Stroke: Diagnosis and Treatment

Diagnosis 

Evaluation should include a detailed history of symptom onset, a thorough physical (including neurologic) examination, and imaging tests to determine whether the stroke is hemorrhagic or ischemic. Evaluation of the cardiac rhythm is also essential. Paroxysmal atrial fibrillation may easily be missed if the patient is not closely monitored.

Laboratory tests normally include a complete blood count (CBC), blood glucose level, erythrocyte sedimentation rate (elevated in temporal arteritis or other vasculitides), lipoprotein and triglyceride levels, and coagulation tests. Young patients and those without cardiovascular risk factors may have abnormal antiphospholipid antibodies (specifically lupus anticoagulant).

Computed tomography (CT) scan of the brain helps determine whether a stroke is hemorrhagic or ischemic, and is the initial study of choice. However, areas of infarct due to ischemia are often not acutely visible. CT is necessary before thrombolysis consideration, which must be given within three hours of the earliest symptom onset. Some newer, intravascular techniques may extend this brief window, but currently they are available only in tertiary care settings.

Subarachnoid hemorrhage on CT scan strongly suggests an aneurysm, although an arteriovenous malformation is also a possibility. Aneurysms and other vascular malformations can often be identified by CT scan or by magnetic resonance imaging (MRI), but cerebral angiogram (conventional or CT angiogram) is the preferred method, particularly for identification of aneurysms. MRI (diffusion– and perfusion–weighted images) is best for detecting ischemic strokes and can show damaged areas that are at risk even at the earliest stages of stroke.

Carotid duplex ultrasonagraphy, arteriography, or magnetic resonance angiography (MRA) may determine if stroke has occurred as a result of carotid occlusion. MRA is generally more accurate than carotid duplex studies.

Treatment 

Transient ischemic attack (TIA)

Because the risk of recurrent strokes is high in patients who have suffered a TIA or stroke, it is essential to identify the cause and implement therapy to reduce risk.

• Antiplatelet therapy with aspirin or its alternatives (eg, clopidogrel, ticlopidine, or aspirin plus dipyridamole) can reduce stroke risk.
• Warfarin should be considered if cardiac thrombi and/or atrial fibrillation are involved. Investigation for cardiac abnormalities (including right to left shunts) should be considered, particularly in young patients with stroke or TIA, or if there is a high index of suspicion for embolus.
• Patients at high risk for stroke may require carotid endarterectomy if stenosis is over 70% on the symptomatic side. Treatment of stenosis in patients without prior ischemic symptoms remains controversial, although very high grade stenosis may warrant surgical consideration.
• If hypercoagulability is suspected (particularly in a young individual with few other stroke risk factors), screening for known causes of hypercoagulibility is appropriate.

Ischemic stroke  

Ischemic stroke may lead to rapid (2–5 days) neurologic deterioration resulting from cerebral edema or hemorrhagic conversion of infarct, and patients may be at risk for brain herniation. Close monitoring should occur in the intensive care unit using the Glasgow coma scale, regular CT imaging, and possibly intracranial pressure monitoring.

Treatment with low–molecular–weight heparin and/or warfarin require initial ruling out of hemorrhage and baseline evaluation of the prothrombin time, partial thromboplastin time, platelet count, international normalized ratio (INR), and other tests to assess coagulation status, if indicated. 

Thrombolytic agents (eg, tissue plasminogen activator) dissolve artery–blocking clots in the brain during the critical early stages of stroke. They are of proven benefit only when administered within 3 hours of stroke onset. Later, the risk of intracerebral hemorrhage outweighs benefit).  

Antiplatelet agents (eg, aspirin, aspirin–dipyridamole, clopidogrel) should be given within 48 hours of stroke if no contraindication exists.

Some studies have also found emergency carotid endarterectomy to be effective. 

Neuroprotective agents have failed to show benefits thus far in clinical trials.

Hemorrhagic stroke 

Treatment of intracerebral hemorrhage depends on the extent of the hemorrhage and its location.

Medical or surgical decompression may be indicated.

Subarachnoid hemorrhage due to an aneurysm or arteriovenous malformation may warrant surgery, depending on the patient’s age and clinical status.

A stroke–outcomes assessment should be performed daily to monitor the level of impairment.¹¹

Many hospitals have specialized stroke–recovery units. The intensity of stroke rehabilitation efforts is associated with the degree of recovery.¹² Speech therapy, physical therapy, and occupational therapy are important treatments during rehabilitation.