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.

Functional Neurological Symptom Disorder


Related Terms

  • Briquet's Syndrome
  • Hysteria
  • Hysterical Blindness
  • Hysterical Deafness
  • Hysterical Paralysis

Differential Diagnosis

Specialists

  • Clinical Psychologist
  • Internal Medicine Physician
  • Neurologist
  • Psychiatrist

Comorbid Conditions

Factors Influencing Duration

Factors that may influence the length of disability include acute onset of symptoms and prompt treatment.

Medical Codes

ICD-9-CM:
300.11 - Conversion Disorder; Astasia-abasia, Hysterical; Conversion Hysteria or Reaction; Hysterical: Blindness, Deafness, Paralysis

Overview

In the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision (DSM-IV-TR), conversion disorder is included in somatoform disorders, together with somatization disorder, undifferentiated somatoform disorder, pain disorder, hypochondriasis, body dysmorphic disorder, and somatoform disorder (DSM-IV-TR).

In the DSM-5, conversion disorder (CD), recently renamed functional neurological symptom disorder (FNSD), is included in somatic symptom and related disorders, together with somatic symptom disorder, illness anxiety disorder, psychological factors affecting other medical conditions, factitious disorder, other specified somatic symptom and related disorder, and unspecified somatic symptom and related disorder (DSM-5).

CD/FNSD is conceived of as a condition that presents as an impairment or loss of a physical function suggestive of a physical disorder but that is actually the expression of an underlying psychological conflict or need. The symptom(s) are not under voluntary control. Unexplainable physical symptoms seen in CD/FNSD may include a disturbance of sensation, muscle strength, seizures, involuntary movement, or some combination of these. Psychodynamic theory proposes that these symptoms develop in the presence of unconscious psychological conflict and stress, which in turn is expressed ("converted") in the form of a physical ailment. The physical symptom is thought to reduce anxiety by preventing conscious recognition of the frightening underlying psychological conflict. This is the primary gain from the symptoms.

The individual may also benefit from the symptoms in other ways (secondary gain) such as gaining attention or support from family and friends, a reward of some kind, or avoidance of unwanted responsibilities. Although most individuals appear unconcerned emotionally about their illness and are unaware of any psychological conflicts, some experience anguish over their new symptoms. The symptoms are not intentionally or consciously faked as in malingering or factitious disorder, but there is no known medical condition to account for the findings. Instead of corresponding to any known anatomic or neurological patterns typical of illness having a physical basis, the symptoms may instead correspond to the individual's concept of a disease.

CD/FNSD is diagnosed only after a thorough medical examination fails to find a physical explanation for the symptoms. Some diseases take years for diagnosis so CD/FNSD should be considered a tentative, working diagnosis. Even when a known disease is present, CD/FNSD can still exist if the symptoms cannot be explained by the medical illness. Up to two-thirds of those with CD/FNSD also have a neurological condition.

The symptoms of CD/FNSD are not drug-related or part of a culturally approved ritual or behavior. CD/FNSD is not diagnosed if symptoms are limited to pain or sexual dysfunction. These have separate diagnoses.

Incidence and Prevalence: The prevalence of CD/FNSD is unknown. In secondary care, CD/FNSD is found in about 5% of referrals to neurology clinics. The estimated incidence of individual persistent conversion symptoms is 2 to 5/100,000 per year (DSM-5).

Source: Medical Disability Advisor



Causation and Known Risk Factors

Predisposing causes include prior physical disorders, exposure to people with real physical symptoms, and severe psychosocial stressors. Onset is usually between ages 10 and 35. It is more frequent in women (anywhere from 2 to 10 times more prevalent than in men), and in rural settings, lower socioeconomic groups, and military personnel exposed to combat. Studies indicate that CD/FNSD may be found in between 1% to 14% of general medical and surgical inpatients (DSM-IV-TR).

Source: Medical Disability Advisor



Diagnosis

History: According the DSM-IV-TR, individuals with CD/FNSD have at least one symptom or deficit affecting voluntary motor or sensory function, suggestive of a neurological or other general medical disease (individual has history of a sensory disturbance [i.e., numbness, double vision, blindness, deafness, or hallucinations], muscle disturbance [localized weakness or paralysis, incoordination, difficulty swallowing, or a "lump in the throat"], convulsions [seizures], or some combination of these). Since the initiation or exacerbation of the symptom or deficit is preceded by conflicts or other stressors, psychological factors are judged to be associated with the symptom or deficit. The symptom or deficit is not deliberately produced or feigned (as in factitious disorder or malingering) and after an appropriate workup, the symptom or deficit cannot be explained by a medical disease, or by the effects of a drug or other substance such as alcohol, or as a culturally typical behavior or experience. The symptom or deficit produces clinically significant distress or impairment in occupational, social, or other areas of functioning or warrants medical evaluation. The symptom or deficit, however, is not limited to pain or sexual dysfunction, does not occur only during the course of somatization disorder, and is not better explained by another mental disorder. It is necessary to specify the type of symptom or deficit: with motor symptom or deficit, with sensory symptom or deficit, with seizures or convulsions, or with mixed presentation (DSM-IV-TR).

According to the DSM-5, individuals with CD/FNSD have one or more symptoms of alteration of voluntary motor or sensory function; there is incompatibility between the symptom and recognized neurological or medical conditions; the symptom or deficit is not better accounted for by another medical or mental disorder; and the symptom or deficit produces significant distress or impairment in social, occupational, or other areas of functioning or warrants medical evaluation. The ICD-9-CM code for conversion disorder is 300.11 regardless of the symptom type; the ICD-10-CM code depends on the symptom type. It is necessary to specify the symptom type: with weakness or paralysis, or with abnormal movement (tremor, dystonic movement, myoclonus, gait disorder); with swallowing symptoms; with speech symptom (dysphonia, slurred speech); with attacks or seizures; with anesthesia or sensory loss; with special sensory symptom (hearing, visual, or olfactory disturbance); or with mixed symptoms. Also, it is necessary to specify if the episode is acute (presence of the symptoms during less than 6 months) or persistent (presence of symptoms during 6 months or more), and if there is or is not a psychological stressor (DSM-5).

Physical exam: The exam shows findings inconsistent with medical knowledge. Numbness is often in a pattern resembling a glove or stocking, not the pattern of the known nerve supply. A paralyzed body part may not perform according to known nerve and muscle anatomy. Muscle strength may be normal in muscles opposite the "paralyzed" ones and reflexes are normal. For example, Hoover's sign may be present and/or the patient may be able to walk on her/his tiptoes despite marked weakness of those muscles when they are tested while the patient is in bed. Various specialized examination maneuvers can help the doctor differentiate complaints related to physical causes from those that are conversion symptoms; e.g., in hysterical blindness, nystagmus is observed when the individual is confronted with a moving painted cylinder (optokinetic nystagmus), confirming that from a physiologic standpoint, the visual pathways are intact.

Tests: Neurological tests are normal. Electromyogram (EMG) and nerve conduction velocity testing are normal in "paralyzed" muscles. Somatosensory evoked potential testing is normal in limbs with no sensation. Electroencephalogram (EEG) is normal in conversion seizures. Psychological tests such as the Minnesota Multiphasic Personality Inventory - 2 (MMPI-2) may show a profile characteristic of CD/FNSD.

Note: It must be kept in mind that just because a physical diagnosis cannot be established as the cause of the presenting symptomatology, it does not necessarily mean that the cause is a mental one. That is to say that the presence of medically unexplained symptomatology does not necessarily establish the presence of a psychiatric condition. The first step in identifying the presence of a mental disorder is excluding the presence of malingering and/or of factitious disorder. Although factitious disorder is conscious and purposeful, it is classified as a psychiatric disorder. The strong need for this step is especially true whenever there is a medicolegal context associated with the presenting problem(s). Additionally, using DSM-5 and/or ICD-9-CM or ICD-10-CM, the clinician will find that many presentations fail to fit completely within the boundaries of a single mental disorder. There are systematic ways to go about making psychiatric diagnoses, however.

Source: Medical Disability Advisor



Treatment

A good doctor-patient relationship is essential to treatment. Therapeutic measures include a tactful presentation of the diagnosis to the individual, explanation and reassurance, stress management training, and physical or occupational therapy to prevent complications of certain symptoms of CD/FNSD. Psychotherapy, based on a psychodynamic theory, is thought to be helpful by resolving the intrapsychic conflict manifested in the conversion symptom. As an alternative, non-challenging application of cognitive-behavioral therapy may be more effective - the goals being to unlearn maladaptive responses and to learn more appropriate responses to stressors. Because individuals may be resistant to the idea that symptoms are the result of a psychological problem, therapy of any type is usually couched in terms of stress reduction and coping skills for a chronic illness. Therapy should avoid reinforcing the sick role as a solution to the problem. In group therapy, social support and interaction are used to reduce anxiety. Hypnotherapy may or may not be useful. Treatment of a comorbid anxiety or depressive disorder with psychotherapy and/or pharmacotherapy may lead to substantial improvement in the CD/FNSD; drug therapy is used only if there is a coexisting anxiety or depressive disorder. The drugs amobarbital or midazolam may be used as part of a hypnosedative interview in treatment-resistant cases. As physically based (organic) illness and CD/FNSD may coexist, all individuals with conversion symptoms should be treated as if they have an organic illness.

Source: Medical Disability Advisor



Prognosis

Conversion symptoms are generally self-limited and may resolve within 2 weeks if hospitalization is part of the treatment. While psychotherapy may lead to dramatic recovery in some individuals, recurrence of symptoms is seen in approximately one-fourth of individuals within 1 year of the first episode ("Functional"). Factors associated with good outcome include being male, sudden onset of symptoms, occurrence of symptoms following a stressful event, good health before appearance of conversion symptoms, and lack of accompanying physical or psychiatric disorder. Symptoms of paralysis and blindness have a good prognosis while seizures and tremor have a worse outlook. The longer the individual has been in the sick role and regressed, the more difficult treatment can be. If the individual has other psychopathology or a chaotic social situation, disability can be prolonged. A documented neurological disease may also determine disability.

Source: Medical Disability Advisor



Complications

Loss of muscle tone or bulk related to not using the affected limb is a rare complication. Individuals may hurt themselves when falling, convulsing, or as a result of "blindness." CD/FNSD may lead to a vicious cycle in which "sick" behavior is reinforced through increased attention, avoidance of responsibility, or other secondary gain. This in turn may lead to worsening of conversion symptoms or development of new ones.

Source: Medical Disability Advisor



Ability to Work (Return to Work Considerations)

Work restrictions or accommodations are necessary only infrequently and for the most serious cases. In these instances, time-limited restrictions and work accommodations should be individually determined based on the characteristics of the individual's disorder or response to the disorder, the functional requirements of the job and work environment, and the flexibility of the job and work site. The purpose of the restrictions/accommodations is to help maintain the worker's capacity to remain at the workplace without a work disruption or to promote timely and safe transition back to full work productivity.

Risk: Risk of recurrence may be increased in individuals who work in health care settings or in positions where there is exposure to people with real physical impairments and conditions. Individuals with CD/FNSD who have disturbances of sensation, muscle strength, vision, or hearing, and those who exhibit seizures or hallucinations may present a risk to coworkers.

Capacity: Capacity in individuals with conversion disorder is not affected. As long as risk is adequately addressed, individuals with conversion disorder may work without limitations.

Tolerance: Tolerance is not typically a concern with this diagnosis. Individuals with conversion disorder may improve any perceived tolerance deficits by being compliant with treatment (e.g., stress management training, cognitive behavioral therapy, psychotherapy, hypnotherapy).

Source: Medical Disability Advisor



Maximum Medical Improvement

MMI is expected at 12 months of treatment or less.

Note: MMI is estimated under the assumption that the vagaries involved in psychiatric diagnoses have been taken into consideration.

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 an extensive medical examination ruled out any underlying medical explanation or other cause of the symptoms?
  • Was clinically significant distress or impairment in social, occupational, or other important areas of functioning evident or reported by the individual?
  • Was diagnosis of conversion disorder confirmed?

Regarding treatment:

  • Because a trusting relationship with the physician is essential to treatment, has individual established a good doctor-patient relationship? If not, what can be done to build or restore this relationship?
  • If anxiety or depressive disorders are present, are these disorders being effectively addressed with drug therapy?
  • If individual is resistant to the idea that symptoms are a result of a psychological problem, would individual be more accepting if behavioral therapy was presented as stress reduction or coping skills for a chronic illness?
  • Would individual benefit from a group therapy environment where social support and interaction are used to reduce anxiety?

Regarding prognosis:

  • Since a strong positive correlation exists between duration of conversion symptoms and the time required to resolve them, what was the interval between onset of symptoms and start of treatment?
  • Has the individual experienced any recurrences that may predict future episodes?

Source: Medical Disability Advisor



References

Cited

"Functional Neurological Symptom Disorder." Prognosis. 22 Feb. 2014. 21 Apr. 2015 <http://www.prognosisapp.com/library/case/Prognosis/Functional-Neurological-Symptom-Disorder>.

Diagnostic and Statistical Manual of Mental Disorders (DSM-5). 5th ed. American Psychiatric Association, 2013.

Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR). 4th ed. Washington, DC: American Psychiatric Association, 2000.

Source: Medical Disability Advisor






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