Conversion Disorder (Functional Neurological Symptom Disorder)
What is Conversion Disorder?
Conversion symptoms are altered motor or sensory functioning, which may include pseudoseizures, either with or without impaired consciousness. In the ICD-10 diagnostic manual, the different types of Conversion Disorder are referred to as Dissociative Disorders of Movement and Sensation. Conversion Disorder is also known as Functional Neurological Symptom Disorder (FND).:1345 Some forms of conversion disorder are referred to as psychogenic disorders, e.g., Psychogenic Blindness. Psychogenic disorders have physical symptoms only, but the symptoms are caused unintentionally and unknowingly as a result of the person's state of mind. The term 'psychogenic' suggests that psychological factors are the sole cause, and ignores the role of biological factors.
Unexplained, but Involuntary symptomsConversion Disorder symptoms cannot be fully explained by neurological or other medical conditions, or by substance use, and are not intentionally produced. A psychological stressor is not essential for diagnosis but can is often specified. A separate diagnosis of Factitious Disorder is given if symptoms are feigned/malingered. :627-628,  Symptoms may be inconsistent, often changing during examination and/or with a person's level of stress.,  An accepting rather than judgmental approach towards symptoms is helpful.
How Common is Conversion Disorder?Although brief periods of conversion symptoms are common, persistent individual conversion symptoms are very rare in the general population, occurring at approximately 2-5 people per 100,000 per year. Conversion disorder is found in approximately 5% of referrals to neurology clinics.:630
- Can occur at any age
- Non-epileptic seizures are most common in a person's 30s, and motor symptoms in a person's 40s.
- Neurological disorders that cause similar symptoms, e.g. non-epileptic seizures are in people with epilepsy
- History of childhood abuse/
- Stressful life events often present
- 2-3 times more common in females :629-630
Common Forms of Conversion Disorder
Neuroimaging of Conversion DisorderRecent research has shown differences in brain activation in people with Conversion Disorder compared to Healthy Controls. This does not mean that permanent 'brain damage' has occurred, the test results show only that the brain is working in a different way, for example viewing faces with negative emotions causes different brain activation responses, as shown in the picture.
Neuroimaging studies of Posttraumatic Stress Disorder and Dissociative Identity Disorder have also showed differences in the amygdalae.
Treating Conversion Disorder can gradually alter this pattern, even 'talking therapy' alone has been shown to be effective in altering and improving brain activation patterns, for example in Posttraumatic Stress Disorder.
Possible Causes or ContributorsBiological Factors
Excessive cortisol arousal and impaired communication within the brain can inhibit awareness of bodily sensations. Subtle impairments may be found on neuropsychological tests.
Symptoms have a symbolic relationship to an unconscious psychological conflict, e.g., vaginisms protect the patient from expressing unacceptable sexual desires.
Symptoms of illness learned in childhood can begin as a way of coping with an impossible situation.
It is often associated with dissociative symptoms, e.g., Depersonalization/
- Children and adolescents often fare better than adults
- Short duration of symptoms and accepting the diagnosis appear to improve outcomes
- 'Maladaptive' personality traits, co-occurring physical illness and receipt of disability benefits may worsen the outcomes
- Onset may begin after either physical trauma (e.g, injury) or psychological trauma
Treating Conversion Disorder: A Case StudyEven when a clear psychological cause is known, some physical treatment may be helpful in combination with 'talking therapy', as described in this case.
The Conversion Disorder hand tremor shown in the video occurred in a 13-year-old girl, who was treated with both a customized wrist brace and psychological therapy using Cognitive Behavioral Therapy. Her severe 'psychogenic tremor' was diagnosed as a Dissociative Motor Disorder and was video taped at different stages during treatment. The videos were useful in showing the girl clear evidence of her improvements. The cause was psychological: severe performance and exam anxiety at school, combined with her parents' difficult relationship. Her hand tremor prevented writing and attending school, increasing her avoidance of school.
"Stop pretending" made things worseThe tremor was inconsistent, reducing when her concentration was on something else and would stop when she grasped something, e.g., clasping her hands together. Finding no neurological or physical cause for the tremor, a physiotherapist told her to "stop pretending" which led to prolonged sadness and anger in the girl, and an increase in the tremor. Secondary gain is sometimes referred to in Conversion Disorder - despite not being part of the diagnostic criteria.:628 This means the person's Conversion Disorder causes an indirect benefit - any secondary gain from not needing to attend school was clearly canceled out by her inability to sleep or eat normally due to the tremor, plus the distress it caused her. She was also hospitalized, and agreed to attend the psychiatric unit. Even in cases where secondary gain is present, this should not be used as a basis for diagnosis.:628
TreatmentShe had anxiety-reduction sessions, and learned Progressive Muscle Relaxation. Her customized wrist brace to help her write, and she practiced writing daily. This reduced her school anxiety and avoidance, and she began attending again. She also had private lessons in the subjects she struggled with the most. In her treatment it was key for her to understand what triggered the tremor and prevented it from diminishing. 
From the girl's perspective, she found what helped most was:
- being more active rather than listening to music alone
- physical and social activity
- identifying and discussing her feelings with others
- eventually mastering the relaxation methods to reduce stress,
- and attending physical therapy aimed at symptom reduction 
Dissociative Motor DisordersCode F44.4
"The commonest varieties of Dissociative Motor Disorder are loss of ability to move the whole or a part of a limb or limbs. Paralysis may be partial, with movements being weak or slow, or complete. Various forms and variable degrees of incoordination (ataxia) may be evident, particularly in the legs, resulting in bizarre gait or inability to stand unaided (astasia-abasia). There may also be exaggerated trembling or shaking of one or more extremities or the whole body. There may be close resemblance to almost any variety of ataxia, apraxia, akinesia, aphonia, dysarthria, dyskinesia, or paralysis." :126
Dissociative Movement Disorder This includes psychogenic aphonia and psychogenic dysphonia.
Dissociative Convulsions / PseudoseizuresCode F44.5
"Dissociative convulsions (pseudoseizures) may mimic epileptic seizures very closely in terms of movements, but tongue-biting, serious bruising due to falling, and incontinence of urine are rare in dissociative convulsion, and loss of consciousness is absent or replaced by a state of stupor or trance." :126
Dissociative anaesthesia and sensory lossCode F44.6
"Anaesthetic areas of skin often have boundaries which make it clear that they are associated more with the patient's ideas about bodily functions than with medical knowledge. There may also be differential loss between the sensory modalities which cannot be due to a neurological lesion. Sensory loss may be accompanied by complaints of paraesthesia. Loss of vision is rarely total in dissociative disorders, and visual disturbances are more often a loss of acuity, general blurring of vision, or "tunnel vision". In spite of complaints of visual loss, the patient's general mobility and motor performance are often surprisingly well preserved. Dissociative deafness and anosmia are far less common than loss of sensation or vision." :126
This includes psychogenic deafnessPsychogenic Deafness.
Mixed Dissociative [conversion] DisordersCode F44.7
Mixtures of the following disorders should be diagnosed as mixed dissociative [conversion] disorder :
- dissociative amnesia
- dissociative fugue
- dissociative stupor
- trance and possession disorders
- dissociative motor disorders
- dissociative convulsions
- dissociative anaesthesia and sensory loss disorders
Dissociative Identity Disorder/Multiple Personality Disorder and the ICD equivalent of Dissociative Disorder Not Otherwise Specified are coded under F44.81 and F44.8 respectively, a person can be diagnosed with both a Dissociative Motor or Sensory Disorder and DID/DDNOS.
Probable and Definite DiagnosisIf the person has a physical disorder involving the nervous system, or is a previously well-adjusted individual with normal family and social relationships, then a probable or provisional diagnosis may be given instead. A probable or provisional diagnosis should remain if it isn't possible to understand why the symptoms have developed, meaning if no link with a psychological cause or environmental trigger has been found. :122
For a definite diagnosis:
- "there should be no evidence of physical disorder; and
- sufficient must be known about the psychological and social setting and personal relationships of the patient to allow a convincing formulation to be made of the reasons for the appearance of the disorder." :122
The following conditions must be ruled out as causes: early stages of progressive neurological disorders (e.g., multiple sclerosis, systemic lupus erythematosus). Multiple and ill-defined somatic complaints (physical symptoms without a physical cause) should be classified elsewhere, under somatoform disorders or neurasthenia. Isolated dissociative symptoms which occur only as part of major mental health diagnoses (e.g., schizophrenia or severe depression) should be ruled out. Feigning symptoms (knowlingly pretending to have symptoms which you do not have) can be difficult for clinicians to distinguish from the dissociative disorders involving movement/sensation; clinicians are advised to use detailed observation, obtain an understanding of person's personality, the circumstances when the symptoms first started, and the consequences of recovery versus continued disability. Patients feigning symptoms can stop symptoms at any time they choose.
DSM-5 Conversion DisorderCode 300.11
Alternative name: Functional Neurological Symptom Disorder
The DSM-5 classifies this is in the Somatic Symptom and Related Disorders sectional.
- "A. One or more symptoms of altered voluntary motor or sensory function.
- B. Clinical findings provide evidence of incompatibility between the symptom and recognized neurological or medical conditions.
- C. The symptom or deficit is not better explained by another medical or mental disorder.
- D. The symptom or deficit caused clinically significant distress or impairment in social, occupational, or other important areas of functioning or warrants medical evaluation."
Specify symptom type: (F44.4)
- With weakness or paralysis
- With abnormal movement e.g., tremor, dystonic movement, myoclonus, gait disorder (F44.4)
- With swallowing symptoms (F44.4)
- With speech symptoms e.g., dysphonia, slurred speech (F44.5)
- With attacks or seizures (F44.6)
- With anesthesia or sensory loss (F44.6)
- With special sensory symptom e.g. visual, olfactory, or hearing disturbance (F44.7)
- With mixed symptoms" :627-628
- Acute episode: Symptoms present for less than 6 months.
- Persistent: Symptoms occurring for 6 months or more.
- With psychological stressor (specify stressor)
- Without psychological stressor