2 Cerebrovascular Emergency: Acute Stroke Diagnosis and Management
Abstract
Stroke is one of the leading causes of disability in the USA. Timely acute interventions in the form of tPA and endovascular therapy have changed the landscape of acute stroke care. Having an organized and efficient system of care is extremely important for delivering acute stroke care. This chapter details the components of acute stroke care from the emergency room to the neurocritical care unit. The chapter covers pre- and post-tPA and endovascular care as well as post stroke complication management in the neurocritical care unit.
Keywords: acute stroke, tPA, endovascular therapy, neurocritical care
2.1 Epidemiology
• Stroke is the fifth leading cause of death in North America
• It is the leading cause of disability
• 795,000 people/year have a stroke in North America
2.2 Etiology
2.2.1 Nonmodifiable Risk Factors
• Age
• Sex
• Race
• Family history
2.2.2 Modifiable Risk Factors
• Hypertension
• Diabetes mellitus
• Hyperlipidemia
• Smoking
• Excessive alcohol use
• Obstructive sleep apnea
2.2.3 Stroke Subtypes
According to TOAST9 classification there are five subtypes of ischemic stroke:
1. Large artery atherosclerosis
2. Cardioembolism
3. Small vessel occlusion (lacunar stroke)
4. Stroke of other determined etiology
• Mechanical valves
• Atrial fibrillation/flutter
• Left atrial (LA) appendage thrombus
• Left ventricular (LV) thrombus
• Recent myocardial infarction (MI)
• Dilated cardiomyopathy
• Endocarditis/infection
• Patent foramen ovale
• Atrial septal aneurysm
• Congestive heart failure
• Vasculopathies
• Hypercoagulable state
5. Stroke of undetermined etiology/cryptogenic
2.3 Common Clinical Presentations
Presentation depends on the vascular territory. See ▶ Table 2.1.
F.A.S.T. is the acronym most associated with recognition of early stroke signs:
F = Facial weakness
A = Arm weakness
S = Speech difficulty
T = Time to call 9–1-1
Once in the emergency department a more thorough examination using the National Institutes of Health Stroke Scale (NIHSS) is completed (▶ Table 2.2).
2.4 Differential Diagnosis for Acute Ischemic Stroke
• Intracerebral hemorrhage (ICH)
• Subarachnoid hemorrhage (SAH)
• Migraine with aura (most auras DO NOT last beyond 60 minutes nor present with loss of function)
• Transient global amnesia
• Postictal Todd’s palsy (history of epilepsy or prior Todd’s palsy, short duration with improvement)
• Hypoglycemia (rapid improvement with glucose correction)2
Table 2.1 Common clinical presentation by vascular territory
Vascular territory | Symptoms |
Middle cerebral artery | Contralateral facial droop, weakness and sensory loss (arm > leg), aphasia, neglect, contralateral homonymous hemianopia, ipsilateral gaze deviation |
Anterior cerebral artery | Contralateral hemiplegia (leg > > face and arm), abulia, rigidity, gait apraxia, urinary incontinence |
Posterior cerebral artery | Contralateral homonymous hemianopia, alexia, contralateral sensory loss, cortical blindness, visual hallucinations, optic ataxia, gaze apraxia |
Subcortical | Contralateral hemiplegia or hemisensory loss (usually face = arm = leg), no cortical features (aphasia, neglect), thalamic strokes may have aphasia, delirium, other cortical features |
Basilar artery | Cranial nerve palsy, crossed sensory deficits, dizziness, diplopia, dysarthria, dysphagia, vertigo, nausea/vomiting, hiccups, contralateral weakness, ataxia, nystagmus, coma |
2.5 Acute Stroke Diagnosis, Treatment, and Management4
2.5.1 Stroke Activation (▶ Fig. 2.1)
• ABC: airway, breathing, circulation
◦ O2 saturation > 94% (supplemental oxygen is not recommended if the patient is not hypoxic)
◦ Finger-stick glucose should be > 50
• Intravenous (IV) access
• History: Past medical, surgical, and medication (ask about antiplatelet and anticoagulant agents)
• Check electrocardiogram (ECG)—rule out acute ST-elevation myocardial infarction (STEMI)
• Send STAT labs: Coagulation panel and platelet
• Perform focal stroke examination using NIHSS (▶ Table 2.2 shows the pictures and sentences used for questions 9 and 10 on the scale.)
Fig. 2.1 Thomas Jefferson University acute stroke algorithm for in-house and emergency room activation.
Table 2.2 (a) NIH stroke scale. (b) Supplement to questions 9 and 10 on the National Institutes of Health Stroke Scale (NIHSS) used to determine deficits in language and speech. (1–3) Assessment of aphasia: (1) describing the picture, (2) reading the short sentences, and (3) naming the objects listed. (4) Words repeated by the patient to assess dysarthria. (Reproduced with permission from National Institute of Neurological Disorders and Stroke (NINDS).)
NIH stroke scale | ||
Category | Description | Score |
1a. Level of consciousness (LOC) | 0 = Alert 1 = Drowsy 2 = Stuporous 3 = Coma |
|
1b. LOC questions | 0 = Answers both correctly 1 = Answers one correctly 2 = Answers neither correctly |
|
2. Best gaze | 0 = Normal 1 = Partial gaze palsy 2 = Forced deviation |
|
3. Visual | 0 = No visual loss 1 = Partial hemianopia 2 = Complete hemianopia 3 = Bilateral hemianopia |
|
4. Facial palsy | 0 = No facial palsy 1 = Minor facial palsy 2 = Partial facial palsy 3 = Complete facial palsy |
|
5a. Motor left arm | 0 = No drift 1 = Drift 2 = Can’t resist gravity 3 = No effort against gravity 4 = No movement UN = Amputation/Joint fusion |
|
5b. Motor right arm | 0 = No drift 1 = Drift 2 = Can’t resist gravity 3 = No effort against gravity 4 = No movement |
|
6a. Motor left leg | 0 = No drift 1 = Drift 2 = Can’t resist gravity 3 = No effort against gravity 4 = No movement UN = Amputation/Joint fusion |
|
6b. Motor right leg | 0 = No drift 1 = Drift 2 = Can’t resist gravity 3 = No effort against gravity 4 = No movement UN = Amputation/Joint fusion |
|
7. Limb ataxia | 0 = Absent 1 = Present in one limb 2 = Present in two limbs |
|
8. Sensory | 0 = Normal 1 = Partial loss 2 = Severe loss |
|
9. Best languagea | 0 = No aphasia 1 = Mild to moderate aphasia 2 = Severe aphasia 3 = Mute |
|
10. Dysarthriab | 0 = Normal articulation 1 = Mild to moderate dysarthria 2 = Near to unintelligible 3 = Intubated or other barrier |
|
11. Extinction and inattention | 0 = No neglect 1 = Partial neglect 3 = Complete neglect |
|
| Total |
|
| ||
See ▶ Table 2.2(a) aAsk patient to name items, describe the picture, read a sentence, intubated patients should write response if able. bEvaluate speech clarity by asking patient to repeat the listed words Abbreviations: LOC, level of consciousness; NIHSS, National Institute of Health Stroke Scale. | ||
• Check STAT computed tomography (CT) of head (▶ Fig. 2.2)
◦ Rule out hemorrhage
◦ Rule out large completed ischemic stroke
◦ Identify acute middle cerebral artery (MCA) or basilar occlusion
• Assess eligibility for IV tPA (▶ Table 2.3 and ▶ Fig. 2.3)
◦ If eligible, dosing for tPA is 0.9 mg/kg with a maximum dose of 90 mg.
◦ A bolus of 10% is given over the first minute followed by the remaining dose over 1 hour.
◦ If a patient is ineligible for tPA then administer 325 mg aspirin orally or 300 mg aspirin rectally (provided no hemorrhage on CT of head).
Fig. 2.2 (a, b) Examples of a dense occlusion of an artery due to acute thrombus: (a) Dense occluded right middle cerebral artery (MCA). (b) Dense occluded basilar artery. (c, d) Examples of computed tomography (CT)scan finding that would exclude a patient from receiving intravenous (IV) tPA. (c) A completed right middle cerebral artery (MCA) stroke. (d) A right thalamic hemorrhage.
• Blood pressure goals (▶ Fig. 2.4):
◦ Blood pressure must be controlled prior to administering IV tPA to minimize the bleeding risk. Goal is < 185/110.
◦ With tPA administration, maintain a blood pressure (BP) goal of < 180/105.
◦ If tPA is NOT given then the BP goal should be < 220/110 during the first 24 hours.
◦ Avoid agents like hydralazine, nitroprusside, and nitroglycerin due to their vasodilatory effect.
• ▶ Fig. 2.1 outlines the pathway for further imaging in patients with suspected large vessel occlusion or dense vessel on plain CT head. CT angiogram (CTA) of head and neck to identify artery occlusion and CT perfusion to evaluate size of core infarct and penumbra (▶ Fig. 2.5).
2.6 Criteria for Endovascular Therapy
Early studies published in 2013 (IMS-III, SYNTHESIS, and MR RESCUE) failed to show benefit of endovascular treatment of acute ischemic stroke.6,7,8
Between 2015–2018, multiple studies have shown the benefit of endovascular treatment with or without tPA.1,10,11,12 Based on the findings of these studies, the American Heart Association/American Stroke Association published new guidelines in 2018 supporting endovascular treatment with stent retriever provided the following criteria are met:4
Table 2.3 Eligibility criteria, warnings, and contraindications to intravenous tPA (Alteplase)
Eligibility criteria within the 3 hours window |
|
| Recommended for both severe stroke and for mild but disabling strokes |
| Age ≥ 18 years; equally recommended for ages < 80 and > 80 years under 3 hours of onset |
Warnings for IV tPA within the 3 hours window |
|
| Clinical syndrome not consistent with ischemic stroke |
| Recent history of intracranial hemorrhage |
Contraindications for IV tPA within the 3 hours window |
|
| Active intracranial hemorrhage (i.e., subdural hematoma, epidural hematoma, subarachnoid hemorrhage, or spontaneous intracerebral hemorrhage) |
| Active internal bleeding |
| Clinical presentation suggesting cerebral aneurysm rupture and/or subarachnoid hemorrhage |
| Delay in patient arrival, unknown time of onset and/or “wake up” stroke |
| Current severe uncontrolled hypertension (SBP > 185 mm Hg or DBP > 110 mm Hg) despite aggressive treatment |
| Presence of intracranial conditions that may increase the risk of bleeding (neoplasm either primary or metastatic; cerebral arteriovenous malformation, etc.) |
| Ischemic stroke in the setting of infective endocarditis |
| Recent intracranial or intraspinal surgery within prior 3 months (lumbar puncture within 7 days does NOT apply) |
| Recent severe head trauma or history of post-traumatic stroke within 3 months |
| History of structural gastrointestinal malignancy or recent gastrointestinal hemorrhage within 3 weeks |
| Known or suspected aortic dissection |
Bleeding diathesis/coagulopathy or thrombocytopenia including but not limited to: • Known INR > 1.7 and/or elevated PT > 15 seconds • Known administration of therapeutic doses of heparin or low-molecular-weight heparin within 24 hours of presentation or elevated aPTT > 40 seconds • Known platelet count < 100,000/mm3 • Known use of direct thrombin inhibitors or factor Xa inhibitors (BOACs) within 48 hours of stroke symptoms assuming normal renal function | |
Eligibility criteria for the 3 to 4.5 hours window |
|
| Age < 80 years |
| NO history of both stroke and diabetes mellitus |
| NIHSS < 25 |
| Not on oral anticoagulant agents |
| No evidence of ischemia of > 1/3 of the MCA territory |
Additional warnings within the 3 to 4.5 hours windowa |
|
| Age > 80 years |
| History of prior stroke and diabetes mellitus |
| NIHSS > 25 |
Additional contraindications within the 3 to 4.5 hours window |
|
| Current use of oral anticoagulant and/or INR > 1.7 |
| Patients with imaging evidence of ischemic injury involving more than one-third of the MCA territory |
aDeemed Class IIb (possible benefit > risk) so it may be considered. | |
Adapted from the AHA/ASA 2018 Guideline for the Early Management of Acute Ischemic Stroke3 Abbreviations: aPTT, activated partial thromboplastin time; DBP, diastolic blood pressure; INR, international normalized ratio; MCA, middle cerebral artery; NIHSS; PT, prothrombin time; SBP, systolic blood pressure. | |
