Nervous System & Special Senses

Carotid stenosis: screening and revascularization decisions

Clinical Overview and When to Suspect Carotid Stenosis

— Prevalence of ≥50% stenosis rises with age: ~0.5% at 50, ~10% by age 80

— Accounts for ~10–15% of all ischemic strokes

— Strongly correlated with traditional atherosclerotic risk factors: HTN, dyslipidemia, DM, tobacco, age, male sex, family history

— Ipsilateral hemispheric TIA: transient hemiparesis, hemisensory loss, aphasia (dominant hemisphere)

— Amaurosis fugax (transient monocular blindness — "curtain coming down") from retinal artery embolism

— Recent (<6 months) ischemic stroke in carotid territory

— Incidentally discovered cervical bruit

— Pre-CABG or major vascular surgery workup in selected high-risk patients

— Patient with known PAD/CAD reporting nonspecific symptoms

— Rationale: low prevalence, harms of false positives (unnecessary angiography, periprocedural stroke), no demonstrated mortality benefit

— Does not apply to symptomatic patients or those with focal neurologic events

Definition: atherosclerotic narrowing of the extracranial internal carotid artery (ICA), graded by NASCET criteria as mild (<50%), moderate (50–69%), or severe (70–99%); near-occlusion and total occlusion are separate categories with distinct management.

Epidemiology:

When to suspect (symptomatic disease):

When to suspect (asymptomatic disease):

USPSTF screening recommendation (2021): Grade D — recommend against screening for asymptomatic carotid stenosis in the general adult population.

Step 3 management: A 68-year-old man on routine visit has an asymptomatic cervical bruit. Do not order carotid duplex reflexively — auscultation alone is not an indication. Order duplex only if he has had focal neurologic symptoms referable to a carotid territory.

Board pearl: Vertigo, syncope, generalized weakness, and bilateral visual loss are not carotid-territory symptoms — workup should pivot to posterior circulation or cardiac etiology, not carotid duplex.

Presentation Patterns and Key History

— TIA features: sudden onset, focal, lasts minutes (typically <1 hour), full resolution; ABCD² score helps risk-stratify 2-day stroke risk

— Anterior circulation localization: contralateral arm/face weakness or numbness, expressive/receptive aphasia (left/dominant), neglect or constructional apraxia (right/nondominant), gaze deviation toward the lesion

— Amaurosis fugax: painless transient monocular vision loss, described as a shade or curtain; lasts seconds to minutes; from cholesterol embolus (Hollenhorst plaque) to ophthalmic/retinal artery

— Stroke: same deficits but persistent ≥24 h or with imaging correlate

— Exact timing, duration, and laterality of symptoms

— Whether symptoms are stereotyped (recurrent same deficit suggests fixed plaque)

— Vascular risk factors: smoking pack-years, BP/lipid/glucose control, family history of premature stroke or MI

— Prior cardiovascular events: MI, PAD, prior CEA/stenting

— Current antiplatelet, statin, anticoagulant use

— Atrial fibrillation history (alternative embolic source — changes management)

— Functional baseline and life expectancy (revascularization requires ≥3–5 year expected survival to benefit)

Symptomatic vs asymptomatic is the single most important historical distinction — it drives every downstream decision.

Symptomatic carotid stenosis (within prior 6 months):

Crescendo TIA: ≥2 TIAs in 24 h or ≥3 in 72 h — medical emergency, admit for urgent workup and expedited revascularization.

Asymptomatic: no neurologic events in 6 months, despite documented stenosis.

Key historical elements to obtain:

Key distinction: Posterior circulation symptoms — vertigo, diplopia, dysarthria, dysphagia, ataxia, bilateral visual symptoms, drop attacks — point to vertebrobasilar disease, not carotid. Carotid duplex is the wrong test.

Board pearl: Globally non-focal symptoms (lightheadedness, "feeling weak all over," presyncope) are not TIAs regardless of bruit findings; pursue cardiac, metabolic, or orthostatic causes instead.

Physical Exam Findings and Hemodynamic Assessment

— Auscultate over the carotid bifurcation (just below the angle of the mandible) with the diaphragm during quiet breath-holding

— A bruit suggests turbulence but correlates poorly with degree of stenosis: it can be absent in critical stenosis (flow too low) and present with non-stenotic turbulence

— Sensitivity ~50%, specificity ~60% for ≥70% stenosis

— Distinguish from a transmitted cardiac murmur (aortic stenosis radiates to carotids — listen at the base of the heart first)

— Full NIH Stroke Scale if recent event

— Look for subtle residual deficits: pronator drift, mild dysarthria, visual field cuts (homonymous hemianopia from posterior MCA/PCA watershed)

— Fundoscopy: Hollenhorst plaques (bright, refractile cholesterol emboli at retinal artery bifurcations) confirm embolic source; retinal pallor in branch retinal artery occlusion

— Check BP in both arms (>15 mmHg difference suggests subclavian stenosis)

— Palpate peripheral pulses; auscultate abdominal, femoral bruits — atherosclerosis is systemic

— Look for signs of heart failure, AAA, or PAD

— Severe bilateral carotid disease can produce hemodynamic TIAs triggered by orthostasis, dehydration, or aggressive BP lowering

— Watershed infarcts (anterior/posterior MCA borderzone) suggest hypoperfusion rather than pure embolic mechanism

Cervical bruit:

Neurologic exam:

General vascular exam:

Cardiac auscultation: rule out AS (radiates to carotids), AF (alternative embolic source), and S3/S4.

Hemodynamic considerations:

Step 3 management: Asymptomatic 72-year-old with isolated carotid bruit and no neurologic symptoms — do not order carotid duplex. Document the bruit, optimize cardiovascular risk factors (statin, BP, antiplatelet if indicated by ASCVD risk), and continue routine care.

Board pearl: The absence of a bruit does not rule out severe stenosis; the presence of one is not an indication for imaging absent symptoms or planned high-risk surgery.

Diagnostic Workup — Initial Labs and Imaging

— Noninvasive, no contrast, no radiation, widely available, inexpensive

— Measures peak systolic velocity (PSV), end-diastolic velocity, and ICA/CCA ratio

— PSV ≥125 cm/s → ≥50% stenosis; PSV ≥230 cm/s → ≥70% stenosis

— Limitations: operator-dependent; calcification creates shadowing; differentiation of near-occlusion from total occlusion is difficult on DUS alone

— Recent (<6 months) TIA or non-disabling ischemic stroke in carotid territory

— Amaurosis fugax with cholesterol embolus on fundoscopy

— Hollenhorst plaque incidentally identified

— Pre-op evaluation in selected patients with prior stroke/TIA undergoing CABG

— Not indicated: asymptomatic bruit, nonspecific dizziness, syncope, isolated headache

— CBC, BMP (renal function before contrast)

— Fasting lipid panel, HbA1c

— ECG and telemetry monitoring to evaluate for atrial fibrillation (alternative embolic source)

— Troponin if any chest symptoms or ECG changes

— TSH, hypercoagulability workup only in young patients or cryptogenic stroke

— Noncontrast head CT first to exclude hemorrhage (especially if tPA candidate)

— MRI brain with DWI is more sensitive for small acute infarcts and identifies clinically silent strokes — guides urgency

First-line imaging when carotid evaluation is indicated: carotid duplex ultrasound (DUS)

Indications for carotid imaging (Step 3-relevant):

Adjunctive labs at the time of TIA/stroke workup:

Brain imaging in symptomatic patients:

CCS pearl: For a patient with new TIA, order in parallel — head CT (now), ECG (now), carotid duplex (today), labs (now), echocardiogram (within 24–48 h), and admit or fast-track TIA clinic depending on ABCD² score.

Board pearl: In the patient with recent TIA, carotid duplex within 24 hours is the standard — delayed imaging misses the window when revascularization most effectively prevents recurrent stroke (greatest benefit if performed <2 weeks).

Diagnostic Workup — Advanced and Confirmatory Studies

— Excellent spatial resolution; visualizes aortic arch, full extracranial and intracranial circulation

— Differentiates near-occlusion ("string sign") from total occlusion — critical because totally occluded ICAs are not revascularized

— Identifies tandem intracranial lesions that may alter strategy

— Limitations: iodinated contrast (caution in CKD), radiation, heavy calcium can overestimate stenosis

— Time-of-flight (no contrast) or contrast-enhanced (gadolinium)

— Tends to overestimate stenosis severity; flow gaps can mimic occlusion

— Useful in patients with iodine allergy or moderate CKD (use TOF if eGFR <30)

— Historical gold standard; now reserved for discordant noninvasive studies or planned stenting

— Risk of periprocedural stroke ~0.5–1% — not a screening tool

— Most centers require two concordant noninvasive studies (DUS + CTA or DUS + MRA) before revascularization, especially for asymptomatic stenosis

— If discordant → DSA or repeat with corroborating modality

— TTE first; TEE if mechanism unclear (PFO, LAA thrombus, aortic arch atheroma)

— Prolonged ambulatory rhythm monitoring (30-day event monitor or implantable loop recorder) if cryptogenic — paroxysmal AF found in up to 30%

CT angiography (CTA) head and neck:

MR angiography (MRA):

Digital subtraction angiography (DSA):

Confirmatory strategy:

Cardiac embolic source evaluation in any TIA/stroke patient:

Step 3 management: A patient with recent left-hemispheric TIA has duplex showing 70–99% left ICA stenosis. Confirm with CTA neck before scheduling CEA — do not proceed to surgery on duplex alone unless your institution's accredited lab has a documented concordance protocol.

Key distinction: Near-occlusion (string sign) with collapsed distal ICA behaves more like total occlusion — revascularization benefit is uncertain to absent; treat with optimal medical therapy rather than urgent CEA/CAS.

Risk Stratification and Management Logic

— Symptomatic vs asymptomatic

— Degree of stenosis (NASCET method)

— Surgical/procedural risk and life expectancy

— 70–99% stenosis: revascularization clearly beneficial — NASCET showed absolute risk reduction ~16% over 2 years (NNT ~6)

— 50–69% stenosis: moderate benefit, particularly in men, age >75, hemispheric (not retinal-only) symptoms — NNT ~22

— <50% stenosis: medical therapy only; revascularization harmful

— Near-occlusion or total occlusion: medical therapy only

— ≥70% stenosis: revascularization yields small absolute benefit (~1% per year stroke risk reduction) only if perioperative stroke/death rate <3% and life expectancy ≥3–5 years

— Modern intensive medical therapy (high-intensity statin, dual or single antiplatelet, BP and DM control, smoking cessation) has narrowed this benefit substantially

— Many guidelines now favor medical therapy for most asymptomatic patients

— <70%: medical therapy only

— Within 2 weeks of index event is optimal — greatest absolute risk reduction

— Avoid within 48 h of a large completed stroke (risk of hemorrhagic conversion)

— Crescendo TIA → urgent intervention

The central decision tree rests on three factors:

Symptomatic patients (TIA or non-disabling stroke <6 months):

Asymptomatic patients:

Timing of revascularization (symptomatic):

Patient factors favoring CEA over CAS: age >70, tortuous aortic arch, heavy plaque calcification

Factors favoring CAS over CEA: prior neck surgery/radiation, high cervical lesion, severe cardiopulmonary comorbidity, restenosis after prior CEA

Step 3 management: For symptomatic 70–99% stenosis, target CEA within 14 days while concurrently starting high-intensity statin, antiplatelet, and BP control. Do not delay medical therapy waiting for surgery.

Board pearl: The most important number to memorize — revascularization is only justified if perioperative stroke/death rate <6% (symptomatic) or <3% (asymptomatic).

Pharmacotherapy — First-Line Regimen

— Aspirin 81 mg daily is the default lifelong agent for all patients with carotid atherosclerosis (symptomatic or asymptomatic)

— Clopidogrel 75 mg is an acceptable alternative, particularly in aspirin intolerance

— DAPT (aspirin + clopidogrel) after recent minor stroke or high-risk TIA (ABCD² ≥4): use for 21 days (CHANCE/POINT trials), then de-escalate to monotherapy — longer DAPT increases bleeding without further benefit

— DAPT for 1–3 months after carotid stenting (procedure-specific), then aspirin monotherapy lifelong

— High-intensity statin for all: atorvastatin 40–80 mg or rosuvastatin 20–40 mg daily

— LDL target <70 mg/dL (some guidelines now <55 mg/dL for very high-risk ASCVD)

— Add ezetimibe if LDL not at goal, then PCSK9 inhibitor for refractory cases

— Statins have plaque-stabilizing and anti-inflammatory effects beyond LDL lowering

— Target <130/80 mmHg per AHA/ACC for established ASCVD

— First-line: ACEi/ARB or thiazide; add CCB as needed

— Avoid aggressive lowering in acute symptomatic phase if severe bilateral disease (risk of hemodynamic TIA)

Antiplatelet therapy (cornerstone of stroke prevention):

Statin therapy:

Blood pressure control:

Diabetes management: A1c individualized (~7%); prefer GLP-1 RAs or SGLT2 inhibitors for cardiovascular risk reduction

Smoking cessation: highest-yield modifiable risk factor; offer varenicline, bupropion, or NRT plus counseling at every visit

Anticoagulation: not indicated for carotid stenosis alone; reserved for concomitant AF, mechanical valve, or specific thrombophilia

Step 3 management: For a new TIA patient with 80% symptomatic stenosis: start aspirin 81 mg + clopidogrel 75 mg (DAPT × 21 days), atorvastatin 80 mg, lisinopril titrated to goal, smoking cessation counseling, and schedule CEA within 14 days.

Board pearl: Adding warfarin or a DOAC to antiplatelet therapy for carotid stenosis without AF increases bleeding without reducing stroke — a common distractor.

Procedures — Revascularization Options

— Gold standard; open surgical removal of plaque via cervical incision

— Performed under general or regional anesthesia; shunt and patch angioplasty per surgeon preference

— Periprocedural stroke/death risk: 2–3% at experienced centers

— Cranial nerve injury (hypoglossal, marginal mandibular, recurrent laryngeal) in 3–7%, mostly transient

— Preferred in: age >70, anatomically accessible lesions, low surgical risk

— Endovascular balloon angioplasty with self-expanding stent and embolic protection device

— Higher periprocedural stroke risk (especially in elderly, tortuous arches)

— Lower MI risk than CEA

— Preferred in: prior neck surgery/radiation, high cervical lesions, restenosis after CEA, severe cardiopulmonary disease

— Newer hybrid technique with direct common carotid access and flow reversal for embolic protection

— Lower stroke risk than transfemoral CAS; intermediate risk profile

— Increasingly favored in high-surgical-risk patients

— Continue aspirin throughout the perioperative period

— Add clopidogrel ≥5 days before CAS/TCAR; continue DAPT 1–3 months post-stent

— Strict BP control to prevent hyperperfusion syndrome

— Duplex at 1 month, 6 months, 12 months, then annually

— Watch for restenosis (5–10% at 1–2 years)

— Total ICA occlusion

— Life expectancy <3–5 years

— Severe disabling stroke with poor recovery potential

— Active intracranial hemorrhage

Carotid endarterectomy (CEA):

Carotid artery stenting (CAS) — transfemoral:

Transcarotid artery revascularization (TCAR):

Periprocedural management:

Post-procedure surveillance:

Contraindications to revascularization:

CCS pearl: Post-CEA, order neuro checks q1h × 4 then q2h, strict BP control (SBP 100–140), aspirin continued, monitor for neck hematoma (airway emergency), and discharge home POD 1–2 with surgery follow-up in 2 weeks and duplex at 1 month.

Board pearl: Carotid revascularization is not appropriate for an acute completed stroke; wait until clinical stabilization (often 1–2 weeks) to avoid hemorrhagic conversion.

Special Populations — Elderly and Renal/Hepatic Impairment

— Higher absolute stroke risk → larger absolute benefit from revascularization if life expectancy and functional status permit

— CEA preferred over CAS in this population — CREST trial showed significantly higher periprocedural stroke risk with stenting in patients >70

— Carefully assess frailty, cognitive baseline, and goals of care before offering surgery

— Asymptomatic stenosis in patients >80 with multiple comorbidities: medical therapy alone is usually appropriate

— eGFR <30: avoid iodinated contrast (CTA) if possible — use duplex + MRA (TOF, non-contrast) for confirmation

— Hold metformin around contrast administration if eGFR <30 or AKI

— Provide IV isotonic saline hydration pre/post contrast in moderate CKD

— Avoid gadolinium-based contrast if eGFR <30 (NSF risk with older agents); use group II macrocyclic agents cautiously if essential

— Statin dosing largely unchanged in CKD; avoid simvastatin >40 mg

— Statins are first-line even with stable chronic liver disease and Child-Pugh A; avoid in decompensated cirrhosis

— Check transaminases at baseline; mild elevations (<3× ULN) are not a contraindication

— Substitute pravastatin or rosuvastatin (less hepatic metabolism) if concerns

— Higher GI bleed risk → add PPI for those with prior GI bleed, age >75, or concomitant NSAIDs

— Reassess bleeding risk continuously; never extend DAPT beyond evidence-based duration (21 days post-TIA, 1–3 months post-CAS)

Elderly (≥75–80 years):

Renal impairment:

Hepatic impairment:

Dual antiplatelet considerations in elderly:

Step 3 management: An 82-year-old with 75% symptomatic left ICA stenosis, eGFR 28, and good functional status: confirm with duplex + TOF MRA (no contrast), proceed to CEA within 2 weeks (avoid CAS at this age), high-intensity statin, aspirin, intensive BP control.

Board pearl: Age alone is not a contraindication to CEA; frailty, dementia with poor functional baseline, and life expectancy <3 years are the relevant disqualifiers.

Special Populations — Pregnancy, Younger Patients, and Other Subgroups

— Atherosclerotic carotid stenosis is rare in reproductive-age women

— When carotid arterial pathology occurs in pregnancy, consider carotid dissection (especially peripartum), fibromuscular dysplasia (FMD), vasculitis (Takayasu in young women), or moyamoya

— Imaging: duplex first; MRA without gadolinium if needed; avoid CTA radiation

— Management individualized with neurology, MFM, and vascular surgery

— Atherosclerosis less common — pursue alternative etiologies

— Carotid/vertebral dissection: consider with neck pain, recent trauma/chiropractic manipulation, Horner syndrome; treat with antiplatelet or anticoagulation (CADISS trial — equivalent outcomes)

— Fibromuscular dysplasia: "string of beads" on imaging, mid-to-distal ICA; screen for renal artery FMD

— Vasculitis (Takayasu, GCA in older), connective tissue disease (Ehlers-Danlos type IV, Marfan), radiation-induced stenosis (prior head/neck cancer)

— Accelerated, diffuse, often bilateral carotid disease

— Surgical planes are scarred — CAS or TCAR preferred over CEA

— Combined or staged CEA + CABG remains controversial; decision individualized by symptom dominance and lesion severity

— Symptomatic carotid disease + asymptomatic CAD → carotid first

— High surgical risk → favor CAS or TCAR

Pregnancy:

Young patients (<50) with carotid disease or stroke:

Patients with prior head/neck radiation:

Patients with concurrent severe CAD:

Patients with severe COPD, CHF, or unstable cardiac disease:

Step 3 management: A 34-year-old woman with right hemispheric TIA and right ICA "string of beads": diagnose FMD, start antiplatelet therapy, screen renal arteries with imaging, evaluate for refractory HTN, and refer to vascular medicine — not to revascularization unless flow-limiting and symptomatic despite medical therapy.

Key distinction: Carotid dissection in a young patient with neck pain after minor trauma is the classic "do not miss" — treat medically, not surgically.

Complications and Adverse Outcomes

— Recurrent stroke risk up to 15–20% in first 2 weeks after TIA — drives urgency of revascularization

— Disabling stroke with permanent neurologic deficit

— Vascular dementia from accumulated silent infarcts

— Stroke (2–3% at experienced centers) from embolization or clamp ischemia

— MI (1–2%) — leading cause of 30-day mortality

— Cranial nerve injury (3–7%): hypoglossal (tongue deviation toward lesion), marginal mandibular branch of facial (asymmetric smile), recurrent laryngeal (hoarseness), great auricular (earlobe numbness) — most transient

— Neck hematoma: airway emergency — bedside opening of incision may be life-saving

— Hyperperfusion syndrome: ipsilateral headache, seizures, ICH 2–7 days postop after revascularization of critical stenosis; risk reduced by strict BP control

— Restenosis (5–10% at 1–2 years), often from neointimal hyperplasia

— Stroke (higher than CEA, especially in elderly)

— Distal embolization during plaque disruption

— Access site hematoma, pseudoaneurysm, retroperitoneal bleed (transfemoral)

— Bradycardia/hypotension from carotid sinus stimulation during balloon inflation — pretreat with atropine

— In-stent restenosis (~5%)

— GI bleeding, especially with prolonged DAPT, NSAIDs, or anticoagulant co-therapy

— Intracranial hemorrhage rare but devastating

Of untreated symptomatic severe stenosis:

Periprocedural complications of CEA:

Periprocedural complications of CAS:

Bleeding from antiplatelet/DAPT:

CCS pearl: Post-CEA patient develops severe ipsilateral throbbing headache, BP 200/110, then a seizure on POD 3 — recognize hyperperfusion syndrome, aggressively lower BP with IV labetalol or nicardipine to SBP <140, get CT head to exclude ICH, and admit to ICU.

Board pearl: Tongue deviation toward the operative side after CEA = ipsilateral hypoglossal (CN XII) injury; usually resolves in weeks.

When to Escalate Care — ICU, Consult, and Inpatient Triage

— Any acute ischemic stroke (regardless of severity)

— Crescendo TIAs (≥2 in 24 h or ≥3 in 72 h)

— TIA with ABCD² score ≥4 or symptomatic ≥50% carotid stenosis discovered on workup

— Patient awaiting expedited CEA/CAS within 14 days

— Large MCA territory stroke with risk of malignant edema

— Post-CEA or post-CAS within first 12–24 h if hemodynamically labile, severe contralateral disease, or prior hyperperfusion

— Hyperperfusion syndrome with seizure or ICH

— Airway compromise from neck hematoma

— Status epilepticus

— Neurology/stroke service: all TIA and stroke patients — diagnosis confirmation, mechanism workup, tPA/thrombectomy eligibility in acute setting

— Vascular surgery: for any symptomatic ≥50% or asymptomatic ≥70% stenosis being considered for revascularization

— Interventional neuroradiology or vascular surgery (endovascular): for CAS/TCAR candidates

— Cardiology: if AF, severe CAD, or planned combined surgical approach

— Anesthesia preop clinic: for elderly or comorbid surgical candidates

— Appropriate for low-risk TIA (ABCD² <4) without ongoing symptoms, with reliable patient and rapid same-day imaging/labs

— Many systems use this to safely avoid admission while ensuring 24-hour workup

— Large vessel occlusion candidate for thrombectomy

— Need for advanced neuro-imaging or neurosurgical backup

— High-risk revascularization needing specialized vascular team

Admit to stroke unit or inpatient telemetry:

ICU-level care indications:

Urgent consultations:

Outpatient TIA clinic (rapid-access pathway):

Transfer to comprehensive stroke center:

Step 3 management: Patient with TIA today, ABCD² of 5, and 75% symptomatic ICA stenosis on outpatient duplex — admit, start DAPT and high-intensity statin, BP control, MRI brain, echo, telemetry, and arrange CEA within 14 days. Do not send home.

Key Differentials — Within Cerebrovascular Disease

— Atrial fibrillation is the leading cardioembolic cause — workup with ECG, telemetry, prolonged monitoring (30-day or implantable loop in cryptogenic stroke)

— LV thrombus post-MI, dilated cardiomyopathy with EF <35%

— Mechanical or rheumatic valve disease

— Endocarditis (fever, new murmur, Janeway/Osler lesions)

— PFO with paradoxical embolism (younger patients, Valsalva-related event)

— Aortic arch atheroma ≥4 mm

— Distinguishing feature: strokes in multiple vascular territories simultaneously strongly suggest cardioembolism, not carotid

— Lipohyalinosis of penetrating arteries from chronic HTN and DM

— Classic syndromes: pure motor, pure sensory, sensorimotor, ataxic hemiparesis, clumsy hand-dysarthria

— Small deep infarcts on MRI; no cortical signs; no carotid lesion responsible

— Vertigo, diplopia, dysarthria, dysphagia, ataxia, crossed deficits

— Workup: posterior circulation imaging (CTA/MRA), not carotid duplex

— More common in Asian, Black, and Hispanic populations

— Treat with intensive medical therapy (SAMMPRIS trial — stenting worse than medical)

— Younger patient, neck pain/headache, often post-traumatic; Horner syndrome with carotid dissection

— Treat with antiplatelet or anticoagulation

Cardioembolic stroke/TIA:

Small vessel (lacunar) disease:

Vertebrobasilar (posterior circulation) disease:

Intracranial atherosclerosis:

Carotid or vertebral dissection:

Fibromuscular dysplasia: young women, "string of beads," mid-to-distal ICA

Vasculitis: Takayasu (young women), GCA (>50 with headache, jaw claudication, elevated ESR), primary CNS angiitis

Hypercoagulable states: antiphospholipid syndrome, factor V Leiden — consider in young or cryptogenic stroke

Key distinction: Same-side recurrent stereotyped events strongly suggest fixed carotid plaque; variable territory events with AF suggest cardioembolism — opposite management.

Key Differentials — Other-Category Mimics

— Seizures with Todd paralysis: transient weakness after focal seizure — preceded by positive symptoms (twitching, march), longer duration of postictal deficit, history of seizure disorder

— Complicated migraine (hemiplegic migraine): young patient, headache, slow-march positive sensory symptoms (visual scotoma evolving), then deficit; family history common

— Hypoglycemia: can mimic any focal deficit; always check fingerstick glucose in any acute neurologic presentation

— Conversion disorder/functional neurologic disorder: inconsistent exam, Hoover sign, give-way weakness

— Syncope/presyncope: global LOC without focal deficit — not a TIA

— Peripheral vestibular disease (BPPV, vestibular neuritis): isolated vertigo with positional triggers; HINTS exam differentiates from central causes

— Bell palsy: isolated peripheral CN VII (forehead involved) — distinct from cortical facial weakness which spares forehead

— Mononeuropathy (e.g., radial nerve palsy, peroneal palsy) misread as central weakness

— Giant cell arteritis — older patient, jaw claudication, scalp tenderness, elevated ESR/CRP — emergent steroids, biopsy

— Optic neuritis (MS) — painful, monocular, subacute over days

— Retinal vein occlusion — sudden painless vision loss, often complete and persistent

— Migraine aura with visual symptoms — bilateral homonymous, slow march

— Radiated aortic stenosis murmur — auscultate base of heart, check for systolic ejection murmur and delayed carotid upstroke (pulsus parvus et tardus)

— Venous hum (benign in young patients, disappears with neck rotation)

— Hyperdynamic states (anemia, thyrotoxicosis, pregnancy)

Stroke and TIA mimics (clinical events that look neurologic but are not vascular):

Causes of amaurosis fugax mimics:

Causes of cervical bruit mimics:

Step 3 management: Any patient presenting with new "focal weakness" gets immediate fingerstick glucose, BP, ECG, and noncontrast head CT before deciding the event is a TIA — missing hypoglycemia or hemorrhage is a sentinel error.

Board pearl: Forehead-sparing facial weakness = central (UMN); forehead-involved = peripheral (Bell palsy) — not carotid territory.

Secondary Prevention and Long-Term Plan

— Antiplatelet therapy: aspirin 81 mg daily indefinitely (or clopidogrel if intolerant); DAPT only for guideline-specified short windows

— High-intensity statin (atorvastatin 80 mg or rosuvastatin 40 mg) with LDL goal <70 mg/dL; ezetimibe or PCSK9i if needed

— BP target <130/80 mmHg with ACEi/ARB, thiazide, or CCB

— Diabetes: A1c ~7%; prefer GLP-1 RA or SGLT2i for cardiovascular benefit

— Smoking cessation: counseling + pharmacotherapy at every visit

— Physical activity: ≥150 min/week moderate aerobic activity

— Diet: Mediterranean or DASH; sodium <2.3 g/day

— Weight management: BMI 18.5–24.9; address obesity with lifestyle, GLP-1 RA as indicated

— Moderate alcohol at most; avoid binge drinking

— Aspirin 81 mg (lifelong)

— Clopidogrel 75 mg (21 days post-TIA; or 1–3 months post-CAS, then stop)

— Atorvastatin 80 mg

— Lisinopril (titrated)

— PPI if DAPT and high GI bleed risk

— Influenza vaccine annually, COVID-19 boosters, pneumococcal per schedule

— Strict BP control to prevent hyperperfusion (first 1–2 weeks)

— Wound check; report neck swelling immediately

— Resume normal activity gradually; no heavy lifting × 2 weeks (post-CEA)

— Primary care follow-up within 1–2 weeks of discharge

— Stroke/vascular neurology at 1 month

— Vascular surgery follow-up with surveillance duplex at 1, 6, 12 months, then annually

Lifelong medical optimization is the foundation regardless of revascularization status:

Discharge medications after TIA/stroke or revascularization (typical bundle):

Post-revascularization-specific:

Care coordination:

Step 3 management: At discharge after CEA, the "ABCDES" bundle — Antiplatelet, BP control, Cholesterol (statin), Diabetes/Diet, Exercise/Education, Smoking cessation — operationalizes secondary prevention.

Follow-Up, Monitoring, and Counseling

— Carotid duplex at 1 month, 6 months, and 12 months, then annually

— Watch for restenosis (5–10% at 1–2 years): typically asymptomatic neointimal hyperplasia at <2 years; recurrent atherosclerosis at >2 years

— Repeat revascularization considered for symptomatic restenosis ≥70%

— Annual duplex if known stenosis ≥50%

— Less frequent (every 2–3 years) if <50% and stable

— Lipid panel 4–12 weeks after statin initiation/change, then every 6–12 months

— BMP every 6–12 months if on ACEi/ARB or diuretic

— A1c every 3–6 months if diabetic

— Liver enzymes only if symptomatic on statin (not routine)

— Stroke survivors: PT/OT/speech therapy as indicated; cognitive screening (MoCA) at 1–3 months; screen for post-stroke depression (PHQ-9) at every visit

— Driving: most states require physician notification or symptom-free period (typically ≥3 months) — know your state's specific reporting laws

— Return-to-work guidance individualized

— Sexual activity safe once cardiovascular status stable

— Sudden facial droop, arm weakness, speech difficulty (FAST)

— Sudden monocular vision loss

— Severe headache, especially post-revascularization (hyperperfusion warning)

— Neck swelling, difficulty breathing post-CEA

— Verify smoking status, BP logs, glucose/A1c, medication adherence at every visit

— Use shared decision-making tools for ongoing risk discussions

Surveillance imaging post-revascularization:

Surveillance of contralateral asymptomatic disease:

Medication monitoring:

Counseling and rehabilitation:

Patient education red flags requiring 911:

Lifestyle adherence checks:

Step 3 management: A patient 6 months post-CEA reports a new TIA: order urgent duplex of the operated side (restenosis?), repeat brain imaging, evaluate medication adherence, and re-engage vascular surgery — do not assume the issue is purely medical.

Board pearl: Post-stroke depression affects ~30% of patients and worsens functional recovery — screen routinely with PHQ-9 and treat with SSRIs (sertraline first-line).

Ethical, Legal, and Patient Safety Considerations

— Must disclose periprocedural stroke/death rate, MI risk, cranial nerve injury, restenosis risk

— Compare with risks of medical management

— Document understanding of alternatives, including watchful waiting with intensive medical therapy — especially important for asymptomatic stenosis where benefit is modest

— Use shared decision-making aids when available; document the conversation

— Aphasic patients may retain decisional capacity; use yes/no questions, writing, or AAC tools before declaring incapacity

— Neglect, anosognosia, or dementia may impair capacity — involve surrogate per state law and POLST/MOLST documents

— Avoid defaulting to family without first attempting direct patient assessment

— Some states (e.g., California, Pennsylvania, Nevada, New Jersey, Oregon, Delaware) mandate physician reporting of conditions impairing driving — know your jurisdiction

— Advise all post-stroke patients of driving restrictions; document the discussion

— TIA patients: typically a symptom-free interval (1 month commonly) before resuming driving

— High-risk hand-off after TIA — must ensure 24–48 hour follow-up, medication reconciliation, expedited surgical scheduling

— Discharge from ED without confirmed duplex and follow-up is a sentinel safety event

— Closed-loop communication with PCP via direct call or secure message, not just an EHR note

— Disparities in stroke care: women, Black, and Hispanic patients receive less timely revascularization — actively address access barriers

— Verify insurance coverage and arrange social work support for procedure scheduling and medication affordability

— USPSTF Grade D — do not screen asymptomatic adults with carotid duplex; ordering it without indication exposes patients to false positives, unnecessary angiography, and harm

Informed consent for revascularization:

Capacity assessment in stroke patients:

Driving and reporting laws:

Transitions of care (Step 3 staple):

Health equity considerations:

Avoiding overtreatment:

Step 3 management: A 78-year-old with mild dementia and asymptomatic 80% stenosis: engage the surrogate, weigh life expectancy and procedural risk, document a shared decision often favoring medical therapy — not every severe stenosis needs surgery.

High-Yield Associations and Rapid-Fire Facts

NASCET method: stenosis = (1 – minimum residual lumen / normal distal ICA diameter) × 100

Symptomatic 70–99% stenosis: CEA within 14 days — NNT ~6 over 2 years

Symptomatic 50–69%: modest CEA benefit; favor men, age >75, hemispheric symptoms

Asymptomatic ≥70%: revascularize only if perioperative stroke/death <3% and life expectancy ≥3–5 years

Periprocedural threshold: <6% (symptomatic), <3% (asymptomatic) for benefit

DAPT after TIA/minor stroke: 21 days (CHANCE/POINT); longer = bleeding without benefit

DAPT after CAS: 1–3 months, then aspirin monotherapy

Amaurosis fugax + Hollenhorst plaque → carotid duplex

Ipsilateral TIA + 80% stenosis → CEA within 2 weeks

String sign / near-occlusion → medical therapy, not revascularization

Total ICA occlusion → no revascularization benefit

CEA preferred if age >70, accessible anatomy, low surgical risk

CAS/TCAR preferred if prior radiation/neck surgery, high cervical lesion, severe cardiopulmonary disease

CREST trial: CEA and CAS similar overall; CEA fewer strokes, CAS fewer MIs; CEA better in elderly

NASCET, ECST: established symptomatic CEA benefit; ACAS, ACST: asymptomatic benefit (modest, pre-statin era)

SAMMPRIS: intracranial stenting worse than medical therapy

POINT/CHANCE: DAPT × 21 days post-TIA

CADISS: antiplatelet = anticoagulant for cervical dissection

Cranial nerves at risk in CEA: CN XII (tongue deviates toward lesion), CN VII marginal mandibular branch (smile asymmetry), CN X recurrent laryngeal (hoarseness), great auricular (earlobe numbness)

Hyperperfusion syndrome: unilateral throbbing headache, seizure, ICH 2–7 days post-revasc; severe HTN risk factor

Carotid sinus reflex during CAS balloon inflation → bradycardia, hypotension — pretreat with atropine

Hollenhorst plaque = bright cholesterol embolus at retinal arteriole bifurcation

USPSTF: Grade D — do not screen asymptomatic adults with carotid duplex

Board pearl: When in doubt on Step 3 — symptomatic + ≥70% + accessible anatomy + reasonable life expectancy = CEA within 2 weeks; asymptomatic in a high-risk elderly patient with comorbidities = medical therapy.

Board Question Stem Patterns

— 68 y/o man, 30 pack-year smoker, transient painless monocular vision loss yesterday lasting 5 minutes; fundoscopy shows refractile plaque

— Answer: order carotid duplex; expect ≥50% ipsilateral ICA stenosis

— Next step if 80% stenosis: aspirin + statin + CEA within 14 days

— 70 y/o asymptomatic woman at annual visit, cervical bruit noted; otherwise well

— Wrong answers: duplex, CTA, angiography

— Correct: optimize ASCVD risk factors (statin, BP, antiplatelet per risk), no carotid imaging (USPSTF Grade D)

— Three episodes of right arm weakness over 48 h, fully resolved

— Action: admit, urgent duplex, DAPT × 21 days, high-intensity statin, expedited CEA

— Patient with vertigo, diplopia, ataxia, dysarthria

— Wrong answer: carotid duplex

— Correct: posterior circulation imaging (CTA/MRA head and neck)

— 80% stenosis with "string sign" and collapsed distal ICA after symptomatic TIA

— Wrong answer: urgent CEA

— Correct: intensive medical therapy; surgical benefit unclear

— POD 3 after CEA, severe ipsilateral headache, BP 210/115, then seizure

— Action: aggressive BP control (IV labetalol/nicardipine to SBP <140), CT head, ICU

— Day 1 post-CEA, tongue deviates toward surgical side

— Diagnosis: ipsilateral hypoglossal (CN XII) injury — usually transient

— 35 y/o woman with TIA, MRA shows mid-distal ICA beading

— Diagnosis: FMD; treat antiplatelet, screen renal arteries

— Acute hemiparesis, glucose 38 — give dextrose first; deficit resolves

— Correct: medical therapy; revascularization not indicated due to limited life expectancy

Pattern 1 — "Curtain over the eye":

Pattern 2 — "Bruit without symptoms":

Pattern 3 — "Crescendo TIA":

Pattern 4 — "Wrong territory":

Pattern 5 — "Near-occlusion trap":

Pattern 6 — "Hyperperfusion":

Pattern 7 — "Tongue deviation":

Pattern 8 — "Young woman with string of beads":

Pattern 9 — "Hypoglycemia mimic":

Pattern 10 — "Asymptomatic ≥70% in 85-year-old with dementia":

Board pearl: Look for the timing of symptoms — "yesterday" or "this week" with severe stenosis = expedite CEA within 14 days; >6 months ago = treat as asymptomatic.

One-Line Recap

Carotid stenosis management hinges on symptoms, severity, and surgical risk: revascularize symptomatic 70–99% stenosis within 14 days, individualize 50–69%, and treat virtually all asymptomatic disease with intensive medical therapy unless ≥70% stenosis coexists with low surgical risk and ≥3–5 years of life expectancy.

Workup trigger: Order carotid duplex only for patients with carotid-territory symptoms (TIA, non-disabling stroke, amaurosis fugax) — not for asymptomatic bruits (USPSTF Grade D).

Revascularization rule: Symptomatic ≥70% stenosis → CEA within 14 days at a center with periprocedural stroke/death <6%; symptomatic 50–69% → individualize; asymptomatic ≥70% → revascularize only if <3% periprocedural risk and life expectancy ≥3–5 years; near-occlusion or total occlusion → medical therapy only.

Medical therapy is universal: aspirin 81 mg lifelong, high-intensity statin to LDL <70, BP <130/80, A1c ~7%, smoking cessation, Mediterranean diet, exercise — and DAPT × 21 days after TIA/minor stroke or 1–3 months after CAS.

Common traps: posterior circulation symptoms (vertigo, diplopia, ataxia) are not carotid; hypoglycemia and seizure with Todd paralysis mimic stroke (always check glucose); string sign behaves like occlusion; tongue deviating toward the side of recent CEA = CN XII injury; severe headache + HTN days after CEA = hyperperfusion syndrome until proven otherwise.

Step 3 final answer mindset: Pair every revascularization decision with intensive medical optimization, structured follow-up (duplex at 1, 6, 12 months then annually; PCP within 1–2 weeks; neurology and vascular surgery follow-up), post-stroke depression screening, and shared decision-making documented in the chart — particularly when life expectancy or asymptomatic status makes the benefit margin narrow.