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.

Concussion, Cerebral


Related Terms

  • Brain Injury
  • Head Injury
  • Head Trauma
  • Traumatic Brain Injury

Differential Diagnosis

Specialists

  • Family Physician
  • Neurologist
  • Neurosurgeon
  • Psychiatrist

Comorbid Conditions

  • Seizure disorders

Factors Influencing Duration

Length of disability will be affected by the level of concentration required on the job; the severity of the head injury; and any complications such as brain damage, symptoms of post-traumatic syndrome, and mental impairment. Mild complaints associated with MTBI and post concussive syndromes may challenge return to work efforts.

Medical Codes

ICD-9-CM:
850.0 - Concussion with No Loss of Consciousness
850.11 - Concussion, With Loss of Consciousness of 30 Minutes or Less
850.12 - Concussion, With Loss of Consciousness from 31 to 59 Minutes
850.2 - Concussion with Moderate Loss of Consciousness
850.3 - Concussion with Prolonged Loss of Consciousness and Return to Pre-existing Conscious Level
850.4 - Concussion with Prolonged Loss of Consciousness, without Return to Pre-existing Conscious Level
850.5 - Concussion with Loss of Consciousness of Unspecified Duration
850.9 - Concussion, Unspecified

Overview

A cerebral concussion describes a sudden change in mental status after a head injury, with no immediate or delayed evidence of structural brain damage. The change in mental status may or may not be accompanied by a loss of consciousness.

Consciousness may be lost for a few seconds in a mild injury, or for hours or days after a more severe injury. The loss of consciousness results from a blow to the head. In a mild concussion, there is a temporary or transient loss of consciousness (LOC) and possible impairment of the higher mental functions, such as loss of memory of events preceding the injury (retrograde amnesia) and emotional instability (lability). A severe concussion produces prolonged unconsciousness with impairment of the function of the brain stem, such as transient loss of respiratory reflex, blood vessel (vasomotor) activity, and dilation of the pupils (mydriasis).

Mild concussions are very common and may occur without loss of consciousness. Mild concussions, like more serious concussions, are associated with confusion or memory loss. But with mild concussion, these complaints clear within 24 hours. The initial physical exam is normal or mildly abnormal with Glasgow Coma Scale ratings of 13 to 15 (see Tests below). Mild concussions may be associated with post concussion syndrome and subtle changes on psychometric testing lasting for several months. Individuals who have sustained mild concussions are more sensitive to recurrent head trauma. Mild concussions may also be referred to as mild traumatic brain injury (MTBI).

Concussion differs from contusion in that in the former, the injury is functional (affecting the functions but not the structure), whereas in the latter it is organic (pertaining to an organ). If unconsciousness persists for more than 6 hours (coma), it is likely that permanent brain tissue injury has occurred.

Incidence and Prevalence: Annual incidence of traumatic brain injury in the US is approximately 200 per 100,000 individuals. Although the majority (75% to 80%) will sustain a mild concussion (MTBI), the remainder will experience a moderate to severe head injury that will result in permanent disability; mortality is 10% (Shepard).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Males are approximately twice as likely as females to sustain a concussion; people ages 15 to 24 and people over 75 are the age groups with the highest risk. Additionally, blacks have the highest death rate among ethnicities from a concussion ("Risks").

Source: Medical Disability Advisor



Diagnosis

History: The individual may have a history of an injury to the head, followed by loss of consciousness (LOC). Transient loss of consciousness or brief loss of contact with the environment is the characteristic feature of a simple concussion. Loss of consciousness may be prolonged when there is swelling, hemorrhage, or diffuse nerve (axonal) injury (DAI), or contusion or laceration of the outer brain (cortex). Severity of the symptoms and recovery time depend on the degree of brain damage. Individuals with a concussion may be slightly dazed for a few minutes and complain of headaches for 12 hours or longer. Mental confusion may be prolonged. If surgery was needed to repair other injuries occurring at the time of the concussion, post-surgical shock may also be present. Headaches and dizziness may be present after head injury.

Physical exam: The physical exam may reveal inadequate oxygen reaching the cells (hypoxia), characterized by rapid heartbeat, high blood pressure, dizziness, mental confusion, and peripheral constriction of blood vessels; shock; and multiple injuries. A neurologic evaluation is done to diagnose coma in the absence of external trauma. The examiner may also test for abnormal eye movements (tonic deviations of the eyes), rhythmic movements of the eyes (nystagmus), and pupillary reflex abnormalities. One-sided paralysis (hemiplegia), impairment of language function (aphasia), and cranial nerve paralysis (palsy) are neurologic signs that may be seen, depending on the extent and site of the brain damage.

Tests: The Glasgow Coma Scale has been used as a semiquantitative measure of the severity of brain injury and provides a guide to outcome. CT evaluates the acute, serious head injury to identify any evidence of bleeding within the brain or signs of brain damage. MRI and PET studies may be important in the evaluation of late stages of recovery from head injury but are not important in acute care. Lumbar puncture may be done to examine the cerebrospinal fluid (CSF) if there is question of infection. Electroencephalogram (EEG) is not considered to be a useful test following acute brain injury, but can help identify and guide treatment of persistent symptoms (post-concussion syndrome). Mild concussions (MTBI) may be associated with subtle, long term changes in neuropsychologic or intelligence tests. But these tests generally are not appropriate for medical management and are rarely used.

Source: Medical Disability Advisor



Treatment

Treatment of individuals with cerebral concussion is either operative or nonoperative. Nonoperative therapy consists of general care of the individual and control of intracranial pressure (ICP).

Severely injured individuals are typically treated in an intensive care unit (ICU) and observed for multiple injuries, pulmonary function and infection, bladder function, nutrition, and skin care. The individual should be examined frequently to evaluate LOC and the presence or absence of signs of injury to the nerves. If the individual remains comatose for more than 12 hours, nutrition can be administered by nasal tube or parenterally. The administration of sedative drugs should be avoided in acute injury. Anticonvulsant drugs can be used if seizures develop. Care should be taken to make sure the individual is not dehydrated by ensuring adequate fluid intake by injection, if necessary.

Source: Medical Disability Advisor



Prognosis

The outcome for the individual with a head injury is related to the site and severity of the injury. With mild concussions (MTBI) or minor degrees of cerebral swelling, individuals fully recover from loss of consciousness. However, minor complaints and subtle changes in thinking or emotions may persist for some time. The mortality rate is zero in individuals with simple concussion and less than 2% when there is a mild degree of cerebral swelling. The mortality rate increases when the cortex is contused (5%) or lacerated (41%). Death may result immediately after the injury or from complications.

Source: Medical Disability Advisor



Rehabilitation

Individuals who sustain a concussion may present with a variety of physical and cognitive disabilities, depending on the severity of the injury. Individuals with mild concussions require no specific therapy and are able to return to their prior level of function after a brief period of rest.

Individuals with severe concussions may lapse into a period of sustained unconsciousness, otherwise known as a coma. Individuals in the early stages of coma are unresponsive and would require a general program of stretching, sensory stimulation, and positioning to decrease the risk of bedsores. Those with moderate to severe concussions may present with cognitive, perceptual, and motor control deficits.
Physical and occupational therapists treat deficits in balance, coordination, motor planning, and ambulation with emphasis on enhancing functional capabilities. Therapists also instruct individuals in energy conservation techniques and endurance training. Adaptive equipment or assistive devices may be necessary to facilitate independence with activities of daily living (ADLs) and mobility.

Individuals with poor motor control of the facial muscles may require speech therapy for improved clarity of speech and increased safety in swallowing. Speech therapists instruct individuals in oral exercises to strengthen muscles of the face and tongue, and guide individuals in choosing safe food textures and thicknesses to decrease the risk of food/drink aspiration. Individuals may require a communication board or interactive computer if there is difficulty speaking or understanding speech (aphasia) due to the brain injury.

A neuropsychologist may be necessary for individuals with more severe deficits to help guide the course of rehabilitation and help individuals and their families make long-range decisions. Individuals are assessed in areas such as planning, perception, concentration, attention span, orientation, memory, problem solving, and social judgment. Social workers coordinate the care of individuals in areas ranging from discharge planning to finding support groups. Vocational counselors coordinate with therapists, and help individuals keep future career plans realistic and ease the transition back to work. Vocational counselors may also focus individuals on new careers that may be more appropriate under their current level of disability.

Source: Medical Disability Advisor



Complications

Complications of head injuries include bleeding in the skull (subarachnoid, extradural, subdural, or intracerebral hemorrhage). Some leaking of blood into the spaces in the skull is expected in any individual with an injury to the head. Leaking of blood may be a warning sign to the physician that the brain has been injured and serious damage to the brain or its coverings may have occurred. A rare complication caused by distortion of the brain by an extradural or subdural hemorrhage is injury to the wall of the carotid or other arteries followed by thrombosis of these blood vessels (cerebral thrombosis). Thrombosis of the cerebral arteries may develop several days or weeks after head injury in elderly individuals with cerebral hardening of the arteries (arteriosclerosis). Head trauma can also cause arteriovenous fistulas formed as a laceration of the internal carotid artery in the brain. After a concussion head injury that involves skull fracture or leakage of cerebral spinal fluid (CSF), infections such as meningitis or brain abscess may also occur.

The most common symptoms of brain damage are paralysis of one side of the body (hemiplegia) and speech disturbances. In addition, seizures may occur immediately after or within the first few days of a head injury. Seizures are related to the acute brain damage or to the presence of intracerebral hemorrhage, or infection. In most individuals, seizures do not develop until months after the injury occurred, and are an infrequent symptom of the acute phase of a head injury. A pre-existing neurological condition (i.e., epilepsy) may further lengthen disability. Less common complications of brain injuries are the formation of a cyst in the intracranial space secondary to a skull fracture, and brain lesions.

Psychosis and mental disorders are usually transient complications, and some impairment of mental faculties is common after a head injury. Long-term psychotic episodes are rare. Serious mental problems are found only in cases of severe injury. Post-traumatic syndrome occurs in approximately 35% to 40% of individuals who sustain minor or severe injuries to the head and consists of a group of symptoms including headache, dizziness, insomnia, irritability, restlessness, excessive perspiration (hyperhidrosis), inability to concentrate, depression, and other personality changes.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Individuals with simple concussion are usually allowed to return to their usual activities after 24 hours of observation. The period of bed rest and convalescence for individuals with more severe head injuries depends on their response to treatment. Return to active work should be deferred for 2 to 3 months after hospital discharge if there has been a severe degree of brain injury. Mild, general post concussive complaints such as headaches, fatigue, decreased concentration, sleep disturbances, dizziness, or irritability can complicate return to work.

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 history of a head injury followed by loss of consciousness?
  • How long was individual unconscious?
  • Does individual complain of a headache or dizziness?
  • On exam, did individual have a rapid heartbeat, high blood pressure, dizziness, mental confusion, peripheral constriction of blood vessels, and shock? Were there other injuries?
  • Was a complete neurological examination done? Did individual have tonic deviations of the eyes, nystagmus, or pupillary reflex abnormalities? Was hemiplegia, aphasia, or palsy present?
  • What was individual's initial Glasgow Coma Scale score?
  • Has individual had a CT scan, MRI or PET? Was a lumbar puncture done? Did individual have an EEG later?
  • Have conditions with similar symptoms been ruled out?

Regarding treatment:

  • Did individual's treatment consist of observation and discharge?
  • Was surgery necessary? Did individual then receive the appropriate supportive care in intensive care?

Regarding prognosis:

  • Is individual active in rehabilitation?
  • Does individual have a home exercise program?
  • Is individual's employer able to accommodate any necessary restrictions?
  • Does individual have any conditions that may affect ability to recover?
  • Does individual have any complications such as subarachnoid, extradural, subdural, or intracerebral hemorrhage? Did individual have a cerebral thrombosis? Did individual develop any arteriovenous fistulas? Did individual develop meningitis or brain abscess? Has a cyst formed in the intracranial space? Does individual have a seizure disorder? Does individual have post-traumatic syndrome?

Source: Medical Disability Advisor



References

Cited

Bernhardt, David T. "Concussion." eMedicine. Eds. Joseph P. Garry, et al. 6 Aug. 2009. Medscape. 27 Oct. 2009 <http://emedicine.medscape.com/article/92095-overview>.

Cunha, John P. "Concussion." eMedicine Health. Ed. Melissa Conrad Stoppler. 12 Dec. 2009. WebMD, LLC. 27 Oct. 2009 <http://www.emedicinehealth.com/concussion/article_em.htm>.

Dawodu, Segun T. "Traumatic Brain Injury (TBI): Definition, Epidemiology, Pathophysiology." eMedicine. Eds. Rajesh R. Yadav, et al. 30 Mar. 2009. Medscape. 27 Oct. 2009 <http://emedicine.medscape.com/article/326510-overview>.

Langlois, Jean A., Wesley Rutland-Brown, and Karen E. Thomas. "Traumatic Brain Injury in the United States: Emergency Department Visits, Hospitalizations, and Deaths." National Center for Injury Prevention and Control. Jan. 2006. Centers for Disease Control and Prevention. 27 Oct. 2009 <http://www.cdc.gov/ncipc/pub-res/TBI_in_US_04/TBI%20in%20the%20US_Jan_2006.pdf>.

Pangilinan, Percival H., et al. "Classification and Complications of Traumatic Brain Injury." eMedicine. Eds. Everett C. Hills, et al. 2 Apr. 2008. Medscape. 27 Oct. 2009 <http://emedicine.medscape.com/article/326643-overview>.

Source: Medical Disability Advisor






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