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.

Encephalitis


Medical Codes

ICD-9-CM:
072.2 - Mumps Encephalitis; Mumps Meningoencephalitis
139.0 - Late Effects of Viral Encephalitis
323.01 - Encephalitis and Encephalomyelitis in Viral Diseases Classified Elsewhere
323.2 - Encephalitis, Myelitis, and Encephalomyelitis in Protozoal Diseases Classified Elsewhere
323.41 - Other Encephalitis and Encephalomyelitis Due to Other Infections Classified Elsewhere
323.51 - Encephalitis and Encephalomyelitis following Immunization Procedures
323.61 - Infectious Acute Disseminated Encephalomyelitis (ADEM)
323.62 - Postinfectious Encephalitis and Encephalomyelitis, Other
323.71 - Toxic Encephalitis and Encephalomyelitis
323.81 - Causes of Encephalitis, Myelitis, and Encephalomyelitis , Other
323.9 - Encephalitis, Unspecified Cause

Related Terms

  • Cerebritis
  • Encephalomyelitis
  • Equine Encephalitis

Overview

Encephalitis is an acute inflammatory disease of the brain. It can be a serious, life-threatening medical condition, but can also be so mild that it is barely noticeable (subclinical).

Its origins (etiology) may be bacterial, viral, or, in some cases, unknown, though most cases are caused by viruses (Gondim). In certain locations, it is not uncommon for the viral source to be mosquito or tick-borne. Other means of viral transmission include ingestion of infected goat's milk and accidental injection or inhalation of the virus.

In urban areas where mosquitoes are less prevalent, the disease is more commonly caused by a group of viruses called enteroviruses, that is, viruses that multiply primarily in the intestinal tract. An increasing number of cases are caused by infection with the human immunodeficiency virus (HIV). Encephalitis can also occur as a secondary complication following viral infections such as measles, chickenpox, rubella, and mumps. In the US, most cases of viral encephalitis are caused by the herpes simplex virus (HSV) (Gondim).

Incidence and Prevalence: It is impossible to determine true incidence, since reporting policies are not standardized or rigorously enforced and incidence varies with the etiology of the encephalitis. In the US, encephalitis is estimated to affect 3.5 to 7.4 out of 100,000 individuals annually; the most frequent type of encephalitis is herpes simplex encephalitis (HSE), affecting 2-4 Americans per million annually and comprising 10% of all cases (Gondim).

Source: Medical Disability Advisor



Diagnosis

History: The initial symptoms are a vague feeling of discomfort or illness (malaise), fever, headache, loss of appetite (anorexia), aches in muscles (myalgia) or joints (arthralgia), fatigue or weakness, and nausea. Symptoms progress to confusion, agitation, hallucinations, and subtle changes in personality. In later stages, mental disturbances become more apparent and there may be difficulty talking (dysphasia), problems with hearing, muscle weakness, seizures, double vision (diplopia), perception of foul smells, severe disorientation, and coma. In secondary viral encephalitis, the disease may develop 5 to 10 days after onset of an initial viral infection such as mumps, measles, or chickenpox. Encephalitis might be suspected when there is a change in mood along with headache and fever. The individual may be from, or have recently traveled to, a region where mosquitoes and/or ticks are prevalent, and have been bitten. Individuals may report a recent viral infection, such as measles, mumps, or chickenpox. They may also complain of a back or neck ache.

Physical exam: There is evidence of fever, a stiff neck and/or back, tremors, seizures, paralysis of extremities, abnormal walk (gait), and abnormal reflex reactions. Deep loss of consciousness (coma) may occur and last for days or weeks. A change in alertness or consciousness may also point the physician toward the diagnosis.

Tests: A lumbar puncture may reveal increased pressure of the cerebrospinal fluid (CSF) and is used to collect spinal fluid for analysis, which may show increased protein content and cell count (usually lymphocytes). A computed tomography (CT) or magnetic resonance imaging (MRI) of the brain may detect lesions in the lobes of the brain near the temple and ear (temporal lobe lesions) caused by a herpes viral infection. Measuring the electrical activity of the brain by electroencephalography (EEG) is also useful to diagnose herpes simplex encephalitis, but a sample of brain tissue collected for microscopic examination (brain biopsy) may be necessary to confirm this diagnosis and exclude other treatable diseases. Occasionally, taking a sample of the individual's blood during the disease and comparing it with a sample after the disease has resolved (acute and convalescent antibody titers) may be the only way of making a specific diagnosis of a viral infection. Polymerase chain reaction (PCR) and enzyme-linked immunosorbent assay (ELISA) can be used to identify certain viruses.

Source: Medical Disability Advisor



Treatment

Treatment of all forms of encephalitis, other than herpes encephalitis and varicella-zoster encephalitis, is entirely supportive. Supportive measures are used to maintain the individual's hydration, electrolyte balance, and nutritional needs and include fluids, nutrients, and electrolytes given intravenously. In otherwise stable individuals, elevating the head (to manage increased intracranial pressure) and monitoring the neurologic status are supportive measures. Medication may be needed to reduce fever (antipyretics), intracranial pressure, and inflammation (glucocorticoids), and to prevent seizures (anticonvulsants). Pain medication (analgesic) is given to reduce headache.

When more aggressive treatment is indicated, the use of diuresis may be recommended, provided that circulatory volume can be protected.

Herpes simplex encephalitis is also treated with antiviral medication (acyclovir and vidarabine) specific to treating herpes simplex viral infections. Varicella-zoster virus (VZV) encephalitis is treated with acyclovir or ganciclovir.

Other antiviral drugs are used with variable success rates in the treatment of encephalitis due to other viruses (such as cytomegalovirus [CMV], and HIV). Suspected or confirmed bacterial infections are treated with antibiotics.

Source: Medical Disability Advisor



Prognosis

The origin of the encephalitis determines prognosis. For HSE, the death rate is 70% without medical intervention (Gondim). In mild cases, full recovery occurs within 2 to 3 weeks. Eastern equine encephalitis is associated with severe disease and high mortality rates. Severe cases usually require hospitalization and produce significant mental impairment, including memory loss, the inability to speak coherently, lack of muscle coordination, paralysis, and hearing or vision defects. Individuals under the age of 30 and those only lethargic at the onset of treatment are more likely to survive than individuals who are older or comatose.

Source: Medical Disability Advisor



Differential Diagnosis

Source: Medical Disability Advisor



Specialists

  • Infectious Disease Internist
  • Neurologist
  • Neurosurgeon

Source: Medical Disability Advisor



Rehabilitation

Individuals recovering from encephalitis may require physical, occupational, and speech therapy depending on the impairments present; those individuals may have lack of muscle coordination, decreased balance, paralysis, hearing and vision deficits, and an inability to speak coherently. The frequency and duration of rehabilitation should be determined by the severity of impairments.

Individuals recovering from encephalitis may have impaired coordination. In occupational therapy, individuals perform fine motor coordination exercises. In physical therapy, individuals work on gross motor coordination. Individuals work on sitting and standing balance in both physical and occupational therapy. Sitting balance can be improved by having an individual sit on a therapy ball. Physical therapists may focus on exercises to improve standing balance in order to preserve the ability to walk.

Individuals with paralysis also require physical and occupational therapy. Both disciplines train caregivers to stretch the arms and legs to maintain adequate flexibility. Occupational therapists instruct individuals in self-care strategies and methods, and may order adaptive equipment to make tasks easier. Physical therapists help individuals to improve gross motor skills. Physical therapy also addresses walking, and individuals learn to walk using crutches or leg braces, where appropriate. For those individuals who cannot safely ambulate, a wheelchair may be ordered. Individuals learn to propel the wheelchair both indoors and outdoors, over ramps and curbs.

Individuals with decreased vision may need a home safety assessment. Occupational therapists can identify tripping hazards, and can assist in rearranging the layout of rooms to increase safety. Physical therapists can instruct individuals on how to use a cane to help them negotiate stairs. Occupational therapists can order equipment that may make daily living easier, such as a telephone with larger numbers.

Individuals who present with the inability to speak coherently may require speech therapy. Speech therapists focus on skills such as word finding and sentence completion. Individuals and their caregivers may also learn methods to increase concentration, such as providing a low-stimulus environment in order to decrease distractibility.

Individuals with difficulty hearing may require speech therapy to learn new strategies for communication, such as reading lips or using sign language. Individuals may also learn how to use amplification devices and hearing aids to increase their hearing.

Source: Medical Disability Advisor



Comorbid Conditions

  • AIDS
  • Immunosuppressive diseases

Source: Medical Disability Advisor



Complications

Possible complications include seizures; brain damage that causes loss of sensation, coordination, and power in specific areas of the body, and/or speech difficulties; and death. The membranes that cover and enclose the brain (meninges) may also be involved, and these membranes may become inflamed (meningoencephalitis).

Source: Medical Disability Advisor



Factors Influencing Duration

The severity of the inflammation and symptoms, involvement of other nervous system structures, the individual's response to treatment, the presence of complications, and any permanent brain damage may influence length of disability.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Restrictions or accommodations need to be considered on an individual basis since the severity and complications of encephalitis are variable. If there are lingering speech and motor/coordination problems, job duties may need to be reassessed, depending on the nature of the job. Responsibilities requiring significant amounts of public speaking may be in jeopardy if there is permanent speech impairment. Jobs requiring a great deal of mobility and physical labor may also need to be reassessed.

Risk: Risk of working with encephalitis is dependent on the severity of the disease and the type of symptoms present. Individuals with cognitive impairment, diplopia, seizures, or decreased muscle strength and balance should not be allowed to work at heights, with machinery, or in safety-sensitive jobs. Time off from work may be needed to attend rehabilitation sessions during recovery.

Capacity: Individuals with severe encephalitis may have significantly reduced capacity secondary to residual neurological and cognitive impairment. Job reassignment may be necessary for individuals who perform heavy or very heavy work. Neuropsychological evaluation can help characterize the limitations.

Tolerance: Tolerance is dependent on the type and severity of the encephalitis. Contact physician for details. Less complex jobs would be expected to have an earlier tolerance for return to work.

Accommodations: Employers willing to accommodate activities as needed can have employees return to work earlier.

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 recently been exposed to mosquitoes or ticks? Ingested goat's milk?
  • Does individual have a history of intestinal tract infection (enterovirus)?
  • Is individual HIV positive? Is individual immunosuppressed by any other condition?
  • Has individual recently had measles, chickenpox, rubella, or mumps? Is individual infected with herpes simplex virus (HSV)?
  • Is there a vague feeling of discomfort or illness (malaise), fever, headache, loss of appetite (anorexia), and nausea? Does individual report a stiff neck and back?
  • Is there a change of personality and confusion? Does individual have more apparent mental disturbances, difficulty talking (dysphasia), weakness, seizures, or severe disorientation that suggests later stage disease?
  • Was lumbar puncture done to collect spinal fluid? Were CT, MRI of the brain, or electroencephalography (EEG) performed? Was a brain biopsy required?
  • Was a diagnosis of encephalitis confirmed?

Regarding treatment:

  • For herpes or varicella-zoster encephalitis, did individual receive antiviral medication? Was the medication effective?
  • For other forms of encephalitis, did individual receive supportive treatment, including fluids, nutrients, and electrolytes given intravenously?
  • Were medications administered to reduce fever (antipyretics), intracranial pressure, and inflammation (glucocorticoids)? To prevent seizures (anticonvulsants) and relieve pain (analgesics)?
  • Did individual require aggressive treatment to eliminate excess fluid (diuresis)? If used, was diuresis effective?

Regarding prognosis:

  • What was the cause and severity of the disease? If severe, did individual lose memory, ability to speak coherently, or muscle coordination?
  • Is the individual paralyzed?
  • Are hearing or vision deficits present?
  • Have seizures occurred?
  • Have the membranes that enclose the brain (meninges) also been involved (meningoencephalitis)?
  • How significantly is individual impaired? How will these impairments affect individual's daily activities?

Source: Medical Disability Advisor



References

Cited

de Assis Aquino Gondim, Francisco, et al. "Viral Encephalitis." eMedicine. 6 Dec. 2013. Medscape. 22 Apr. 2015 <http://reference.medscape.com/article/1166498-overview>.

Source: Medical Disability Advisor