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ABPN Neurocritical Care study materials
ABPN Neurocritical Care study resources

ABPN Neurocritical Care practice questions

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Question 1Neurocritical Care Fundamentals and Neurophysiology

A patient with a large hemispheric infarct develops progressive drowsiness. The Monro-Kellie doctrine predicts which of the following as an intracranial mass expands within a closed skull?

  1. Compensatory displacement of cerebrospinal fluid and venous blood precedes measurable pressure rise Correct answer.
  2. Arterial blood volume is the primary compartment displaced to maintain pressure
  3. Intracranial pressure rises linearly and immediately with the first milliliter of edema
  4. Brain tissue volume expands freely without any pressure consequence

Explanation

The Monro-Kellie doctrine holds that the total volume of brain, blood, and cerebrospinal fluid is fixed within the rigid skull. Early compensation occurs by shifting CSF into the spinal subarachnoid space and reducing venous blood volume, so intracranial pressure stays near normal until these reserves are exhausted.

Question 2Neurocritical Care Fundamentals and Neurophysiology

Cerebral perfusion pressure is calculated from mean arterial pressure and intracranial pressure. Which formula is correct?

  1. CPP = (MAP + ICP) / 2
  2. CPP = MAP + ICP
  3. CPP = MAP − ICP Correct answer.
  4. CPP = ICP − MAP

Explanation

Cerebral perfusion pressure equals mean arterial pressure minus intracranial pressure, since ICP acts as the downstream opposing pressure to cerebral blood flow. This relationship guides blood pressure targets in patients with elevated ICP.

Question 3Neurocritical Care Fundamentals and Neurophysiology

Which structure is the primary site of cerebrospinal fluid production?

  1. Ependymal lining of the third ventricle
  2. Perivascular glymphatic channels
  3. Choroid plexus Correct answer.
  4. Arachnoid granulations

Explanation

The choroid plexus of the lateral, third, and fourth ventricles produces the majority of CSF through active secretion. Arachnoid granulations are the main site of absorption rather than production.

Question 4Neurocritical Care Fundamentals and Neurophysiology

The cerebral blood flow autoregulation curve describes the response to changes in mean arterial pressure. Over which mean arterial pressure range is flow normally maintained relatively constant in healthy adults?

  1. 50 to 80 mm Hg
  2. 150 to 200 mm Hg
  3. 60 to 160 mm Hg Correct answer.
  4. 20 to 50 mm Hg

Explanation

In normotensive adults, cerebral autoregulation keeps blood flow stable across a mean arterial pressure of roughly 60 to 160 mm Hg through myogenic arteriolar constriction and dilation. Outside this range, flow becomes pressure-passive.

Question 5Neurocritical Care Fundamentals and Neurophysiology

A patient is intubated after a severe traumatic brain injury. Which arterial carbon dioxide target best supports cerebral vasoconstriction to lower intracranial pressure while avoiding ischemia?

  1. PaCO2 of 30 to 35 mm Hg Correct answer.
  2. PaCO2 of 55 to 60 mm Hg
  3. PaCO2 of 45 to 50 mm Hg
  4. PaCO2 of 20 to 25 mm Hg sustained continuously

Explanation

Carbon dioxide is a potent cerebral vasodilator, so mild hypocapnia to roughly 30 to 35 mm Hg reduces cerebral blood volume and ICP. More aggressive or prolonged hypocapnia risks cerebral ischemia from excessive vasoconstriction.

Question 6Neurocritical Care Fundamentals and Neurophysiology

Which finding on the electroencephalogram is most characteristic of nonconvulsive status epilepticus?

  1. Continuous generalized rhythmic delta with no evolution
  2. Diffuse beta activity with normal reactivity
  3. Periodic discharges at a fixed 1 Hz without clinical change
  4. Repetitive epileptiform discharges or rhythmic activity evolving in frequency and amplitude Correct answer.

Explanation

Nonconvulsive status epilepticus shows ongoing electrographic seizures, typically repetitive spikes, polyspikes, or rhythmic activity that evolves in frequency, amplitude, and morphology. Evolution and rhythmicity distinguish ictal patterns from static encephalopathic patterns.

Question 7Neurocritical Care Fundamentals and Neurophysiology

A comatose patient has absent pupillary light reflexes and no corneal reflexes, but retains a gag reflex and spontaneous respirations. Which level of the neuraxis is most consistent with these findings?

  1. Midbrain and pontine dysfunction Correct answer.
  2. Bilateral cortical injury with intact brainstem
  3. Isolated medullary lesion
  4. Cervical spinal cord injury

Explanation

Loss of pupillary and corneal reflexes localizes to the midbrain and pons, while preserved gag and respiratory drive indicate functioning medullary centers. This pattern reflects rostrocaudal brainstem dysfunction sparing the medulla.

Question 8Neurocritical Care Fundamentals and Neurophysiology

A patient with subarachnoid hemorrhage has a serum sodium of 122 mmol/L, is euvolemic on assessment, and has rising intracranial pressure. Which approach is most appropriate for managing the hyponatremia?

  1. Hypertonic saline with a goal of gradual sodium correction Correct answer.
  2. Rapid correction to 140 mmol/L within 12 hours
  3. Free water administration to match urine output
  4. Fluid restriction to 800 mL per day

Explanation

Hyponatremia in subarachnoid hemorrhage often reflects cerebral salt wasting with volume depletion, and fluid restriction can worsen hypovolemia and cerebral ischemia. Hypertonic saline with controlled, gradual correction treats both the sodium deficit and elevated ICP.

Question 9Neurocritical Care Fundamentals and Neurophysiology

Which waveform pattern on intracranial pressure monitoring is associated with preserved cerebral compliance, appearing as a triphasic wave with a small amplitude?

  1. Lundberg B waves
  2. Lundberg A waves
  3. P1-dominant normal waveform Correct answer.
  4. Plateau waves of 50 mm Hg lasting minutes

Explanation

The normal ICP waveform has three peaks, with the percussive P1 peak dominant, reflecting arterial pulsation against compliant brain tissue. Loss of compliance shifts dominance toward P2 and P3.

Question 10Neurocritical Care Fundamentals and Neurophysiology

A patient with severe traumatic brain injury is being monitored with jugular venous oximetry. A jugular bulb oxygen saturation of 45% most likely indicates which of the following?

  1. Excessive cerebral oxygen delivery
  2. Increased cerebral oxygen extraction from ischemia Correct answer.
  3. Global cerebral hyperemia
  4. Complete absence of cerebral blood flow

Explanation

Jugular bulb saturation reflects the balance of oxygen delivery and consumption. Values below roughly 50% indicate increased oxygen extraction, suggesting cerebral ischemia or reduced perfusion.

Question 11Neurocritical Care Fundamentals and Neurophysiology

A patient with status epilepticus has received escalating antiseizure medications without clinical or electrographic response. Which agent is most appropriate as a continuous infusion for refractory status epilepticus?

  1. Midazolam Correct answer.
  2. Phenytoin
  3. Levetiracetam
  4. Valproate

Explanation

Refractory status epilepticus is treated with continuous intravenous anesthetic infusions, most commonly midazolam, propofol, or pentobarbital, titrated to electrographic burst suppression. Benzodiazepine infusions provide rapid titratability and reliable seizure suppression.

Question 12Neurocritical Care Fundamentals and Neurophysiology

A patient in the intensive care unit is declared brain dead. Which prerequisite must be satisfied before clinical brain death testing can be performed?

  1. Core temperature above 36°C and exclusion of confounding drugs or metabolic derangements Correct answer.
  2. A serum glucose above 400 mg/dL
  3. Administration of a barbiturate to suppress cortical activity
  4. Presence of spontaneous respirations at the time of testing

Explanation

Brain death determination requires correction of confounders, including hypothermia, sedative or neuromuscular blockade effects, and severe metabolic derangements, before clinical testing. The apnea test then assesses absence of respiratory drive.

Question 13Neurocritical Care Fundamentals and Neurophysiology

A patient with a large middle cerebral artery infarct has a mean arterial pressure of 130 mm Hg and an intracranial pressure of 20 mm Hg. What is the cerebral perfusion pressure?

  1. 130 mm Hg
  2. 110 mm Hg Correct answer.
  3. 150 mm Hg
  4. 90 mm Hg

Explanation

Cerebral perfusion pressure is MAP minus ICP, so 130 − 20 equals 110 mm Hg. This value guides whether blood pressure support is sufficient for collateral perfusion in acute ischemic stroke.

Question 14Neurocritical Care Fundamentals and Neurophysiology

In a patient with acute ischemic stroke, which cerebrovascular change occurs in the ischemic penumbra as perfusion pressure falls?

  1. Loss of carbon dioxide reactivity before loss of pressure reactivity
  2. Maximal arteriolar dilation with oxygen extraction fraction rising Correct answer.
  3. Immediate infarction of the entire territory
  4. Arteriolar constriction with reduced oxygen extraction

Explanation

In the penumbra, autoregulatory vasodilation attempts to maintain perfusion, and the oxygen extraction fraction rises as delivery falls. Tissue remains viable but at risk, which is why pressure-dependent perfusion must be preserved.

Question 15Neurocritical Care Fundamentals and Neurophysiology

A patient with a frontal lobe mass exhibits grasp and suck reflexes. Which phenomenon do these represent?

  1. Frontal release signs Correct answer.
  2. Extrapyramidal rigidity
  3. Cerebellar signs
  4. Brainstem release signs

Explanation

Grasp, suck, and snout reflexes are frontal release signs reflecting loss of cortical inhibition over brainstem-mediated reflexes. They indicate frontal lobe dysfunction rather than brainstem injury.

Question 16Neurocritical Care Fundamentals and Neurophysiology

A patient with severe hyponatremia from syndrome of inappropriate antidiuretic hormone is corrected too rapidly. Which neurologic complication is most concerning?

  1. Subarachnoid hemorrhage
  2. Osmotic demyelination syndrome Correct answer.
  3. Wernicke encephalopathy
  4. Cerebral venous sinus thrombosis

Explanation

Overly rapid correction of chronic hyponatremia can cause osmotic demyelination, typically presenting with delayed quadriparesis, dysarthria, or altered consciousness. Correction rates are therefore limited, generally to no more than 8 to 10 mmol/L per day.

Question 17Neurocritical Care Fundamentals and Neurophysiology

During an apnea test in a potential brain-death donor, the patient becomes hypotensive with a systolic pressure of 70 mm Hg and oxygen saturation of 80%. What is the most appropriate next step?

  1. Interpret the result as a positive apnea test
  2. Continue the test to completion regardless of instability
  3. Abort the test, reconnect the ventilator, and stabilize the patient Correct answer.
  4. Increase the oxygen flow and continue the test

Explanation

The apnea test must be aborted if the patient becomes hemodynamically unstable or hypoxemic, because these conditions confound the assessment and endanger the patient. The ventilator is reconnected and the patient stabilized before considering a repeat test.

Question 18Neurocritical Care Fundamentals and Neurophysiology

A patient with a traumatic brain injury has an intracranial pressure waveform in which the P2 peak exceeds P1. What does this finding most likely indicate?

  1. Artifact from the transducer
  2. Improved cerebral compliance
  3. Reduced intracranial compliance with elevated risk of herniation Correct answer.
  4. Normal arterial pulsation

Explanation

Loss of the normal P1-dominant waveform with P2 exceeding P1 reflects reduced intracranial compliance and impaired buffering of arterial pulsation. This pattern warns of elevated ICP and herniation risk.

Question 19Neurocritical Care Fundamentals and Neurophysiology

A patient with refractory status epilepticus is placed in burst suppression with a propofol infusion. Which complication is most characteristic of prolonged high-dose propofol?

  1. Osmotic demyelination
  2. Neuroleptic malignant syndrome
  3. Propofol infusion syndrome with metabolic acidosis and rhabdomyolysis Correct answer.
  4. Serotonin syndrome

Explanation

Prolonged high-dose propofol can cause propofol infusion syndrome, marked by metabolic acidosis, rhabdomyolysis, hyperkalemia, and cardiac dysfunction. Doses are limited and alternatives such as midazolam or pentobarbital are considered for extended suppression.

Question 20Neurocritical Care Fundamentals and Neurophysiology

A patient with a large hemispheric infarct is being considered for decompressive hemicraniectomy. Which physiologic rationale best supports this intervention?

  1. It directly restores perfusion to the infarcted core
  2. It increases cerebral perfusion pressure by lowering intracranial pressure and reducing herniation risk Correct answer.
  3. It eliminates the need for blood pressure control
  4. It reverses cytotoxic edema within the infarct

Explanation

Decompressive hemicraniectomy removes the rigid skull constraint, lowering ICP and thereby improving cerebral perfusion pressure in at-risk tissue and reducing herniation risk. It does not salvage the infarct core or reverse established edema.

Question 21Cerebrovascular Disease and Neurointerventional Critical Care

A patient with aneurysmal subarachnoid hemorrhage is admitted with a Hunt and Hess grade of 4. Which clinical feature defines this grade?

  1. Drowsiness, confusion, or mild focal deficit
  2. Moderate to severe headache, nuchal rigidity, no neurologic deficit other than cranial nerve palsy
  3. Stupor, moderate to severe hemiparesis, possible early decerebrate rigidity Correct answer.
  4. Asymptomatic or mild headache with slight nuchal rigidity

Explanation

The Hunt and Hess scale grades SAH by clinical condition: grade 1 is asymptomatic or mild headache, grade 2 is moderate-severe headache with nuchal rigidity and no focal deficit beyond cranial nerve palsy, grade 3 is drowsiness/confusion or mild focal deficit, grade 4 is stupor with moderate-severe hemiparesis, and grade 5 is deep coma. Grade 4 reflects depressed consciousness plus a focal motor deficit.

Question 22Cerebrovascular Disease and Neurointerventional Critical Care

Which finding on noncontrast head CT most strongly suggests an underlying vascular lesion in a patient with lobar intracerebral hemorrhage?

  1. Hemorrhage centered in the basal ganglia
  2. Hemorrhage centered in the thalamus
  3. A subcortical hemorrhage abutting the cortex in a young normotensive patient Correct answer.
  4. Symmetric intraventricular extension

Explanation

Lobar hemorrhages, especially in younger or normotensive patients without typical hypertensive risk factors, raise suspicion for structural vascular lesions such as arteriovenous malformations, cavernomas, or amyloid angiopathy. Deep locations (basal ganglia, thalamus) are more typical of hypertensive small-vessel disease.

Question 23Cerebrovascular Disease and Neurointerventional Critical Care

A patient with acute ischemic stroke receives intravenous alteplase. Which blood pressure threshold should be maintained during and for 24 hours after infusion?

  1. Systolic below 220 mm Hg and diastolic below 120 mm Hg
  2. Systolic below 140 mm Hg and diastolic below 90 mm Hg
  3. Systolic below 185 mm Hg and diastolic below 110 mm Hg Correct answer.
  4. Systolic below 160 mm Hg and diastolic below 100 mm Hg

Explanation

Before and during alteplase, blood pressure must be below 185/110 mm Hg, and after infusion it should be maintained below 180/105 mm Hg for 24 hours to reduce hemorrhagic transformation risk. The 185/110 threshold is the pre- and intra-infusion criterion.

Question 24Cerebrovascular Disease and Neurointerventional Critical Care

A patient with a large hemispheric infarct develops progressive drowsiness and a fixed dilated pupil. Which intervention is the most appropriate next step for malignant cerebral edema?

  1. High-dose corticosteroids
  2. Hypertonic saline bolus followed by urgent decompressive hemicraniectomy evaluation Correct answer.
  3. Immediate therapeutic hypothermia induction
  4. Routine lumbar puncture for pressure relief

Explanation

Malignant cerebral edema after large hemispheric infarction is managed with osmotic therapy (hypertonic saline or mannitol) and early decompressive hemicraniectomy, which reduces mortality and improves functional outcomes in selected patients. Corticosteroids are not effective for cytotoxic edema and can worsen outcomes.

Question 25Cerebrovascular Disease and Neurointerventional Critical Care

Which aneurysm location is most commonly associated with a nonaneurysmal perimesencephalic pattern of subarachnoid hemorrhage?

  1. Basilar tip
  2. No aneurysm is typically identified in the perimesencephalic pattern Correct answer.
  3. Posterior communicating artery
  4. Anterior communicating artery

Explanation

Perimesencephalic SAH is characterized by blood centered around the midbrain with a normal angiogram in most cases and a benign clinical course. It is generally considered nonaneurysmal, though repeat imaging may be warranted in atypical cases.

Question 26Cerebrovascular Disease and Neurointerventional Critical Care

A patient presents with sudden severe headache and CT shows subarachnoid hemorrhage. Which medication should be started promptly to reduce the risk of delayed cerebral ischemia?

  1. Heparin
  2. Nimodipine Correct answer.
  3. Mannitol
  4. Phenytoin

Explanation

Nimodipine, a calcium channel antagonist, is recommended for all patients with aneurysmal SAH to reduce the incidence and severity of delayed cerebral ischemia and poor outcomes. It is typically given orally or enterally for 21 days.

Question 27Cerebrovascular Disease and Neurointerventional Critical Care

Which imaging modality is the preferred initial study to exclude subarachnoid hemorrhage in a patient presenting within 6 hours of sudden severe headache?

  1. Carotid duplex ultrasound
  2. MRI brain without contrast
  3. Noncontrast head CT Correct answer.
  4. Lumbar puncture

Explanation

Modern noncontrast head CT has very high sensitivity for SAH when performed within 6 hours of symptom onset, and a negative scan in this window can generally exclude SAH without further testing. Lumbar puncture is reserved for equivocal CT findings or later presentations.

Question 28Cerebrovascular Disease and Neurointerventional Critical Care

A patient with an unruptured cerebral arteriovenous malformation is being counseled. Which feature most strongly increases the annual risk of hemorrhage?

  1. Superficial venous drainage
  2. Prior hemorrhage from the AVM Correct answer.
  3. Small nidus diameter
  4. Absence of associated aneurysms

Explanation

Prior AVM hemorrhage is the strongest predictor of subsequent hemorrhage, raising annual risk substantially compared with unruptured lesions. Other features such as deep location, deep venous drainage, and associated aneurysms also increase risk.

Question 29Cerebrovascular Disease and Neurointerventional Critical Care

A patient with acute ischemic stroke and a large vessel occlusion is being evaluated for endovascular thrombectomy. Which finding on CT most strongly predicts poor outcome despite reperfusion?

  1. A large established infarct core on perfusion imaging Correct answer.
  2. A small ischemic core with a large penumbra
  3. A distal M2 occlusion
  4. A favorable collateral score

Explanation

A large established infarct core indicates irreversible tissue loss that will not recover with reperfusion and is associated with poor outcomes and higher hemorrhagic risk. Thrombectomy selection favors small core with substantial penumbra.

Question 30Cerebrovascular Disease and Neurointerventional Critical Care

A patient with aneurysmal SAH develops hyponatremia on day 5 with clinical signs of hypovolemia. Which management approach is most appropriate?

  1. Hypertonic saline for rapid sodium correction regardless of volume status
  2. Demeclocycline to induce aquaresis
  3. Fluid restriction to correct the sodium
  4. Volume repletion with isotonic crystalloid and avoidance of hypotonic fluids Correct answer.

Explanation

Hyponatremia in SAH is commonly due to cerebral salt wasting with hypovolemia, so treatment is volume repletion with isotonic fluids. Fluid restriction can worsen vasospasm-related ischemia and is avoided.

Question 31Cerebrovascular Disease and Neurointerventional Critical Care

A patient with a spontaneous intracerebral hemorrhage on warfarin has an INR of 3.2 and is deteriorating. Which intervention is most appropriate for urgent reversal?

  1. Four-factor prothrombin complex concentrate plus intravenous vitamin K Correct answer.
  2. Platelet transfusion
  3. Fresh frozen plasma alone
  4. Vitamin K alone

Explanation

Urgent warfarin reversal for intracranial hemorrhage requires four-factor prothrombin complex concentrate for rapid factor replacement plus intravenous vitamin K for sustained reversal. PCC achieves faster and more complete correction than plasma alone.

Question 32Cerebrovascular Disease and Neurointerventional Critical Care

Which finding on transcranial Doppler most suggests vasospasm after aneurysmal SAH?

  1. Reversal of flow in the ophthalmic artery
  2. Loss of the pulsatility index
  3. Mean flow velocities in the middle cerebral artery exceeding 120 cm/s Correct answer.
  4. Systolic velocity below 60 cm/s

Explanation

Elevated mean flow velocities in the MCA, typically above 120 cm/s, suggest vasospasm, with higher velocities correlating with greater severity. Trending velocities and the Lindegaard ratio improve specificity.

Question 33Cerebrovascular Disease and Neurointerventional Critical Care

A patient with a basilar artery occlusion presents with fluctuating consciousness and quadriparesis. Which statement about revascularization is most accurate?

  1. Thrombectomy is not beneficial for posterior circulation occlusions
  2. Posterior circulation strokes have a longer therapeutic window because the brainstem tolerates ischemia indefinitely
  3. Intravenous thrombolysis is contraindicated in posterior circulation stroke
  4. Endovascular thrombectomy may be considered even beyond 6 hours in selected patients with basilar occlusion Correct answer.

Explanation

Basilar artery occlusion carries high mortality, and endovascular thrombectomy may benefit selected patients presenting beyond 6 hours, particularly with a favorable imaging profile. Randomized trials support reperfusion in appropriately selected cases.

Question 34Cerebrovascular Disease and Neurointerventional Critical Care

A patient with a cerebellar hemorrhage develops progressive lethargy and obstructive hydrocephalus. Which intervention is most appropriate?

  1. Observation with serial imaging
  2. Lumbar drainage
  3. Hypertonic saline alone
  4. Suboccipital decompressive craniectomy with hematoma evacuation Correct answer.

Explanation

Cerebellar hemorrhages larger than 3 cm with brainstem compression or hydrocephalus warrant urgent surgical evacuation, often with suboccipital craniectomy. Early surgery prevents herniation and improves outcomes.

Question 35Cerebrovascular Disease and Neurointerventional Critical Care

Which parameter best guides the assessment of delayed cerebral ischemia in a sedated, intubated patient with SAH?

  1. Routine lumbar puncture
  2. Continuous EEG and bedside neuromonitoring trends Correct answer.
  3. Serum lactate
  4. Daily noncontrast CT

Explanation

In sedated patients, clinical examination is unreliable, so continuous EEG and multimodal neuromonitoring (such as TCD trends and invasive brain oxygen) help detect ischemia. EEG can reveal new slowing or seizures indicating ischemia.

Question 36Cerebrovascular Disease and Neurointerventional Critical Care

A young patient has a cervical carotid dissection after trauma. Which antithrombotic strategy is generally preferred for secondary stroke prevention in the absence of contraindications?

  1. Lifelong dual antiplatelet therapy
  2. Antiplatelet therapy or anticoagulation for 3 to 6 months Correct answer.
  3. Immediate carotid endarterectomy
  4. No therapy if the dissection is asymptomatic

Explanation

Cervical artery dissection is typically treated with antiplatelet therapy or anticoagulation for 3 to 6 months, with similar outcomes between strategies in observational data. Therapy is individualized based on bleeding risk and infarct size.

Question 37Cerebrovascular Disease and Neurointerventional Critical Care

A patient with a ruptured anterior communicating artery aneurysm undergoes coiling. Which electrolyte and endocrine complication should be monitored for?

  1. Hyperkalemia and hypothyroidism
  2. Hypercalcemia and diabetes insipidus
  3. Hypoglycemia and adrenal hyperplasia
  4. Hyponatremia and hypothalamic-pituitary dysfunction Correct answer.

Explanation

Aneurysms near the anterior communicating artery and hypothalamus can cause hyponatremia and hypothalamic-pituitary dysfunction. Monitoring sodium and endocrine function is important in the acute and subacute period.

Question 38Cerebrovascular Disease and Neurointerventional Critical Care

Which factor most increases the risk of hemorrhagic transformation after intravenous thrombolysis for acute ischemic stroke?

  1. Distal small vessel occlusion
  2. Mild stroke severity
  3. Early ischemic changes on CT and large infarct burden Correct answer.
  4. Normal blood pressure

Explanation

Extensive early ischemic changes and large infarct burden increase the risk of hemorrhagic transformation after thrombolysis. Other risk factors include severe hypertension, anticoagulation, and low platelet count.

Question 39Cerebrovascular Disease and Neurointerventional Critical Care

A patient with a large MCA infarct is being considered for decompressive hemicraniectomy. Which statement best reflects the evidence?

  1. Surgery is contraindicated in patients older than 50
  2. Surgery has no effect on mortality
  3. Surgery should be offered only after herniation occurs
  4. Surgery within 48 hours reduces mortality and improves functional outcomes in selected patients Correct answer.

Explanation

Pooled randomized data show that decompressive hemicraniectomy within 48 hours of malignant MCA infarction reduces mortality and improves functional outcomes in selected patients, including older adults in some analyses. Timing and patient selection are key.

Question 40Cerebrovascular Disease and Neurointerventional Critical Care

Which finding on CT angiography most directly identifies a ruptured aneurysm in a patient with SAH?

  1. An outpouching at a vessel bifurcation corresponding to the distribution of blood Correct answer.
  2. Ventricular enlargement
  3. Diffuse cerebral edema
  4. Loss of gray-white differentiation

Explanation

CT angiography identifies an aneurysm as a focal outpouching, typically at a vessel bifurcation, and the location should correspond to the blood distribution. Catheter angiography remains the reference standard when CTA is equivocal.

Question 41Cerebrovascular Disease and Neurointerventional Critical Care

A patient with an intracerebral hemorrhage is on apixaban and presents within 2 hours of symptom onset. Which reversal strategy is most appropriate?

  1. Andexanet alfa or four-factor PCC based on institutional protocol Correct answer.
  2. No reversal is needed for direct oral anticoagulants
  3. Vitamin K
  4. Protamine sulfate

Explanation

For life-threatening intracranial hemorrhage associated with factor Xa inhibitors, andexanet alfa or four-factor PCC is used according to institutional protocol. Protamine and vitamin K do not reverse factor Xa inhibitors.

Question 42Cerebrovascular Disease and Neurointerventional Critical Care

A patient develops angiographic vasospasm refractory to medical therapy after SAH. Which endovascular approach is most established?

  1. Embolization of the spastic vessel
  2. Intra-arterial vasodilator infusion with or without balloon angioplasty Correct answer.
  3. Mechanical thrombectomy of the spastic vessel
  4. Stent placement across the spastic segment

Explanation

Refractory vasospasm is treated with intra-arterial vasodilators such as milrinone or verapamil, and balloon angioplasty for proximal larger vessels. These approaches improve vessel caliber and perfusion.

Question 43Cerebrovascular Disease and Neurointerventional Critical Care

A patient with a ruptured AVM is managed in the neurocritical care unit. Which statement about AVM hemorrhage management is most accurate?

  1. Anticoagulation should be started to prevent venous thrombosis
  2. Blood pressure control and treatment of the AVM by a multidisciplinary team are priorities Correct answer.
  3. Immediate surgical resection is mandated for all ruptured AVMs regardless of location
  4. Stereotactic radiosurgery is the first-line treatment in the acute rupture phase

Explanation

Acute AVM hemorrhage is managed with blood pressure control, intracranial pressure management, and definitive treatment planned by a multidisciplinary team. Immediate resection is not required for all lesions, and radiosurgery has a latency period unsuitable for acute rupture.

Question 44Cerebrovascular Disease and Neurointerventional Critical Care

A patient with SAH develops a new focal deficit and TCD velocities are rising. Which management step best aligns with current practice for suspected delayed cerebral ischemia?

  1. Induce hypertension to improve cerebral perfusion while maintaining euvolemia Correct answer.
  2. Administer a thrombolytic
  3. Immediately perform a lumbar puncture
  4. Initiate fluid restriction to reduce cerebral edema

Explanation

For suspected delayed cerebral ischemia, induced hypertension is used to improve perfusion, with maintenance of euvolemia. Fluid restriction and thrombolysis are inappropriate, and lumbar puncture is not part of the management.

Question 45Cerebrovascular Disease and Neurointerventional Critical Care

A patient with a large hemispheric infarct develops central herniation despite osmotic therapy. Which intervention is most likely to be life-saving?

  1. Decompressive hemicraniectomy Correct answer.
  2. Lumbar drainage
  3. High-dose barbiturate infusion as monotherapy
  4. Hyperventilation to a target PaCO2 of 20 mm Hg for 24 hours

Explanation

Decompressive hemicraniectomy is the definitive intervention for malignant cerebral edema with herniation, reducing mortality. Hyperventilation provides only transient bridge benefit and prolonged hypocapnia risks ischemia.

Question 46Cerebrovascular Disease and Neurointerventional Critical Care

A 62-year-old man with a history of hypertension presents with sudden onset of the worst headache of his life. Noncontrast head CT is negative, but lumbar puncture performed 12 hours after symptom onset shows uniformly bloody cerebrospinal fluid that does not clear between tubes and xanthochromia. Which vascular lesion is most likely responsible?

  1. Cerebral arteriovenous malformation
  2. Cavernous malformation
  3. Ruptured saccular (berry) aneurysm Correct answer.
  4. Dural arteriovenous fistula

Explanation

The combination of a thunderclap headache, negative CT, and xanthochromic CSF indicates subarachnoid hemorrhage. The most common cause of nontraumatic subarachnoid hemorrhage is rupture of a saccular (berry) aneurysm, typically at branch points of the circle of Willis. Xanthochromia reflects bilirubin from red blood cell breakdown and confirms hemorrhage when CT is negative.

Question 47Cerebrovascular Disease and Neurointerventional Critical Care

A 55-year-old woman with a ruptured middle cerebral artery aneurysm is admitted after coiling. On day 6, she becomes confused and develops a new right-sided weakness. Transcranial Doppler shows elevated mean flow velocities in the left middle cerebral artery. CT perfusion shows a mismatch with a small core and a large area of prolonged transit time in the left MCA territory. Which management strategy is most appropriate?

  1. Perform immediate decompressive hemicraniectomy
  2. Administer intravenous thrombolysis
  3. Induce hypertension to improve collateral perfusion Correct answer.
  4. Start high-dose corticosteroids

Explanation

The clinical picture is consistent with delayed cerebral ischemia due to vasospasm after subarachnoid hemorrhage. The cornerstone of management is induced hypertension (often with norepinephrine) to augment cerebral perfusion pressure and collateral flow, provided the aneurysm has been secured. This approach is supported by CT perfusion findings of a penumbra at risk.

Question 48Cerebrovascular Disease and Neurointerventional Critical Care

A 48-year-old man is found unresponsive and brought to the emergency department. Head CT shows a primary intraventricular hemorrhage with blood casting the third and fourth ventricles and early hydrocephalus. He has no intraparenchymal hemorrhage. Which additional vascular imaging study is most appropriate to identify the underlying cause?

  1. CT angiography of the head Correct answer.
  2. MRI of the brain with gadolinium
  3. Carotid duplex ultrasound
  4. Transcranial Doppler ultrasound

Explanation

Primary intraventricular hemorrhage in an adult is often caused by a vascular lesion such as an arteriovenous malformation or aneurysm, and CT angiography is the preferred initial noninvasive study to detect these. MRI may be complementary but is less sensitive for acute vascular pathology. Duplex and transcranial Doppler do not reliably identify intraventricular sources.

Question 49Cerebrovascular Disease and Neurointerventional Critical Care

A 70-year-old woman with atrial fibrillation on dabigatran presents with an acute right middle cerebral artery syndrome. Noncontrast CT shows a hyperdense MCA sign but no hemorrhage. Her last dose of dabigatran was 8 hours ago, and her renal function is normal. Which statement best reflects the appropriate use of intravenous thrombolysis in this patient?

  1. Intravenous thrombolysis should be given at half dose because of the anticoagulant effect
  2. Intravenous thrombolysis can be given if idarucizumab is administered first to reverse dabigatran
  3. Intravenous thrombolysis is contraindicated because of recent direct oral anticoagulant use Correct answer.
  4. Intravenous thrombolysis is safe if the activated partial thromboplastin time is normal

Explanation

Current guidelines state that intravenous thrombolysis should not be administered to patients who have taken a direct oral anticoagulant within 48 hours, unless coagulation tests are normal or the anticoagulant has been reversed. In this case, dabigatran was taken within 48 hours, so thrombolysis is contraindicated. Mechanical thrombectomy remains an option if a large vessel occlusion is confirmed.

Question 50Cerebrovascular Disease and Neurointerventional Critical Care

A 58-year-old man with a ruptured anterior communicating artery aneurysm is treated with endovascular coiling. On day 3, he becomes progressively confused and develops bilateral leg weakness. Serum sodium is 128 mEq/L, and he appears euvolemic. Which pathophysiologic mechanism best explains this syndrome?

  1. SIADH from hypothalamic injury Correct answer.
  2. Primary polydipsia due to thirst center damage
  3. Osmotic demyelination from rapid correction of hyponatremia
  4. Cerebral salt wasting from atrial natriuretic peptide release

Explanation

Hyponatremia after subarachnoid hemorrhage is often due to SIADH, particularly with anterior communicating artery aneurysms that may injure the hypothalamus. SIADH is characterized by euvolemia, low serum osmolality, and inappropriately concentrated urine. Cerebral salt wasting, in contrast, is associated with hypovolemia.