ESSENTIALS OF DIAGNOSIS
Stroke presents as a neurologic deficit or headache of abrupt onset.
Hemorrhagic strokes can be intracerebral or subarachnoid.
Urgent neuroimaging studies are essential for diagnosis.
In the past decade, stroke declined from the third to the fifth leading cause of death in the United States, which is testament to a half-century of progress in cerebrovascular disease prevention and acute care. It remains, however, a leading cause of disability, with up to half of all patients who survive a stroke failing to regain independence and needing long-term health care. Stroke primarily affects older adults, and for each successive decade after the age of 55 years, the stroke rate doubles for both men and women.
Ischemic stroke, insufficient blood flow to the brain, accounts for 80% of strokes, whereas bleeding that destroys and compresses the brain parenchyma, intracerebral hemorrhage (ICH), accounts for 15%. Bleeding that occurs in the subarachnoid space, subarachnoid hemorrhage (SAH), accounts for 5% of strokes.
An ischemic stroke presents as an acute neurologic deficit. Older patients have more severe stroke deficits at presentation than do younger patients. The neurologic impairment reflects the area of the brain affected. Although the presenting focal neurologic symptoms are variable, 80% of patients present with unilateral weakness; 90% have a speech and/or motor deficit. In addition, deficits in sensation, vision, language, cognition, and balance may occur. Sudden-onset, severe headache is the classic presentation for aneurysmal SAH. In addition to focal neurologic symptoms, headache and a decreased level of consciousness may also develop in ICH if the hemorrhage becomes sufficiently large.
After the onset of symptoms, timely evaluation and diagnosis are paramount. This is because the effect of thrombolysis is time dependent. Thus, neurologic screening tools like the Cincinnati Stroke Scale (Table 38–1) can be useful in early triage. The three most predictive examination findings for the diagnosis of acute ischemic stroke are facial paresis, arm drift/weakness, and abnormal speech.
Table 38–1.Cincinnati Stroke Scale. |Favorite Table|Download (.pdf) Table 38–1. Cincinnati Stroke Scale.
Normal: Both sides of face move equally
Abnormal: One side of face does not move at all
Normal: Both arms move equally or not at all
Abnormal: One arm drifts down compared to the other
Normal: Patient uses correct words with no slurring
Abnormal: Slurred or inappropriate words or mute
If any 1 of these 3 signs is abnormal, the probability of a stroke is 72%
In patients suspected of stroke, diagnostics occur in two phases: (1) acute triage and (2) investigations into etiology after stroke is established as the diagnosis.