Conversion disorder
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| ICD-10 | F44 |
|---|---|
| ICD-9 | 300.11 |
Conversion Disorder is a DSM-IV diagnosis which describes neurological symptoms such as weakness, sensory disturbance and attacks that look like epilepsy but which cannot be attributed to a known neurological disease.
The DSM-IV definition, which is by no means agreed upon by all those working in the field, is as follows:
- One or more symptoms or deficits are present that affect voluntary motor or sensory function suggestive of a neurologic or other general medical condition.
- Psychological factors are judged, in the clinician's opinion, to be associated with the symptom or deficit because conflicts or other stressors precede the initiation or exacerbation of the symptom or deficit. A diagnosis where the stressor precedes the onset of symptoms by up to 15 years is not unusual.
- The symptom or deficit is not intentionally produced or feigned (as in factitious disorder or malingering).
- The symptom or deficit, after appropriate investigation, cannot be explained fully by a general medical condition, the direct effects of a substance, or as a culturally sanctioned behavior or experience.
- The symptom or deficit causes clinically significant distress or impairment in social, occupational, or other important areas of functioning or warrants medical evaluation.
- The symptom or deficit is not limited to pain or sexual dysfunction, does not occur exclusively during the course of somatization disorder, and is not better accounted for by another mental disorder.
The condition has a complex history. These symptoms are also described as functional, non-organic, hysterical, psychogenic, depending on your aetiological point of view. Critics claim that the diagnosis is essentially a belief system based upon the Judaeo-Christian tradition that influenced much of Freud's thinking. (See Why Freud was Wrong, Webster). In the International Classification of Diseases they are termed Dissociative. Critics who refute the concept of dissociative disorders hold that, as Frederick Crews stated, "dissociation is the perfect psychoanalytic-style vehicle for creation of a pseudoscience, since there is no way to disprove its existence and recovered memories never need be tested by comparing them with conscious memories. After all, if children dissociate themselves from the experience, one could not expect them to have any memories of the event." (Frederick Crews, The Memory Wars: Freud's Legacy in Dispute)
A more precise label is Functional Neurological Deficit, which research has shown to be a more acceptable term in doctor-patient relationships (Stone et al), stressing as it does the inabilty of tests to explain the symptom or symptoms. As neurologists depend upon inconsistency for diagnosis, there can be tension with colleagues in mental health. "When I send a patient to a consultant psychologist I'm told there is nothing wrong with them. That's why I send them to a psychiatrist; he always finds something wrong" - Dr. P. Nichols. Such disagreement appears to be common.
That there should be a temporal relationship between symptom onset and some external event of psychological conflict is a question in debate.
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[edit] History
There has been a long history of symptoms misdiagnosed as having no underlying physical cause. In women, the term Female hysteria was used to refer to a wide spectrum of symptoms ranging from fainting to anxiety. As a term it goes back over 2000 years and was thought to relate to abnormal motions of the uterus. From the 17th century onwards, Thomas Willis, Robert Whytt and others increasingly realised the problem was in fact localised to the brain and mind.
In the 19th century, physicians such as Silas Weir Mitchell in the US and Paul Briquet and Jean-Martin Charcot in France developed ideas about patients with these neurological symptoms which would now be classed as neuropsychiatric. Charcot specialised in treating patients who were suffering from a variety of unexplained physical symptoms including paralysis, contractures (muscles which contract and cannot be relaxed) and seizures. Some of these patients sporadically and compulsively adopted a bizarre posture (christened arc-de-cercle) in which they arched their body backwards until they were supported only by their head and their heels.
"Charcot eventually came to the conclusion that many of his patients were suffering from a form of hysteria which had been induced by their emotional response to a traumatic accident in their past – such as a fall from a scaffold or a railway crash. They suffered, in his view, not from the physical effects of the accident, but from the idea they had formed of it... However many of the most basic diagnostic techniques which are taken for granted by modern physicians had still to be discovered. The lumbar puncture, which is the only way in which Breuer could have tested his momentary hunch that Anna O. was suffering from meningitis, was not developed until 1891, and was not in general use until the early part of the twentieth century. X-rays, which would eventually become one of the most useful of all diagnostic aids, were discovered only in 1895 – the same year in which Studies on Hysteria was published. The electroencephalogram, which would revolutionise neurology and psychiatry and lead to the final definition of temporal lobe epilepsy, was not invented until 1929, and was not in general use until the 1940s. Many other basic techniques of neurological investigation would not be developed until even later. The computed tomography scan, for example, which uses X-ray transmission readings to generate an image of the brain and which can display some lesions, tumours and other signs of pathology directly, began to be generally used only in the late 1970s. Not only were these diagnostic techniques unavailable to Breuer, Freud and their contemporaries, but neurology and psychiatry were relatively young and under-organised branches of medicine whose stores of knowledge were only just beginning to be built up." (Webster, Why Freud Was Wrong).
It is also now recognised that many of Charcot's demonstrations of hysteria were faked (Szasz, the Myth of Mental Illness). As many neurologist's remain ignorant of Charcot's methodology at the Salpêtrière in the diagnosis of hysteria he is often held up as a champion of neuropscyhiatry (Stone et al). It is doubtless though that as neurology continues to emerge from diagnostic darkness further techniques are likely to be developed and previously unvisualised abnormalities and conditions recognised.
The term "Conversion disorder" is a legacy of Freud and the psychotherapy movement. He viewed these apparently neurological symptoms as a result of the conversion of intrapsychic distress in to physical symptoms. It is worth bearing in mind that much of Freud's work is now viewed with scepticism, and it may be that patients Freud thought were hysterical may actually have suffered from organic illness, such as "Anna O." (see Alison Orr-Andrewes, "The case of Anna O: A Neuropsychiatric perspective" in Journal of the Psychoanalytic Association 1987, vol 35 p.399).
In the 1960s the London Psychiatrist Eliot Slater recognised that finding a life event just before the onset of a symptom was an entirely unreliable way of diagnosing conversion disorder.
“Unfortunately we have to recognise that trouble, discord, anxiety and frustration are so prevalent at all stages of life that their mere occurrence near to the time of onset of an illness does not mean very much.” — Eliot Slater
He also suggested that conversion disorder was largely a 'delusion and a snare' since many of the people said to have it would eventually go on to develop a neurological disease that in hindsight could explain their original symptoms. This echoed the earlier sentiments of Steyerthal:
"Within a few years the concept of hysteria will belong to history ... there is no such disease and there never has been. What Charcot called hysteria is a tissue woven of a thousand threads, a cohort of the most varied diseases, with nothing in common but the so-called stigmata, which in fact may accompany any disease." — Armin Steyerthal (1908)
Studies since 1970 have shown that misdiagnosis still occurs but at a rate of around 5% which is the same as for other neurological and pscyhiatric symptoms (Stone et al BMJ 2005). However canadian studies (Hyde, the complexity of diagnosis) find a misdiagnosis rate in 80% of patients labelled with CFS/functional symptoms. In the United Kingdom it would appear that the diagnosis rate is a social phenomenon produced by the modus operandi of health care systems. Most patients only receive investigations at the onset of illness and many illnesses, such as MS, are hard to diagnose initially. Patients also tend to produce functional symptoms in response to the disbelief and prompting of a neurologist as Slater also recognised. Inconsistency could thus be seen as merely an expression of self-consciousness and desperation in the light of distressing symptoms. It is interesting in this light to note however that 20% of MS patients are re-classified as having functional symptoms and there is a high co-morbidity of functional symptoms alongside recognised organic brain disease. This was first recognised by the neurologist Arthur Hurst in his work on soldiers suffering from functional symptoms following organic illness.
Historically, conversion disorder was thought to manifest itself in many different ways. Conversion disorders were thought to be triggered by acute psychosocial stress that the individual could not process psychologically. This overwhelming distress was thought to cause the brain to unconsciously disable or impair a bodily function which would relieve or prevent the patient from experiencing this stressor again. This is in stark contrast to the modern understanding that patients remain distressed by their symptoms in the long term (Stone et al JR Soc Med 2005; 98:547-548) and generally any hypothesised stressor is removed temporally and symbolically from the onset of symptoms. Therefore, the psychosocial stress cannot be seen to be "converted' into a physical symptom that relieve suffering, when in actual fact they increase it. Historically, the patient, by definition, was considered to be unaware of this process, and often not concerned with his deficit — a feature called la belle indifference. Research now shows this to be untrue (Stone et al as above).
More recently, research is attempting to examine the complex nature of these symptoms and the absurdity of a dualist approach which attempts to suggest that symptoms are either all organic or all psychiatric. Functional neuroimaging has shown intriguing findings with respect to the neural correlates of these symptoms (best example is Vuilleimier et al Brain Vol. 124, No. 6, 1077-1090, June 2001). Vuilleimier's statement when interviewed that this "supports Freud's hypothesis" is considered to be deeply inaccurate by Freudian Scholars as Vuilleimier's findings of abnormal cerebral perfusion do not fit anatomically with the autonomous unconscious of classical Freudian thought.
[edit] Diagnosis
Conversion disorder can present with any motor or sensory symptom in the body including:
- Weakness / Paralysis of a limb or the entire body hysterical paralysis or motor conversion disorders
- Impaired hearing or vision
- Loss / Disturbance of sensation
- Impairment or loss of speech--- hysterical aphonia
- Psychogenic non-epileptic seizures
- Fixed Dystonia unlike normal dystonia
- Tremor, Myoclonus or other movement disorders
- Astasia-abasia or Gait Problems
- hysterical pregnancy (even though though this is common in other mammals to ensure enough milk for the group's offspring)[1]
Diagnosis depends not on the absence of findings of neurological disease but on the subjective discerning of positive evidence of conversion symptoms.
La belle indifférence has been described as a characteristic feature of conversion. It is characterized by the inappropriate and paradoxical absence of distress despite the presence of an unpleasant symptom. Patients often deny emotional difficulty. Traditionally associated with conversion disorder, la belle indifférence, histrionic personality, and secondary gain are clinical features that appear to have no diagnostic significance. Although presence of these features supports the diagnosis, they have no diagnostic validity because the diagnosis of conversion disorder ultimately depends upon clinical findings that clearly demonstrate that the patient's symptomatology is not caused by organic disease. [2]
One study reported 5 patients with hysterical conversion reactions after injury or infarction to the left cerebral hemisphere. [3]
Conversion symptoms are remarkably consistent between patients, just as Parkinson's disease is consistent between patients. There may be positive evidence of patterns of weakness (for example Hoover's Sign or a non-pyramidal pattern of weakness) or a typical gait problem (for example a 'dragging monoplegic gait). For Psychogenic non-epileptic seizures a range of features of the attacks must be taken in to consideration and the diagnosis may need confirmation with videotelemetry.
Diagnosis is not easy and should preferably only be made by a neurologist with experience of the condition. The Nightingale Foundation has however found that 80% of patients with functional symptoms are misdiagnosed (the complexities of diagnosis, Hyde, Handbook of ME) with diagnostic procedures by most physicians of poor quality and tests been far from exhaustive. The common procedure of neurologists relying on the reports of radiologists rather than viewing MRI scans themselves is seen as deeply flawed.
Patients with conversion symptoms will typically have multiple other symptoms which may include fatigue, sleep disturbance, memory and concentration difficulties, pain (neck, back, muscles), bowel and bladder sensitivity
[edit] Prevalence
In the US: True conversion reaction is rare. Predisposing factors, according to the DSM-IV, include prior physical disorders, close contact to people with real physical symptoms, and extreme psychosocial stress. In the United Kingdom however 40% of neurological referrals are deemed to be suffering from conversion disorder (Stone, Carson & "Wessely School" psychiatrists)
Incidence has been reported to be 15-22 cases per 100,000 people. In patients with chronic pain, incidence was 0.22%. Conversion reaction may occur more often in rural settings, where patients may be naive about medical and psychological issues. In one study, high rates were seen in Appalachian males. The disorder is observed more commonly in lower socioeconomic groups and may be more common in military personnel exposed to combat situations.
Cultural factors may play a significant role. Symptoms that might be considered a conversion disorder in the US 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.
Internationally: At the National Hospital in London, the diagnosis was made in 1% of inpatients. Iceland's incidence of conversion disorder is reported to be 15 cases per 100,000 persons. [4]
[edit] Incidence Disparity Due to Sex
Sex ratio is not known although it has been estimated that women patients outnumber men by 6:1. Many authors have related the development of conversion disorder in women with sexual maladjustment. Other authors disagree, stating that men are as likely to experience conversion symptoms as women. Men seem to be especially prone if they have suffered an industrial accident or have served in the military. In a study at the University of Iowa conducted from 1984-1986, patients diagnosed with conversion disorder were in large part men, especially those with a history of military combat. [5]
[edit] Aetiology
Studies report that 64% of patients with conversion disorder show evidence of an organic brain disorder, compared with 5% of control subjects.
Some bacterial and viral pathogens can also mirror conversion symptoms and non-pyramidal weakness as they alter brain chemistry and function rather than gross structure (forthcoming publication). However testing, especially in the United Kingdom, remains primitive with for example, only dark field microscope studies providing conclusive evidence of spirochete infection. Progress in the US is much more advanced which could explain the discrepancy in diagnostic rates.
An earlier study revealed that a medical explanation eventually emerged from presenting chief complaints in only 7% of patients. Incidence of true neurological disease discovered at a latter date is extremely rare, largely due to advances in diagnostic testing. [6]
[edit] The Extent to Which Age and Life Experiences Influence Incidence
Conversion disorder may present at any age but is rare in children younger than 10 years or in persons older than 35 years. Some studies have reported another peak for patients aged 50-60 years.
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.
In pediatric patients, incidence of conversion is increased after physical or sexual abuse. Incidence also increases in those children whose parents are either seriously ill or have chronic pain. [7]
[edit] Are people with conversion disorder malingering?
Often a patients reaction to the diagnosis of conversion disorder is to be offended that the doctor thinks they are crazy or making their symptoms up. Many doctors still regard these symptoms as 'not genuine' and not deserving of attention. However, many doctors do regard them as genuine but struggle to know how to communicate with patients
If patients with conversion symptoms were malingering there would be a number of problems from clinical practice to sort out:
- Evidence from long term studies showing that symptoms persist at follow up many years later
- Patients with conversion symptoms generally desire tests, malingerers would not
- There is remarkable consistency between patients (who have not met each other)
[edit] Treatment
Treatment may include the following
1. Explanation - This must be clear and coherent. It must emphasise the genuineness of the condition, that it is common, potentially reversible and does not mean that the sufferer is a 'psycho'. Taking an aetiologically neutral stance by describing the symptoms as functional may be helpful but further studies are required. Ideally the patient should be followed up neurologically for a while to ensure that the diagnosis has been understood
2. Physiotherapy where appropriate
3. Treatment of comorbid depression or anxiety if present
There is little evidence based treatment of conversion disorder (Ruddy and House - Cochrane Collaboration). Other treatments such as cognitive behavioural therapy, hypnosis, psychodynamic psychotherapy need further trials. It should also be noted that psychoanalytic treatments, on which CBT is based, were singularly unaffective with Freud and Breuer's patients.
[edit] See also
[edit] References
- Was ist Hysterie? Eine Nosologische Betrachtung by Armin Steyerthal. Halle: Carl Marhold Verlag, 1908.
- Stone, et al, "Eliot Slater's myth of the non-existence of hysteria", J. R. Soc. Med., vol. 98, 547-548, December 2005.
