Stroke in a Young Patient (Acute Ischemic) Case File

Stroke in a Young Patient (Acute Ischemic) Case File

Eugene C. Toy, MD, Ericka Simpson, MD, Pedro Mancias, MD, Erin E. Furr-Stimming, MD

CASE 13

A 22-year-old previously healthy college student presents to the emergency department with a chief complaint of gait instability and a right eyelid droop. He began noticing these symptoms 2 days ago, the morning after a friend put him in a choke hold during a wrestling match. He managed to break free after a struggle and subsequently noticed a right temporal headache after the wrestling match. The patient’s temperature is 36.4°C (97.6°F); heart rate is 64 beats/min; and blood pressure is 118/78 mm Hg. General physical examination is unremarkable. The neurologic examination reveals ptosis of the right eye and anisocoria, with a pupillary diameter of 2 mm on the right and 4 mm on the left. Light reactivity is intact directly and consensually. Extraocular movements are normal. There is a mild left hemiparesis involving the left lower face and left arm and leg. His has a hemiparetic gait and tends to fall to the left without assistance. The electrocardiogram (ECG) is normal. Complete blood count, electrolytes, blood urea nitrogen (BUN), creatinine, glucose, urinalysis, prothrombin time (PT), and partial thromboplastin time (PTT) are normal. Noncontrast computed tomography (CT) of the head shows an area of a hypodensity in the right frontal-parietal region.

▶ What is the most likely diagnosis and mechanism?

▶ What is the next diagnostic step?

ANSWERS TO CASE 13:

Stroke in a Young Patient (Acute Ischemic)                                        

Summary: A 22-year-old man presents with a right Horner syndrome and right hemispheric ischemic stroke after relatively minor trauma to his neck.

• Most likely diagnosis and mechanism: Acute ischemic stroke caused by right carotid artery dissection as a result of trauma
• Next diagnostic step: Cerebral arteriogram

ANALYSIS

Objectives

1. Understand the signs and symptoms of stroke.
2. Recognize the less typical stroke etiologies that often affect younger patients.
3. Be familiar with the diagnostic workup of stroke in a young patient.

Considerations

The diagnosis of a stroke relies on an appropriate clinical history, neurologic findings, and supportive brain and often vascular imaging studies. Although the majority of strokes occur in patients 65 years or older, many strokes occur in patients 55 years or younger. Just as in older patients, a stroke should be suspected in a younger patient presenting with acute/subacute focal neurologic deficits. In the case presented, a “choke hold” injured the patient’s right carotid artery, leading to ischemia to the right side of the brain and associated structures supplied by the right carotid artery.

APPROACH TO:

Stroke in a Young Patient                                        

DEFINITIONS

CAROTID DISSECTION: A tear in the carotid arterial wall can result in luminal obstruction, thromboembolic complications, and/or pseudoaneurysm formation. Dissections can also occur in the vertebral arteries, or less commonly, the large intracranial arteries.

PATENT FORAMEN OVALE (PFO): A persistent opening in the interatrial septum associated with paradoxical embolism in patients with cryptogenic stroke.

ARTERIOVENOUS MALFORMATIONS: Congenital high-pressure, high-flow cerebral vascular malformations characterized by direct arteriovenous shunting.

CLINICAL APPROACH

The diagnostic evaluation in a younger patient suffering from a stroke is typically more extensive than an older individual because of the greater likelihood of a nonatherosclerotic etiology. Some of these thrombophilia conditions are discussed next. The workup may include brain magnetic resonance imaging (MRI), cerebral computed tomography angiography (CTA) or magnetic resonance angiography (MRA) of the intracranial and cervical vessels, transesophageal echocardiogram, and laboratory studies including lipid panel, homocysteine levels, protein C, protein S, antithrombin III, anticardiolipin antibody, lupus anticoagulant, factor V Leiden mutation, prothrombin gene mutation, and a toxicology screen. Other studies that can be indicated in the appropriate clinical setting might include lumbar puncture to evaluate for infection/inflammation, blood cultures, vasculitis serologies, screening for HIV or sickle cell disease, Holter monitoring, and “formal” cerebral angiography.

ETIOLOGIES AND CLINICAL PRESENTATIONS

The same causes of stroke in older patients can affect younger adults, especially in younger patients who possess the traditional atherosclerotic risk factors such as hypertension, coronary heart disease, diabetes mellitus, and hyperlipidemia. The largest categories of stroke in the general population are cardioembolic, large-vessel atherothrombotic, and lacunar infarcts. A patent foramen ovale (PFO) is detectable in approximately 15% to 30% of the general population, but its prevalence is higher in younger patients with cryptogenic ischemic stroke. The mechanism is presumed to be paradoxical embolism. Transesophageal echocardiography (TEE) is the most common tool to detect a PFO, although its sensitivity is impaired by the need to sedate a patient for the examination. Alternatively, a transcranial Doppler bubble study is highly sensitive for a right-to-left cardiac shunt but may result in false positives from a noncardiac source, such as a pulmonary arteriovenous malformation (AVM). Atrial septal aneurysms are also linked to cryptogenic stroke and best evaluated by TEE.

The clinical manifestations of arterial dissections depend on the vessel involved. Carotid artery dissections typically begin with ipsilateral neck pain or headache and a Horner syndrome (ipsilateral ptosis, miosis, and depending on the location of the dissection, anhydrosis) followed by retinal or cerebral ischemia. The presence of any two of the three elements in the triad strongly suggests the diagnosis of carotid dissection. Craniocervical dissection is commonly, but not always, preceded by head or neck trauma such as a motor vehicle accident, chiropractic neck manipulation, or a bout of severe coughing, vomiting, or sneezing (Figure 13–1). Fibromuscular dysplasia, Ehlers-Danlos syndrome, and Marfan syndrome are predisposing conditions for spontaneous craniocervical dissection due to associated pathology of the arterial wall. Conversely, vertebral artery dissections typically present with occipitocervical pain, which may be followed by a variety of posterior circulation ischemic symptoms including vertigo, dysarthria, visual field deficit, ataxia, and diplopia.

AVMs and the lower-flow cavernous angiomas are associated with intracerebral hemorrhage as well as seizures and other neurologic presentations.

Figure 13–1. Cerebral arteriogram of internal carotid artery (ICA) dissection. (Reproduced, with permission, from Brunicardi FC, et al. Schwartz’s Principles of Surgery. 8th ed. New York, NY: McGraw-Hill; 2004:Fig. 22–92.)

Moyamoya disease is an idiopathic noninflammatory cerebral vasculopathy characterized by progressive occlusion of the large arteries at the circle of Willis, most commonly the distal internal carotid artery. The characteristic moyamoya vessels refer to collateral circulation formed by the small penetrating arteries that hypertrophy in response to chronic cerebral ischemia, which have the appearance of a puff of smoke, which is roughly what moyamoya means in Japanese.

Drugs of abuse, especially cocaine and amphetamines, are associated with both ischemic and hemorrhagic stroke. Oral contraceptives are a risk factor for thromboembolic stroke, especially in women older than 35 years who smoke. A history of intravenous drug abuse should raise the suspicion of endocarditis and HIV disease. Other rarer infectious etiologies of stroke include tuberculous meningitis and varicella zoster.

Hypercoagulable conditions can also predispose to stroke. These include malignancy, antiphospholipid antibodies, protein C deficiency, protein S deficiency, antithrombin III deficiency, factor V Leiden mutation, prothrombin gene mutation, and hyperhomocysteinemia. Some of these entities are most clearly linked to venous thromboembolism, which is particularly relevant to patients with cerebral venous thrombosis or a PFO.

Treatment

Treatment is tailored to the specific stroke etiology. Antithrombotic drugs are a mainstay of secondary prevention and therapy for most patients with ischemic stroke. Very few randomized clinical trials have been performed to help guide the choice of antiplatelet or anticoagulant treatment for the specific stroke subtypes discussed above. One such trial revealed no significant difference between aspirin and warfarin in patients with ischemic stroke associated with an antiphospholipid antibody. Similar studies comparing aspirin to anticoagulation in cervical artery dissections have shown no significant difference in efficacy.

Endovascular closure of PFO is currently under investigation and not recommended outside of a clinical trial. Because a substantial proportion of carotid or vertebral dissections spontaneously recanalize, stenting is usually reserved for patients who show no vessel recanalization after 3 to 6 months or who have unstable-appearing pseudoaneurysms. The treatment of AVMs can employ a combination of surgery, radiation, and endovascular therapies. Surgical revascularization procedures such as encephaloduroarteriosynangiosis or superficial temporal artery–middle cerebral artery (STA-MCA) bypass are frequently performed for moyamoya disease.

COMPREHENSION QUESTIONS

13.1 As compared to stroke in patients younger than 55, which of the following risk factors is more common in an individual older than 55?

A. Atrial fibrillation

B. PFO

C. Carotid dissection

D. Moyamoya disease

13.2 A 45-year-old woman is brought into the emergency room with symptoms of an acute stroke. She has a history of two miscarriages and unexplained leg cramping. Which of the following is most likely to be present in this patient’s condition?

A. An arteriovenous malformation

B. Elevated antiphospholipid antibodies

C. Moyamoya disease

D. Carotid dissection

13.3 An 18-year-old man is seen by his pediatrician for right-sided arm weakness. The pediatrician is suspicious of a PFO. Which of the following is the best examination to confirm this finding?

A. ECG

B. Auscultation of the heart

C. Echocardiogram

D. Arterial blood gas

ANSWERS

13.1 A. Atrial fibrillation is more common in older adults. This predisposes patients to an intramural thrombus forming in the left atrium, which may embolize to the brain. The other etiologies (carotid dissection, moyamoya, PFO) are more common in a young patient presenting with a stroke.

13.2 B. Antiphospholipid antibody syndrome is a known cause of arterial and venous hypercoagulability and recurrent miscarriages. In this patient, who manifests other symptoms of the antiphospholipid antibody syndrome, anticoagulation is appropriate. On the other hand, in a patient with an isolated laboratory value showing antiphospholipid antibodies and stroke but no other symptoms, antiplatelet therapy has been proven to be equally

efficacious as anticoagulation.

13.3 C. Most patients with a PFO are asymptomatic; however, when the patient gets older, a small deep vein thrombosis (DVT) (usually in the lower extremities) can then embolize, traveling from the right side of the heart to the left side of the heart and to the brain, leading to TIA or stroke. This patient is only 18 years old and a search for venous thromboembolism and thrombophilia workup are important. TEE is the best method to detect a PFO.

    CLINICAL PEARLS    

▶ Horner syndrome in a patient with headache and recent head or neck injury suggests carotid or vertebral dissection. ▶ An etiology often discovered in a young patient with cryptogenic stroke is a PFO. ▶ The young patient is more likely to have an “unusual” cause of stroke, although in up to 10% of patients no etiology is found. ▶ Approximately 10% to 14% of ischemic strokes occur in adults ages 18 to 45 years.

REFERENCES

Mohr JP, Wolf PA, Grotta J, et al. Stroke: Pathophysiology, Diagnosis, and Management. 5th ed. New York, NY: Elsevier; 2011. 

Mozaffarian D, Benjamin EJ, Go AS, et al. Heart disease and stroke statistics—2015 update: a report from the American Heart Association. Circulation. 2015;e29-e322. 

Ropper AH, Brown RH. Adams and Victor’s Principles of Neurology. 8th ed. New York, NY: McGraw-Hill; 2005.

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