Nejm 2002;347:1687

Cause:Carotid or aortic arch (Nejm 1992;326:221) plaque and/or platelet emboli, cardiac emboli, vascular spasm, hypercoagulable states, and idiopathic

Pathophys:Most thought to be from platelet emboli generated in eddies downstream from carotid stenotic areas; plaque ulcerations correlate poorly with TIA; occasionally are vasospastic; can rx w calcium channel blocker (Nejm 1993;329:396)

Sx:

Lateralized neurologic sx, usually lasting <5-10 min but always <1 h w no evidence of CVA by imaging (Nejm 2002;347:1713)

Anterior circulation sx: amaurosis fugax (Stroke 1990;21:201), weakness of arm > face > leg paresis (middle cerebral artery pattern), leg > arm > face paresis (anterior cerebral artery pattern)

Posterior circulation sx: bilateral blindness, diplopia, numbness in face and mouth, slurred speech, quadriplegia

Si:

Carotid bruit, but correlates poorly with symptomatic disease; in elderly, asx bruit present in 10% and does not correlate with CVA rate in or out of affected carotid distribution

Subsequent stroke, 5% w/i 2 d (Jama 2000;284:2901), 8% in 1st month, 5%/yr for 3 yr, 3%/yr thereafter; 41% will die of MI.

R/o tumor, can mimic exactly (Arch Neurol 1983;40:633); r/o carotid or vertebral dissections (see below); post-.zoster cerebral vasculitis (Nejm 2002;347:1500) if zoster w/i wks-mos ago, reversible w acyclovir rx iv; r/o hypoglycemia

Lab:

Noninv:(all about 85% sens and 90% specif Ann—IM 1995;122:360) Not substitutable for angiography (Nejm 1998;339:1415, 1468; Stroke 1995;26:1747)

• Carotid Doppler or duplex ultrasound
• Magnetic resonance angiography

Xray:CT to r/o bleed or MRI to r/o stroke (Neurol 2004;62:S29); carotid angiography, if ready to operate; % stenosis denominator is normal carotid, not bulb or post-stenotic dilated area

Rx:

of asx carotid bruit: (see below)

Meds:

• Aspirin 30 mg qd after 300-mg load as good as higher doses and has fewer side effects (Nejm 1991;325:1261); or as Aggrenox (Med Let 2000;42:11) long-acting 25 mg ASA + 200 mg dipyridamole po bid; better than ASA alone (NNT = 104—Nejm 2008;359:1238; ACP J Club 2006;145:57); $90/mo
• Clopidogrel (Plavix) 75 mg po qd
• Ticlopidine (Med Let 1992;34:65) 250 mg po qd but not as good as ASA (Jama 2003;289:2947) but causes gi side effects often and agranulocytosis in 1%, $80/mo
• Warfarin for people age >60 yr w Afib and intrinsic heart disease, hypertension, LVH, or previous TIA (Ann IM 1994;121:41, 54) (Transient Ischemic Attack)

Stenting (Nejm 2010; 363:1180, Nejm 2008;358:1572, Nejm 2006;355:1660, 1726) at least in patients less than 70, vs postop ASA and clopidogrel (Plavix) in high-risk pts (and maybe others?); as good as open endarterectomy vs postop risk of death or CVA 3× higher?

Surgical endarterectomy (Jama 1992;268:3120) of stenosis >70% (Nejm 1995;332:238), in patients with TIA or mild CVA reduces strokes by 17% (NNT = 6) (Nejm 1991;325:445); stenosis of 50-70% in symptomatic pts equivocally helped (Nejm 1998;339:1415). If asx carotid stenosis >60-70%, (NNT-5) = 16 (Nejm 2000;342:1743; Jama 1995;273:1421, 1459 vs Lancet 2004;363:1491; ACP J Club 2004;141:31; Nejm 2000;342:1693), and clearly if >80% (Ann IM 1995;123:720 vs 723; ACP J Club 1995;123[1]:2; Lancet 1995;345:209); but still debatable if asx (S. Kolkin 5/97) since NNT-3 = 36 (ACP J Club 1999;130:59), and cost per stroke avoided = $500K (Ann IM 1997;126:338); presumes a combined cmplc rate of angiography and surgery of <3%; often much higher morbidity in community hospitals, but only 1+% in big centers (Ann IM 2004;140:303)