Study guide
18.1 Cerebral Venous Sinus Thrombosis, PRES & Reversible Cerebral Vasoconstriction Syndrome
ABIM Critical Care Medicine Study Guide Exam
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1 Chapter 1: Exam Orientation: Format, Blueprint & Study Strategy
1.1 ABIM Critical Care Medicine Exam: Format, Blueprint & Study Strategy
2 Chapter 2: Acute Respiratory Failure & ARDS
2.1 ARDS Definition, Pathophysiology & Phenotypes 2.2 Lung-Protective Mechanical Ventilation 2.3 Refractory ARDS: Prone Positioning, Neuromuscular Blockade & VV-ECMO
3 Chapter 3: Obstructive Airways, Pulmonary Vascular & Pleural Emergencies
3.1 Severe Asthma & COPD Exacerbations in the ICU 3.2 Massive & Submassive Pulmonary Embolism 3.3 Pulmonary Hypertension & Right Ventricular Failure in the ICU 3.4 Massive Hemoptysis, Complex Pleural Effusions & Thoracic Drainage
4 Chapter 4: Airway, Parenchymal & Nonthrombotic Pulmonary Emergencies
4.1 Airway Management, Upper-Airway Obstruction & Artificial-Airway Complications 4.2 Diffuse Alveolar Hemorrhage, Interstitial Lung Disease, Pulmonary Vasculitis & Noncardiogenic Edema 4.3 Severe Community-Acquired & Viral Pneumonia 4.4 Nonthrombotic Embolism (Air, Fat, Amniotic Fluid, Tumor, Septic) & Acute Chest Syndrome
5 Chapter 5: Mechanical Ventilation Modes, Dyssynchrony & Liberation
5.1 Mechanical Ventilator Modes & Advanced Breath Delivery 5.2 Patient-Ventilator Dyssynchrony & Waveform Analysis 5.3 Ventilator Liberation, Spontaneous Breathing Trials & Post-Extubation Support
6 Chapter 6: Shock Syndromes & Hemodynamic Principles
6.1 Shock Classification, Cellular Pathophysiology & Biomarkers 6.2 Hemodynamic Monitoring: Arterial Lines, CVP & Pulmonary Artery Catheter 6.3 Dynamic Assessment of Fluid Responsiveness & Resuscitation Targets
7 Chapter 7: Vasoactive Therapies & Mechanical Circulatory Support
7.1 Vasopressors & Inotropes: Pharmacology & Clinical Titration 7.2 Temporary Mechanical Circulatory Support: IABP, Impella & TandemHeart 7.3 Venoarterial ECMO (VA-ECMO) & Differential Hypoxemia 7.4 Post-Cardiac Arrest Care, Targeted Temperature Management & Neuroprognostication
8 Chapter 8: Acute Kidney Injury & Renal Replacement Therapy
8.1 KDIGO AKI Classification, Etiologies & Diagnostic Evaluation 8.2 Continuous Renal Replacement Therapy (CRRT) vs Intermittent Hemodialysis 8.3 Indications & Timing for RRT in Critical Illness: AKIKI & STARRT-AKI
9 Chapter 9: Electrolyte, Acid-Base & Endocrine Emergencies
9.1 Severe Dysnatremias: Hyponatremia, Hypernatremia & Osmotic Demyelination 9.2 Potassium, Calcium, Magnesium & Phosphate Disorders 9.3 Complex & Mixed Acid-Base Disorders: Boston vs Copenhagen vs Stewart 9.4 Endocrine Crises: DKA, HHS, Thyroid Storm, Myxedema Coma & Adrenal Crisis
10 Chapter 10: Glycemic Control, Hyperammonemia, Pituitary & Adrenal Disorders
10.1 ICU Glycemic Control & Severe Hypoglycemia 10.2 Non-Hepatic Hyperammonemia & Metabolic Encephalopathy 10.3 Pituitary Emergencies, Adrenal Excess & Critical Illness-Related Corticosteroid Insufficiency
11 Chapter 11: Acute Coronary Syndromes & Cardiac Arrhythmias
11.1 Acute Coronary Syndromes & Mechanical Complications of Myocardial Infarction 11.2 Critical Tachyarrhythmias: Atrial Fibrillation with RVR, VT & VF 11.3 Critical Bradyarrhythmias, Conduction Blocks & Temporary Cardiac Pacing
12 Chapter 12: Acute Heart Failure, Valvular & Pericardial Emergencies
12.1 Acute Decompensated Heart Failure & Cardiogenic Pulmonary Edema 12.2 Acute Valvular Regurgitation & Prosthetic Valve Emergencies 12.3 Pericardial Tamponade & Acute Aortic Syndromes
13 Chapter 13: Myocardial Disease, Hypertensive & Cardiac Device Emergencies
13.1 Fulminant Myocarditis, Stress & Peripartum Cardiomyopathy, and Hypertrophic Cardiomyopathy 13.2 Hypertensive Emergencies & Ruptured Abdominal Aortic Aneurysm 13.3 Implanted Cardiac Devices, LVAD Emergencies & Electrical Storm
14 Chapter 14: Sepsis & Systemic Infectious Diseases
14.1 Sepsis-3 Definitions & Surviving Sepsis Campaign 2026 Guidelines 14.2 Refractory Septic Shock & Adjunctive Therapies 14.3 Multidrug-Resistant Pathogens & Antimicrobial Stewardship in the ICU
15 Chapter 15: ICU-Acquired & Severe Focal Infections
15.1 Hospital-Acquired & Ventilator-Associated Pneumonia 15.2 Central Line-Associated Bloodstream Infections & Catheter-Associated UTIs 15.3 Intra-Abdominal Sepsis, Necrotizing Soft Tissue Infections & CNS Infections
16 Chapter 16: Focal, Special-Host & Systemic Infections
16.1 CNS Infections Beyond Bacterial Meningitis: Encephalitis, Brain Abscess & Epidural Abscess 16.2 Infections in the Immunocompromised Host, Tropical & Bioterror Infections 16.3 Infective Endocarditis, Device Infections & Other Focal Cardiovascular Infections 16.4 Antimicrobial Pharmacokinetics, Allergy, Toxicity & Infection Prevention 16.5 Gastrointestinal & Hepatobiliary Infections: Fulminant C. difficile, Typhlitis, CMV Colitis & Abscesses
17 Chapter 17: Neurocritical Care & Coma
17.1 Coma, Altered Mental Status & Acute Delirium in the ICU 17.2 Status Epilepticus & Non-Convulsive Status Epilepticus 17.3 Acute Ischemic Stroke & Intracranial Hemorrhage
18 Chapter 18: Cerebrovascular Syndromes, Encephalopathy & Withdrawal States
18.1 Cerebral Venous Sinus Thrombosis, PRES & Reversible Cerebral Vasoconstriction Syndrome 18.2 Alcohol & Sedative Withdrawal, Wernicke Encephalopathy & Drug-Induced Encephalopathy
19 Chapter 19: Intracranial Hypertension & Neuromuscular Weakness
19.1 Intracranial Pressure Monitoring, Cerebral Perfusion & Tiered ICP Management 19.2 Acute Neuromuscular Respiratory Failure, ICU-Acquired Weakness & Brain Death Determination
20 Chapter 20: Traumatic Brain Injury, Spinal Cord Injury & Toxin-Mediated Paralysis
20.1 Traumatic Brain Injury Management & Paroxysmal Sympathetic Hyperactivity 20.2 Acute Spinal Cord Injury, Neurogenic Shock & Autonomic Dysreflexia 20.3 Toxin-Mediated Paralysis & Neuromuscular Crises: Botulism, Tetanus, Tick Paralysis & Myasthenic Crisis
21 Chapter 21: Gastrointestinal, Hepatic & Abdominal Emergencies
21.1 Acute Upper & Lower Gastrointestinal Bleeding in the ICU 21.2 Acute Liver Failure & Severe Acute Pancreatitis 21.3 Abdominal Compartment Syndrome & Acute Mesenteric Ischemia
22 Chapter 22: Luminal GI Emergencies & Complications of Cirrhosis
22.1 Esophageal, Gastric & Bowel Emergencies: Perforation, Obstruction, Ogilvie Syndrome & Colonic Ischemia 22.2 Complications of Cirrhosis: Alcohol-Associated Hepatitis, Hepatorenal Syndrome & Pulmonary Vascular Syndromes
23 Chapter 23: Trauma, Burns & Perioperative Critical Care
23.1 Polytrauma Resuscitation, Damage Control & Massive Transfusion 23.2 Severe Burn Injury, Inhalation Injury & Environmental Emergencies 23.3 Perioperative Critical Care for High-Risk Surgical Patients
24 Chapter 24: Thoracic Trauma, Environmental Injury & Obstetric Critical Care
24.1 Thoracic Trauma: Flail Chest, Pulmonary Contusion, Great Vessel & Tracheobronchial Injury 24.2 Environmental Injury: Drowning, Diving, Altitude, Heat, Cold, Electrical & Radiation 24.3 Obstetric & Genitourinary Emergencies and the Physiology of Pregnancy
25 Chapter 25: Transplantation, Donor Management & Post-Cardiac Surgery Care
25.1 Solid Organ Transplant Recipients & Deceased Donor Management 25.2 Post-Cardiac Surgery Critical Care: Bleeding, Tamponade, Low Output & Vasoplegia
26 Chapter 26: Hematologic Emergencies, Toxicology, Critical Ultrasound & ICU Liberation
26.1 Hematologic Emergencies in the ICU: HIT, DIC, TMA & Anticoagulant Reversal 26.2 Critical Care Toxicology, Toxidromes & Specific Antidotes 26.3 Critical Care Point-of-Care Ultrasound (POCUS) 26.4 ICU Liberation, Analgosedation, Goals of Care & Critical Care Ethics
27 Chapter 27: Transfusion Medicine, Hematologic & Oncologic Disorders
27.1 Transfusion Medicine: Products, Thresholds, Reactions & Apheresis 27.2 Red and White Cell Disorders, Hemoglobinopathies, Factor Deficiencies & Hypercoagulable States 27.3 Oncologic Emergencies, Hematopoietic Cell Transplant Complications & Cellular Therapy Toxicity
28 Chapter 28: Clinical Pharmacology, Adverse Drug Reactions & Specific Poisonings
28.1 Pharmacokinetic Principles, Dose Adjustment & Drug Interactions in Critical Illness 28.2 Adverse Drug Reactions: Anaphylaxis, Severe Cutaneous Reactions & Hyperthermic Syndromes 28.3 Specific Poisonings: Sodium-Channel Blockers, Lithium, Valproate, Theophylline, Iron, Sulfonylureas & Methemoglobinemia
29 Chapter 29: Ethics, Research Methods, Administration & Abdominal Ultrasound
29.1 Advance Care Planning, Nonbeneficial Treatment, Informed Consent & Confidentiality 29.2 Critical Care Research Methods, Statistics, IRB Oversight & Quality Improvement 29.3 Abdominal, Vascular & Procedural Point-of-Care Ultrasound
18.1 Cerebral Venous Sinus Thrombosis, PRES & Reversible Cerebral Vasoconstriction Syndrome
Key Takeaways Explain This Topic AI
Anticoagulation is indicated in cerebral venous sinus thrombosis even with hemorrhagic venous infarction, because the hemorrhage results from venous congestion rather than primary arterial bleeding.
In the TO-ACT trial, endovascular thrombectomy for severe cerebral venous sinus thrombosis did not improve outcomes over anticoagulation alone.
Vitamin K antagonists are preferred over direct oral anticoagulants in cerebral venous sinus thrombosis associated with antiphospholipid syndrome.
PRES causes symmetric posterior vasogenic edema; management is blood pressure control with a 20% to 25% reduction in the first hour, seizure control, and removal of the precipitating drug.
Glucocorticoids worsen outcomes in reversible cerebral vasoconstriction syndrome, where treatment is nimodipine, trigger removal, and blood pressure control.
Last updated: October 2026
Cerebral Venous Sinus Thrombosis (CVST)
Risk factors : oral contraceptives, pregnancy and the puerperium, thrombophilia (factor V Leiden, prothrombin gene mutation, antiphospholipid syndrome), malignancy, dehydration, head trauma, nephrotic syndrome, inflammatory bowel disease, paroxysmal nocturnal hemoglobinuria, and local infection (mastoiditis, sinusitis, meningitis). Vaccine-induced immune thrombotic thrombocytopenia (VITT) is a specific, rare cause after adenoviral-vector vaccines.
Presentation : it mimics many things.
Headache in most patients, sometimes thunderclap.
Seizures , which are far more common than in arterial stroke.
Raised intracranial pressure with papilledema and visual loss (an isolated intracranial hypertension syndrome).
Focal deficits and encephalopathy.
Cavernous sinus thrombosis : proptosis, chemosis, and palsies of cranial nerves III, IV, V1, V2, and VI.
Imaging :
Non-contrast CT may show a dense triangle or cord sign ; contrast CT shows the empty delta sign in the superior sagittal sinus.
CT venography or MR venography confirms the diagnosis; MRI shows the thrombus and venous infarction.
Venous infarcts cross arterial territories , are often bilateral and parasagittal, and are hemorrhagic in up to 40% .
Treatment :
Anticoagulation , with therapeutic low-molecular-weight heparin preferred to unfractionated heparin, even in the presence of hemorrhage : the bleeding is a consequence of venous hypertension, and anticoagulation relieves it.
VITT is the exception to usual heparin use: give non-heparin anticoagulation and intravenous immunoglobulin, and avoid platelet transfusion.
Transition to a vitamin K antagonist for 3 to 12 months; direct oral anticoagulants are reasonable in many patients, but vitamin K antagonists are preferred in antiphospholipid syndrome .
Seizure control : treat clinical or electrographic seizures; prophylaxis is considered with supratentorial lesions.
Raised intracranial pressure : head elevation, osmotherapy, acetazolamide for isolated intracranial hypertension, serial lumbar punctures or shunt for refractory visual loss, and decompressive craniectomy for impending herniation from a large venous infarct, which can be life-saving even in severe cases.
Endovascular therapy : the TO-ACT trial found no benefit from thrombectomy, so it is reserved for selected patients who deteriorate despite anticoagulation.
Treat an infectious source with antibiotics and drainage.
Posterior Reversible Encephalopathy Syndrome (PRES)
Mechanism : failure of cerebral autoregulation with endothelial dysfunction, producing vasogenic edema preferentially in the posterior circulation, where sympathetic innervation is sparse.
Triggers :
Severe or rapidly rising hypertension.
Preeclampsia and eclampsia .
Calcineurin inhibitors (tacrolimus, cyclosporine) and sirolimus.
Cytotoxic and targeted agents (cisplatin, gemcitabine, bevacizumab, tyrosine kinase inhibitors), and CAR-T therapy .
Kidney failure, autoimmune disease, sepsis, and rapid correction of anemia with transfusion.
Presentation : headache, seizures (often the presenting event, sometimes status epilepticus), visual disturbance including cortical blindness, and encephalopathy. Blood pressure can be only modestly elevated, particularly with calcineurin inhibitors.
Imaging : symmetric parieto-occipital white-matter vasogenic edema , hyperintense on T2 and FLAIR, with no restricted diffusion in most cases (which distinguishes it from infarction). Atypical frontal, brainstem, or cerebellar involvement occurs, and hemorrhage is present in a minority.
Management :
Lower blood pressure by about 20% to 25% in the first hour with a titratable agent (nicardipine, clevidipine, labetalol); avoid overshoot, which causes infarction.
Treat seizures with antiseizure medication; magnesium is the agent for eclampsia, along with delivery.
Stop or reduce the offending drug ; for calcineurin inhibitors, switch agents or reduce the level.
Treat kidney failure and electrolyte disturbance.
Prognosis : most patients recover within days to weeks. Hemorrhage, infarction, and severe edema predict permanent deficits; recurrence is uncommon.
Reversible Cerebral Vasoconstriction Syndrome (RCVS)
Hallmark : recurrent thunderclap headache over days to weeks, often triggered by exertion, Valsalva, sexual activity, or bathing.
Triggers : vasoactive drugs (cocaine, amphetamines, triptans, SSRIs, nasal decongestants, cannabis), the postpartum state, blood products and immunoglobulin, and pheochromocytoma.
Imaging : multifocal segmental narrowing of the circle of Willis and its branches, the string-of-beads appearance , which reverses within about 12 weeks . Complications include convexity (sulcal) subarachnoid hemorrhage early, then ischemic infarction and intracerebral hemorrhage later. CSF is typically near-normal, which helps distinguish it from vasculitis.
Management :
Remove vasoactive triggers.
Nimodipine or verapamil for headache control, acknowledging limited outcome evidence.
Avoid blood pressure extremes; treat severe hypertension cautiously.
Avoid glucocorticoids , which are associated with worse outcomes.
Short-term rest and avoidance of Valsalva maneuvers.
Distinguishing the Three (and Their Mimics)
- Feature CVST PRES RCVS
- Headache pattern Progressive, sometimes thunderclap Dull, with encephalopathy Recurrent thunderclap
Key imaging Absent venous flow, empty delta sign, venous infarct crossing territories Posterior vasogenic edema without restricted diffusion Segmental arterial narrowing that reverses
- Hemorrhage Lobar hemorrhagic venous infarct Occasional Convexity subarachnoid hemorrhage
- Treatment Anticoagulate Blood pressure control, stop the trigger Nimodipine, stop the trigger
- Steroids Not indicated Not indicated Harmful
Mimics to exclude : aneurysmal subarachnoid hemorrhage (lumbar puncture with xanthochromia, CT angiography), cervical artery dissection, primary CNS vasculitis (abnormal CSF, non-reversing stenoses), pituitary apoplexy, and intracranial hypotension.