A high mortality rate from strokes exists among African – American men, possibly as a result of the high frequency of hypertension, obesity, and diabetes mellitus in this group. Thrombotic strokes are twice as common among whites. Hemorrhagic strokes are three times more common among African – Americans than among whites. Hispanics, American Indians, and Asian – Americans have a higher stroke incidence than whites. The brain it supplies. Permanent damage can result from a stroke because of anoxia of the brain. The vessel most commonly affected is the middle cerebral artery. The patient may be unconscious and may experience seizures. Both unconsciousness and seizures result from generalized ischemia and the brain’s response to abrupt hypoxia
Assessment
Collection of subjective data that are important with a patient experiencing a stroke includes the description of the onset of symptoms; and the presence of headache; any sensory deficit, such as numbness or tingling; the inability to think clearly; and the headache may be described as sudden and explosive. The patient’s ability to understand the condition should be assessed.
Collection of objective data includes the presence of hemiparesis or hemiplegia, any change in the level of consciousness, signs of increased intracranial pressure, respiratory status, and the presence of aphasia. The exact clinical picture varies, depending on the area of the brain affected (Figure 14-17 ). When the middle cerebral artery is affected, as is most common, the signs and symptoms seen include contralateral paralysis or paresis, contralateral sensory loss, dysphasia or aphasia if the dominant hemisphere is involved, spatial-perceptual problems, changes in judgment and behavior if the nondominant hemisphere is involved, and contralateral (homonymous) hemianopia (Figure 14-18).
Diagnostic Test
CT is the primary diagnostic test used to diagnose a stroke. CT can indicate the size and location of the lesion and differentiate between ischemic and hemorrhagic stroke. CT angiography (CTA) provides visualization of vasculature. MRI is used to determine the extent of brain injury. MRI has greater specificity than CT. PET is also very useful in assessing the extent of tissue damage by showing the metabolic activity of the brain. After TIAs, a cerebral angiogram may be done. Doppler, computed tomographic angiography (CTA), or magnetic resonance angiography (MRI) studies of the carotid arteries may be performed. The results of these noninvasive carotid artery studies determine whether the more invasive cerebral angiogram is performed.