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.

Brain Injury


Related Terms

  • Brain Dysfunction
  • Concussion
  • Encephalopathy
  • Head Injury
  • Head Trauma
  • Mild Traumatic Brian Injury
  • MTBI
  • Organic Brain Syndrome
  • Post-traumatic Stress Disorder
  • PTSD
  • TBI
  • Traumatic Brain Injury

Differential Diagnosis

  • Alcohol abuse
  • Brain tumor
  • Depression
  • Diabetes
  • Drug abuse
  • Encephalitis
  • Hypothyroidism
  • Meningitis
  • Pre-existing psychological factors
  • Stroke

Specialists

  • Internal Medicine Physician
  • Neurologist
  • Neurosurgeon
  • Occupational Therapist
  • Physiatrist (Physical Medicine and Rehabilitation Specialist)
  • Physical Therapist
  • Psychiatrist
  • Speech Therapist

Comorbid Conditions

  • Alcohol abuse
  • Behavioral impairment
  • Bleeding disorders
  • Cognitive impairment
  • Drug abuse
  • Hypertension
  • Liver disease
  • Mental illness
  • Migraine headaches
  • Multiple sclerosis (MS)
  • Obesity
  • Seizure disorders
  • Social impairment

Factors Influencing Duration

Factors that influence the length of disability are age, severity of injury, concomitant injuries, and an individual's willingness and ability to follow a treatment plan. Additionally, the length of disability depends on the condition of the individual before the injury, the immediate damage brought on by the impact of the injury, and secondary brain damage resulting from the body's response to the initial trauma.

Overview

Brain injury occurs when the tissues of the brain suffer an acute injury that results in temporary, chronic, or permanent damage and / or dysfunction. The brain is a very sensitive organ subject to injury from a variety of insults. Some of the major causes of brain injury include trauma, lack of oxygen (hypoxic/anoxic injury), lack of blood flow (ischemia), infection, and metabolic disorders.

Brain hypoxia and ischemia may result from traumatic brain injury, circulatory problems such as cerebral vessel spasm or stroke, and lack of oxygenation that may occur during cardiopulmonary arrest. Lack of adequate oxygen to the brain causes cell (neuron) death that can be localized or widespread. The extent of brain cell death influences the degree of neurological impairment and disability.

Metabolic disorders that may contribute to brain injury include liver failure, low blood sugar (hypoglycemia), kidney (renal) failure, and toxic exposures to such substances as alcohol, drugs, sedatives, poisons, and some heavy metals. In general, brain injury associated with metabolic disorders is widespread throughout the entire brain.

Brain injury can result in loss of body movement (paralysis), weakness of muscles, abnormal muscle stiffness, abnormal muscle movements (spasticity), memory loss (amnesia) or impairment, loss of consciousness, coma, personality changes, blindness, seizures, or disruption of various chemical processes of the body. The process of brain injury is often divided into primary injury, which occurs at the time of the precipitating fall, accident, or assault, and secondary injury, which can develop hours, days, weeks, or even months later, as a result of related biochemical or physiological damage.

One of the most common forms of brain injury is concussion, in which there is transient unconsciousness and a sudden change of mental status without obvious structural brain damage. See Concussion for more details.

Incidence and Prevalence: Most cases of traumatic brain injury (TBI) are not severe enough to require hospitalization, and thus the prevalence and incidence of this injury is underreported. Each year an estimated 1.7 million Americans sustain a TBI; about 1,365,000 are treated in emergency rooms, 275,000 are hospitalized, and 52,000 of them die. Nearly 500.000 of the emergency room visits for TBI are for children 14 years and younger.

In the US at least 3.2 million individuals require help to perform activities of daily living (ADLs) due to brain injury. More than 5.3 million individuals in the US have experienced at least one TBI. Adults 75 and older are the most likely to be hospitalized for TBI and to die from their injuries. TBI occurs in all age groups but more so in those aged 0 to 4, 15 to 19, and those over the age of 64 (CDC, Faul).

Males are three times as likely as females to die of TBI (Coronado).

Source: Medical Disability Advisor



Causation and Known Risk Factors

The major causes of TBI are falls (35.2%), motor vehicle accidents (17.3%), being struck by or colliding with stationary or moving objects (16.5%), and assaults, including assaults with firearms (10%). Activities such as sports and other recreational activities, and professions that involve the potential for injury or violence are often associated with TBI, especially mild TBI (Faul). Alcohol often plays a role in the leading causes of TBI (Chen). Motor vehicle accidents occur most frequently in the 15 to 24 year-old age group (Coronado).

Among all firearm-related TBI deaths, about 74% are suicides, 22% are homicides, and 4% are unintentional, of unknown intentionality, or are related to legal intervention. This distribution changes by race/ethnicity. Among blacks, 66% are homicides; black men aged 20 to 24 and 25 to 34 years have the highest annual average rate of firearm-related TBI deaths (43.6 and 28.8 per 100,000 population, respectively).

Among individuals 65 years and older, falls are the most common cause of TBI (Faul). The risk of fall-related TBI dramatically increases with age. Compared to individuals aged 55 to 65, those aged 65 to 74, 75 to 84, and older than age 84 are 2.2, 7.1, and 17.8 times as likely to die of TBI, respectively (Coronado).

Source: Medical Disability Advisor



Diagnosis

History: History may reveal a motor vehicle accident, fall, or physical assault. The individual (or family members) may report signs of confusion or disorientation, or the individual may have been found unconscious. In such cases, it is important to determine how long the individual was unconscious and whether amnesia occurred. Other symptoms include headaches, nausea, vomiting, loss of muscle control, muscle weakness, paralysis, blurred vision, dizziness, impaired memory, anxiety, irritability, decreased concentration, insomnia, sleepiness, and seizures. Past medical history may reveal episodes of seizures, personality changes, frequent falls, or loss of control of normal movements. There may also be a history of alcohol or drug abuse. Individuals with history of concussion may experience persistent rebound headaches from frequent use or overuse of analgesics.

The Rancho Los Amigos Levels of Cognitive Functioning Scale is a brain injury assessment tool that may be used throughout brain injury care to determine the severity of any deficit in cognitive functioning.

Physical exam: The exam includes evaluation of level of consciousness, pupil response, vital signs, motor function, reflexes, and memory. The level of consciousness is the most sensitive indicator of neurological function. The Glasgow Coma Scale (GCS) that includes eye, verbal, and motor responses, is an internationally recognized tool for evaluating the severity of a brain injury within 48 hours of injury and may be used to predict outcome. A GCS score of 15 is normal, although brain injury may still have occurred. Mild brain injury typically falls within a score of 13 to 15. Moderate injury falls within a score of 9 to 12, and severe injury within a score of 3 to 8. The GCS score of 3 is the lowest possible score and represents a deep coma state. The lower a GCS score, the higher the likelihood of morbidity and mortality from the brain injury.

An individual's vital signs are obtained as a baseline measurement and then monitored for changes throughout the recovery. Loss of the normal autoregulation of blood pressure and pulse, called the Cushing's reflex, is a hallmark of severe brain injury or imminent crisis. This generally results in a sudden rise in blood pressure and a slowing of the pulse.

Breathing rate and pattern also is evaluated and may indicate which area(s) of the brain has been injured. Irregularities in breathing patterns may indicate pressure or damage to the respiratory centers in the medulla oblongata and pons.

Pupils normally are equal in size, round, and briskly reactive to light. Brain injury and pressure on the nerves leading to the pupils can produce changes in pupil size, shape, and reaction to light and movement. These changes can be correlated with the severity and type of brain injury. A sudden enlargement (dilation) of one pupil (anisocoria) is an ominous sign that requires immediate intervention. This typically signals increased pressure on one side of the brain, causing the brain to shift downward in the skull cavity (uncal or tonsillar herniation).

Drooping of one side of the face is a classic sign indicating damage to the nerve pathways that supply the muscles of the face. Reflexes may be overactive (hyperreflexia), reflecting pressure on motor pathways that control movement. The head and neck may be bruised and swollen. There may be blood in the ear and behind the eardrum (Battle's sign), and the individual may show signs of hearing difficulty. Darkening under the eye (raccoon's eyes) may signify fracture of the base of the skull. Speech can be slurred or absent (mutism). Difficulties with expressive or receptive language may be seen (dysphasia or aphasia). The individual may show a lack of normal sense of smell (anosmia), which may reflect damage to the foremost part of the brain behind the forehead (frontal lobe). There may be evidence of memory loss.

A specialized part of the physical exam done on an individual in a coma is called ice water caloric testing. The physician uses a syringe to irrigate the external auditory canal with ice water to cool the eardrum. The resulting pattern of movement of the eyes (nystagmus) helps determine what nerves or part of the brain are injured.

Tests: Since trauma to the head is often associated with fracture or other injury to the neck, the neck should be stabilized on a special board (cervical board) until neck fracture is ruled out by x-ray. Tests include x-rays of the skull or other areas where fracture is suspected, computed tomography (CT) scans, or magnetic resonance imaging (MRI) of the head and neck. If the initial injury is severe, these imaging studies may be used to determine whether surgical intervention is needed. Lab tests include blood chemistry tests. Drug and alcohol screens should be performed if the cause of brain injury is unclear. A brain wave test (electroencephalogram [EEG]) may be useful in some cases where seizures are noted or suspected.

A variety of sophisticated imaging techniques, such as functional MRI (fMRI), single-photon emission computed tomography (SPECT), and positron emission tomography (PET) may be used for further assessment of initial injury or for tracking areas of injury by related changes in brain functioning, shifts in the position of brain tissue, or a variety of neurochemical or cellular events. Imaging is limited, however, in its ability to assess extent of injury and predict the individual’s future functional limitations, if any. Observing the individual’s actual functional limitations, both at injury and throughout the recovery process, offers a more reliable assessment of the actual extent of brain injury.

Source: Medical Disability Advisor



Treatment

As in any acute emergency, the individual's airway, breathing, and circulation must be maintained. Depending on the nature and severity of the injury, this may require administration of oxygen, intravenous fluids, and medications acting on the heart or blood vessels; assisted breathing (intubation and mechanical ventilation); and cardiopulmonary resuscitation (CPR). Accompanying problems, such as disturbances in blood chemistry or infections, should be treated. When there is trauma to the head, neck fracture and spinal cord injury must be assumed until ruled out. More severe cases of brain trauma may require immediate surgical intervention (craniotomy) to relieve pressure on the brain from swelling and bleeding (e.g., subdural hematoma). Drugs that decrease brain swelling, control seizures, or lower blood pressure also may be used. As recovery progresses, individuals may be prescribed medications to address excessive fatigue, attention deficits, depression, agitation, spasticity, or memory loss.

If loss of consciousness does not last more than 20 to 30 minutes or post-traumatic amnesia is less than 24 hours, if head CT or MRI shows no bleeding or damaged areas, and if neurological examination shows no focal abnormalities, then individuals usually can be released from the hospital and observed at home by a family member. More severe cases usually require hospital observation of the individual's vital signs such as pulse, respiration, and blood pressure. The pupils, reflexes, level of consciousness, and neurological function should be checked regularly.

Source: Medical Disability Advisor



Prognosis

The outcome varies markedly depending on the severity of the brain injury and appropriate, prompt management of the complications that may be associated with the traumatic event. Prognosis is often excellent, with complete recovery expected in mild brain injury with loss or alteration in consciousness lasting less than 30 minutes, normal brain CT or MRI, and normal neurological examination. The outcome is usually better in younger individuals. Recognition and rapid surgical intervention to remove accumulating blood or blood clots (craniotomy with evacuation of hematoma) can be life saving and is vital to improving the outcome of brain-injured individuals. A primary cause of death in those with brain injury is delay in surgical intervention. Causes of such delays may be failure to recognize the rate and significance of the bleeding and deterioration of neurological function or lack of access to surgical intervention.

Recovery may take weeks to months. In adults, most recovery after severe brain injury occurs within the first 6 months. However, recovery may continue for up to 2 years or longer, in part based on the primary neuropathology of the injury. Possible outcomes include memory loss, seizures, intellectual impairment, personality changes, muscular weakness in an arm or leg, depression, language problems, or slurred speech, but patterns of recovery vary. The injury may be fatal in cases of damage to the vital centers that regulate breathing and blood flow.

Source: Medical Disability Advisor



Rehabilitation

An individual with a brain injury that has caused physical and mental deficits may need rehabilitation to facilitate recovery. The overall objective for rehabilitation of individuals with TBI is to return them as quickly and as fully as possible to the mainstream of their lives. This requires achieving functional recovery and assisting the individual in coping with disabilities that may remain.

A coordinated treatment approach from a team of healthcare professionals is necessary for treatment to succeed. Participants in the rehabilitation program can include physical, occupational, speech, and recreational therapists, social workers, and vocational counselors. Therapists must set goals to make effective use of time and resources when treating severe symptoms that have resulted from trauma to the brain. Rehabilitation varies for each individual because of the uniqueness of the problems after each particular brain injury. Involving family members in treatment can help motivate and support the individual. Sensory stimulation from a nearby radio or individuals talking may be helpful even when the individual's level of consciousness has decreased.

A physiatrist can best assess the degree of mental and functional disability following brain injury. Rehabilitation is then recommended based on the degree of deficits. Most individuals with severe brain injury (e.g., initial GCS scores less than 8) benefit from formal neurorehabilitation. Some individuals with major brain injury and significant mental and functional deficits may be referred to an inpatient rehabilitation facility. Even after regaining consciousness, the individual may still be confused and easily distracted and will benefit from exercises to promote memory return. Instruction designed to help the individual carry out simple tasks can be as elementary as motivating individuals to receive an object in their hand or assisting them to go from a sitting position to a standing position.

In rehabilitation of a brain injury, the therapist must sequence activities from easy to more difficult. For example, the therapist must teach the individual to roll in bed and rise from a chair before beginning instruction in proper walking patterns. Once the individual regains his or her thinking processes, rehabilitation may turn to the needs of muscular strength, endurance, and flexibility. To correct muscle imbalance, the therapist will use techniques that make the muscular and nervous systems work together. Group activities may take place in mat classes, wheelchair classes, or in other activities such as volleyball games.

When appropriate, the final phase of rehabilitation following brain injury involves the individual's return to work. Both physical and mental exercises are now directed toward meeting work requirements. The rehabilitation therapist may need to make modifications for those with various levels of head trauma.

Source: Medical Disability Advisor



Complications

Persistent memory or thinking problems, headaches, depression, moodiness (labile mood), sleep apnea, weakness, numbness, paralysis, visual problems, agitation, seizures, spasticity, vertigo, and sexual dysfunction may complicate brain injury, depending on the location of the injury and its severity. Some individuals may experience difficulties with speaking or with understanding speech, or with fine or gross motor control. Brain injury that results from violence or combat may become associated with post-traumatic stress disorder (PTSD). Some individuals may have altered medication tolerance due to their brain injury, with adverse side effects even from medications prescribed or used before the injury. Physicians may discontinue medications that interfere with cognitive function or replace them with less disruptive alternatives.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

In mild or less severe cases, a worker may temporarily need shorter work hours or frequent breaks. Time off from work for ongoing rehabilitation and treatment may be necessary. Individuals experiencing memory problems, depression, or PTSD may require ready access to, or time off for, employee assistance programs or regularly scheduled counseling sessions. Memory problems may be addressed with proactive strategies including electronic memory aids. Individuals who have trouble concentrating may benefit from using headsets, environmental sound machines, or personal watches and timers to reduce distractions and improve productivity. Sensitivity training for coworkers may benefit overall workplace interaction and cooperation, as well as increase productivity and address potential problems before they arise.

In cases of extensive brain injury, individuals may be left with permanent disabilities that prevent them from performing their previous duties. Such cases require adjustment in duties and expectations, vocational rehabilitation or training, and possibly a complete change in job assignment. Accommodations may need to be made so that the workplace is wheelchair-accessible for individuals with limited mobility.

Preventing and reducing the recurrence of brain injury may mean revising workplace procedures and policies to require that individuals wear helmets in appropriate work areas or while riding bicycles or motorcycles, and to follow applicable laws regarding seat belts and child restraints when traveling in motor vehicles. Inspecting workplace flooring and coverings to remove hazards, or installing handrails on stairways, may help prevent serious falls. When possible, firearms on site should be stored unloaded in locked cabinets or safes.

For more information refer to "Work Ability and Return to Work," pages 326–328.

Risk: Individuals with brain injuries are not at risk of harm from work activities. Temporary reassignment of tasks may be necessary if the individual is experiencing seizures or has significant cognitive impairment.

Capacity: Capacity may be limited if cognitive or motor impairment is present. Functional testing may be needed to determine work ability. Contact physician for details.

Tolerance: Tolerance is dependent on the individual’s complaints of headache and fatigue, which may be mitigated by modification of work tasks. With severe TBI, personality changes may affect the individual’s motivation at work.

Source: Medical Disability Advisor



Maximum Medical Improvement

360 days.

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:

  • Has individual experienced a TBI?
  • Does individual have circulatory problems such as cerebral vessel spasm or stroke?
  • Did lack of oxygenation occur during cardiopulmonary arrest?
  • Does individual have liver failure, hypoglycemia, or kidney failure?
  • Was individual exposed to toxic substances such as alcohol, drugs, sedatives, poisons, and some heavy metals?
  • On exam, what was level of consciousness, pupil response, vital signs, motor function, reflexes, and memory?
  • What was individual's initial GCS score? Score on Rancho Los Amigos Scale?
  • What were individual's vital signs? Have they been stable or labile?
  • Was pupil testing normal or abnormal? Does individual have raccoon eyes?
  • Is there drooping on one side of the face? Are the reflexes overactive?
  • Is there blood in the ear or behind the eardrum? Any hearing difficulty?
  • Does individual have any speech abnormalities?
  • What were the results of ice water caloric testing on the individual?
  • Was the neck stabilized until a fracture was ruled out?
  • Has individual undergone skull x-rays? Brain and neck CT? MRI? EEG?
  • Has individual undergone neuropsychological evaluation?
  • Were PET, fMRI, or SPECT used to assess primary or secondary injuries?
  • Did individual undergo blood chemistry tests? Drug and alcohol screenings?
  • Were conditions with similar symptoms ruled out?
  • Were concomitant injuries evaluated?

Regarding treatment:

  • Were intubation and mechanical ventilation needed? Was CPR necessary?
  • Was it necessary to perform a craniotomy?
  • Was individual given drugs to reduce brain swelling? To control seizures and blood pressure?
  • Are there any injury complications, such as persistent memory or thinking problems? Speech problems? Speech comprehension problems? Depression? Weakness? Visual problems? PTSD?
  • Were concomitant injuries successfully treated?
  • Was individual hospitalized or released to home care?

Regarding prognosis:

  • Has individual's score on the Rancho Los Amigos Scale changed?
  • Can individual's employer accommodate any necessary restrictions?
  • Does individual have access to services or products that can address memory or attention deficits?
  • Has neuropsychological evaluation and therapy or other employee assistance been provided?
  • Is individual actively participating in a brain injury rehabilitation program? Are family members involved in the rehabilitation process?
  • Does individual have any underlying conditions that may affect recovery?

Source: Medical Disability Advisor



References

Cited

"Traumatic Brain Injury." MedlinePlus. 1 May. 2014. National Library of Medicine. 5 May 2014 <http://www.nlm.nih.gov/medlineplus/traumaticbraininjury.html>.

Centers for Disease Control and Prevention. "Traumatic Brain Injury." CDC. 6 Mar. 2014. Centers for Disease Control and Prevention. 5 May 2014 <http://www.cdc.gov/TraumaticBrainInjury/index.html>.

Chen, C. M. , et al. "Alcohol Use at Time of Injury and Survival Following Traumatic Brain Injury: Results from the National Trauma Data Bank." Journal of Studies on Alcohol and Drugs 73 (2012): 531-541.

Coronado, V. G. , et al. "Surveillance for Traumatic Brain Injury-Related Deaths--United States, 1997-2007." Morbidity and Mortality Weekly Report 60 (2011): 1-32.

Dawodu, Segun T. "Traumatic Brain Injury: Definition, Epidemiology, Pathophysiology." eMedicine. Eds. Denise I. Campagnolo, et al. 6 Mar. 2013. Medscape. 5 May 2014 <http://emedicine.medscape.com/article/326510-overview>.

Faul, Mark. "Traumatic Brain Injury in the United States: Emergency Department Visits, Hospitalizations and Deaths 2002-2006." CDC. Mar. 2010. Centers for Disease Control and Prevention. 5 May 2014 <http://www.cdc.gov/traumaticbraininjury/pdf/blue_book.pdf>.

Talmage, J. B. , J. M. Melhorn, and M. H. Hyman, eds. Work Ability and Return to Work, AMA Guides to the Evaluation of. Second ed. Chicago: AMA Press, 2011.

Source: Medical Disability Advisor






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