Diagnostic Approach to Stroke in Young Patients

Initial Imaging Evaluation

The American College of Radiology recommends MRI with diffusion-weighted imaging (DWI) as the imaging procedure of choice for stroke detection in young patients, demonstrating 77% sensitivity within the first 3 hours compared to only 16% for CT 2, 3
MRI remains superior to CT for detecting infarction up to 12 hours after symptom onset and can detect significant intracranial hemorrhage as readily as CT 2, 3
Susceptibility-weighted imaging (SWI) should be included to improve detection of blood products, depict cerebral venous structures, and identify intravascular thrombus (appearing as "blooming" artifact within vessels) 2, 3
MRA or CTA from aortic arch to vertex should be completed within 24 hours to evaluate both extracranial and intracranial circulation 4, 5
MRA should include cervical vessels in all cases of unexplained stroke, as cerebral arterial abnormalities are found in 25% of young stroke patients 2, 3
Very high-resolution MRI with vessel wall imaging may show thickening or enhancement in arteriopathies, which are the most common cause (53%) of pediatric stroke 2, 3

The American Heart Association recommends both transthoracic and transesophageal echocardiography should be performed in young stroke patients, as cardiac disorders account for 31% of pediatric strokes 1, 3
Transesophageal echocardiography is particularly important for detecting patent foramen ovale, atrial septal abnormalities, and potential sources of cardioembolism not visible on transthoracic studies 1
Initial C-reactive protein ≥10 mg/L dramatically increases likelihood of infectious endocarditis (OR 22), which is confirmed in 1.7% of stroke presentations 6
12-lead ECG should be completed immediately upon presentation 4, 7
Extended cardiac monitoring (telemetry) should be performed to detect paroxysmal atrial fibrillation and other arrhythmias 4

Complete blood count, electrolytes, coagulation studies (aPTT, INR), renal function (creatinine, eGFR), random glucose, and troponin should be obtained routinely 4, 7
Hypercoagulable state testing should be performed in patients <50 years of age, as the yield is significantly higher in younger populations 6
Toxicology screening for cocaine and other drugs of abuse should be done at presentation, as cocaine use within 24 hours increases stroke risk >6-fold in young adults 6
When diagnostic algorithms are used, monogenic causes of stroke are detected in 7% of cases, making genetic testing an important consideration 6

Arteriopathies are the leading cause of stroke in young patients (53%), requiring detailed vascular assessment 3
Evaluation for arterial dissection should be pursued when suspected, as this may require referral to a level three facility for specialized management 1
Basilar artery occlusion and vertebral artery dissection should be specifically evaluated, as basilar circulation strokes account for 4.6% of pediatric cases 2, 3
Acute or chronic head and neck disorders account for 23% of pediatric strokes and should be investigated 3
52% of children have multiple risk factors, necessitating comprehensive evaluation across all categories 3

Stroke in young patients for which no cause can be found after initial workup requires referral to a level three comprehensive stroke unit 1
Suspected cardioembolic stroke not associated with atrial fibrillation and not previously investigated requires specialized evaluation 1
Patients requiring investigations unavailable at the initial facility (e.g., suspected arterial dissection, need for catheter laboratory procedures) should be transferred 1