Stroke: Due to ischemia 2/2 cerebrovascular occlusion. Typically thrombotic or embolic. P/w variety of neurologic sx incl. wkness, numbness, aphasia, dysarthria, gaze deviation, ataxia, gait instability. Sx usually acute onset, but may fluctuate or “stutter” over several days.
Risk factors: Age, HTN, hyperlipidemia, smoking, DM, hypercoagulability, cardiac arrhythmias, e.g., atrial fibrillation, cardiomyopathy, and cardiac thrombus, among many others.
Initial steps in evaluating acute stroke: Determine time last seen well. Note: If pt awakens w/sx, time of onset is when last seen normal, not discovery time.
Evaluate for acute recanalization or decompressive therapies when:
Presentation w/in 6 h of onset or any duration for basilar thrombus.
Large MCA or large cerebellar infarct (>1/3 cerebellum or encroaching fourth ventricle) w/risk of edema, hydrocephalus, of mass effect.
Determine if meets criteria for IV TPA. See below for indications & contraindications.
Contact neurointerventionalist or facility w/an interventional service to determine if candidate for IA TPA or mechanical clot retrieval.
IV TPA
Indications: Age ≥18 yr; significant neurologic deficit expected to result in longterm disability; CT brain does not show hemorrhage or well-established new infarct; acute ischemic stroke sx w/time of onset clearly defined as < 4.5 h. (NEJM 2008;359:131).
Contraindications (0-3 h)
Additional contraindications (3-4.5 h)
Hypodensity > 1/3 MCA territory on CT
All 0-3 h contraindications apply
Hemorrhage on CT
NIHSS > 25
Stroke, TBI, intracranial procedure < 3 mo
Oral anticoagulant use (regardless of PT/PTT)
h/o ICH, brain aneurysm, AVM, tumor
Combination of previous stroke and DM
Resolving or minimal deficit
Cautions for IV tPA
Suspicion of SAH
NIHSS > 22 (most centers still treat)
Trauma or surgery < 15 days
Glucose < 50 or > 400
Active or GI/GU bleeding < 22 days
Known L heart thrombus
Recent LP or noncompressible arterial puncture
Pericarditis, endocarditis, high risk for septic emboli
INR > 1.7, PT > 15, PTT > 40, Plt < 100, other known bleeding diathesis
Liver or kidney dz causing increased bleeding risk
Use of novel oral anticoagulants
Pregnancy
SBP > 185, DBP > 110 despite meds
Ophthalmic hemorrhage
Sz at onset (if deficits thought to be postictal)
Life expectancy < 1 yr/other severe comorbidity
IV TPA administration
Initial workup & labs as above. Check list of contraindications. Double-check time window (<4.5 h). Obtain consent from pt or family.
TPA dose: 0.9 mg/kg w/a max dose of 90 mg. Give 10% as bolus IV over 1 min & the remainder over 60 min.
Maintain goal SBP < 180, DBP < 105. If BP needs to be lowered, use labetalol 5-20 mg IV q10-20min or nicardipine infusion 5-15 mg/h. Monitor pt in an ICU or specialized stroke care unit for at least 24 h. Avoid arterial sticks, anticoagulation, and antiplatelet agents for 24 h. During the first 24 h after TPA is given, check BP q15min × 2 h, then q30min × 6 h, and then q1h for 24 h after starting Rx.
F/u CT brain at 24 h. STAT CT if change in neurologic exam.
When stabilized: routine workup. (See chapter on Vascular Neurology.)
Stroke pts w/anterior occlusion treatable w/in 6 h of onset (MR CLEAN RCT; n = 500; 89% also receiving IV tPA; 17% crossover to nontreatment; median 260 min from stroke onset to groin puncture and 85 min from stroke onset to IV tPA [Berkhemer OA, et al. NEJM 2015.]). Ninety-day mRS improved among intervention subjects (32.6% vs. 19.1%) w/o significant difference in mortality or sICH.
Post-IV tPA stroke pts w/in 4.5 h of ischemic stroke onset w/internal carotid or M1 or M2 occlusion, CT infarct < 70 mL, and > 10 mL salvageable brain tissue on perfusion imaging (EXTEND-IA RCT, n = 70, median 210 min at initiation of endovascular therapy and 145 min from stroke onset to IV tPA; Campbell BCV, et al. NEJM 2015.). Both early (>8 point reduction in NIHSS or NIHSS < 1 at day 3; 80% vs. 37%) and delayed (mRS 0-2 at 90 days; 71% vs. 40%) improvement.
Stroke pts w/proximal anterior circulation occlusion w/in 12 h of symptom onset, excluding those w/large core infarct or poor collateral circulation on CT/CTA (ESCAPE RCT, n = 316; 75% receiving IV tPA, median 134 min from stroke onset to CT; 51 min from CT to groin puncture; and 110 min from onset to IV tPA; only 15% randomized at >6 h after onset [Goyal M, et al. NEJM 2015.]). Improved outcome at 90 days (mRS 0-2 53% intervention vs. 29% control), mortality (10.4% vs. 19.0%), no difference in sICH. Nonsignificant trend towards benefit of intervention at >6 h.
Factors Suggesting Likely Benefit from Endovascular Stroke Therapy for Anterior Circulation Stroke
NIHSS ≥ 8
Time ≤ 6 h for anterior circulation
Normal baseline functional status
Life expectancy > 12 months
Preparing pt for IA TPA/mechanical thrombolysis: If pt is a candidate for IA TPA or mechanical clot retrieval, contact a neurointerventionalist or a facility w/a neurointerventional service. Maintain O2 sat > 92%, manage w/o intubation if possible to speed time to reperfusion. Treat fever w/Tylenol. Keep pt NPO. Avoid Foley, NGT, femoral catheters, a-line, or central venous line unless necessary. Do not give heparin. Do not ↓BP unless MI or BP > 220/120 (or > 185/110 if IV TPA given). If BP needs to be lowered, use labetalol 5-20 mg IV q10-20min or nicardipine IV 5-15 mg/h. Monitor BP q15min or continuously. Pt will need 24 h ICU observation.
After IA TPA/mechanical thrombolysis: Pt will need STAT CT head right after procedure to evaluate for ICH & admission to ICU for post-TPA/intervention monitoring. F/u CT head at 24 h. When stabilized, complete routine stroke workup; see chapter on Vascular Neurology (JAMA 1999;282:2003).
INTRACEREBRAL HEMORRHAGE
Presentation: Sx vary depending on the location w/in the brain or spinal cord. May include weakness, sensory loss, aphasia, field deficits, gaze deviation, neglect, altered mental status, headache, n/v, ataxia, & dysmetria. Typically sudden onset; may be more gradual w/subdural hematoma (SDH) or occur over several hrs or days if the hemorrhage is expanding. Common locations: cerebral lobes, basal ganglia, thalamus, pons, & cerebellum.
Risk factors or potential underlying causes: HTN, amyloid angiopathy, aneurysm, vascular malformation, trauma, neoplasm, VST, hemorrhagic conversion of stroke, vasculitis, coagulopathy, cocaine, amphetamines, alcohol, a variety of infections among many others.
Dx: CT/CTA head & neck. Note the location & size of hemorrhage, degree of mass effect or herniation, & presence of intraventricular blood or hydrocephalus. Conventional angiogram in select cases to evaluate for vascular malformation, aneurysm, or vasculitis, which was not seen on CTA. Consider routine MRI brain to evaluate for underlying mass lesion or stroke.
Rx
ABCs: intubation for depressed level of consciousness/inability to protect airway. A-line, goal SBP 100-160. Central line, if anticipated will need 23% saline or become hypotensive.
Consider urgent neurosurgical evaluation, particularly if aneurysm rupture, AVM, dural AV fistula, symptomatic SDH, intraventricular extension, hydrocephalus, mass effect/herniation, cerebellar hemorrhage, depressed mental status. If IVH or hydrocephalus, urgent neurosurgical consult for external ventricular drain or intracranial pressure monitoring.
Labs: CBC, Chem 7, PT-INR, PTT, blood bank sample, d-dimer, fibrinogen, LFTs. If INR > 1.3 or recent heparin or other anticoagulant use, correct coagulopathy STAT.
Calculate vol. of ICH = (a × b × c)/2, where a = length, b = width, & c = number of cuts on CT brain multiplied by slice thickness in cm. If significant mass effect, consider osmotic agents & hypertonic saline as needed. (See below for management of acute elevation in ICP). Avoid corticosteroids. Consider surgical evacuation in select cases of cerebellar ICH. No e/o benefit from surgical evacuation of basal ganglia, thalamic, & pontine ICH (Stroke 1997;82:2126).
Consider admission to an intensive care unit for close monitoring. F/u CT brain in 6 h. STAT CT if change in neurologic exam (NEJM 2001;344:1450; Lancet 2009;373:1632; MGH Adult ICH Protocol 2008).
