Chapter 13: Stroke

Cerebral vascular accidents, more commonly known as stroke, occur when an area of the brain dies because of lack of blood flow. The brain needs a constant supply of oxygen and sugar to live, without blood flow the nerves in the brain will die.

The major causes of stroke are clogging of an artery in the brain, a blood clot in one of the blood vessels, bleeding in the brain, low blood pressure and a blood clotting disorders. Strokes cause permanent brain damage and are the leading cause of disability and death worldwide. The amount of disability is dependent on the size of the stroke. Stroke is the third leading cause of death in the United States with almost 150,000 deaths from strokes occurring annually. The total cost for strokes is estimated to be approximately 70 billion dollars in 2009 (1).

Strokes come in two different types: ischemic and hemorrhagic. Ischemic strokes, which make up 80% of strokes, are associated with a lack of blood flow to a certain area of the brain – like a heart attack of the brain. This type of stroke occurs because of either blood clots or severe vessel narrowing in the brain.

Hemorrhagic strokes entail bleeding into the brain, depriving an area of the brain of blood flow. This is a much less common type of stroke, occurring in about 20% of strokes. This type of stroke is associated with increased pressure in the brain due to the accumulation of blood, which presses on brain tissues. Hemorrhagic strokes commonly result from breaking of blood vessels in the brain

The brain is a complex organ and having a basic understanding can help you appreciate the complications of stroke. The upper brain is divided into two hemispheres with each hemisphere divided into four different lobes: frontal, parietal, temporal and occipital lobes.

The frontal lobes control thinking, body movements and behavioral function. The parietal lobes regulate sensation, thinking and hand eye coordination. The temporal lobes regulate emotion and serve as the memory center. The occipital lobes are the visual center of the brain. The back of the brain –called the cerebellum – is responsible for balance and coordination. The brainstem, which is below the cerebellum, controls involuntary movements such as heart rate, temperature regulation and breathing. There are four main arteries to the brain: two carotid arteries and two vertebrobasilar arteries. These four arteries break down into smaller arteries and perfuse the areas of the brain.

A ruptured aneurysm is an explosion of a blood vessel in the brain. After the rupture the vessel goes into a spasm and there is damage to the surrounding area. An aneurysm that is noted on brain imaging that has not ruptured needs intervention with surgery if the aneurysm is greater than 10 mm. If the aneurysm is less than 10 mm than following the patients with serial scans of the brain is appropriate.

Transient ischemia attacks (TIA), or mini strokes, are a temporary blockage of an artery. TIAs involve a lack of blood flow to an area of the brain associated with a blocked artery. It is fully reversible within 24 hours and result in no permanent damage.

Risk Factors

Many of the same risk factors that put one at risk for heart attacks put one at risk for stroke. Those affected with conditions below are at high risk for stroke.

Symptoms

Symptoms of stroke are variable and depend on which area of the brain is not getting blood flow. If the stroke is coming from a lack of blood flow from the carotid arteries symptoms such as one-sided weakness and speech difficulties are common. Strokes from lack of blood flow to the brain stem commonly result in double vision, dizziness, and difficulty walking. Symptoms are typically of sudden onset.

Diagnosis

Diagnosis of stroke is done by history and physical exam and confirmed by pictures of the head. When a patient presents to the doctor with signs and symptoms suggestive of a stroke the physician performs a physical exam. Pictures of the head in the form of a CAT scan or MRI are the first line diagnostic tests for confirming stroke.

If the diagnosis is made within three hours, medicines to break the clot up can be initiated. It is therefore essential to make the diagnosis rapidly. Surgical intervention can be performed on some patients with stroke if the diagnosis is attained quickly.

A variety of conditions mimic stroke and need to be ruled out during the initial evaluation. Subdural hematoma, a slow leak of blood in the brain, occurs after a trauma. Seizures, which are an abnormal firing of the nerves in the brain, can mimic a stroke. Other conditions that imitate stroke include migraine headaches, meningitis, drug overdoses, high or low blood sugars, and brain tumors.

Other tests are employed under certain circumstances. Electrocardiogram, which is a picture of the electric activity of the heart, is done to assess heart rhythms. Certain cardiac rhythms can cause stroke. Common blood tests include a complete blood count, blood electrolytes, and bleeding times. Spinal taps are done to evaluate for any bleeding into the central nervous system that is not seen on CAT scan.

After the initial diagnostic evaluation is done, further testing is started to determine the cause of a stroke. This includes an echocardiogram, which is an ultrasound of the heart, or a transesophageal echocardiogram (TEE). A TEE involves placing an instrument down the throat and taking a picture of the heart from inside the esophagus. The TEE is the diagnostic test of choice because it is the most sensitive test in picking up clots that form in the heart that may travel to the brain.

Carotid doppler ultrasounds are performed to look at the large arteries that carry blood from the heart to the head. Magnetic resonance angiography and computed tomography angiography are other ways doctors can look at the large arteries taking blood to the brain. Digital subtraction angiography is performed when other tests are inconclusive and extra information is needed to determine a treatment option.

Treatment

Treatment for stroke depends and the type of stroke and the time frame it is diagnosed. Ischemic strokes that are diagnosed within three hours of onset are candidates for clot busting medications. These clot busting medications cannot be used in all patients and have risk associated with them. Medicine is given intravenously to break up the clot and restore normal blood flow to the brain. The patient is at risk for bleeding with this treatment. There are many contraindications to this treatment, some include: not being able to give the medicine within three hours of the stroke, very high blood pressure, head injury, recent surgery or a stomach bleed.

Hemorrhagic strokes are treated significantly different than ischemic strokes. Control of blood pressure is an essential element of treatment, not allowing pressure to go too high or too low. Neurosurgeons are often involved in the care of these patients to place a tube in the brain to decrease the pressure.

Much more could be said about the treatment of acute stroke, but at this point we will look at how you should take care of yourself after you have had a stroke. This requires multiple measures and a lot of health care responsibility.

Interventions, both medical and lifestyle, are used to prevent recurrent stroke. Controlling and treating risk factors (blood pressure and cholesterol levels) is an essential step in prevention. The most important preventative intervention may be stopping cigarette smoking. Exercise should be initiated or maintained. Weight loss in obese patients is beneficial. Blood thinners such as aspirin, ticlopidine (Ticlid) or clopidogrel (Plavix) reduce the stickiness of blood cells and decrease the risk for future strokes.

Depending on the cause of the stroke, surgery may be your best treatment to prevent another stroke. Individuals who have blockages in the carotid arteries of greater than 70% after a stroke are potential candidates for carotid endarterectomy.

Complications of strokes are numerous and various depending on the size and location of the stroke. Strokes on the left side on the brain can cause problems with speech including inability to speak, inability to understand speech or difficultly articulating. This occurs because the brain sends signals through nerves to the mouth, tongue, throat that control speech and damage to this area results in problems with speech and language. Aphasia, a lack of ability to speak or understand speech, is common after stroke. Swallowing problems can also occur after stroke due to nerve damage to the same nerves that control speaking. This increases the risk of patients developing pneumonia as food can slid into the lung.

Paralysis usually affects one side of the body, which is known in the medical community as hemiplegia. The paralysis usually resolves more proximally. Meaning movement of shoulders and hips come back before the hands and feet. Fine motor movements are more difficult to return.

Spasticity is uncontrollable muscle tightness and is common after a stroke. Braces to the limb and medication can help treat spasticity. It sometimes resolves spontaneously. This commonly presents with stiffening in the fingers, arms and legs. Muscle spasms, involuntary muscle contractions, muscle jerking and increased reflexes are other problems after a stroke.

Strokes affect perception, intellect, behavior and emotions. The change in perception can affect any of the five senses but a decrease in sensation is common after stroke. This increases risk of injury from heat or cold. Change in intellect can result in problems with memory and can result in dementia. Lack of motivation, inability to control emotions, depression and anger are common behavioral manifestation after a stroke.

Bladder or bowel problems can occur after a stroke. Urinary problems can take the form of leaking small amounts of urine, retaining urine, feeling the need to go frequently or frequent urinary tract infections. Bladder incontinence commonly occurs because stroke can damage nerves that control bladder function. Constipation, or the passage of hard stools or infrequent stools, is common after stroke. This can be treated with dietary changes and/or stool softeners.

Sexual function can be impaired after stroke. Many psychological factors are associated with stroke that may limit performance such as worry about recurrent stroke. Strokes cause cognitive changes, which may change the individual’s outlook or desire for sex. Language problems can limit the ability of the stroke survivor to communicate his/her needs for sex. Spasticity can limit functional ability and ability to perform. Catheters, which are sometimes needed after stroke, can limit the ability to have sexual relations.

Blood clots can crop up after stroke due to the immobility. Health care providers will try to prevent clots with the use of early mobilization, blood thinners and special stockings.

Swelling is another complication that often affects limbs that are paralyzed by the stroke. The best treatment for this swelling, called edema, is compression and elevation; water pills can be used if not responsive to the non-drug treatments.

Prognosis after stroke is difficult to predict. Stroke victims who show early recovery tend to have a better long-term prognosis. Neurological recovery typically peaks the first few months after that stroke with limited improvement after the first three months but some improvement may be noticed for up to one year.

Rehabilitation is most effective if it is started early. The ability to recover from stroke is also affected by how well the other areas of the brain are able to compensate for the damaged area. This ability will decrease as one ages. Stroke victims with multiple medical problems prior to having a stroke are at increased risk for a poor recovery. The medical concerns that are most diagnostic of a poor return to baseline functioning include: anemia, arthritis, heart disease, atrial fibrillation, lung disease, diabetes, malnutrition, and poor fitness.

The stroke survivor may require special services to function properly in the community. Home health care in the form of nurses, nurse aids, or therapists can assist the stroke survivor. Cleaning services and landscaping services may be necessary to help care for the home. Disability aids including walkers, canes and wheelchairs can aid the stroke patient maintain independence.

Even with the use of community services many are disabled after a stroke where they need more assistance to care for themselves. Many people will enter an assisted living facility or a nursing home. For some it is a short-term adventure to get rehabilitation but some suffer profound disability requiring long-term placement in an environment with 24-hour care.