Zebra or Just Another Breed of Horse? A Medical Maxim Examined for Rare Disease Awareness Day

 Zebra, or an Unrecognized Horse?  A Medical Maxim Put to the Test
“If you hear hoofbeats, don’t think zebras.”
-Medical School Maxim
Many in the medical community have heard the commonly bantered about medical school maxim, “If you hear hoofbeats, don’t think zebras,”  dissuading newly minted doctors from seeking a diagnosis of a rare disease for patients with unusual symptoms not explained by routine, standardized tests.  The maxim never made much sense to me.  For one thing, as a metaphor it falls rather flat and as a maxim it lacks the resonance of truth.  Why wouldn’t someone think of zebras when hearing hoofbeats?  Why not wart hogs, cattle, antelopes, giraffes, or any such bovine or quadruped in possession of hooves?  Horses are not the only animal that make hoofbeat sounds when they run.
Finding the origins of truisms can often shed some light on how they came in to being and how they may have become popularized, generally accepted over time, and eventually distorted.  What I found about the zebras and hoofbeats medical maxim is that it apparently originated with  Dr. Theodore Woodward in the 1940's.  Dr. Woodward had an excellent reputation as a diagnostician and was a well-respected medical school professor.  Interestingly, the phrase about zebras and hoofbeats used today is a distortion of what Dr. Woodward actually said, that being “Don’t look for zebras on Green Street.”  At the very least this statement does make more sense as an aphorism because while it is true that a zebra makes hoofbeat sounds, it is not likely that a zebra would present itself on a street in downtown Baltimore.   How would this phrase become distorted over time, becoming misapplied in such a way as to be a potential source of under diagnosis and misdiagnosis of human disease?
Everyone has probably heard at one time or another, of  the whispering parlor game.  Several people are seated in a row and a sentence is whispered to the first person, who then whispers it to the next person, who then whispers it to his neighbor, and so on, until the last person in the row is reached.  This last person then stands up and says out loud what had been whispered to him.  The first person says the original statement out loud and everyone has a good laugh at how distorted the sentence became over several whisperings. 
Perhaps in the same way, a maxim repeated over several decades gradually loses its original intent as modifications and omissions distort it in to a fragmentary misinterpretation.  The playwright Henrik Gibson, in his play “An Enemy of the People” perhaps reflected this best through his character Dr. Stockman:
“A normally constituted truth lives, as a rule, seventeen or eighteen years, at the outside twenty, seldom longer, after which it presumably becomes a lie, a ghost.”
Maxims can become distorted with time and retelling.  What else may be at work to give a maxim a shelf life?  Time itself brings new discoveries in to being.  A new social paradigm can make earlier beliefs no longer apt.  In the case of the “hoof beats and zebra” maxim, medical knowledge about diseases once considered rare but are no longer found to be so erodes the analogy in an increasing number of cases.  One such example is interstitial cystitis, once thought to be a very rare disease of post menopausal women.  But decades of patient advocacy, networking and fund raising for research has changed medical understanding of the disease to include both men and women of all ages in the diagnosis, as well as a significantly higher prevalence in the general population than originally thought.  Such is the changing paradigm of a disease that loses its “zebra on Green Street” status.  In fact, I would hold that many, if not most, so called rare diseases are simply under-diagnosed.  Something rarely looked for is rarely found.
Did the “zebra on Green Street” analogy, then, ever have any use, and if so, what might that have been and why?  There is a use in medicine for training towards the  counter intuitive.  A surgeon must train to overcome the natural instinct that cutting in to a living human being’s flesh is a force of destruction.  An emergency room doctor who recoils with horror at an accident victim instead of setting immediately and dispassionately to work would not be of much use.
 Research suggests that the human mind intuitively recalls with greater acuity that which is unusual or extreme than those things that are ordinary and mundane.  Perhaps that is just one of the brain’s defense mechanisms - strange things impress more deeply because something that is out of order can be a threat worthy of instant recall.   By extension a medical student confronting a patient with a rare disease would remember that patient more vividly than the one who presents with a common cold.  The suggestion here is that the novice diagnostician must use trained reason to counteract the possibility that a rare disease memory will cause him to somehow “hallucinate” this disease recurring in a larger population than is the medically accepted norm.  And that is where the “zebra on Green Street” maxim comes in to play.  It was originally intended to protect a patient from unnecessary tests and possible inappropriate treatments through the mind’s error of over inclusion.
But what if seeing a disease in a larger population than is the medically accepted norm, is in fact the correct perception?  As medical knowledge increases, the trend seems to be precisely a discovery of higher than originally accepted prevalence of the so-called rare diseases.  Even discounting the probable actual higher incidence of individual rare diseases, it might do well to consider that if the current figure of approximately  6000 recognized rare diseases is correct,  odds are that a given population will have a distribution of these.  And diagnoses of exclusion are therefore somewhat suspect, for the sheer volume of possibilities makes a full exclusion rather unlikely.  Some of factors involved in impediments towards excluding rare diseases: www.ncbi.nlm.nih.gov/books/NBK56184/
Given what medical science knows today, rare diseases may indeed be much more common than the possibility of seeing a zebra on Green street.  Perhaps we need a new metaphor to describe them and a counter maxim as an antidote to the errors of exclusion promulgated by a maxim in need of retirement.  Maybe a person with a disease considered to be rare is more like an uncommon breed of horse, or even a not so uncommon breed of horse destined to live in an era in which only a limited number of horse breeds are recognized.  I sometimes think of myself not as a zebra in a world of horses, but as a Shetland Pony in a world that only sees the more common quarter horses, American painted horses, Arabian and Appaloosa.  Is there a possible aphorism as an antidote to the zebra on Green Street?  Something light hearted that is an equally apt metaphor for the error of under inclusion? I think so.  It might be something like, “If you hear hoofbeats, don’t assume that it can only be an American painted horse in your grandmother’s barn in Alabama.”

Rare Disease Awareness Day

The last day in February has been designated Rare Disease Awareness Day.  Since this year February has an extra last day, I have decided to write two entries acknowledging the event.
Since being diagnosed with Ehlers-Danlos last year, I have been astounded at the time it took to obtain the diagnosis, the persistent misunderstanding of the ailment in the medical community and the lack of awareness of its existence in the general population.   Fellow patients often make the same observation, a diagnosis after years of a search for answers to devastating health problems leading to the question, “What took so long?”
 I reflected on the amount of time and effort required in my own diagnoses.  (There are two disorders considered rare and perhaps more to come!)  In reviewing what was required to obtain a diagnosis and all the stumbling blocks that I encountered along the way, I came up with two antithetical lists; one for what impeded progress and the other for what set things on course towards identifying the cause of medical problems.   With proper time, effort and research every item on either list could be a treatise for rare disease awareness.  For now my time and research is limited but I will begin with this enumeration followed by commentary, some for this month and the rest for later.
 Unlike the popular adage that good news should come first, I like the problem first then solution later approach.  My list on the side of impediments begins with number one:
1. Symptoms are misinterpreted as benign features rather than hints at or actual markers for disease.
In my case, this happened twice, both with my tritanopia as well as my Ehlers-Danlos.  The main diagnostic marker for Ehlers-Danlos is marked joint flexibility and often silky or doughy skin that is hyper-elastic.    Pronounced flexibility in itself is often  a benign and often advantageous thing.  My nine-key reach was great for piano.  My flexibility was wonderful for dance, yoga, gymnastics and marshal arts.  But with Ehlers-Danlos the flexibility that creates advantage is unfortunately a sign of a connective tissue disorder.  Joints are loose because the collagen that comprises the  tendons and ligaments that hold bones in place is defective.  For reasons that may still be unclear, the illness can also result in autonomic nervous system damage, chronic severe headaches, cardiac problems, gastro-intestinal problems, and chronic fatigue.  For those who are not too fatigued to be active, activity often results in subluxations, torn tendons and dislocations.  It can become an incredibly painful disease. 
I never thought of my hyperflexibility as a symptom, even after becoming disabled.  It took a long time to connect the dots to connective tissue disease.   No doctors ever asked about joint laxity, and since I thought of it as a characteristic rather than a symptom, I never mentioned it.  The criteria for Ehlers Danlos Syndrome flexibility has traditionally been the Beighton scale, a list of nine or so point of  joint laxity in the thumb, small finger, back, elbows, and knees. It seems like a silly measurement, as many people are flexible way beyond the norm in areas outside of these markers but not always within them.  And there seems to be little accounting for age related arthritis diminishing flexibility.  Nevertheless, other than the geneticist who finally diagnosed me, there were no doctors in my care (I must have seen at least twenty or so during the five year course of this illness) who had heard of the Beighton scale or knew how to apply it.  Well, there was one doctor who thought he had tested me for hyper flexibility by coming in to my room at the hospital, wiggling the thumb of my right hand and then leaving the room.  That hardly counts.
Ironically, until the diagnosis of Ehlers Danlos seemed imminent, I had not realized the extent of my skin elasticity and joint laxity myself.  I looked at pictures of Ehlers Danlos patients and thought what looked like circus freak shore acts were anatomically impossible until I tried them myself and found that I could do all of them, and then some.  I never knew, for instance, that I could bend my thumb forward to touch my wrist until I looked at an EDS photo and saw that patients can do that.  Why would anyone want to?  But it does explain now why other patients have to have that little plastic ID bracelet cut off when they leave the hospital.  Not me.  I just dislocate my thumb and pull the bracelet up and over it.
For the past several months, every now and then I insinuated my Ehlers Danlos skin and joint features in to my art work.  The flexible thumb and tongue made their way into a small ceramic Harpy rattle.  The skin that pulls out over my eyebrows became a peculiar detail in a self portrait for the last illustration of my poetry chapbook, My Women My Monsters.  The last poem and illustration for this text became, fittingly, My Monster Myself.  It seemed the perfect euroboric way to end that story.  But the search for answers to the rare disease patients’ plaintive cry “why did it take so long?” is the beginning of my next story.

Would that Clay Could Look Like Wood

I sent a picture of my recently finished pit fired ceramic bowl to a friend.  “It looks like wood,” she commented.  Excellent, I thought.  I have always loved wood turned vessels but had not the resources to collect them personally.  In an effort to emulate the objects of desire I experimented with burnished vessels made from local clays that already had a cedar or oak like coloring.  The browns, pinks and whites were from the Santee area.  The orange and reds were from the Edisto.
The red clay from Edisto was slumped in a plaster bowl shape and then altered with carving in the leather hard stage.  The surface design was created by burnishing the clay surface, bisque firing, then smoke firing in the pit.  Instead of doing the usual metal box within the outdoor kiln to house this bowl, I placed the bowl directly into the ashes and let various and sundry burning organic matter fall onto it.  Since the fire was kept burning for several hours, an ash glaze began to form.  The finished product is pictured above.
For the smaller bowl, I took the brownish red clay from Santee and kneaded it together with the buff white in order to create a marbleized effect.  After smoothing out the surface of the bowl, the variegated clay was revealed by scraping the bowl down.  This bowl was placed in the tin container inside the pit kiln - I wanted to smoke it but not have it go so black that the design would be obscured.  The combination of small dots of black and the slight browning of the design imparted the overall effect of a bowl carved from a wood burl.  Success!
I once heard that many sculptors like to work in clay because ceramic is the great imitator of visual art.  Indeed, one can make it look like brick, stone, and sometimes even wood.

Oh So Very Black

For the most part, my attempt to revise ceramic vessels by firing them over again in a reduction kiln resulted in improvements.  Sometimes they got worse, other times they just became different.  In the case of two refired lidded vessels they went from very little smoke pattern to very dark.  But because the darkness had a variable texture and shine, I decided to keep them.  On the larger jar, there were a few spots of delaminating glaze.  On this covered the areas with gold leaf.  The pot itself had a somewhat metallic sheen from the high heat and organic matter, almost like raku ware.  The gold touches worked okay on the pot for this reason.
The smaller jar got quite dark indeed.  The left is the before, the right after. 

From Bottle to Bowl: More Ceramic Revisions

At the end of last year, I had decided to cull through my collection of small ceramic vessels and musical instruments in order to revise what I could and discard the rest.  That project was finally completed with the last pit firing a few days ago.  The project took much longer than I had anticipated because I should have just thrown out more and salvaged less.  My proclivity towards art rescue  prevailed over common sense and everything that could possibly be restored by re-tuning, resurfacing and firing over again was “fixed” in such a way.  Some fixes were successful, others not, and a few were more trouble than they were worth. 
I post today a small example of a piece that overlaps a successful fix that was still more trouble than it was worth.  The pit fired bowl pictured above had started out as a reduction pit fired bottle with a strange stopper.  I didn’t like the surface so I sanded it down.  In order to make it truly a nice shape I sanded down quite a while - so far that the top part of the bottle fell off.  Now it became a bowl.  So I threw away the odd stopper, finished the edge of what was now a very different vessel, and added variously colored stains and terra sigillata.  This went back in to the pit for a smoke firing and a delightful little piece emerged.  But would such a piece recover the hours that went in to the revision?  I doubt it, unless it can be counted as hours spent in learning from experience.

Monumental Little Things

I had been making a series of miniature sculptures, thinking of ways to make them somehow look monumental despite being only two inches high.    I’m not sure what I would use such things for.  A diorama of a modern sculpture garden perhaps replete with moss, miniature benches and tiny pewter people.
The inspiration, I think, comes from the sculptures of Isamu Noguchi http://www.noguchi.org/noguchi that  I enjoyed seeing on my walks as a teenager in Princeton, New Jersey.  I loved those sculptures.  They seemed the perfect marriage of the man made and organic, natural forms.  They were large rocks just barely altered by human touch.  Some of the later sculptures of Max Ernst were like those too.  But I only became familiar with those much later. 
The materials from which these mini sculptures were made are natural to this part of South Carolina.  I mined local clay from which to sculpt them.  I burnished this natural clay, sometimes added some terra sigillata, then bisque fired them.  I then fired them in a traditional pit fire with local organic materials such as Spanish moss.  It is fascinating to think that art can be produced from all the stuff that can be mined from the ground or pulled off trees from one’s own back yard.
In firing these objects recently I did acquire some new and useful knowledge.  The sculptures were put inside larger, hollow vessels in my pit firing.  In fact, this technique may be yet another reason for their creation.  Pit firing takes a lot of effort - stoking the fire with wood and organic materials all day.  For this reason I like to make use of every square inch of space.  Covered jars and vases can be filled with other, smaller ceramic objects like beads and small whistles.  Hence the little sculptures.  After this last firing of my filled vessels, however, I noticed that two little sculptures had not made it in to the pit.  What to do?  I figured that they were small enough to stuff in to a coffee can filled with cedar chips and sticks.  I decided to see if a mini fire would work for the small sculptures.  So I lit the fire in the can and let things burn down for about an hour.  I then smothered it with some Spanish moss and put a piece of metal on top held down by a rock.  The next day I spilled out the contents and found nicely blackened ceramic pieces.  Pleased that this did not require a monumental effort I decided that  this would be a good technique for later if I just want to fire up a small collection of beads or other small objects.
These small three dimensional objects  are more like creative notes than finished art work.  They look like ideas for sculptures.  Perhaps that is exactly what they are - concepts for art that reality precludes the manifestation of.   Would that I could work in steel or concrete.  For now these little trinkets will rest on my desk until I put them away.

Bugle Taps for the Demise of a Ceramic Horse

In my last post, I related the tale of the difficulties I was having finishing two ceramic sculptures of horses.  Sadly, one of those broke a leg once again and had to be “put down.”  I have posted a picture of the sculpture once again in his intact state and in his deconstructed melt down. Not wanting to repair the broken leg once again I knocked the sculpture apart, soaked it in water, then wedged the clay back into a solid lump, ready to be used again at a later date.
The sculpture that did not break yet was decorated with a terra sigillata surface, burnished and put into the kiln.  Today marks the bisque firing.  Since I’ve been having difficulties with sculpture lately, I’m trying not to keep hopes too high that there is not some fault line or trapped air bubble waiting for the heat of the kiln to explode it.  Pretty thing, though, and a pity if he breaks as well.

The Trouble with Large Ceramic Horses

I completed and framed five drawings for an upcoming exhibition of horses at Gallery West in North Columbia.  The gallery owner liked my small clay sculptural whistles as well so I offered to make horse  statuettes from the same caramel colored local clay.  I came up with  a small collection of horse statuettes in various lively positions; grazing, leaping, stretching.  I then decided to offer my agent two larger horse sculptures.  I was fascinated by the ceramic sculptures of horses from the Chinese Han and Tang dynasties and wanted to make something stylistically similar - a horse with a small, narrow head, a stout body, a large saddle and legs smaller at the back than the front. 
The idea of making larger horses was fine, but the execution was problematic.  How to make a large, heavy body on long legs using a plastic medium like clay?  It was not easy.  Even though I followed archeaological examples I found of ancient ceramic horses made with hollow bodies and solid legs, I could never time the drying time on the legs well enough so that they would support the heavy body.  Hence they would break off when I turned the horse right side up.  Not wanting to melt the clay horses down again, I would re-attach the legs, sometimes using clay melting vinegar, patch it up and wait.  It took a few weeks of carving, drying, re-hydrating then carving some more but they were finally roughed out.  Now the test will be to see if they remain intact through the final drying, sanding, burnishing, firing and pit firing. 
To get an idea of scale, I have photographed the original horse statuette underneath the larger version of the ceramic horse.  These larger horses might survive the tooling around yet to come. Given the trouble they were to create, however, I most definitely do not plan to make them again.