Sunday, February 24, 2013

1878-1885: Asthma no longer a confused term x


By introducing the art of percussion to his medical practice, Jean Corvisant realized that many cases of asthma are actually diseases of other organs.  When his student, Rene Laennec, introduced percussion with auscultation to his practice, he quickly observed that asthma was truly an abused term.  

These are the two 19th century asthma experts we can thank for giving us the tools necessary for differentiating asthma from other diseases and diagnosing it as a disease.  In other words, prior to the 1820s anything that causes dyspnea was regarded as asthma, and after the 1820s asthma was more carefully diagnosed.

It is by these discoveries that asthma is divided into different categories, each of which ultimately become disease entities of their own:

  • Cardiac Asthma: Dyspnea due to heart disease is now heart failure 
  • Kidney Asthma: Dyspnea due to kidney disease, now known as kidney failure
  • Bronchitic asthma: Dyspnea due to chronically inflamed air passages and excessive sputum production, now known as chronic bronchitis
William Pepper and Louis Star published a book in 1885 called "A System of Practical Medicine.  In the opening pages they explain the following: 
Ignorant to a great extent of pathological anatomy and unprovided with the improved methods of physical diagnosis which we now possess, they (previous asthma writers) described as asthma not only the dyspnoea due to cardiac and pulmonary diseases, but also that occasioned by affections of the pleura and greater vessels. Covering such an extensive range of territory, it was found necessary to subdivide the disease into a number of varieties, each author classifying them according to his conception of the cause, seat, and nature of the trouble. Some of these—e. g. a. dyspeptic-urn—still find a place in medical literature, but the vast majority of them, having ceased to be of any practical significance, have been discarded, and are now only interesting as examples of the crude and fanciful notions which prevailed in an age during which science rather retrograded than advanced. Of the writers of this period, Willis in the seventeenth century is especially worthy of notice as being the first to describe the nervous character of asthma. Without discarding the accepted forms of the disease, he mentions another variety, characterized by spasmodic action of the muscles of the chest, to which he gave the name asthma convulsivumThe improvement in physical diagnosis resulting from the brilliant discoveries of Auenbrugger (percussion) and Laennec (stethoscope) greatly curtailed the domain of asthma with the aid of auscultation (use of stethoscope to hear lung sounds) and percussion it was discovered that most of the cases hitherto regarded as asthma were only symptoms of some organic disease.  (1, page 184)
J.B. Berkart, in his 1878 book "On Asthma: It's pathology and treatment," wrote the following:
ALL early historical traces of the affection at present called asthma are lost. Although the disease is said to be mentioned in the Bible, and described by Hippocrates, Areteaus, Galen, and Celsus, there is not the least evidence that those remarks apply to the asthma of to-day. For in the former systems of medicine, all cases presenting the same conspicuous symptoms were, regardless of their anatomical differences, considered as of a kindred nature, and grouped into classes according to imaginary types. (2, page 12)
I know these quotes are almost trivial, yet I find it interesting because these physicians, in this era, were privy to the idea that they were taking part in the rapid evolution of the definition of the disease they were studying -- asthma. Or, more accurately, they were seeing the evolution of differential diagnosis of the various disease processes that often result in dyspnea. 

In essence, Laennec's discovery sparks a leap through time.  Where 7,000 years of asthma suffering resulted in little progress in the way of asthma wisdom and treatment, the next 81 years -- part of which we are now observing -- provides for asthmatics more than all those 7,000 years combined. I think that Pepper and Star and Berkart and most other authors of pulmonary diseases in this era were well aware that this was happening.

And we learn that between 1816 and 1900 many different theories about what causes asthma are created, and every one of these theories has followers.  Each expert wrote his own definition of asthma based on his beliefs about the disease, and his own experiments and observations, and his own remedies based on these beliefs."

By the various proofs, by the various debates, that transpired during the 19th century about the disease we call asthma, and of other related diseases, it resulted in a significant fine tuning the definition of asthma.  Yet in the end, the two theories that won the day were:
  1. Spasmotic theory of asthma (a.k.a. bronchospasm or convulsive): There was evidence to support it
  2. Nervous theory of asthma (a.k.a. it's all in your head): There was no evidence to disprove it.
Or, more commonly, that these two theories of asthma were intertwined, such that some mysterious event or object (such as a certain food, a full stomach, laughter, strong emotion, excitement, dust, or cat) excites the nervous system, which in turn sends a message to the bronchial muscles to contract. 

By the end of the 19th century the ground was set for an even bigger leap through time as far as asthmatics are concerned.  By 1899 adrenaline was isolated, and this sets off a wave of wisdom that greatly improves the lives of asthmatics. Yet for the time being (no pun intended), we find ourselves drifting from cozy doctor's offices in large Victorian homes to laboratories of some of the worlds greatest asthma experts. 


References:
  1. Pepper, William,  Louis Star, "A System of Practical Medicine," Volume 3, page 184
  2. Berkart, J.B., "On Asthma: It's pathology and treatment," 1878, London,  Chapter II, "History of Asthma," page 12

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