ASTHMA. INTRODUCTION. ASTHMA is a complaint which is mentioned in the oldest writings, but the name of Asthma was given to all kinds of diseases, if accompanied by difficulty in breathing; this caused a great confusion of ideas, which it took centuries to correct. According to Bergson, the Bible (Exodus) mentions a disease which must be looked upon as Asthma. According to the same author, Homer and Herodotus also knew the complaint, and advised those who suffered from Asthma to use warm sand baths. In the works of Hippocrates Asthma is mentioned several times, and he gives the name of Asthma to all respiratory difficulties that are accompanied by accelerated breathing. Celsus distinguishes between dyspnoea, asthma and orthopnoea; dyspnoea being the milder form of the complaint, orthopnoea the more severe. Aretaus gives an exact description of asthmatic attacks, and separates only asthma and dyspnoea, regarding orthopnoea as a symptom of asthma. From this time up to the middle ages Galen's opinions were in this case, as everywhere else in medicine, predominant. He knew only dyspnoea, whose subordinates are orthopnea and apnœa. It was only towards the end of the 17th century, that Willisius established the category of nervous spastic asthma,† * Bergson, Das krampfhafte Asthma der Erwachsenen, Nordhausen, 1850. † See Ramadge, Asthma, London, 1835, p. 86. B which had already been indicated by v. Helmont.* The characteristics of this form of Asthma were, that the patient's lungs were perfectly healthy (viscera omnia sana, præsertim pulmones),† and that Asthma, therefore, was now placed as an independent disease, in contrast to earlier authors who looked upon it as a symptom. Floyer, who himself suffered from asthma for 30 years, wrote a capital work on the subject, he considers a convulsive contraction of the bronchial tubes to be the cause of the asthmatic attacks, whereas dyspnoea, which is distinctly separated from asthma, is caused by a compression of the lungs. He makes a sharp distinction between the asthma that has a visible cause, and the one that has no distinct origin, and where no pathological change is to be found. This last, the essential asthma of the present day, he calls Asthma periodicum flatulentum, whereas Willis has named it, A. convulsivum et spasmodico-flatulentum or A. spasmodicum. This theory of Floyer as regards the bronchial spasms was later on acknowledged by Cullen§. Darwin in his Zoonomia declares that Asthma convulsivum has the same character as all other cramps and epilepsies, and that it can originate from nearly all distant parts of the body. Already in former times numerous observations have appeared, which endeavoured to prove that asthma could originate from pathological conditions in other organs. Willis and Hoffmann mention cases, where the presence of bilious stone has been the cause of asthmatic attacks, Ruysch has observed the same thing in cases of renal stone. Floyer has seen asthma in women suffering from uterine diseases. Wainwright knew a lady who contracted asthma every time she * See Floyer, A treatise of the Asthma, London, 1717, Dedication, p. 5. † See Ramadge, Ibid, p. 94. Floyer, Ibid. § Cullen, Practice of Physick, 1777, referred to by Bree, Recherches pratiques sur les disordres de la respiration, traduit de l'anglais, 1819, p. 108. had her menses. It was generally the abdominal viscera and specially the stomach, that was considered to be the reflex origin of asthma.* In accordance with the tendency to schematize after etiological principles, which was predominant, in the last century, Asthma was divided into a multitude of forms such as: asthma humidum, hæmorrhoidale, abdominale, flatulentum, leucorrhoicum, menstruale, spasticum, nocturnum, etc., which served to make the confusion complete. In the beginning of this century the theory of the purely nervous asthma was partly given up again, on account of the numerous pathological and anatomical examinations, which nearly always found more or less alterations in the lungs of patients who died of asthma. Bree raised a series of objections against the spastic nature of asthma, which in part were founded upon false suppositions; this can be explained by the circumstance, that the so-called idiopathic asthma was not a distinctly defined disease, acknowledged by all, but on the contrary amongst other things embraced oedema of the lungs, asthma uræmicum, etc. Bree does not actually deny the possibility of the bronchial spasms taking some part in the cause of asthma, but it is only secondary; the primary cause is an exudation in the bronchial tubes, by which the lungs (specially the muscles of respiration) are stimulated to contraction, in order to expel the mucus which they contain. Bree's theory however lost ground as soon as the process of auscultation had been learnt, as it was thereby proved that an attack of asthma is not preceded by bronchitis, but that it is not till later on during the attack that the rales are heard, (see amongst others Ramadge).† Ramadge again maintains the nervous character of asthma, and considers a spasm of the trachea and the bronchial tubes to be the cause; in this respect he compares * Bree, Recherches pratiques sur les disordres, etc., 1819, p. 208. asthma to colic of the bowels. Laennec acknowledges the spas"catarrhe sec" to be the most modic asthma, but believes his frequent cause. Rokitansky* considers emphysema as the palpable origin of the so-called nervous asthma. Romberg on the contrary maintains the independence of the nervous asthma, and describes it as a bronchial cramp, spasmus bronchialis. It was especially after the publication of Bergson's prize work,‡ that a decided separation was made between the idiopathic nervous asthma, characterized by its periodical attacks, which are separated by perfectly free intervals, and the numerous forms of difficulty in breathing, which appear purely symptomatic in many different complaints of the chest. To Bergson the idiopathic nervous asthma is an independent neurosis of the organs of the chest, whose origin is a cramp or spasm which like all other neuroses can be caused by a central or peripheral irritation of the nervous centre. The majority of the following authors consider asthma to be a bronchial spasm, and as they knew of the existence of the bronchial muscles, have a better ground for their opinion than the older authors whose belief in bronchial spasms was merely hypothetical. The presence of muscles in the fine bronchial tubes has been known only since the beginning of this century through the works of Reisseisen and Sömmering. § The power of contraction of these fine muscles has on the one side been confirmed through experiments made by Prochaska, Reisseisen, Haller, Varnier, Treviranus, Wedemeyer, Williams, Longet, and Volkmann, whilst on the contrary Budd has vainly attempted to cause any contraction of the bronchial tubes, either by placing the electric current on the surface of the lungs or in the place * Rokitansky, Lehrb. d. path. Anatomie, 1844, II. B., p. 64. where the bronchial tubes were cut (see Bergson's work, p. 76, et seq.) As a decided opponent of the theory of bronchial spasms we find Wintrich, who like Budd could not obtain any contraction of the bronchial tubes by irritation of the stems of the vagus. He meanwhile does not deny the possibility of a spasm in the bronchial muscles, but merely denies its being the cause of the nervous asthma.* He has found by experiments that only one-fifth of the vital tonus of the lungs is due to organic muscular fibres in the bronchial tubes, while the remaining four-fifths depend upon the elastic fibres in the tissue of the lung. A spasm of these muscles can, therefore, only be of small and insignificant influence, and does not give a satisfactory explanation of the nature of asthma, for both the expiratory and inspiratory muscles exceed in strength all the bronchial muscles put together. Wintrich on the contrary thinks that asthma can be explained by a tonic spasm of the diaphragm alone or combined with the respiratory muscles. It must here be remarked, that Willis has already mentioned spasms of the diaphragm as being the cause of asthma, and Neumann has expressed the opinion that most cases of asthma might be the result of a spasm of the diaphragm (referred to by Mehlis†). Only a tonic contraction of the diaphragm can explain the deep immovable position it occupies in many cases of nervous asthma. Wintrich's opinion was in every respect confirmed by a work of Bamberger in which he, on the bases of careful observation and post mortem examination of a case, considers asthma to be caused by a spasm of the diaphragm. Wintrich's conception of the case had besides Bamberger only a few partizans. Sée alone *Wintrich, Virchow's Handb. d. Pathologie, 1854. V.B. Erste Abth., p. 190. Mehlis, Die Krankh. des Zwerckfells der Mennschen, Eisleben, 1845, p. 81. Bamberger, Ueber Asthma nervosum, Würzb. med. Zeitschr. VI. B., p. 102, Separatabdruck. |