association with various other morbid conditions, the term is not
unfrequently vaguely employed. It is difficult, of course, to define a
disease whose etiology is so directly related to so many distinct
morbid conditions. Indeed, there are few diseases, general or local,
which are not at some time in their history associated with more or
less derangement of the digestive process. For purposes of limitation,
therefore, it will be understood that we now refer to chronic
functional forms of indigestion which depend largely, at least, on a
purely nervous element, and for this reason are not infrequently
described as sympathetic dyspepsia. Doubt has been expressed as to
whether such forms of disease ever exist, but that we encounter purely
functional forms of dyspepsia, corresponding to the dyspepsia apyretica
of Broussais, would appear to be a well-recognized clinical fact.
What the precise relation is between digestive disturbances and the
nervous system we may not fully understand, no more than we understand
how a healthy condition of nervous endowment is essential to all vital
processes. Even lesions of nutrition are now known to depend upon
primary disturbance of nervous influence. This is seen in certain skin
diseases, such as herpes zoster, which closely follows the destruction
of certain nerves. And it is well known that injury of nerve-trunks is
not unfrequently followed by impaired nutrition and failure in
reparative power in the parts to which such nerves are distributed.
Indeed, so marked is the influence of the nervous system over the
nutritive operations that the question has been considered as to
whether there are {437} trophic nerves distributed to tissue-elements
themselves whose special function is to keep these elements in a
healthy state of nutrition. The proof, at least, that the digestive
process is, in some unexplained way, under the immediate influence of
the nervous system, either cerebro-spinal or trophic, is both varied
and abundant. The digestive secretions are known to be the products of
living cells which are abundantly supplied with nerve-fibres, and we
can readily believe that the potential energy of this cell-force is
probably vital and trophic. At any rate, it is unknown in the domain of
ordinary chemistry. The digestive ferments, as clearly pointed out by
Roberts, are the direct products of living cells. Their mode of action,
he claims, bears no resemblance to that of ordinary chemical affinity.
It has a distinctly physiological character. Nor do they derive their
vital endowments from material substances. "They give nothing material
to, and take nothing from, the substances acted on. The albuminoid
matter which constitutes their mass is evidently no more than the
material substance of a special kind of energy--just as the steel of a
magnet is the material substratum of the magnetic energy, but is not
itself that energy" (Roberts). That this living cell-force is partly,
at least, derived from the nervous system is clear from the well-known
effects of mental emotion, such as acute grief, despair, etc., in
putting an immediate stop to the digestive process. Experiments on the
lower animals have also shown the direct influence of the nervous
system over gastric secretion. Wilson Philip showed by various
experiments on rabbits and other animals that if the eighth pair of
nerves be divided in the neck, any food which the creatures may
afterward eat remains in the stomach undigested, and after death, when
the nerve has been divided, the coats of the stomach are not found
digested, however long the animal may have been dead. Bernard also
excited a copious secretion by galvanization of the pneumogastric, and
by section of the same nerve stopped the process of digestion and
produced "pallor and flaccidity of the stomach." Recently doubt has
been thrown on these statements of Bernard and Frerichs. Goltz
concludes, from observations made on frogs, that nerve-ganglia,
connected by numerous intercommunicating bundles of nerve-fibres, exist
in the walls of the stomach, the irritation of which gives rise to
local contractions and peristaltic movements of the stomach, and that
these ganglia influence the gastric secretion. However this may be, it
still remains true that these gastric ganglia are in connection,
through the vagi, with the medulla oblongata, and are thus influenced
by the cerebro-spinal nerve-centres. And clinical observation confirms
what theoretical considerations would suggest. Thus, strong mental
impressions are known to produce sudden arrest of secretion, and that
which arrests secretion may, if continued, lead to perversion of the
same.
Impressions made upon the nerves of special sense are also known to
affect the salivary and gastric secretions. The flow of saliva is
stimulated by the sight, the smell, the taste, and even thought, of
food. Bidder and Schmidt made interesting experiments on dogs bearing
upon this point. They ascertained by placing meat before dogs that had
been kept fasting that gastric juice was copiously effused into the
stomach. Other secretions are known to be similarly affected. Carpenter
by a series of well-observed cases has shown the direct influence of
mental conditions on the {438} mammary secretion. The nervous
association of diabetes and chronic Bright's disease is interesting in
this connection, and the direct nervous connection betwixt the brain
and the liver has been shown by numerous experiments. It is maintained
by modern physiologists that "the liver--indeed each of the
viscera--has its representative area in the brain, just as much as the
arm or leg is represented in a distant localized area" (Hughlings
Jackson). And in harmony with this view Carpenter long since pointed
out the fact that if the volitional direction of the consciousness to a
part be automatically kept up for a length of time, both the functional
action and the nutrition of the part may suffer. It has been described
by him as expectant attention, and it has, as we shall see, important
practical bearings on the management of gastric affections. Sympathetic
disturbance of the stomach is also connected with direct disease of the
brain. This is seen in cases of concussion. The almost immediate
effects of a blow are nausea and vomiting, and the same thing is
observed in local inflammation of the meninges of the brain.
Many forms of functional dyspepsia due to nervous disturbance of a
reflex character will be pointed out when discussing the etiology of
the disease.
ETIOLOGY.--Among the agencies affecting the digestive process in atonic
forms of dyspepsia may be mentioned--
First, predisposing causes;
Second, exciting causes.
In general terms it may be said that all conditions of depressed
vitality predispose to the varied forms of atonic dyspepsia. These
conditions range through an endless combination of causes, both
predisposing and exciting. There is not a disturbed condition of life,
extrinsic or intrinsic, that may not contribute to this end. In some
cases it may be the effects of hot and enervating climates; in others
the alterations in the elementary constituents of the blood may be
apparent; while in still others the cause may be exhausting discharges,
hemorrhages, profuse suppuration, venereal excesses, sedentary
occupations, and long-continued mental and moral emotions.
Heredity may also predispose to functional dyspepsia. Certain faulty
states of the nervous system are specially liable to be transmitted
from parent to offspring--not always in the exact form in which they
appeared in the parent, but in forms determined by the individual life
of the offspring. For obvious reasons, growing out of our modern
American civilization, the inheritance of a faulty nervous organization
is apt to spend itself upon the digestive apparatus. The inordinate
mental activity, the active competitions of life, the struggle for
existence, the haste to get rich, the disappointments of failure,--all
contribute to this end. The general tendency of American life is also
in the direction of a highly-developed and morbidly sensitive nervous
system, and functional dyspepsia is a natural sequence of this. The
symptoms of dyspepsia thus caused usually manifest themselves at an
early period of life.
Age also predisposes to weak digestion. The stomach becomes weak as age
advances, in common with all the functions of the body, and consequent
upon this weakness there is diminished excitability of the gastric
nerves, with diminished muscular action of the walls of the stomach and
deficient secretion of the gastric juice. Chronic structural changes
are {439} also apt to occur in advanced life. The gastric glands become
atrophied and the arteries become atheromatous, so that with symptoms
of indigestion there are often associated loss of consciousness at
times, vertigo, irregular action of the heart, etc. These general facts
have an important bearing upon the hygienic management of dyspepsia in
the aged. They require, as a rule, less food than the young and
vigorous. In times when famine was more frequent than now it was found
that the older a human being was, the better deficiency of food was
borne. Hippocrates tells us, in his _Aphorisms_, that old men suffer
least from abstinence. Their food should be such, both in quantity and
quality, as the enfeebled stomach can digest. There is less demand for
the materials of growth, and consequently for animal food. Moderate
quantities of alcohol, judiciously used, are also specially adapted to
the indigestion of the aged. It has the double effect of stimulating
the digestive process and at the same time checking the activity of
destructive assimilation, which in old age exhausts the vital force.
And in order to more effectively arrest destructive metamorphosis great
caution should be taken against excessive muscular fatigue, as well as
against sudden extremes of temperature. Loss of appetite from deficient
formation of gastric juice is a common symptom in old age. This is not
often successfully treated by drugs, and yet medicines are not without
value. The sesquicarbonate of ammonium acts as a stimulant to the
mucous membrane and to the vaso-motor nerve, and in this way becomes a
valuable addition to the simple vegetable bitters. Dilute hydrochloric
acid with the vegetable bitters may also be tried. Condiments with the
food directly stimulate the action of the enfeebled stomach. The old
remedy of mustard-seed is not unfrequently useful, and pepper, cayenne,
horseradish, and curries act in a similar manner in torpid digestion.
And in cases of great exhaustion associated with anæmia benefit may be
derived from small doses of iron added to tincture of columbo or
gentian.
Nor should it be forgotten that in the opposite extreme of life the
digestive capacity is extremely limited. The infant's digestion is
readily disturbed by unsuitable alimentation. For obvious reasons it
does not easily digest starchy substances. The diastasic ferment does
not exist in the saliva of young sucking animals, at least to any
extent. No food is so suitable for early infantile life as the mother's
milk, provided the mother herself is healthy. It contains in an easily
digestible form all the constituents necessary to the rapidly-growing
young animal. Van Helmont's substitute of bread boiled in beer and
honey for milk, or Baron Liebig's food for infants, cannot take the
place of nature's type of food, which we find in milk. If a substitute
has to be selected, there is nothing so good as cow's milk diluted with
an equal quantity of soft water, or, what in many cases is better,
barley-water, to which may be added a teaspoonful of powdered sugar of
milk and a pinch of table-salt and phosphate of lime. Lime-water may be
added with advantage. Dilution of alimentary substances is an important
condition of absorption in the infant stomach.
Anæmia is a common predisposing cause of indigestion. Indeed, as a
widely-prevailing pathological condition few causes stand out so
prominent. It affects at once the great nutritive processes, and these
in turn disturb the functional activity of all the organs of the body.
Not only are the gastric and intestinal glands diminished in their
{440} functional activity by impoverished or altered blood, but the
movements of the stomach are retarded by weakened muscular action. It
is impossible to separate altered blood from perverted tissue-structure
and altered secretion. Indigestion produced by anæmia is difficult of
treatment, on account of the complexity of the pathological conditions
usually present, the anæmia itself being generally a secondary
condition. Careful inquiry should be made, therefore, into the probable
cause of the anæmia, and this should, if possible, be removed as an
important part of the treatment of the dyspepsia. Nothing will more
promptly restore the digestive capacity in such cases than good,
healthy, well-oxidized blood. Indeed, healthy blood is a condition
precedent to the normal functional activity of the stomach.
To these general predisposing causes may be added indigestion occurring
in febrile states of the system. The cause here is obvious. In all
general febrile conditions the secretions are markedly disturbed; the
tongue is dry and furred; the urine is scanty; the excretions lessened;
the bowels constipated; and the appetite gone. The nervous system also
participates in the general disturbance. In this condition the gastric
juice is changed both quantitatively and qualitatively, and digestion,
as a consequence, becomes weak and imperfect--a fact that should be
taken into account in regulating the diet of febrile patients. From
mere theoretical considerations there can be no doubt that fever
patients are often overfed. To counteract the relatively increased
tissue-metamorphosis known to exist, and the consequent excessive
waste, forced nutrition is frequently resorted to. Then the traditional
saying of the justly-celebrated Graves, that he fed fevers, has also
rendered popular the practice. Within certain bounds alimentation is
undoubtedly an important part of the treatment of all the essential
forms of fever. But if more food is crowded upon the stomach than can
be digested and assimilated, it merely imposes a burden instead of
supplying a want. The excess of food beyond the digestive capacity
decomposes, giving rise to fetid gases, and often to troublesome
intestinal complications. The true mode of restoring strength in such
cases is to administer only such quantities of food as the patient is
capable of digesting and assimilating. To this end resort has been had
to food in a partially predigested state, such as peptonized milk, milk
gruel, soups, jellies, and beef-tea; and clinical experience has thus
far shown encouraging results from such nutrition in the management of
general fevers. In these febrile conditions, and in all cases of
general debility, the weak digestion does not necessarily involve
positive disease of the stomach, for by regulating the diet according
to the digestive capacity healthy digestion may be obtained for an
indefinite time.
Exhaustion of the nerves of organic life strongly predisposes to the
atonic forms of dyspepsia. We have already seen how markedly the
digestive process is influenced by certain mental states, and it is a
well-recognized fact that the sympathetic system of nerves is
intimately associated with all the vegetative functions of the body.
Without a certain amount of nervous energy derived from this portion of
the nervous system, there is failure of the two most important
conditions of digestion--viz. muscular movements of the stomach and
healthy secretion of gastric juice. This form of indigestion is
peculiar to {441} the ill-fed and badly-nourished. It follows in the
wake of privation and want, and is often seen in the peculiarly
careworn and sallow classes who throng our public dispensaries. In this
dyspepsia of exhaustion the solvent power of the stomach is so
diminished that if food is forced upon the patient it is apt to be
followed by flatulence, headache, uneasy or painful sensations in the
stomach, and sometimes by nausea and diarrhoea. It is best treated by
improving in every possible way the general system of nutrition, and by
adapting the food, both in quantity and quality, to the enfeebled
condition of the digestive powers. Hygienic measures are also of great
importance in the management of this form of dyspepsia, and especially
such as restore the lost energy of the nervous system. If it occur in
badly-nourished persons who take little outdoor exercise, the food
should be adapted to the feeble digestive power. It should consist for
a time largely of milk and eggs, oatmeal, peptonized milk gruels, stale
bread; to which should be added digestible nitrogenous meat diet in
proportion to increased muscular exercise. Systematic outdoor exercise
should be insisted upon as a sine quâ non. Much benefit may be derived
from the employment of electric currents, and hydrotherapy has also
given excellent results. If the indigestion occur in the badly-fed
outdoor day-laborer, his food should be more generous and mixed. It
should consist largely, however, of digestible nitrogenous food, and
meat, par excellence, should be increased in proportion to the exercise
taken. Medicinally, such cases should be treated on general principles.
Benefit may be derived from the mineral acids added to simple bitters,
or in cases of extreme nervous prostration small doses of nux vomica
are a valuable addition to dilute hydrochloric acid. The not unfrequent
resort to phosphorus in such cases is of more than doubtful utility.
Some interesting contributions have been recently made to this subject
of gastric neuroses by Buchard, Sée, and Mathieu. Buchard claims that
atonic dilatation of the stomach is a very frequent result of an
adynamic state of the general system. He compares it to certain forms
of cardiac dilatation--both expressions of myasthenia. It may result
from profound anæmia or from psychical causes. Mathieu regards mental
depression as only second in frequency. Much stress is laid upon
poisons generated by fermenting food in the stomach in such cases. It
may cause a true toxæmia, just as renal diseases give rise to uræmia.
Of course treatment in such cases must be addressed principally to the
general constitution.
But of all predisposing causes of dyspepsia, deficient gastric
secretion, with resulting fermentation of food, is perhaps the most
prevalent. It is true this deficient secretion may be, and often is, a
secondary condition; many causes contribute to its production; but
still, the practical fact remains that the immediate cause of the
indigestion is disproportion between the quantity of gastric juice
secreted and the amount of food taken into the stomach. In all such
cases we have what is popularly known as torpidity of digestion, and
the condition described is that of atony of the stomach. The two main
constituents of gastric juice--namely, acid and pepsin--may be
deficient in quantity or disturbed in their relative proportions. A
certain amount of acid is absolutely essential to the digestive
process, while a small amount of pepsin may be sufficient to digest a
large amount of albuminoid food. {442} Pure unmixed gastric juice was
first analyzed by Bidder and Schmidt. The mean analyses of ten
specimens free from saliva, procured from dogs, gave the following
results:
_Gastric Juice of a Dog_.
Water 973.06
Solids 26.94
Containing--Peptone and pepsin 17.19
Free hydrochloric acid 3.05
Alkaline chlorides 4.26
Ammonium chloride 0.47
Chlorine 5.06
| Lime 1.73
Phosphates | Magnesia 0.23
| Iron 0.08
They proved by the most careful analyses that fresh gastric juice
contains only one mineral acid--namely, hydrochloric; since which time
Richet has been able to prove that "this acid does not exist in a free
state, but in loose combination with an organic substance known as
lucin," the chloride of lucin. And just here the curious and puzzling
question arises as to the secretion of a mineral acid from alkaline
blood. Ewald, the distinguished lecturer in the Royal University of
Berlin, tells us that "a brilliant experiment of Maly's has thrown
unexpected light upon this. There are fluids of alkaline reaction which
may contain two acid and alkaline mutually inoffensive salts, but still
have an alkaline reaction, because the acid reaction is to a certain
extent eclipsed; for instance, a solution of neutral phosphate of soda
(Na_{2}HPO_{4}) and acid phosphate of soda (NaH_{2}PO_{4}) is alkaline.
Such a solution placed in a dialyzer after a short time gives up its
acid salt to the surrounding distilled water, and one has in the
dialyzer an alkaline fluid outside an acid fluid." He thus proved that
the acid phosphate of sodium is present in the blood in spite of its
alkaline reaction.
Lack of the normal amount of the gastric secretion must be met by
restoring the physiological conditions upon which the secretion
depends. In the mean time, hydrochloric and lactic acids may be tried
for the purpose of strengthening the solvent powers of the gastric
secretion.
EXCITING CAUSES.--The immediate causes of dyspepsia are such as act
more directly on the stomach. They embrace all causes which produce
conditions of gastric catarrh, such as excess in eating and drinking,
imperfect mastication and insalivation, the use of indigestible or
unwholesome food and of alcohol, the imperfect arrangement of meals,
over-drugging, etc.