We employ the term simple goiter to designate chronic enlargement of
the thyroid gland not due to inflammation, exophthalmic goiter, or
malignancy, although the latter conditions are frequently associated
with or follow the former. There is usually an enlargement of the gland
in cretinism, and occasionally in myxedema, but the functional grade of
the gland is far different from that in other diseases of the thyroid.
The disease is very prevalent in certain regions of Europe and
Asia, although in the United States it is not so common, except
in the environs of the Great Lakes, the District of Columbia, and
the Northwest states. The second decade of life, probably owing to
adolescent changes, especially in girls, develop the greater number of
goiters. It is infrequently congenital, and occasionally a case will
develop as early as four or five years of age.
=Etiology.=—Disturbed innervation of the gland unquestionably seems
to be the predisposing cause of the deranged secretion and vascular
changes, which if continued finally lead to hypertrophy and hyperplasia
of the tissues. These lesions are found from the fifth dorsal to the
occiput and to the corresponding ribs. They probably involve secretory
fibers of the sympathetic that emerge from the upper dorsals, first to
fifth inclusive, maximum effect second, third and fourth. “Evidence is
presented that the impulses pass to outlying neurones whose cell bodies
are located close below the superior cervical ganglion and also in the
inferior cervical ganglion.”[107]. In both these ganglia impulses to
the thyroid pass from preganglionic fibers to the outlying neurones.
This also includes the area of vasomotor[108] innervation of the head
and neck.
In a number of cases cervical lesions alone will disturb the thyroid
innervation, especially from the second to fourth segments. These may
involve the superior cervical sympathetic, owing to its relationship
to the rectus capitis anticus major muscle. Then there are afferent
association fibers that pass down through the lateral horns and whose
connecting fibers emerge via the upper dorsal.
The lymphatic drainage of the thyroid should not be neglected.
Lesions of the upper ribs and clavicles are very prone to impede its
circulation, and thus predispose to secondary infections.
Infection from septic foci are important secondary factors. This is
particularly true of focal infections of the upper respiratory tract
and buccal cavity, although infections and toxins from various regions
may be exciting factors. Toxemia due to intestinal stasis is not rarely
an important consideration.
McCarrison insists that infection from certain waters is the cause of
goiter. He finds that boiling the water renders it harmless.
=Pathologically=, the first effect upon the gland is to lessen its
iodine content. The circulation is increased, with hyperplasia of
the epithelial tissue, and a lessened amount of colloid material.
If the condition continues, the alveoli will again become distended
with the colloid material so that the epithelial tissue cells are
almost flattened. This represents the so-termed =colloid goiter=. The
gland, commonly the whole organ, though one side may be involved, is
fairly uniform in size. In rare instances, the gland may surround the
trachea—the so-termed circular goiter. Hemorrhages may occur, and there
may be various alterations and degenerations. When the vessels are
much dilated, it is often called a vascular goiter, though the colloid
changes are present.
The =nodular goiter= is another form characterized by new formation of
gland tissue that is not diffuse but circumscribed. These cases are apt
to follow persistent involvement of the gland at puberty. The two forms
may occur together, and there may be various combinations and changes.
In the nodular goiter there is comparatively little colloid. There are
many blood-vessels, and small hemorrhages are frequent. This latter
point should be remembered by those who treat over the gland, which at
best is a doubtful procedure. Various changes may take place, as local
points of =necrosis=, =cystic= formation, and =calcification=, are not
uncommon.
=Symptoms.=—The essential feature in goiter is distension of the
alveoli and formation of new ones, associated with dilated vessels, and
usually degeneration of the colloid. Often the function of the gland
is not noticeably disturbed. Usually, it is for the pressure symptoms
or the unsightliness, due to the distension, that the patient seeks
relief. Pressure upon the windpipe, gullet, or blood-vessels is not
rare, and may cause more or less difficulty in breathing or swallowing.
Coughing and huskiness may be troublesome. The recurrent nerves and
vagus may be compressed. Disturbance of the heart, such as palpitation,
tachycardia, and hypertrophy may be caused by the effect of pressure
upon the blood-vessels, or to changes in the secretory function of the
gland.
=Treatment.=—Adjustment of the upper dorsal and cervical lesions will
be followed by recovery in the majority of cases. Dr. Still emphasized
the point that the vertebral ends of the first ribs are frequently
displaced upward and outward. This lesion is often found in cases
following confinement. The effect of the change here is probably to the
stellate ganglion, or to the lymphatic drainage of the gland. Treatment
over the gland should be cautiously given, if at all. Definite
correction of the lesioned vertebræ and ribs will be sufficient, but
muscular manipulation and halfway measures are practically useless.
Lesions of the lower spine may be the primary source of a compensatory
lesion of the upper dorsal, or they may derange the pelvic organs, or
be the predisposing factor of intestinal stasis. Attention to possible
focal infections, and thorough elimination, are to be considered. In
goitrous regions boiling the water is of value. In obstinate cases the
X-ray may be of service, and as a final resort surgery may be employed.
“Marine observed that the amount of iodine is inversely proportional
to the degree of hyperplasia of the gland, and when the hyperplastic
condition becomes fully developed, scarcely a trace of iodine is
contained in the gland. Later, when the hyperplasia gives place
to colloid goiter, the iodine increases again, both absolutely and
relatively. Moreover, it has been found that if iodine be administered
to an animal suffering from hyperplasia, the hyperplastic condition
very quickly disappears and the animal becomes normal.”[109]. His
viewpoint of the hyperplasia is that an effort is being made to
compensate for an “insufficiency due to inability to absorb or
assimilate sufficient iodine”, and thus the effect of the administered
iodine is to normalize the gland by stimulation.
No one can question that this may be effective under certain
conditions, particularly where there is deficient iodide in the water,
but it is an essential element of the body. But it does not necessarily
follow that because in thyroid disturbance the relationship between
thyroid functioning and the substance containing iodine is upset that
recovery depends upon furnishing more iodine to the body economy. It
may be somewhat parallel to giving iron in anemia, when often the
real difficulty is one of assimilation, and not insufficient iron
in the alimentary canal. Moreover, case after case of goiter has
recovered through osteopathic measures following a most thorough trial
of the iodine treatment. It is very obvious that the cause of the
goiter rested elsewhere. Dogs are susceptible to thyroid enlargement.
Lesioning of the cervical region has resulted in goiter formation,
and recovery has followed adjustment of the lesion. And dogs having
goiter without experimental lesions have frequently been normalized by
adjusting an abnormal cervical spine.