For further information, see CMDT Part 24-09: Stroke
Sudden ("thunderclap") severe headache
Signs of meningeal irritation usually present
Obtundation is common
Focal deficits frequently absent
5–10% of strokes are due to subarachnoid hemorrhage
Trauma is the most common cause
Frequently results from the rupture of an arterial saccular ("berry") aneurysm or from an arteriovenous malformation
Factors associated with a higher risk of subarachnoid hemorrhage
See also Aneurysm, Intracranial
See Table 24–3
Table 24–3.Features of the major stroke subtypes. ||Download (.pdf) Table 24–3. Features of the major stroke subtypes.
|Stroke Type and Subtype ||Clinical Features ||Diagnosis ||Treatment |
|Ischemic Stroke |
|Lacunar infarct ||Small (< 1.5 cm) lesions in the basal ganglia, pons, cerebellum, or internal capsule; less often in deep cerebral white matter; prognosis generally good; clinical features depend on location but may worsen over first 24–36 hours. ||MRI with diffusion-weighted sequences usually defines the area of infarction; CT is insensitive acutely but can be used to exclude hemorrhage. ||Antiplatelet; control risk factors (hypertension, tobacco use, hypercholesterolemia, and diabetes mellitus). |
|Carotid circulation obstruction ||See text—signs vary depending on occluded vessel. ||Noncontrast CT to exclude hemorrhage but findings may be normal during first 6–24 hours of an ischemic stroke; diffusion-weighted MRI is gold standard for identifying acute stroke; electrocardiography, carotid duplex studies, echocardiography, blood glucose, CBC, and tests for hyperlipidemia are indicated; ambulatory ECG monitoring, including extended monitoring in selected instances; CTA, MRA, or conventional angiography in selected cases; tests for hypercoagulable states in selected cases. || |
0–4.5 hours: intravenous thrombolytics (approved in United States up to 3 hours and in Europe up to 4.5 hours).
0–6 hours: endovascular mechanical embolectomy.
6–24 hours: endovascular mechanical embolectomy in select cases.
Secondary prevention: antiplatelet agent is first-line therapy; anticoagulation without heparin bridge for cardioembolic strokes due to atrial fibrillation and other select cases when no contraindications exist; control risk factors as above.
|Vertebrobasilar occlusion ||See text—signs vary based on location of occluded vessel. ||As for carotid circulation obstruction. ||As for carotid circulation obstruction. |
|Hemorrhagic Stroke |
|Spontaneous intracerebral hemorrhage || |
Commonly associated with hypertension; also with bleeding disorders, amyloid angiopathy.
Hypertensive hemorrhage is located commonly in the basal ganglia, pons, thalamus, cerebellum, and less commonly the cerebral white matter.
|Noncontrast CT is superior to MRI for detecting bleeds of < 48 hours duration; laboratory tests to identify bleeding disorder: angiography may be indicated to exclude aneurysm or AVM in younger patients without hypertension. Do not perform lumbar puncture. || |
Lower systolic blood pressure to 140 mm Hg; cerebellar bleeds or hematomas with gross mass effect may require urgent surgical evacuation.
AVM: surgical resection indicated to prevent further bleeding; other modalities to treat nonoperable ...