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Biology 202
2000 Third Web Report
On Serendip


Sooyoun Yi

It is a rainy summer day and there is nothing to do but watch television. You have moped around all morning and now you have decided to sit down and do some serious channel surfing. You spend a good twenty minutes flipping through every channel and reluctantly stop at one of the day time soap operas. Normally, you never would even think of sitting through one of these cheesy shows but somehow it won over the overwhelming choices of the Home Shopping Network and Teletubbies.

A fairly young woman, let us call her Hillary, drives up to a cabin looking excited. The music, though, tells the audience otherwise. She rattles with the keys for a few minutes and finally opens the door to find her husband in bed with her sister, Monica!

{Cut to Commercial}

Hilary has fainted and is taken to the hospital. She slowly comes to as her husband begs for forgiveness. She is disgusted with him and does not want to see him so she turns her head to the opposite side of where his voice is coming from and opens her eyes. She sees nothing. She blinks a couple of times and still just blankness. She lets out a blood-curdling scream as she realizes that she can not see. The doctors run various tests and conclude that nothing is physically wrong with her. All the tests show that she should be able to see but then why can she not? From her obvious frustration, we know that she is not faking it (although there are some that do, called malingers) so what has gone wrong?

What Hillary has is a type of somatoform disorder and more particularly, a conversion disorder. It is the "conversion of emotional stress or mental disturbance into a physical symptom" (5). Physical symptoms are various and can range from tremors, loss of sensation, impaired coordination, difficulty swallowing, urinary retention, seizures, paralysis, deafness, and as in Hillary's case, blindness.

Conversion disorder, though, is only one sub-type of a somatoform disorder. Somatoform disorder is a general term used to describe the appearance of physical symptoms that can not fully be explained by medical conditions. The subtypes are "somatization disorder, conversion disorder, hypochondriasis, body dysmorphic disorder, and pain disorder" (1). The somatoform disorder was actually "called hysterical neurosis but this terminology was discarded in 1980's. Now these disorders are classified simply by symptoms" (3). Somatoform disorder (then called hysteria) was actually first diagnosed in ancient Greek. Then in the 1800's, Freud did much research on this disorder and concluded that "the affect and painful memories of traumatic event can be dissociated from conscious awareness and then can be converted into a somatic symptom that symbolize some aspect of the traumatic episode" (1).

This disorder was formally termed by the Diagnostic and Statistical Manual of Mental Disorders (DSM) in 1952 as conversion reaction. When the second edition of this manual came out in 1968, the name of the condition was changed to hysterical neurosis or conversion type. Then in 1978, the third edition labeled it as conversion disorder and somatization disorder. Finally in DSM-IV, conversion disorder and somatization disorder was sub typed in a general term of somatoform disorder.

As stated before, the people suffering from conversion disorder are usually not conscious of the fact that they are producing these symptoms themselves. So if nothing is physically wrong, why is it that Hillary can not see? Is her brain ignoring the sensory inputs from her eye? Or is her brain receiving the inputs but somehow interpreting them as nothing? Hillary's optical nerves are working fine and generating action potentials, so why is it that she can not see anything? What is keeping her brain from processing the sensory inputs? What is happening in her unconscious mind that is keeping her from seeing?

Some say it is a psychological defense mechanism to "banish unpleasant, painful, and anxiety-provoking mental contents from consciousness" (4). The abrupt and unwarranted formation of these physical symptoms is a way for people to absorb and neutralize the anxiety generated by the tragedy or stress they experienced. It gives people an outlet for dealing with tragic events.

The puzzling aspect of it is, is that is it involuntary. The people suffering from conversion disorder are ignorant of that fact that they, themselves, are causing these symptoms. These unintentional losses of voluntary motor or sensory functions seem like a physical disorder when in fact, there is a deep psychological conflict. Therefore, it is fairly difficult to find the right "treatment" since there really is no physical disorder. There is little that can be done except to help the people with this disorder to understand that physically everything seems normal.

The brain, is "both a transducer of experience as well as a practiced, highly trained organizer of perceptions from the 'milieu interieur' and the 'milieu exterior'" (3). In Bryn Mawr College's Neurobiology and Behavior 202 class' terms, it is a box that can receive signals as well as produce signals. The brain can filter, amplify, and dampen afferent and efferent stimuli from all parts of the body and from itself so why is it that the unconscious part of the brain is choosing to alter the signals it is receiving and producing?

It has been noticed that psychotherapy and hypnosis have helped some people but there is no general consensus on what is the best course of therapy. Therefore, things like drugs do little to help the people with this disorder. I would think, though, that since our minds are just nothing more than action potentials of the nerves (whether it is the conscious mind or the unconscious mind) drugs should be able to help our brains regain control over the voluntary actions which it had given up because of the tragedy. But then the big question that would arise is what kinds of drugs should be given to these people? There is no conclusive study that shows that it is the cause of a certain neurotransmitter. Also, there is no way of pin pointing the root of the problem since people experience different physical symptoms. It seems as though conversion disorder can not be explained fully by medical conditions or treated medically.

So how is it that some people are able to go into spontaneous remission and others even to complete recovery? Has the unconscious mind now decided that it had dealt with the problem long enough and is now allowing the brain to receive, send, and interpret signals? Maybe it is very similar to those firewalkers. They are able to consciously change their set points, which enable them to withstand tremendous amounts of heat without "feeling" it. Although people with conversion disorder are unaware of the fact that their minds are responsible for the physical predicament that they are in, they were somehow able to either inhibit their brains from interpreting what their sensory neurons were telling it or modify the output signals so that it did not correspond to the input signals. The brain can be acting analogously to a bratty kid with his hands over his ears refusing to listen to scolding. Maybe the brain is just refusing to "listen" to the input that the sensory nerves keep sending it and just continue to produce its own output signals. How can the brain just ignore the inputs though? Does that mean that the action potentials are just stopped and kept from stimulating other neurons? And then, are completely different action potentials generated?

It seems to me that people who can walk over hot coals or who can ignore certain sensory inputs are evolutionarily "advanced" (not better but just different) than the regular human species. Would it not be mind boggling if one day a species evolved from humans that would be able to just voluntarily shut off sensory inputs for some kind of defense mechanism? What if temporary blindness became as simple and instantaneous as blinking? What would be the benefits of being able to control these physical characteristics of our body?

This may be very similar to animals that are able to "play dead". The animal best known for playing dead is the opossum. It feigns death as a defense against predators since most predators do not feed on dead animals. Opossums will "lie on its side, keep its eyes open, open its mouth slightly, draw in the corners of its mouth, and drool" (6). The opossums are, though, very much aware of their surroundings. Experiments have shown that the "heart rate and brain waves are no different between an awake opossum and one feigning death" (6). They can stay in this inanimate state for several hours if need be. This is a very successful defense mechanism called thanotosis and many organisms (other than opossums) play dead, such as certain frogs, toads, and even insects. Frogs can remain so rigid and motionless that even respiratory movements is unobserved.

Very similar to these organisms that are able to induce certain physical aspects for survival, maybe humans are capable of influencing our brains to receive and produce certain signals for our benefit. The people said to be "suffering" from this somatoform disorder are not really suffering, per say. In fact, most of the people tend to experience "La belle indifference" which is an inappropriate absence of distress. Many people with conversion disorder have very cavalier attitudes toward this serious symptom and deny any emotional difficulty.

Maybe this indifference has to with the fact that this somatoform disorder is not a disorder but rather an adaptive advantage. A logical question that arises is, though, what would be the advantage of making ourselves go blind or deaf or paralyzing ourselves? A possible explanation could be that the human species, before the development of civilizations, used this as a defense mechanism somehow but as time went on and humans learned to dominate over other organisms, there was no need for this technique and therefore became very much like a vestigial organ. Some people may just be more biologically susceptible to these "disorders".

Conversion disorders "are at a mind-body interface: bodily symptoms/concerns as a psychiatric disorder" (2). Although there is a "disturbance of bodily functioning", the symptoms "do not produce the usual pathological neurodiagnostic signs" (2). Because of this, there seems to be very little that the internist, neurologist, otolaryngologist and ophthalmologist can do. It raises many questions that are yet to be answered and may contribute to the mind-body separation debate that has been going on for years.

WWW Sources

1) Childhood Somatoform Disorders , Detailed outline chock-full of information about somatoform disorder

2) Conversion Disorder , Gives in-depth details about conversion disorder and possible treatments

3) Dissociative and Somatoform Disorders , Good outline about somatoform disorder

4) Medical Definition of Hysteria , Provides good background information about hysterical neurosis

5)Hysterical Neurosis, Concise definition of hysterical neurosis

6) Virginia Opossum , Web site about opossums including "playing dead"

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