Stroke is defined as any disease process that interrupts blood flow to the brain. Ischemic strokes (87%) are more common than hemorrhagic intracerebral (10%) and a traumatic subarachnoid hemorrhage (SAH) (3%) (Table 141-1). A transient ischemic attack (TIA) is a transient neurologic deficit that typically lasts less than 1 to 2 hours, but duration can no longer be used to discriminate between TIA and stroke; they are best thought of as similar disease processes on a continuum.
Table 141-1 Stroke Classification ||Download (.pdf)
Table 141-1 Stroke Classification
Narrowing of a damaged vascular lumen by an in situ process, usually clot formation
Infection (human immunodeficiency virus infection, syphilis, trichinosis, tuberculosis, aspergillosis)
Symptoms often have gradual onset and may wax and wane.
Common cause of transient ischemic attack.
Obstruction of a normal vascular lumen by intravascular material from a remote source
Cardiac tumors (myxomas)
Arterial-arterial emboli from proximal source
Particulate emboli (intravenous drug use)
Typically sudden in onset.
Account for 20% of ischemic strokes.
Low–blood flow state leading to hypoperfusion of the brain
Cardiac failure resulting in systemic hypotension
Diffuse injury pattern in watershed regions.
Symptoms may wax and wane with hemodynamic factors.
Intraparenchymal hemorrhage from previously weakened arterioles
Intracranial pressure rise causes local neuronal damage.
Secondary vasoconstriction mediated by blood breakdown products or neuronal
mechanisms (diaschisis) can cause remote perfusion changes.
Risks include advanced age, history of stroke, tobacco or alcohol use.
More common in Asians and blacks.
Hemorrhage into subarachnoid space
Berry aneurysm rupture
Vascular malformation rupture
May be preceded by a sentinel headache (“warning leak”).
Specific findings in stroke patients depend on regions of the brain that are compromised and the severity of the insult (Table 141-2). It is important to remember that stroke presentation can vary considerably from classically described syndromes.
Table 141-2 Symptoms of Stroke ||Download (.pdf)
Table 141-2 Symptoms of Stroke
Sudden numbness or weakness of face, arm, or leg—especially unilateral
Sudden confusion or aphasia
Sudden memory deficit or spatial orientation or perception difficulties
Sudden visual deficit or diplopia
Sudden dizziness, gait disturbance, or ataxia
Sudden severe headache with no known cause
Loss of consciousness or syncope
Shortness of breath
Sudden pain in the face, chest, arms, or legs
Falls or accidents
Altered mental status
If the anterior cerebral artery is involved, the typical symptoms include contralateral leg weakness and sensory changes. A classic middle cerebral artery stroke presents with hemiparesis (arm > leg), facial plegia, and sensory loss. Weakness in the lower half of the face (variable) and ipsilateral gaze ...