Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Job Classification

In most duration tables, five job classifications are displayed. These job classifications are based on the amount of physical effort required to perform the work. The classifications correspond to the Strength Factor classifications described in the United States Department of Labor's Dictionary of Occupational Titles. The following definitions are quoted directly from that publication.

Sedentary Work Exerting up to 10 pounds (4.5 kg) of force occasionally and/or a negligible amount of force frequently or constantly to lift, carry, push, pull, or otherwise move objects, including the human body. Sedentary work involves sitting most of the time, but may involve walking or standing for brief periods of time. Jobs are sedentary if walking and standing are required only occasionally and other sedentary criteria are met.

Light Work Exerting up to 20 pounds (9.1 kg) of force occasionally and/or up to 10 pounds (4.5 kg) of force frequently, and/or negligible amount of force constantly to move objects. Physical demand requirements are in excess of those for Sedentary Work. Light Work usually requires walking or standing to a significant degree. However, if the use of the arm and/or leg controls requires exertion of forces greater than that for Sedentary Work and the worker sits most the time, the job is rated Light Work.

Medium Work Exerting up to 50 (22.7 kg) pounds of force occasionally, and/or up to 25 pounds (11.3 kg) of force frequently, and/or up to 10 pounds (4.5 kg) of forces constantly to move objects.

Heavy Work Exerting up to 100 pounds (45.4 kg) of force occasionally, and/or up to 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Very Heavy Work Exerting in excess of 100 pounds (45.4 kg) of force occasionally, and/or in excess of 50 pounds (22.7 kg) of force frequently, and/or in excess of 20 pounds (9.1 kg) of force constantly to move objects.

Cerebrovascular Accident


Related Terms

  • Acute Cerebrovascular Disease
  • Brain Attack
  • Cerebral Infarction
  • Craniovascular Accident
  • CVA
  • Stroke
  • Stroke Syndrome

Differential Diagnosis

Specialists

  • Cardiovascular Internist
  • Internal Medicine Physician
  • Neurologist
  • Occupational Therapist
  • Orthotist
  • Physiatrist (Physical Medicine and Rehabilitation Specialist)
  • Physical Therapist
  • Psychiatrist

Comorbid Conditions

Factors Influencing Duration

Delay in treatment of stroke negatively influences recovery. Age at onset also affects recovery, with older adults experiencing longer-lasting effects than those with onset before age 45. Disability varies with the part of the brain affected, the extent of brain damage, and response to treatment.

Medical Codes

ICD-9-CM:
434 - Occlusion of Cerebral Arteries
434.0 - Cerebral Thrombosis; Thrombosis of Cerebral Arteries
434.01 - Cerebral Thrombosis; Thrombosis of Cerebral Arteries; with Cerebral Infarction
434.1 - Cerebral Embolism
434.11 - Cerebral Embolism; with Cerebral Infarction
434.9 - Cerebral Artery Occlusion, Unspecified
434.91 - Cerebral Artery Occlusion, Unspecified; with Cerebral Infarction
435.9 - Unspecified Transient Cerebral Ischemia; Impending Cerebrovascular Accident; Intermittent Cerebral Ischemia; Transient Ischemic Attack [TIA]
436 - Cerebrovascular Disease, Acute, But Ill-defined
437.1 - Cerebrovascular Disease, Other and Ill Defined; Other Generalized Ischemic Cerebrovascular Disease
997.02 - Iatrogenic Cerebrovascular Infarction or Hemorrhage; Postoperative Stroke

Overview

A cerebrovascular accident, commonly known as a stroke, is sudden, localized damage in the brain that results in nervous system (neurologic) deficits. Stroke may result from either interrupted delivery of blood and oxygen to the brain (ischemic stroke) or abnormal bleeding in the brain (hemorrhagic stroke).

The cause of ischemic stroke is blockage (occlusion) of arteries that carry blood and oxygen to the brain or within the brain. The source of the occlusion may be a clot (thrombus) attached to the wall of a blood vessel, the heart, or the valves of the heart. Thrombi are most likely to form in the blood vessels when narrowing of the arteries caused by fatty deposits in the vessel walls (atherosclerosis) leads to turbulent blood flow. Thrombi form along the walls of the heart when portions of the heart muscle are damaged or not able to contract normally (e.g., myocardial infarction, atrial fibrillation, severe congestive heart failure, cardiomyopathy). Thrombi form on valves when there is damage to the valve (endocarditis, mitral stenosis, artificial valves). Certain medical conditions can also cause platelets or red blood cells to become stickier or cause increased blood viscosity, leading to formation of a thrombus. These conditions include polycythemia, multiple myeloma, sickle cell anemia, protein C deficiency, and protein S deficiency.

Occlusion can also be caused by material (embolus) traveling through the blood stream. Examples of an embolus include a thrombus that has broken away from the wall of the blood vessel, heart, or valve; a piece of plaque; or a clump of bacteria.

Non-thrombotic occlusion of small arteries deep in the brain is the most common cause of ischemic stroke. Regardless of the cause of blockage, nerve cells (neurons) and brain tissue die when robbed of blood and oxygen supply. The size and location of the blockage and the extent of damage before blood flow is restored determined the effects of a stroke. Brief ischemic episodes (transient ischemic attacks or TIAs) can occur as warning signs of an impending larger stroke. TIAs occur before almost 30% of ischemic strokes. Symptoms of TIA usually pass quickly; a diagnosis of ischemic stroke is made when neurologic deficits persist for more than 1 hour.

Bleeding from a ruptured blood vessel causes hemorrhagic stroke. The blood vessel may rupture because of high blood pressure (hypertension), increased tendency toward bleeding, an abnormal weakness in the wall of a blood vessel (aneurysm), or abnormal communication between arteries and veins (arteriovenous malformation). For specific information concerning hemorrhagic stroke, see the topic titled Cerebral Hemorrhage.

Conditions that predispose individuals for stroke are hypertension, diabetes mellitus, heart disease, congestive heart failure, and atrial fibrillation, particularly if these conditions are untreated or are poorly controlled. Risk also is increased in individuals who have a history of transient ischemic attacks, cerebrovascular disease, or a family history of stroke.

Incidence and Prevalence: Ischemic strokes account for 85% of all strokes (Becker). Each year 160 out of every 100,000 Americans experience a stroke (Singh). In industrialized countries, stroke is the third leading cause of death and the leading cause of disability in adults (Jauch).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Three-quarters of all strokes occur in adults over the age of 55 (Becker), and the risk of stroke increases with each decade after age 55. Lifestyle risk factors for stroke are high cholesterol, obesity, cigarette smoking, cocaine use (the most common cause of stroke in people under age 55), and heavy use of alcohol.

Men have a higher risk for stroke than women (Becker). The stroke risk for young women who smoke and also take birth control pills (high-estrogen oral contraceptives) is more than 20 times higher than for women who do not smoke and also do not use oral contraceptives. African-Americans have a higher prevalence of hypertension, diabetes, obesity, smoking, and sickle cell anemia, leading to a prevalence of stroke almost twice that in Caucasian populations. The incidence of stroke in African-American males is 93 per 100,000; incidence in African-American females is 79 per 100,000. The incidence of stroke in Caucasian males is 62.8 per 100,000; incidence in Caucasian females is 59 per 100,000 (Jauch). The risk of stroke is reduced by moderate alcohol consumption (6 to 8 oz. of wine daily) and exercise (Sacco).

Source: Medical Disability Advisor



Diagnosis

History: Ischemic stroke may occur suddenly, or symptoms may develop gradually over minutes to hours. The individual also may report symptoms that occurred a day or two before the stroke, such as neck pain or tingling in the arm. Stroke may occur during sleep so that the individual awakes with what appears to be a sudden deficit, such as restricted movement on one side of the body or inability to speak.

Symptoms vary depending on which blood vessel in the brain has been blocked and what part of the brain is affected by the blockage. The pattern of symptoms can help determine whether the stroke involves the front of the brain (anterior circulation) or back of the brain (posterior circulation) including the cerebellum or brain stem. Symptoms may include numbness (paresthesia) or weakness (paresis) in the face, arm, or leg, usually on one side of the body (hemianesthesia or hemiparesis); difficulty in speaking (expressive aphasia) or understanding speech (receptive aphasia); vision loss affecting one or both eyes (visual field cut); double vision (diplopia); slurred speech (dysarthria); difficulty swallowing (dysphagia); difficulty walking (gait ataxia and/or dyspraxia); dizziness; vertigo; or loss of balance or coordination. These symptoms may occur alone or in combination and may be accompanied by a change in the level of consciousness.

Physical exam: Physical findings vary depending on the part of the brain that has been affected by the stroke. In addition to observation of the symptoms described above, other findings may include increased or decreased muscle tone (hypertonia or hypotonia) or changes in reflexes. If the stroke affects blood circulation in the brain stem, the regulation of temperature, blood pressure, and breathing may be affected since the brainstem controls these functions.

The physical examination should localize the site of the damage (lesion), document the neurologic deficits, rule out conditions that can be confused with stroke, and determine potential cardiovascular causes of stroke. The National Institutes of Health Stroke Scale (NIHSS) is a 42-point scale that allows quantification of an individual’s neurologic deficits. This scale can be used to follow changes throughout an individual’s course.

Tests: The following tests are usually ordered: a complete blood count (CBC), blood chemistries for electrolyte levels (sodium, potassium, and chloride), blood glucose level, and lipid levels (HDL cholesterol, LDL cholesterol, triglycerides). Cardiac enzymes are evaluated because of the association between cardiovascular disease and cerebrovascular disease and to rule out a simultaneous heart attack (myocardial infarction). Coagulation studies (prothrombin time or PT, partial thromboplastin time or PTT) reveal clotting or bleeding tendencies. Brain CT and MRI are performed to rule out hemorrhage and confirm an ischemic stroke, localize the affected area, and determine the extent of damage. Electrocardiogram (ECG) and heart rate monitoring are done to evaluate heart function. Oxygen levels may be monitored. Tests to determine the source of thrombi may include carotid Doppler ultrasound to examine the carotid arteries in the neck, and echocardiography to examine the heart valves. Angiography is most important in the preoperative evaluation of carotid disease and in defining the cerebrovascular anatomy in a certain individuals.

Source: Medical Disability Advisor



Treatment

Immediate transport to the hospital is critical for all individuals with suspected stroke. Prompt restoration of blood flow to the area of blockage can prevent further damage from occurring and reduce or reverse injury. Reperfusion agents (thrombolytics) are drugs that can help restore blood flow in ischemic strokes by dissolving clots; however, to be effective, these drugs must be given within 3 hours of symptom onset. Brain CT or MRI is done to rule out a hemorrhagic stroke, which would disallow (contraindicate) the use of thrombolytic agents. Tissue plasminogen activator (tPA) may be given according to protocol if the individual meets strict criteria. Individuals who do not meet criteria for tPA may be given antiplatelet medications (e.g., aspirin) and/or anticoagulants (e.g., heparin and/or warfarin) to prevent additional clot formation that could result in another stroke, a heart attack, or complications of the current stroke. Heparin dosage must be carefully regulated when used for ischemic stroke because it can overcorrect the coagulation problem, resulting in bleeding. Coagulation levels are carefully monitored with use of any anticoagulant. The use of other medications may be indicated to control high blood pressure, fever, brain swelling, or to treat complications such as concomitant heart attack.

Patients are hospitalized for monitoring of vital signs (blood pressure and heart rate), coagulation times (PT and PTT), oxygen levels, electrolyte balance, and other blood chemistries. These parameters must be closely regulated to minimize the amount of brain damage resulting from the stroke and to return to normal the individual’s body chemistry to prevent another stroke.

Source: Medical Disability Advisor



Prognosis

Recovery rates vary depending on the part of the brain affected and the extent of the stroke. Function will be restored in about half of patients with moderate to severe paralysis on one side of the body (hemiplegia) and about 10% will have complete neurologic recovery (Beers). Stroke (all types) has an overall mortality rate of 60.2 per 100,000 individuals; higher mortality occurs in older individuals, in brain stem stroke, or hemorrhagic stroke with alterations of consciousness (Jauch). About 10% to 18% of stroke survivors have a second stroke within a year. Control of risk factors such as high blood pressure, atrial fibrillation, atherosclerosis, obesity, and high lipid levels is important to prevent additional strokes. Of the 4 million people who have had a stroke, about 33% experience mild disability, 20% moderate disability, and 16% require placement in an assisted living facility (Jauch). Rehabilitation is a significant factor in stroke outcomes.

Source: Medical Disability Advisor



Rehabilitation

Individuals who experience a stroke may require a variety of rehabilitation services including physical therapy, occupational therapy, speech therapy, and orthotic management. Therapy should begin as soon as the individual is medically stable, usually within 72 hours. Acute inpatient rehabilitation should continue daily until the individual is discharged from the hospital. Individuals discharged to a rehabilitation hospital or skilled nursing unit should have several hours of therapy daily. Individuals discharged to home should have the appropriate home care services several times a week for about 6 to 9 weeks. Additional outpatient therapy may be indicated.

The focus of occupational therapy is to regain the individual's ability to perform activities of daily living. Occupational therapists help individuals learn new ways to perform activities such as washing dishes and doing the laundry. Individuals may learn either to perform such tasks while sitting down on a kitchen stool or by distributing their weight equally to each leg to maintain good balance while standing. Individuals also learn bathing, toileting, and dressing techniques. Occupational therapists may order equipment such as a tub transfer bench to assist individuals in using the bathtub or elastic shoelaces to promote ease of dressing.

Occupational therapists promote the return of upper extremity and hand function through a variety of activities. Often the upper arm separates (subluxation) from the shoulder girdle due to the loss of muscle tone. Neuromuscular electrical stimulation (NMES) uses electrodes that provide external stimulation to the muscles to counteract this symptom. More frequently, individuals use a hemi-sling that helps support the arm to prevent subluxation. Occupational therapists may stretch the upper extremity and teach self-stretching techniques and strengthening exercises so the arm can regain maximum potential.

Individuals perform tasks requiring weight bearing on the affected extremity to provide nerve impulses to the brain so damaged neural paths can begin to heal. An example of a weight-bearing activity is placing the hands on the bed while seated to help maintain an upright posture. Individuals engage in tasks using both hands, such as holding a cup with the weak hand while pouring a drink with the unaffected hand. As function returns, individuals may engage in fine motor tasks such as handwriting.

Physical therapy focuses on stretching and strengthening any tight or weak musculature. Therapists may passively stretch any affected joints and instruct individuals and their family members on how to perform a stretching and strengthening program. Physical therapy also focuses on transfer training. The physical therapist teaches individuals to roll in bed, transfer from lying to sitting, and from sitting to standing. Physical therapy teaches the individual to roll to both sides and bear weight evenly when sitting and standing. Individuals also learn mobility techniques such as walking and climbing stairs using a pyramid cane, four-pronged cane, or a walker. A wheelchair is ordered for those individuals unable to walk. Individuals learn to propel the wheelchair outside over curbs and ramps.

Orthotic management may also be required for individuals to regain function. A night splint may be made that places the hand in a more functional position. An orthotist may make a leg splint (ankle-foot orthosis) to promote better control of the ankle and knee while walking.

Speech therapy may be required to strengthen the muscles of the face for improved speech and swallowing. Individuals learn to move the facial muscles in a balanced manner both by manual assistance and visual cueing using a mirror. Individuals perform tongue exercises that allow improved speech and easier eating. Individuals learn to speak with greater clarity through activities such as sustained vocal expressions (e.g., saying "ah"). To assist in the swallowing reflex, individuals begin eating semi-moist, pureed food that is easier to swallow and then progress to food that is rich in taste, smell, and texture. Individuals also learn to achieve sucking control and saliva production first by sucking on small ice chips and progressing to sucking thick liquids through a straw.

Individuals may need counseling by a psychologist or psychiatrist to help adjust to their altered functional abilities and body image.

Source: Medical Disability Advisor



Complications

Complications vary with the severity of the stroke, the part of the brain affected, and the amount of time between the onset of stroke and treatment. Individuals who have had an ischemic stroke are at increased risk for having another stroke or myocardial infarction. Heart monitors should be used following stroke, as individuals often will have abnormal or irregular heart rhythms (cardiac arrhythmia), especially atrial fibrillation, which can contribute to thrombus and/or embolus formation and another stroke. Decreased muscle activity following stroke may increase risk of blood clot formation in veins (deep vein thrombosis). These blood clots can travel to the lungs (pulmonary embolism) and cause serious respiratory problems or death. Deep vein thrombosis can be prevented by walking for individuals who are ambulatory, compression stockings for individuals who are confined to bed, and/or by medications.

Cognitive dysfunction may affect memory, level of attention and alertness, ability to communicate clearly, and motor skills. Instructions may be misunderstood or forgotten and the individual may not be able to process information and respond appropriately. The individual may become a threat to his or her own safety, unable to function responsibly, complete tasks, or operate equipment. Depression affects at least one-third individuals with stroke (Jauch).

Difficulty swallowing and decreased alertness can allow food or saliva to enter the lungs (aspiration) and cause sudden death due to choking or lung infection (aspiration pneumonia). Seizures occur in approximately 17% of individuals with ischemic stroke and about half of individuals with hemorrhagic stroke affecting the cortex or gray matter that covers the front part of the brain (Becker). Urinary incontinence and poor bladder function may result in urinary tract infection or kidney problems. Individuals who have had a stroke are at increased risk of falls due to factors such as impaired judgment, poor balance and coordination, and muscle weakness. Uncontrolled muscle spasm can lead to joint stiffness and immobility (contractures). Shoulder injury can result due to decreased muscle tone. Pressure sores (decubitus ulcers) may occur if the individual is immobile and unable to make frequent position changes or is not moved frequently by caretakers. Poor healing of pressure sores and related bacterial contamination may become a source of systemic infection (sepsis).

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

An individual who has experienced a stroke will have varying needs when returning to the workplace. If a cane, walker, or wheelchair is necessary, the work environment should be free of barriers that limit mobility. Individuals may need a quiet work environment to aid concentration if cognition was affected by the stroke. Individuals may need adaptive equipment such as pens and pencils with thicker shafts that allow better gripping. Individuals may need to change job positions if the original job required heavy lifting, prolonged standing, or cognitive skills that have been lost.

Source: Medical Disability Advisor



Failure to Recover

If an individual fails to recover within the expected maximum duration period, the reader may wish to consider the following questions to better understand the specifics of an individual's medical case.

Regarding diagnosis:

  • Does individual have hypertension, blood clotting disorder, diabetes mellitus, history of TIAs or prior stroke, heart disease, or congestive heart failure? Does individual smoke, use cocaine, or abuse alcohol? Does individual have high cholesterol, or is individual obese?
  • What is individual's age? Sex? Family history?
  • Did individual experience a sudden, severe headache and/or loss of consciousness?
  • Has paresthesia or paresis occurred in the face, arm, or leg? Was expressive or receptive aphasia, visual field cut, diplopia, dysarthria, dysphagia, gait ataxia, vertigo, or loss of balance or coordination reported?
  • On physical exam, were increased or decreased muscle tone or changes in reflexes observed?
  • Does individual have difficulty with regulation of temperature, blood pressure, and/or breathing?
  • Was a brain CT or MRI done? ECG and cardiac enzymes performed? Doppler, echocardiogram, or angiography done?
  • Were tests done to ruled out conditions with similar symptoms?

Regarding treatment:

  • Was individual taken to the hospital immediately?
  • Was the tPA protocol administered?
  • Is individual being treated with heparin, aspirin, or warfarin?
  • Is it necessary to administer other medications to control high blood pressure, high blood lipids, severe muscle spasms, or complications such as heart attack?

Regarding prognosis:

  • Has individual addressed modifiable risk factors?
  • Is individual active in rehabilitation? Is a home exercise program in place?
  • Does individual have any complications such as another stroke, myocardial infarction, cardiac arrhythmia, deep vein thrombosis, pulmonary embolism, or aspiration pneumonia?
  • Does individual have seizures, urinary tract infection or kidney problems, other injuries from falls, contractures, bedsores, or sepsis?
  • Is individual depressed?

Source: Medical Disability Advisor



References

Cited

Becker, J. U., C. R. Wira, and Jeffrey L. Arnold. "Stroke, Ischemic." eMedicine. Eds. Richard S. Krause, et al. 18 Nov. 2003. Medscape. 22 Oct. 2004 <http://emedicine.com/emerg/topic558.htm>.

Beers, Mark H., et al., eds. "Ischemic Stroke." The Merck Manual of Diagnosis and Therapy. 18th ed. Whitehouse Station, NJ: Merck Laboratories, 2006.

Elkind, Mitchell, Devin Brown, and Bradford Burke Worrall. "Genetic and Inflammatory Mechanisms in Stroke." eMedicine. Eds. Richard M. Zweifler, et al. 28 Aug. 2003. Medscape. 22 Oct. 2004 <http://emedicine.com/neuro/topic710.htm>.

Jauch, Edward C., Brett Kissela, and Brian Stettler. "Acute Stroke Management." eMedicine. Eds. Thomas A. Kent, et al. 28 Aug. 2004. Medscape. 22 Oct. 2004 <http://emedicine.com/neuro/topic9.htm>.

Sacco, R. L. "Newer Risk Factors for Stroke." Neurology 57 5 (2001): 31-34. MD Consult. 27 Jul. 2004. Elsevier, Inc. 22 Oct. 2004 <http://home.mdconsult.com/das/journal/view/39434791-2/N/12029915?sid=286878571&source=MI>.

Singh, Niten, et al. "Atherosclerotic Disease of the Carotid Artery." eMedicine. Eds. Vincent Lopez Rowe, et al. 7 2006. Medscape. 16 Dec. 2008 <http://emedicine.com/med/topic2964.htm>.

Source: Medical Disability Advisor






Feedback
Send us comments, suggestions, corrections, or anything you would like us to hear. If you are not logged in, you must include your email address, in order for us to respond. We cannot, unfortunately, respond to every comment. If you are seeking medical advice, please contact your physician. Thank you!
Send this comment to:
Sales Customer Support Content Development
 
This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is published with the understanding that the author, editors, and publisher are not engaged in rendering medical, legal, accounting or other professional service. If medical, legal, or other expert assistance is required, the service of a competent professional should be sought. We are unable to respond to requests for advice. Any Sales inquiries should include an email address or other means of communication.