, Orthostatic & Cardiac Causes 1.13 Cardiac Physical Examination, Murmurs & Antithrombotic Selection
3 Chapter 2: Endocrinology, Diabetes & Metabolism (9% of Exam)
2.1 Diabetes Mellitus: Diagnosis, Glycemic Targets & Pharmacotherapy 2.2 Insulin Therapy, Hyperglycemic Emergencies & Chronic Complications 2.3 Thyroid Function Testing & Hypothyroidism 2.4 Thyrotoxicosis, Thyroid Storm & Thyroid Nodules 2.5 Adrenal & Pituitary Disorders 2.6 Hypercalcemia, Hypocalcemia & Disorders of Mineral Metabolism 2.7 Osteoporosis & Paget Disease of Bone 2.8 Ovarian, Testicular & Reproductive Endocrine Disorders 2.9 Hypoglycemia, Endocrine Tumors, Polyglandular Syndromes & Severe Hypertriglyceridemia
4 Chapter 3: Gastroenterology & Hepatology (9% of Exam)
3.1 Esophageal Disease 3.2 Stomach & Duodenal Disease and Gastrointestinal Hemorrhage 3.3 Inflammatory Bowel Disease 3.4 Celiac Disease & Irritable Bowel Syndrome 3.5 Diverticular Disease & Colorectal Cancer Screening 3.6 Viral Hepatitis, Steatotic & Alcohol-Associated Liver Disease 3.7 Cirrhosis & the Complications of Portal Hypertension 3.8 Acute Pancreatitis 3.9 Chronic Pancreatitis & Biliary Tract Disease 3.10 Inherited, Autoimmune & Drug-Induced Liver Disease 3.11 Small Intestinal Disease, Ischemia & Gastrointestinal Complications of HIV
5 Chapter 4: Infectious Disease (9% of Exam)
4.1 Lower Respiratory Tract Infections & Sepsis Syndromes 4.2 Viral Respiratory Pathogens & Tuberculosis 4.3 Central Nervous System Infections 4.4 Skin, Soft Tissue, Bone & Joint Infections 4.5 Infective Endocarditis & Cardiovascular Infection 4.6 Clostridioides difficile & Catheter-Related Bloodstream Infection 4.7 HIV Diagnosis, Antiretroviral Therapy & Prevention 4.8 Opportunistic Infections & Sexually Transmitted Infections 4.9 Fever of Unknown Origin, Neutropenic Fever & Toxic Shock 4.10 Travel-Related Illness, Vector-Borne Disease & Outbreaks 4.11 Infection Prevention, Nosocomial Infection & Postexposure Prophylaxis 4.12 Rheumatic Fever, Poststreptococcal Disease, Enteric & Hepatic Infections
6 Chapter 5: Pulmonary Disease (9% of Exam)
5.1 COPD: Diagnosis, GOLD Classification & Initial Pharmacotherapy 5.2 Interventions That Reduce COPD Mortality & Exacerbation Management 5.3 Asthma: Diagnosis, Stepwise Therapy & Status Asthmaticus 5.4 Interstitial Lung Disease & Idiopathic Pulmonary Fibrosis 5.5 Sarcoidosis, Hypersensitivity Pneumonitis & Occupational Lung Disease 5.6 Pulmonary Embolism: Diagnosis, Risk Stratification & Anticoagulation 5.7 Pulmonary Hypertension & Sleep-Disordered Breathing 5.8 Acute Respiratory Distress Syndrome & Mechanical Ventilation 5.9 Pleural Disease, Empyema & Pneumothorax 5.10 Bronchiectasis, Cystic Fibrosis & Restrictive Lung Disease 5.11 Evaluation of Cough, Dyspnea, Hemoptysis & the Solitary Pulmonary Nodule
7 Chapter 6: Rheumatology & Orthopedics (9% of Exam)
6.1 Rheumatoid Arthritis: Diagnosis & Systemic Manifestations 6.2 Antirheumatic Pharmacotherapy & the Spondyloarthropathies 6.3 Gout: Pathophysiology & Acute Management 6.4 Urate-Lowering Therapy & Calcium Pyrophosphate Deposition Disease 6.5 Osteoarthritis 6.6 Systemic Lupus Erythematosus 6.7 Systemic Sclerosis, Sjogren Syndrome & Inflammatory Myopathies 6.8 The Vasculitides 6.9 Regional Musculoskeletal Syndromes, Back Pain & Sports Injuries 6.10 Other Primary Rheumatic Disorders & Mixed Connective Tissue Disease 6.11 Osteonecrosis & Metabolic Bone Disease
8 Chapter 7: Hematology (6% of Exam)
7.1 Approach to Anemia & the Microcytic Anemias 7.2 Macrocytic, Normocytic & Hemolytic Anemias 7.3 Hemoglobinopathies, Thalassemias & Paroxysmal Nocturnal Hemoglobinuria 7.4 Platelet Disorders, Thrombocytopenia & the Bleeding Patient 7.5 Coagulation Factor Disorders, Thrombophilia & Anticoagulant Reversal 7.6 Acute Leukemias, Chronic Leukemias & Myeloproliferative Neoplasms 7.7 Lymphomas & Plasma Cell Disorders 7.8 Myelodysplastic Syndrome, Myeloproliferative Neoplasms & Porphyria 7.9 Transfusion Medicine & Late Complications of Transplantation
9 Chapter 8: Medical Oncology (6% of Exam)
8.1 Breast, Lung, Colorectal & Prostate Cancer 8.2 Oncologic Emergencies 8.3 Genitourinary & Gynecologic Malignancies 8.4 Head and Neck, Bone & Soft Tissue Cancer and Cancer of Unknown Primary 8.5 Complications of Cancer & Its Treatment 8.6 Cancer Prevention, Survivorship & Psychosocial Care
10 Chapter 9: Nephrology & Urology (6% of Exam)
9.1 Acute Kidney Injury: Staging, Etiology & Urine Microscopy 9.2 Glomerular Disorders & Nephrotic Syndrome 9.3 Nephritic Syndromes, RPGN & Indications for Renal Replacement Therapy 9.4 Chronic Kidney Disease: Staging & Progression Retardation 9.5 Complications of Chronic Kidney Disease: Anemia, CKD-MBD & Acidosis 9.6 Hyponatremia, Hypernatremia & Water Balance 9.7 Potassium Disorders & Systematic Acid-Base Analysis 9.8 Renal Tubular Acidosis & Nephrolithiasis 9.9 Prostate Disorders, Urinary Incontinence & Other Urologic Conditions 9.10 Cystic Kidney Disease, Obstructive Uropathy, Tubulointerstitial Disease & Hematuria
11 Chapter 10: Neurology (4% of Exam)
10.1 Acute Ischemic Stroke: Syndromes & Reperfusion 10.2 Transient Ischemic Attack, Secondary Prevention & Hemorrhagic Stroke 10.3 Headache & Facial Pain 10.4 Seizures, Epilepsy & Movement Disorders 10.5 Multiple Sclerosis & Neuromuscular Junction Disorders 10.6 Motor Neuron Disease & Acute Peripheral Neuropathy 10.7 Cranial Neuropathies & Neuro-Ophthalmology 10.8 Peripheral Neuropathies, CNS Tumors & Other Neurologic Disorders
12 Chapter 11: Psychiatry & Behavioral Health (4% of Exam)
11.1 Major Depressive Disorder & Medical Mimics 11.2 Antidepressant Pharmacotherapy & Treatment-Resistant Depression 11.3 Bipolar Disorder, Mood Stabilizers & Lithium Toxicity 11.4 Anxiety, Stress-Related & Obsessive-Compulsive Disorders 11.5 Alcohol Use Disorder & Withdrawal 11.6 Pharmacotherapy for Alcohol & Opioid Use Disorder 11.7 Toxidromes, Psychiatric Emergencies & Suicide Risk Assessment 11.8 Psychotic, Somatic Symptom, Factitious & Personality Disorders 11.9 Eating Disorders, Sleep Disorders & Sexual Health
13 Chapter 12: Dermatology (3% of Exam)
12.1 Dermatitis, Papulosquamous & Inflammatory Dermatoses 12.2 Acne, Rosacea & Cutaneous Infections 12.3 Herpes Zoster & Autoimmune Blistering Diseases 12.4 Nodules, Tumors & Cutaneous Oncology 12.5 Dermatologic Emergencies & Severe Cutaneous Adverse Reactions 12.6 Pigment Disorders, Alopecia, Nail Disease & Photosensitivity 12.7 Vascular Dermatoses, Environmental Injury & Cutaneous Signs of Systemic Disease
14 Chapter 13: Obstetrics & Gynecology / Women's Health (3% of Exam)
13.1 Contraception, Preconception Care & Teratogenicity 13.2 Hypertensive Disorders of Pregnancy & Gestational Diabetes 13.3 Thyroid Disease & Venous Thromboembolism in Pregnancy 13.4 Menopause & Menopausal Hormone Therapy 13.5 Abnormal Uterine Bleeding, Endometrial Disease & Gynecologic Cancer Screening 13.6 Breast Disorders & Diseases of the Vulva and Vagina 13.7 Menstrual Disorders, Fibroids, Endometriosis & Early Pregnancy Complications
15 Chapter 14: Geriatric Syndromes (3% of Exam)
14.1 Comprehensive Geriatric Assessment & Frailty 14.2 Falls, Gait Assessment & Polypharmacy 14.3 Urinary Incontinence & Pressure Injuries in Older Adults 14.4 Mild Cognitive Impairment, Dementia & Its Subtypes 14.5 Delirium & the Pharmacotherapy of Cognitive Disorders 14.6 Palliative Care, Hospice & Advance Care Planning 14.7 Chronic Wounds, Nutrition, Swallowing, Constipation & Hip Fracture 14.8 Sensory Impairment, Dizziness, Elder Mistreatment & Care Settings
16 Chapter 15: Allergy & Immunology (2% of Exam)
15.1 Anaphylaxis: Recognition & Emergency Management 15.2 Urticaria & Angioedema 15.3 Drug Allergy, Desensitization & Adult Immunodeficiency 15.4 Food Allergy, Insect Venom Hypersensitivity, Serum Sickness & Contrast Reactions 15.5 Rhinitis, Conjunctivitis, Eosinophilic & Mast Cell Disorders
17 Chapter 16: Preventive Medicine, Immunization & Clinical Epidemiology
16.1 The USPSTF Framework & Evidence-Based Cancer Screening 16.2 Cardiovascular & Metabolic Screening and Primary Prevention 16.3 Adult Immunization & Vaccines in Special Populations 16.4 Clinical Epidemiology, Biostatistics & Study Design
18 Chapter 17: Miscellaneous - Ethics, Patient Safety & Quality Improvement (2% of Exam)
17.1 Principles of Bioethics & Decisional Capacity 17.2 Informed Consent, Treatment Refusal & Special Scenarios 17.3 Surrogate Decision-Making, Advance Directives & Confidentiality 17.4 Patient Safety Science, Medical Error & Diagnostic Reasoning 17.5 Quality Improvement Methods, Health Disparities & Health Equity
19 Chapter 18: Perioperative Medicine & Medical Consultation
18.1 Preoperative Cardiovascular Risk Assessment 18.2 Preoperative Pulmonary Risk & Perioperative Medication Management 18.3 Perioperative Anticoagulation, Bridging & Postoperative Complications
20 Chapter 19: Ophthalmology (1% of Exam)
19.1 The Acute Red Eye & Ophthalmic Emergencies 19.2 Painless Vision Loss & Chronic Ophthalmic Disease 19.3 Uveitis, Scleritis & Orbital Disease
21 Chapter 20: Otolaryngology & Dental Medicine (1% of Exam)
20.1 Dizziness, Vertigo & Epistaxis 20.2 Ear Disorders, Hearing Loss & Upper Respiratory Infections 20.3 Oral Cavity, Salivary Gland, Laryngeal & Taste and Smell Disorders
10.1 Acute Ischemic Stroke: Syndromes & Reperfusion
Key Takeaways Explain This Topic AI
Transient ischemic attack, stroke, cavernous sinus thrombosis and other cerebrovascular disease are the enumerated topics.
Non-contrast head computed tomography is obtained first to exclude hemorrhage before any reperfusion therapy.
Intravenous thrombolysis is given within the guideline window measured from last known well, not from symptom discovery.
Blood pressure must be below the guideline threshold before thrombolysis, and is otherwise permitted to remain elevated in acute ischemic stroke.
Mechanical thrombectomy for large vessel occlusion extends the treatment window well beyond the thrombolysis window when perfusion imaging shows salvageable tissue.
Last updated: August 2026
Cerebrovascular diseases represent the leading cause of adult disability and the fifth leading cause of mortality in the United States. For the ABIM Internal Medicine examination, clinicians must demonstrate mastery of vascular neuroanatomy, rapid triage and contraindications for reperfusion therapies (intravenous thrombolysis and endovascular mechanical thrombectomy), acute blood pressure targets, anticoagulant reversal in hemorrhagic stroke, and the recognition and prevention of secondary neurovascular complications.
1. Acute Ischemic Stroke (AIS): Vascular Territories & Clinical Syndromes
Acute ischemic stroke results from focal cerebral hypoperfusion secondary to arterial thromboembolism or in situ thrombosis. Accurate localization based on bedside neurological examination is critical for guiding emergent vessel imaging and endovascular interventions.
Cerebral Vascular Territories
Vascular Territory Culprit Vessel & Anatomical Structures Involved Key Clinical Features & Deficits Examination Pearls & Contrasts
Middle Cerebral Artery (MCA) - Total / Stem Mainstem (M1 segment) supplying primary motor/sensory cortices, internal capsule, basal ganglia Contralateral hemiplegia (face and upper extremity > lower extremity), contralateral hemianesthesia , contralateral homonymous hemianopia , conjugate eye deviation toward the side of the lesion Global aphasia if dominant; profound spatial hemineglect and anosognosia if non-dominant
MCA - Superior Division Lateral frontal lobe (Broca area, motor cortex) Contralateral face and arm weakness > leg; Broca expressive (non-fluent) aphasia (intact comprehension, impaired repetition and fluency) Patients exhibit severe frustration due to preserved insight
MCA - Inferior Division Superior temporal and inferior parietal lobes (Wernicke area) Contralateral superior quadrantanopia ("pie in the sky"); Wernicke receptive (fluent) aphasia (impaired comprehension and repetition, fluent but paraphasic / "word salad" speech) Patients are unaware of their language deficit (anosognosic speech)
Anterior Cerebral Artery (ACA) Medial frontal and parietal cortices, corpus callosum Contralateral lower extremity weakness and sensory loss (leg > arm/face); abulia (profound apathy, psychomotor slowing); urinary incontinence; primitive frontal release reflexes (grasp, snout, palmomental) Transcortical motor aphasia if dominant frontal lobe involved; preserved arm and facial strength
Posterior Cerebral Artery (PCA) Occipital lobe, medial temporal lobe, posterior thalamus, splenium of corpus callosum Contralateral homonymous hemianopia with macular sparing (collateral blood supply to occipital pole from MCA); visual agnosia ; prosopagnosia (inability to recognize familiar faces) Alexia without agraphia (inability to read with intact ability to write) occurs with dominant occipital cortex + splenium infarction; Dejerine-Roussy syndrome (delayed severe central thalamic pain)
Vertebrobasilar - Cerebellar Posterior Inferior Cerebellar Artery (PICA), Anterior Inferior Cerebellar Artery (AICA), Superior Cerebellar Artery (SCA) Ipsilateral limb ataxia , dysmetria, intention tremor, vertigo, spontaneous nystagmus, nausea/vomiting, truncal ataxia Risk of acute cerebellar edema causing obstructive hydrocephalus and brainstem herniation
Vertebrobasilar - Lateral Medullary (Wallenberg) PICA or intracranial Vertebral Artery Crossed sensory deficits : Ipsilateral facial loss of pain/temperature (spinal trigeminal nucleus) + Contralateral body loss of pain/temperature (spinothalamic tract); Ipsilateral Horner syndrome (ptosis, miosis, anhidrosis); ipsilateral ataxia; dysphagia, hoarseness, impaired gag reflex (nucleus ambiguus - CN IX, X) Spares motor strength (corticospinal tract is located in the medial medulla)
Vertebrobasilar - Basilar Artery Trunk Basilar artery thrombosis / occlusion "Locked-in" syndrome : Infarction of the ventral pons causing quadriplegia, bilateral facial palsy, and horizontal gaze palsy; consciousness, cognition, and vertical eye movements / blinking are fully preserved (reticular activating system and midbrain tectum spared) Frequently misdiagnosed as coma; examine voluntary vertical eye movements and eye opening on command
Loading diagram... Emergency Evaluation and Reperfusion Decision Algorithm in Acute Ischemic Stroke
2. Emergency Evaluation & Reperfusion Therapies in Acute Ischemic Stroke
Time is brain: approximately 1.9 million neurons are lost every minute during untreated large-vessel ischemic stroke. Emergent care focuses on exclusion of hemorrhage, blood glucose correction, rapid initiation of intravenous thrombolytic therapy, and immediate triage for mechanical thrombectomy.
Initial Diagnostic Workup
Point-of-Care Blood Glucose: Must be performed immediately upon arrival. Hypoglycemia (<60 mg/dL [3.3 mmol/L]) is a frequent stroke mimic that can cause focal hemiparesis and aphasia; treat rapidly with IV 50% Dextrose (D50W).
Non-Contrast Head CT: The primary purpose is to rule out acute intracranial hemorrhage (ICH). It also detects early ischemic signs such as hyperdense MCA sign, loss of the insular ribbon, cortical sulcal effacement, and loss of gray-white matter differentiation. The ASPECTS (Alberta Stroke Program Early CT Score) evaluates 10 regions of the MCA territory; a score >=6 indicates a favorable small core appropriate for intervention.
NIH Stroke Scale (NIHSS): A validated 11-item quantitative assessment (scores 0-42) of stroke severity: 0 = no stroke; 1-4 = minor stroke; 5-15 = moderate stroke; 16-20 = moderate-to-severe stroke; 21-42 = severe stroke.
Intravenous Thrombolytic Therapy
Pharmacological Agents:
Tenecteplase (TNK-tPA): 0.25 mg/kg IV single bolus over 5-10 seconds (maximum 25 mg). Preferred over alteplase in many stroke centers due to single-bolus convenience, higher fibrin specificity, and non-inferior (or superior) reperfusion rates.
Alteplase (rt-PA): 0.9 mg/kg IV (maximum 90 mg); 10% administered as an initial IV bolus over 1 minute, followed by the remaining 90% infused continuously over 60 minutes.
Treatment Windows:
Standard Window (<=3.0 hours from Last Known Normal [LKN]): Indicated for all eligible patients without contraindications.
Extended Window (3.0 to 4.5 hours from LKN): Supported by the ECASS-III trial. Additional relative exclusions in the 3.0-4.5 hour window include: age >80 years, baseline NIHSS >25, combination of prior stroke and diabetes mellitus, or any oral anticoagulant use regardless of INR.
Blood Pressure Management Surrounding Thrombolysis:
Pre-Thrombolysis Threshold: Systolic BP must be < 185 mmHg and diastolic BP must be < 110 mmHg BEFORE initiating thrombolytic infusion.
Post-Thrombolysis Threshold: Maintain BP < 180/105 mmHg for at least 24 hours following thrombolytic administration.
First-Line IV Antihypertensives:
Labetalol: 10 to 20 mg IV over 1-2 minutes; may repeat or double every 10-20 minutes up to a maximum cumulative dose of 300 mg, or infuse 2-8 mg/min.
Nicardipine: IV infusion starting at 5 mg/h, titrated by 2.5 mg/h every 5-15 minutes to a maximum of 15 mg/h.
Clevidipine: IV infusion starting at 1-2 mg/h, titrated by doubling every 2-5 minutes (maximum 21 mg/h).
Absolute Contraindications to Intravenous Thrombolysis:
Evidence of intracranial hemorrhage on pretreatment non-contrast head CT.
Clinical presentation suspicious for subarachnoid hemorrhage even with normal head CT.
Prior history of intracranial hemorrhage, intracranial neoplasm, arteriovenous malformation (AVM), or intracranial aneurysm.
Significant head trauma or acute ischemic stroke within the preceding 3 months.
Gastrointestinal malignancy or active gastrointestinal bleeding within the preceding 21 days.
Major intracranial or intraspinal surgery within the preceding 3 months.
Persistent severe hypertension (SBP >=185 mmHg or DBP >=110 mmHg) refractory to emergent aggressive antihypertensive therapy.
Active therapeutic anticoagulation: Use of therapeutic Direct Oral Anticoagulants (DOACs: apixaban, rivaroxaban, dabigatran) within 48 hours (unless specific reversal agents are administered or calibrated anti-Xa/thrombin time assays are normal); therapeutic Low-Molecular-Weight Heparin (LMWH) within 24 hours; or Unfractionated Heparin (UFH) within 48 hours with elevated aPTT.
Coagulopathy: Platelet count < 100,000/mcL ; International Normalized Ratio (INR) > 1.7 ; Prothrombin Time (PT) > 15 seconds ; or aPTT > 40 seconds .
Endovascular Mechanical Thrombectomy (EVT)
Mechanical thrombectomy with stent retrievers and direct aspiration catheters has revolutionized the management of acute ischemic stroke caused by Large Vessel Occlusion (LVO) in the anterior circulation (intracranial Internal Carotid Artery [ICA] and Middle Cerebral Artery M1 segment) and basilar artery.
Standard Window (<=6 Hours from LKN): Indicated for patients with: (1) Pre-stroke modified Rankin Scale (mRS) 0-1; (2) Causative LVO of the ICA or MCA M1 segment; (3) Age >=18 years; (4) NIHSS >=6; (5) ASPECTS score >=6. Note: Eligible patients should receive IV thrombolysis while being prepared for EVT without delaying groin puncture.
Extended Window (6 to 24 Hours from LKN): Indicated in carefully selected patients with anterior circulation LVO who meet strict physiological mismatch criteria demonstrated by CT perfusion (CTP) or diffusion-weighted MRI (DWI):
DAWN Trial Criteria (6-24h): Disproportionate clinical deficit (NIHSS) relative to small ischemic core volume (e.g., age >=80 with NIHSS >=10 and core <21 mL; or age <80 with NIHSS >=20 and core <51 mL).
DEFUSE 3 Trial Criteria (6-16h): Initial ischemic core volume <70 mL, mismatch ratio (penumbra to core) >=1.8, and absolute penumbral volume >=15 mL.