Definition

Stroke is an acquired injury of the brain caused by occlusion of a blood vessel or inadequate blood supply leading to infarction or a hemorrhage within the parenchyma of the brain. Ischemic stroke is most commonly due to atherosclerosis of large extracranial or intracranial blood vessels, hypertensive disease of small vessels (lipohyalinosis), or embolism from cardiac or other sources. Approximately 15% of strokes in the United States are hemorrhagic, resulting most commonly from hypertensive hemorrhages, aneurysms, vascular malformations, or cerebral amyloid angiopathy. Approximately 800,000 strokes occur annually in the United States, with a large population of survivors with permanent disability. Important modifiable risk factors for ischemic stroke include hypertension, smoking, diabetes, obesity, sedentary lifestyle, and hyperlipidemia; nonmodifiable risk factors include age, sex, and race/ethnicity. Risk factors for hemorrhage include hypertension and smoking as well as alcohol consumption.

Symptoms

The symptoms of stroke depend on the location of the injury in the brain. For example, a stroke in the distribution of the left middle cerebral artery will typically result in right hemiplegia, aphasia, and right homonymous hemianopia, whereas a lacunar infarct in the left internal capsule may result in a less severe degree of right-sided hemiparesis and few other symptoms. Left hemispatial neglect and impaired attention are common features of right hemispheric stroke. Ischemic strokes generally conform to the vascular territory of a specific artery within the brain and therefore result in characteristic combinations of neurologic impairments that constitute a particular stroke syndrome.

In general, difficulties in walking, performing activities of daily living, speaking, and swallowing are common manifestations of stroke. Cognitive impairments (memory, attention, visual-spatial perception) and impaired communication due to aphasia or dysarthria may be present. Impaired sexual function should be identified because patients may not volunteer functional impairments in this area unless the physician inquires. Loss of libido is common among both stroke survivors and their spouses or other partners and appears multifactorial in origin. Erectile dysfunction in men may result from comorbid conditions (such as diabetes or atherosclerosis), with frequent contributions from side effects of medications including antihypertensives, antidepressants, and anticonvulsant medications.

Weakness, difficulty in speaking or swallowing, aphasia, cognitive disturbance, sensory loss, and visual disturbance are the most common presenting symptoms of stroke, and deficits in these areas often persist even after initial rehabilitation. Weakness (typically hemiparesis) results from loss of motor control primarily, and some stroke survivors retain good strength despite limited ability to perform isolated precise movements of the affected side. Urinary urgency, increased muscle tone, fatigue, depression, and pain are symptoms that may be manifested after a stroke has already occurred. Reflex sympathetic dystrophy (also known as complex regional pain syndrome type I) may occur after stroke, although most post-stroke pain results from mechanical (e.g., joint subluxation) or central (e.g., thalamic pain syndromes) causes.

Depression is common after stroke, affecting as many as 40% of stroke survivors. Depression should be identified as a treatable complication of stroke rather than accepted as a consequence of functional loss.

Physical Examination

A full neurologic examination is appropriate. This includes evaluation of mental status, cranial nerves, sensation, deep tendon reflexes, abnormal reflexes (e.g., Babinski), motor strength and coordination, muscle tone, and functional mobility (sitting, transfers, and ambulation). The protean manifestations of stroke can cause many different combinations of abnormalities in these aspects of the neurologic examination. Common findings include hyperreflexia and hemiparesis on the affected side, with variable degrees of sensory loss. Dysarthria may be present, as can aphasia or hemineglect, depending on the areas affected. Hemiplegic gait is commonly seen, with reduced stride length, reduced knee flexion (“stiff-legged gait”), ankle plantar flexion and inversion, and circumduction to allow clearance of the affected leg. An assessment of mood and affect is important, given the high prevalence of post-stroke depression. Some degree of sadness is typically present as a normal grief reaction to a sudden disabling event and should be distinguished from true major depression on the basis of how pervasive the symptoms are and associated symptoms such as anhedonia. Emotional lability may also occur, with symptoms that tend to be fleeting and changeable. Range of motion in affected limbs should be measured; ankle plantar flexion contractures and upper limb contractures are common in patients with long-standing hemiplegic stroke and interfere with rehabilitation efforts. Shoulder subluxation may occur in hemiparetic patients and should be noted and quantified. Skin is examined for any areas of breakdown. Limb swelling is common and should be noted. The fit and function of leg braces, upper extremity splints, slings, wheelchairs, and ambulatory aids are assessed as part of the routine physical examination.

Functional Limitations

Depending on the impairments that patients have, they may be unable to drive or to use public transportation. Communication difficulties can lead to social isolation. Some individuals require ongoing supervision because of cognitive limitations. In severe cases, individuals with aphasia or cognitive impairments may not be able to live independently. Incontinence due to detrusor instability and urinary urgency can interfere with leaving the home and contribute to skin breakdown and social isolation.

Among stroke survivors older than 65 years who were evaluated 6 months after a stroke, 30% were unable to walk without some assistance, 26% were dependent for activities of daily living, and 26% were institutionalized in a nursing home [1].

Diagnostic Studies

In the acute setting, computed tomography is often the first diagnostic test performed because of the rapidity with which it can be obtained, its widespread availability, and its high sensitivity for cerebral hemorrhage. Magnetic resonance imaging provides greater anatomic resolution and avoids radiation exposure. With diffusion and perfusion-weighted sequences, magnetic resonance imaging abnormalities can be demonstrated at a very early stage, providing important information for acute treatments such as thrombolysis [2]. Magnetic resonance angiography, computed tomographic angiography, noninvasive flow studies, Holter monitoring, and echocardiography are important studies to help determine the cause of a stroke and to determine the best treatment for prevention of recurrent stroke. In selected patients (particularly young individuals or those without typical risk factors), an evaluation for a hypercoagulable state is indicated. In patients with prior stroke, diagnostic studies are typically directed to complications of stroke, such as persistent dysphagia or urinary incontinence. Videofluoroscopic swallowing studies can be useful in swallowing disorders, as can flexible endoscopic evaluation of swallowing. Urodynamic studies may be useful in the assessment of urinary symptoms, particularly if initial treatment with anticholinergic medications is unsuccessful.

When ischemic stroke is diagnosed within the first 3 hours, thrombolytic therapy has been shown to reduce disability [3]. There is evidence that thrombolysis may be useful in selected individuals between 3 and 4.5 hours after stroke onset as well [4