Conversion Disorder in Emergency Medicine

Functional neurological symptom disorder (conversion disorder) is classified as one of the somatic symptom and related disorders in the Diagnostic and Statistical Manual of Mental Disorders of the American Psychiatric Association, Fifth Edition, Text Revision (DSM-5-TR);[1, 2] these were formerly known as somatoform disorders.[3] Although defined as a condition that presents as an alteration or loss of a physical function suggestive of a physical disorder, conversion disorder is traditionally taken to be the expression of an underlying psychological conflict or need.

Conversion symptoms are presumed to result from some unconscious process. The precipitating psychological conflict or stressor may not be apparent initially, but may become evident in the course of obtaining a patient’s history: ideally, it is a psychological issue related symbolically and temporally to symptom onset. Conversion symptoms are not considered to be under voluntary control, and, should not be due to any physical disorder or known pathological mechanism (after appropriate medical evaluation). NB: Conscious/intentional production of physical symptoms is classified as factitious disorder or malingering.

Though classified with somatic symptom/somatoform disorders in DSM-III through DSM-5-TR, conversion disorder is classified as a dissociative disorder in ICD-10, keeping its long association with hysteria (Dissociative Disorders in DSM).[4, 5] Clinical descriptions of conversion disorder date to almost 4000 years ago; the Egyptians attributed symptoms to a "wandering uterus." In the 19th century, Paul Briquet described the disorder as a dysfunction of the CNS.[6, 7] Freud first used the term conversion to refer to the development of a somatic symptom to help bind anxiety around a repressed conflict.[8] In current practice, the term has made it into the popular press.[9, 10]

Presenting symptoms can range far across the field of clinical neurology. Conversion reactions usually approximate lesions in the nervous system’s voluntary motor or sensory pathways. Symptoms most commonly reported are weakness, paralysis, pseudoseizures, involuntary movements (eg, tremors), and sensory disturbances. These losses or distortions of neurologic function cannot adequately be accounted for by organic disease.

Functional MRI (fMRI) and transcranial magnetic stimulation (TMS) studies have shown different activation patterns in patients with conversion symptoms and healthy control subjects; this is in keeping with the "involuntary" nature of conversion symptoms.[11, 12, 13, 14, 15]

Patients whose symptoms are limited to pain or sexual functioning are not classified under conversion disorder; likewise, patients already classified as demonstrating somatization disorder or schizophrenia are also not classified under conversion disorder.

The DSM-5-TR diagnostic criteria for conversion disorder are as follows:[1]

• One or more symptoms of altered voluntary motor or sensory function.

• Clinical findings provide evidence of incompatibility between the symptom and recognized neurological or medical conditions.

• The symptom or deficit is not better explained by another medical or mental disorder.

• The symptom or deficit causes clinically significant distress or impairment in social, occupational, or other important areas of functioning or warrants medical evaluation.

According to psychodynamic theory, conversion symptoms develop to defend against unacceptable impulses.[8] The primary gain, that is to say the unconscious purpose of a conversion symptom is to bind anxiety and keep a conflict internal. A fairly transparent example would be leg paralysis after an equestrian competitor is thrown from his or her horse. The symptom has a symbolic value that is a representation and partial solution of a deep-seated psychological conflict: to avoid running away like a coward, and yet to avoid being thrown again.

According to learning theory, conversion disorder symptoms are a learned maladaptive response to stress. Patients achieve secondary gain by avoiding activities that are particularly offensive to them, thereby gaining support from family and friends, which otherwise may not be offered.[16]

Frequency

True conversion reaction is rare.[17, 18] Predisposing factors include extreme psychosocial stress, and perhaps, rural upbringing. Some psychiatrists suspect that western society has incorporated Freudian notions of unconscious motivations and conflicts: conversion reactions have become too obvious to serve their purpose.

• The incidence of individual persistent conversion symptoms is estimated to be 2-5/100,000 per year.[1]

• Cultural factors may play a significant role.[19] Symptoms that might be considered a conversion disorder in the United States may be a normal expression of anxiety in other cultures.

• One study reports that conversion disorder accounts for 1.2–11.5% of psychiatric consultations for hospitalized medical and surgical patients.

At the National Hospital in London, the diagnosis was made in 1% of inpatients.[20] Iceland's incidence of conversion disorder is reported to be 15 cases per 100,000 persons.

Mortality/Morbidity

Patients diagnosed with conversion disorder may go on to demonstrate serious, traditional medical illness. This has been happening less and less often over the years (29% in 1950s down to 4% in 1990s). Unfortunately, emergency physicians may find themselves sorting out new neurologic symptoms in settings of terrible time pressure: populations statistics may be of little reassurance for any specific individual.

Sex- and age-related demographics

Sex ratio is not known although it has been estimated that women patients outnumber men by 6:1. According to DSM-5, conversion disorder is two to three times more common in females.[1]

Conversion disorder may present at any age but is rare in children younger than 10 years or in persons older than 35 years.[21]

In a University of Iowa study of 32 patients with conversion disorder, however, the mean age was 41 years with a range of 23–58 years.[22]

An Australian study estimated a pediatric incidence of 2.3/100,000 based on 194 cases of conversion disorder found among those reported to the Australian Pediatric Surveilance Unit from 2002–2003. Family loss (death/separation), followed by family violence, were the most commonly identified stressors (precipitants).[23] Prior opinion has been that incidence of conversion is increased after physical or sexual abuse, and that incidence also increases in those children whose parents are either seriously ill or have chronic pain.[24]

Prognostic studies differ in outcome, with recovery rates ranging from 15-74%. Factors associated with favorable outcomes are male gender, acute onset of symptoms, precipitation by a stressful event, good premorbid health, and an absence of organic or psychiatric disorder.[39]

Many patients with conversion reactions have spontaneous remission or demonstrate marked or complete recovery after brief psychotherapy.

Degree of impairment usually is marked and interferes with daily life activities. Prolonged loss of function may produce organic complications such as disuse atrophy or contractures.

Weakness, paralysis, pseudoseizures, involuntary movements (eg, tremors), and sensory disturbances (eg, aphonia, deafness, blindness) are the most frequent complaints. Symptoms often enable patients to avoid an unpleasant situation at home or work, attract attention, or gain support from others. This may become evident through careful questioning.

The symptom must not be under voluntary control. Determining whether or not a symptom is really under voluntary control may be difficult. Features suggestive of voluntary control consist of variability, inconsistency, obvious and immediate benefit, as well as a personality that may suggest dishonesty and opportunism. Symptoms, if they are voluntary, tend to be self-limited and of brief duration.

La belle indifférence was considered a classic feature of conversion disorder. It is characterized by the inappropriate and paradoxical absence of distress despite the presence of an unpleasant symptom. Patients often deny emotional difficulty. Unfortunately, la belle indifférence, histrionic personality, and secondary gain are clinical features that appear to have no diagnostic significance. They can easily be absent in patients with conversion disorder; they can be easily be present in patients with traditional neurologic disorder.

One study reported 5 patients with hysterical conversion reactions after injury or infarction to the left cerebral hemisphere.[25]

Absence of a physical disorder is an important diagnostic feature. Individuals with conversion disorder often have physical signs but lack objective neurological signs to substantiate their symptoms.

Weakness

Weakness usually involves whole movements rather than muscle groups. Weakness affects the extremities more often than ocular, facial, or cervical movements.

With the use of various clinical techniques, weakness of one limb can be demonstrated to cause contraction of opposing muscle groups. Discontinuous resistance during testing of power or give-way weakness may exist.[26] Muscle wasting is absent, and reflexes are normal.

Sensory symptoms

Sensory loss or distortion often is inconsistent when tested on more than one occasion and is often incompatible with peripheral nerve or root distribution.[27]

Discrete patches of anesthesia or hemisensory loss that stop in the midline may be present.

Classic dermatomes in patients with numbness usually are not followed.

Visual symptoms

Visual symptoms include monocular diplopia, triplopia, field defects, tunnel vision, and bilateral blindness associated with intact pupillary reflexes.

Optokinetic nystagmus may be observed in patients with apparent blindness when exposed to a rotating striped drum.

Gait disturbances

Astasia-abasia is a motor coordination disorder characterized by the inability to stand despite normal ability to move legs when lying down or sitting.

Patients walk normally if they think they are not being observed.

Occasionally, while being observed, patients actively attempt to fall. This contrasts with those patients with organic disease who attempt to support themselves.

Pseudoseizures

During an attack, marked involvement of the truncal muscles with opisthotonos and lateral rolling of the head or body is present. All 4 limbs may exhibit random thrashing movements, which may increase in intensity if restraint is applied.

Cyanosis is rare unless patients deliberately hold their breath.

Reflexes (eg, pupillary, corneal) are retained but may be difficult to test due to tightly closed lids.

Tongue biting and incontinence are rare unless the patient has some degree of medical knowledge about the natural course of the disease.

In contrast to true seizures, pseudoseizures primarily occur in the presence of other people and not when the patient is alone or asleep.

True etiology of conversion disorder is unknown. Most clinicians presume conversion reactions are caused by previous severe stress, emotional conflict, or an associated psychiatric disorder.

Many studies confirm high incidence of depression in patients with conversion disorder. As many as half of these patients have personality disorders or display hysterical traits.[28]

In children, conversion disorder is sometimes observed following physical or sexual abuse.

Children who have family members with a history of conversion reactions may be more likely to suffer from conversion disorder. In addition, if family members are seriously ill or in chronic pain, children may be more likely to be affected.

Errors in diagnosis of conversion disorder are not uncommon. With newer diagnostic testing, instances of false-positive diagnoses of conversion disorder in which a neurological disease is later identified are around 4%.

Authors have reported various organic diseases in patients who were initially diagnosed with conversion disorder. In one case report, a woman reporting leg weakness and back pain was subsequently diagnosed with sporadic Creutzfeldt-Jakob disease.[34]  Other patients with underlying psychiatric illnesses were found to have disk herniations, epidural abscesses, or cerebral hemorrhages.[35, 36]  In another case series, 5 patients were identified as having sarcoma-induced osteomalacia, cerebellar medulloblastoma, Huntington chorea, transverse myelitis, and lower extremity dystonia.[37]  Although these case reports were rare, the initial diagnosis of conversion disorder without a complete neurologic examination, appropriate imaging, and other diagnostic testing should be discouraged.[38]

Carefully consider the possibility of an organic etiology.

Some authors have suggested that unnecessary, painful, or invasive testing can result in reinforcement and fixation of symptoms and should be avoided when possible.

Consider laboratory testing to exclude the following clinical entities:

• Electrolyte disturbances

• Hypoglycemia

• Hyperglycemia

• Renal failure

• Systemic infection

• Toxins

• Other drugs

A chest x-ray (CXR) may be considered to diagnose an occult neoplasm.

CT scan or MRI may be performed to exclude a stroke or a space-occupying lesion in the brain or spinal cord.

An electroencephalograph may help distinguish pseudoseizures from a true seizure disorder.

Spinal fluid may be diagnostic in ruling out infectious or other causes of neurologic symptoms.

Any patient diagnosed with a conversion reaction in the ED should be encouraged to pursue psychiatric follow-up. This can be suggested as a way to reduce and manage stress and mitigate exacerbation of physical symptoms (side-stepping arguments about etiology of symptoms). Psychiatric follow-up is especially helpful for rare cases of more serious psychiatric syndromes presenting to an emergency department with physical symptoms.

Many patients have spontaneous remission after outpatient psychotherapy or suggestive therapy.

As of yet, there are no well-established treatment regimens for conversion disorder. There has been more success with the other somatoform disorders.[33]

Treat patients as if their symptoms have an organic origin. Prehospital personnel most often cannot distinguish a conversion reaction from an organic illness.

Emergency physicians must be aware that the diagnosis of conversion disorder does not exclude the presence of underlying disease, and diagnosis should not be made solely on the basis of negative workup results. Approach each patient as if their symptoms had an organic basis, and treat them accordingly.

Consultation is often necessary and should be considered during ED discharge planning for any patients without previous histories of conversion reaction.

• Consultation may be a cost-effective method to eliminate unnecessary hospitalization by streamlining these patients to appropriate outpatient psychiatric follow-up.[17]

• Neurologic consultation may help if the neurological examination is equivocal.

• Psychiatric consultation may be necessary if an organic cause is virtually excluded. Thoughtful questioning may elicit the underlying stressor.

• Another treatment technique is suggestive therapy: an authoritative, not confrontative, pronouncement that "this problem usually resolves in a few hours" is often successful, especially with children. Appropriate attention, for example, repeated vital signs plus adjunctive antianxiety medication, can increase odds of success with adults.[20, 29] Other suggestive therapies for symptom removal include hypnosis and amobarbital interviews.[17]

• Behavior-oriented treatment strategies may be helpful.[30, 31] The goals are to unlearn maladaptive responses and to learn more appropriate responses. Attempt to eliminate the patient's belief that the extremity is paralyzed by telling the patient (1) that all tests indicate the muscles and nerves are functioning normally, (2) the brain is communicating with the nerves and muscles, and (3) this apparent lost ability is recoverable. Although confronting the patient with the fact that the symptoms are not organic is counterproductive, a strategic/paradoxical behavioral intervention around the possibility of psychiatric diagnosis may help.[32]

Drug therapy has not proven reliable. However, a number of psychiatrists recommend a sedative or antianxiety agent. It is usually easiest to give a benzodiazepine, eg, lorazepam 0.5–1 mg (along with a suggestion that symptoms are likely to remit in an hour or so). Amobarbital is falling out of favor as a sedative, or for an Amytal interview, but has been a traditional medication.[17]