Chapter 60 Visual conversion disorder
fabricated or exaggerated symptoms in children
Features and definitions
Many terms have been used (Table 60.1) and many are useful but none perfectly encapsulates what we refer to as visual conversion disorder (VCD).
Table 60.1 – Alternative terminologies used for children with fabricated or exaggerated symptoms
| Terminology | Advantages or disadvantages |
|---|---|
| Conversion disorder (visual conversion disorder, VCD) | The preferred term of the American Psychiatric Association but it implies certain knowledge of the underlying mechanism |
| Hysterical blindness/amblyopia | Incorrectly implies instability or “madness” but it is commonly used |
| Stress-related visual disorder | Many cases are not apparently stressed by any definition |
| Conversion neurosis | Implies a certain knowledge of the underlying mechanism and instability |
| Medically unexplained visual loss | Obscures the meaning from parents and patients |
| Amblyopic schoolgirl syndrome | A sexist and pejorative term |
| Functional visual loss | Meaningless term designed to obscure the meaning from parents and patients |
| Malingering | A term correctly used for someone who deliberately feigns a symptom for some form of gain – compensation, avoidance of work, military service, etc.2 This is usually seen in adults |
| Factitious disorder | A term correctly used for a person acting as if they have an illness by deliberately producing, feigning, or exaggerating symptoms to gain attention or sympathy. Was known as Munchausen’s syndrome |
| Factitious disorder by proxy | Used to be known as Munchausen’s syndrome by proxy. Symptoms or signs produced in a child by a carer to elicit sympathy etc. for the carer |
| Psychogenic blindness | Terms that are still used and can be helpful |
| Non-organic visual loss |
The major characteristics of VCD are as follows (modified from The Diagnostic and Statistical Manual (now IV-SR) of the American Psychiatric Association1):
• One or more symptoms or deficits are present that affect voluntary motor or sensory function suggesting a neurologic or other medical condition.
• Psychologic factors are judged by the clinician to be associated with the symptom or deficit because conflicts or other stressing events precede the initiation or exacerbation of the symptom or deficit by a variable time. It is important to understand that it is often difficult or impossible to find any clearly abnormal stressing event.
• 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 significant distress or impairment in social, educational, or other important areas of functioning or warrants medical evaluation.
• The symptom or deficit is not limited to pain or, in older children, to sexual dysfunction and is not better accounted for by another mental disorder.
Conversion disorder
Conversion disorder was described3 as a loss or distortion of neurologic function not fully explained by organic disease. The patient has an internal conflict, of which they are unaware, which becomes converted into a symptom as a means of expression after dissociation, a mental mechanism whereby underlying feelings and the symptoms are separated. Conversion disorder can be distinguished from other psychiatric disorders mimicking organic loss by its absence of conscious or intentional desire to trick the doctor (or parent). The child with the ocular manifestations of a visual conversion disorder (VCD) develops visual loss due to unconscious problems or mental disturbances outside their awareness. Often such children have a history of previous conversion reactions, not necessarily involving the visual system (e.g. non-organic loss of motor function).
Clinical presentation and symptoms
The child with VCD is between 6 and 16 years, most frequently 10 years old; girls are more frequently affected than boys.4 There may be a family history of illness or of eye disease, such as retinitis pigmentosa.5 The symptoms come on gradually in most cases, often following a marginal failure at a school eye test. Subsequent examinations reveal varying degrees of acuity and visual field loss, often worsening as time goes on but rarely to the extent that the child becomes bilaterally blind. The remarkable thing is how little most children are inconvenienced by an apparently marked visual loss. Repeated objective examinations and further examinations, including neurophysiology and radiology, are all normal. The condition is usually bilateral,4 with the most common complaints being “just not seeing,” blurred vision, or distorted or small images. Occasionally visual field defects are described, commonly “tunnel vision”; hemianopias are occasionally encountered. Central scotomas are rare and should make one think of associated organic disease. Non-ocular defects occasionally also occur,6 including spasm of the near reflex, headaches, voluntary nystagmus, and eye movement tics, contraversive eye deviation, and accommodation paralysis.
The symptoms of VCD have some of the following characteristics:7,8
1. They conform to the child’s concept of a symptom or a disorder.
2. They are definable, if somatic, in terms of positive evidence and, if psychologic, by techniques of clinical examination.
3. They are related to emotional conflict.
4. Despite being profound, the symptoms often cause little concern to the affected child.
5. There is usually only one symptom. It is unusual for this to present like a somatization disorder where the child has multiple symptoms often in more than one organ system.
6. Conversion disorders are rare under 6 years old, and the sex ratio is equal up to 10 years, then females outnumber males by 3 : 1.
7. In children, both visual fields and acuity are affected; adults tend to be monosymptomatic.8
8. Family disharmony is common and incestuous relationships should be borne in mind as an underlying cause.9
9. Patients tend to have equal difficulty with both large and small letters and to read down the letter chart very slowly (and time-consumingly) from the top to the lowest they can achieve, often getting further down the chart if cajoled or, for some, if the test is done competitively. They read the near vision test excruciatingly slowly, often only to a level far disparate from that achieved at distance.
10. A few children have a history of previous psychiatric or psychologic disease6 but it is often difficult to elicit the history. Most are perfectly normal children.
Association with organic disease
Non-organic symptoms are common amongst children referred to a pediatric ophthalmology service.10 Their prompt and correct diagnosis, with appropriate management, saves the doctor, the child, and the parents much heartache and time and saves the discomfort and risk of unnecessary investigations.
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