SOME NEW POINTS ON THE/PATHOLOGICAL 
ANATOMY OF TETANUS* 
By R. W. AMIDON, M. D., 
LATE HOUSE PHYSICIAN, NEW YORK HOSPITAL. 
Until within a few years, the pathological anatomy of 
tetanus was involved in the greatest obscurity. 
This did not depend, however, on the lack of post mortem 
examinations, for their records are numerous, but on the 
fact that in so few instances the microscope was used to verify 
gross lesions and to detect minute ones. 
Investigators contented themselves by saying “the nerve 
looked inflamed or the cord congested or softened,” and so, 
wanting sufficient evidence of actual lesions, the profession 
gradually came to look on tetanus as a purely functional 
disease. 
In the year 1804, appeared J. L. Clarke’s report f of the 
microscopic examinations of the spinal cord in two cases of 
tetanus, in which he found changes hitherto unknown. He 
noted a granular exudation in the anterior fissure, general 
dilatation of the blood-vessels and granular matter in the 
perivascular spaces. 
In 1865 appeared a report of four new cases by the same 
ln one of these the medulla oblongata was exam- 
ined and found normal. The lesions were found in the 
* Read before the New York Neurological Society, April 7, 1879. 
f London Lancet, Sept. 3, 1864. 
t Med. C/ur. Trans., London, Vol. XLVIII, p. 255, 1865. 2 
I?. IV. AM IDO M 
spinal cord chiefly in the gray matter. They consisted in 
dilatation of the arteries, hemorrhages, areas of disintegra- 
tion and cavities containing granular fluid, clear colloid ma- 
terial or debris of nerve-tissue. 
In 1868 W. H. Dickinson,* examining the cord of a case 
of traumatic tetanus, found repletion of the blood-vessels, 
extravasations, and structureless, transparent material about 
the blood-vessels and in the nerve-tissue in both gray and 
white matter. This exudation sometimes occupied pre-ex- 
isting cavities and sometimes seemed to have torn the nerve- 
tissue assunder. This substance, he says is stained pink by 
carmine. 
In 1869 Ogle,f in a case of traumatic tetanus, found the 
fissures of the cord, especially the anterior, occupied by an 
exudation. 
In 1871 T. C. Allbutt,;}; in examining the spinal cords of 
four cases, found congestion of the vessels with thickening 
of their walls, large and small hemorrhages, granular exuda- 
tions through the walls of the vessels, stuffing of the central 
canal with epithelium, yellow degeneration of the motor 
cells and spots of granular disintegration in different situa- 
tions. 
In 1871-2 Clarke again comes forward reporting § the 
microscopic examination of two more cases of tetanus. In 
one case there was congestion of the cerebral gray matter. 
There was also a recent, extra-meningeal blood-clot in the 
anterior part of the cervical and dorsal regions, dilatation of 
the blood-vessels, exudation of a homogeneous material, 
chiefly between the posterior cornua, and irregular cavities 
in the medulla oblongata. 
In the second case he found a coagulum surrounding the 
* Mi'il Chir. Trans., London, Vol. LI, p. 265, 1868. 
f British and Foreign Med. Chir. Ben., April, 1869. 
\ Trans. London Path. Soc., Vol. XXII, P- 27, 1871. 
£5 St. (Jeo. Hosp. Reports, Vol. VI, pp. 319 and 336,1871-2. ANATOMY OF TETANUS. 
3 
theca vertebralis in the dorsal and lumbar regions, dilata- 
tion of the blood-vessels and exudation of a transparent, 
homogeneous material. 
In 1872 Michaud * noticed the exudation of plasma from 
the vessels, and an aggregation of nucleated corpuscles in 
both commissures all around the central canal. 
In 1873 Allbutt f in examining the cords of four cases 
found the vessels thickened, distended and plugged, hemor- 
rhages, submeningeal and into the cord, softening of the cord, 
stuffing of the central canal with epithelium, nuclear prolif- 
eration of connective tissue and atrophy of the cells in the 
anterior horns. 
in 1874 announces the finding of congestion of the 
spinal pia mater, some new cellular material on the inner 
surface of the dura mater, colloid degeneration of the 
white and amyloid degeneration of the gray matter of the 
cord. 
In 1875 Richelot,§ quotes Joffroy| as finding in the 
pons, medulla and cord, vascular distention and hemor- 
rhages. 
He quotes Quinquaud as finding vascular distension in 
the floor of the fourth verticlc, oil globules and amyloid 
bodies outside the vessels in the cord. 
Liouville (Soc. Biologic 1869), he quotes as describing the 
lesions in the cervico-dorsal region of the cord, as distension 
and at places, aneurysmal dilatation of the blood-vessels, 
hemorrhages and a granular, pigmented condition of the 
nerve cells; and in the dorsal region a sero-sanguineous 
effusion about the posterior spinal nerve roots. 
* Arch, de Phys., p. 6<<, Jan., 1572. 
f British and Foreign Med. Chir. Rev., April, 1873, p. 383. 
\ Path. Anatomy of the Nervous Centres p. 355. 1874. 
S Richelot, Pathogenic, Marche, Terminaisons du Tetanos. 
|| Soc. de Biol., 1870, Mem. p. 14. 
I' Leclerc, Considerations sur le tetanos traumatique, These de Paris, 1572. 4 
A\ IV. A MID ON. 
Aufrecht * in 1878 found lesions confined chiefly to the 
cervical region of the cord. 
They consisted in hyperasmia, some hyaline exudation 
about the vessels and in the central canal, degeneration and 
atrophy of the cells in both anterior and posterior horns 
and some spots of granular disintegration. 
Woods f in 1878 records the finding of vascular distention, 
mostly about the central canal, round bodies in the perivas- 
cular spaces and granular disintegrations of the posterior 
horns. 
In the medulla oblongata which he examined, he noted 
vascular dilatation about the hypoglossal and pneumogastric 
nuclei and in the floor of the fourth ventricle. 
He also gives a sketch of an enlarged blood-vessel near 
the hypoglossal nucleus. 
It were an injustice, even while confining our attention to 
those authorities who supplemented their investigations by 
microscopic examinations, to pass over in silence the clinico- 
pathological investigations of one of our most original 
men. 
Dr. J. Marion Sims as early as iB4B,§ stated it as 
his conviction that the form of tetanus, known as trismus 
neonatorum, was caused by the pressure of the occiput, de- 
pressed during labor or by dorsal decubitus, on the medulla 
oblongata. This, to his mind, was conclusively proven by 
the results of autopsies, where the occiput was found de- 
pressed, and by the fact that a vast majority of his cases 
were cured by a lateral or facial decubitus alone. 
In locating the seat of the disease in the medulla and 
pons, he by far antedated many of his successors. 
* Deutsche vied. IVoch., Nos. 14 and 15, 1878. Quoted in Am. Jr. Med. 
Set'., July, 1878 ; Br. Med. Jr., May, 1878 ; and Chicago Jr. Men/, and Nerv- 
ous Diseases, Oct., 1878. 
f London Lancet, Sept. 7, 1878, p. 326. 
, \ Am. Jr. Med. Sci , April, 1846. 
§ Am. Jr. Med. Sci., July and October, 1848. ANATOMY OF TETANUS. 
5 
An article by Gowers * deserves notice as demonstrating 
the existence of lesions like those found in tetanus, in the 
medulla and pons of a person dying of the very similar 
disease, hydrophobia. 
Some facts of great importance in further study will strike 
one on looking over the literature of tetanus. While some 
have considered the disease functional and without lesion; 
while others have paid special attention to the condition of 
nerves in and leading from the wound ; while, as most of 
the authors above quoted, others have in the spinal cord 
sought the only lesion ; how few have gone one step 
higher, and in the medulla oblongata and pons varolii 
sought the characteristic lesion ? 
No systematic attempt seems to have been made to re- 
concile the location of the lesions with the prominent symp- 
toms. 
In the typical case followed to a fatal termination, the 
lesions should correspond to the symptoms present before 
death. 
For example, at an autopsy there is found an embolus 
impacted in the left middle cerebral artery, shutting off the 
blood-current from the centre for speech, and the motor 
centre for the right side of the face and body. On ascer- 
taining the history of the case, it is found the patient was 
suddenly seized with right hemiplegia and aphasia. 
Here the location of the lesion explains fully the symp- 
toms. 
The lesions of tetanus, however, have never been made to 
harmonize with the symptoms. 
To the end of making clearer, this part especially, of the 
pathological anatomy of tetanus, the following case f is pre- 
sented without further preface. 
* Trans. Lond. Path. Soc., 1877. 
f The case was under the care <>f Dr. T. M. Markoe in the New York Hos- 
pital, and is used with his permission. 6 
R. JV. A MID ON. 
Bertha 8., aged 15 years, domestic, German. About 5 p.m., 
June 30, 1877, patient fell two stories, receiving a contused and 
lacerated wound 5 cm. long, extending transversely across the palm- 
surface of the right wrist. Through this wound protruded the 
lower extremity of the upper fragment of the fractured radius. 
1 here was also a slight contusion of the right ankle and back. 
On admission there was considerable pain, hemorrhage and 
shock. 
Reduction of the protruding radius was attempted, under ether 
without avail. 
July Ist .—The patient complains of great pain in the arm, which 
is subdued by morphia administered hypodermically. 
July 2d. Under ether, the protruding bone was cut off and re- 
duction accomplished. The soft parts about and in the wound 
were in a gangrenous state. 
July 3d.—Pulse, 88 ; temperature (axillary), 38.9° C., (102° F.). 
July sth.—At 10 A.M., trismus set in. The teeth at times very 
firmly clinched, often biting the tongue. At 3 p.m., temperature 
in axilla, 39. (103.i° F.). 5.30 p.m., temperature in axilla 
4°-5° C., (104.9° F.). 5.30 p.m., temperature on right cheek, 39.0° 
C., (102.2 F.). About this time the patient complained of pain 
and stiffness in the back of the neck, thirst and fever, and was 
very desirous of being fanned. Dysphagia or difficulty in swallow- 
lowing now began to manifest itself, and tonic spasms of the sterno- 
mastoid and trapezius muscles. 
A short time after the “ Hsus sardonicus ” set in. In this case 
there was no elevation or depression of the angles of the mouth 
giving the face a smiling or forbidding look, but there was simply 
a retraction of the angles of the mouth with some separation of 
the lips so as to show the teeth. 
7.30 p.m., the patient’s cheeks are very red and hot, her face is 
covered with large drops of perspiration. She is still perfectly 
conscious and complains of heat and pain. She asked to have the 
wooden wedge, put between the teeth to prevent biting the tonmie 
removed. ’ 
Respiration was now hurried, the alnse nasi rose and fell, the 
inspiratory movements were labored and often interrupted by 
a spasm of the glottis causing impending suffocation. The pulse 
was rapid and regular, and the extremities cool, 
8 p.m., the struggle for breath ceased. The respiration assumed 
a Cheyne-Stokes character, /. intervals of complete absence of 
respiratory movements alternated with about equal periods of ANATOMY OF TETANUS. 
7 
more or less normal respiration. The apnoeic periods became 
longer, the consciousness was lost, the cheeks paled, the eyes fixed, 
the jaw fell, the spasms relaxed, and at 8.15 p.m., death ensued. 
Temperature 5 min. later in the axilla being 43.30 C., (no° F.), 
and on the surface of the abdomen 40.50 C., (105° F.). 
AUTOPSY 13 HOURS AFTER DEATH. 
Temperature in axilla 33.50 C, (92.3° F.), and on abdomen 
31.250 C, (88° F.). 
The rigor mortis was wanting in the parts tetanized be- 
fore death. 
The cerebral sinuses were filled with blood. 
The brain was superficially finely injected on the superior 
surface of the occipital lobes. There was a vertebral artery 
only on the left side. 
The lungs were oedematous. 
Thin, semi-organized clots were adherent to the mitral and 
tricuspid valves. 
The spleen was enlarged and softened. An examination 
of the right forearm showed rupture of the tendons of the 
palmaris longus and the outer part of the flexor carpi ulnaris, 
while some of the deep and superficial flexor tendons were 
partly ruptured. 
The median nerve was stretched and contused, and was of 
a green color. There was partial rupture of the internal 
lateral ligament of the wrist-joint tearing off the styloid pro- 
cess of the ulna. There was a “ green stick ” fracture of the 
ulna about 5 cm. above its lower extremity and a compound 
fracture of the radius about 2 cm. from its lower articular 
surface. 
A great many signs of blood poisoning were found in the 
organs which are not mentioned. 
The pons, medulla oblongata and upper cervical cord, 
together with the right median nerve were removed and put 
in Muller’s fluid for preservation and hardening. 8 
D. W. A MID ON. 
For the detection of lesions, the pons, medulla and cord 
having been hardened in Mailer’s fluid and alcohol, were 
placed in a microtome, and horizontal transverse sections 
made at short distances all the way from the upper part of 
the cervical enlargement of the cord to the upper border of 
the pons. These sections stained by carmine and put 
through Clarke’s process, i. e., absolute alcohol and oil of 
cloves, were mounted in Canada balsam. 
In studying the present case, it will be well to take up 
first the general lesions and their nature, and then go on to 
a more minute study of the location and significance of these 
lesions. 
In examining the sections, the first deviation from the 
normal structure was noticed in the pia mater. It was 
thickened and vascular. On its free surface there was a con- 
siderable recent exudation product, composed of fibrine and 
cells, and everywhere in its meshes, especially around the 
blood-vessels, there were a great number of very large cells, 
(see Fig. 2), some fusiform and some multipolar, very 
coarsely granular, pigmented and with large oval nuclei. 
These cells are still better brought out by teasing a little 
pia mater when they appear as dark, granular, spindle-shaped 
cells, some 1 mm. long, whose large oval nucleus without a 
nucleolus appears like a vacuole. (See Fig. 3). 
Carmine did not affect these cells at all. 
The next lesions found were hyperaemia and thrombosis. 
In many places the larger vessels seemed filled to repletion, 
(see Fig. 5), while at some points arteries, veins and capil- 
laries were so universally over-distended with blood ele- 
ments, as to suggest the possibility of an embolic or throm- 
botic process. (See Fig. 5). The vessel walls did not 
seem, as some have described them, thickened, but on the 
other hand thinned, from continued over-distention. 
There was seen at certain spots enormous dilatation of the ANA TOM Y OF TE TAN US. 
9 
perivascular spaces, some of which were partly filled by a 
small-celled, granular exudation from the vessel, to whose 
adventit ia it was greatly adherent. The walls of these spaces 
presented a dense infiltrated margin. (See Fig, 5). 
The next lesion consisted in cavities of various sizes in 
the nerve matter, some empty, others filled by a trans- 
parent, colloid material containing some small granules, 
but no cells or nerve debris. The small empty cavities may 
have been perivascular spaces from which the contained 
vessel had dropped out, but to the walls of the larger ones 
might be seen still adherent, some of the colloid material. 
The walls of these cavities have an organized look, not a 
ragged disintegrated edge. (See Fig. 4). 
The connective-tissue bands were enlarged, and the in- 
crease in the number of fixed connective-tissue cells was 
shown by the nuclear proliferation. 
The central canal of the cord was choked with desquam- 
mated epithelium, and there was a granular degeneration of 
some nerve cells. 
The first three sets of lesion named will be designated the 
meningeal, vascular and cavernous, respectively. Having 
enumerated in general the lesions found in the present case, 
it will be seen that few of them present the charm of novelty, 
but it will be the aim of the present paper to elicit some 
new facts as to the hitherto unknown location of the al- 
ready known lesions. 
The sections are now taken in order from below upwards, 
and the character and distribution of the lesions will be more 
minutely studied. The meningeal lesion is confined to the 
upper part of the cervical cord, ceasing at the lower part of 
the medulla. 
It is especially manifested about the nerve roots, both 
anterior, posterior, (see Fig. 2), and spinal accessory. 
In some places the inflamed membrane surrounds and A\ IV. AM WON. 
seems to constrict the roots as they emerge, and in others 
the new cells have pierced the nerve-bundle. 
In sections of the upper cervical cord, few lesions but 
those of the pia mater were seen. On closer inspection how- 
ever, changes in the nerve-tissue were noticed which will be 
better understood by a brief demonstration of the parts. 
The only respect in which they materially differ from the 
spinal cord lower down, is this: Nerve fibres are seen curv- 
ing back from the motor cells of the anterior horns, which, 
joined by fibres emerging from the central gray matter, pass 
fiom the gray matter to a point midway between the ante- 
rior and posterior horns. (See Fig. 7). 
I fere also are seen longitudinal bundles of fibres coming 
from cells lower down, and from time to time curving over 
(see Fig. 6), and passing obliquely through the lateral 
columns to emerge a little nearer the posterior than the 
anterior roots. (See Fig. 7). 
This is the first appearance of the spinal accessory root 
fibres. 
In the central gray matter, from which so many fibres 
come, existed all along engorged blood-vessels, enlarged 
perivascular spaces, with exudation and vacuoles. (See 
Fig. 8). 
A peculiarity worthy of note existed in the central gray 
matter here. In sections all along here for several milli- 
metres there existed, very near the central canal of the cord, 
an enlarged perivascular space containing a large artery and 
vein, and several small vessels. 
The artery was empty, the vein distended with blood- 
corpuscles, and around and between all there was in the 
perivascular space, a coarsely granular material holding in 
its substance some small cells, (probably white blood-corpu- 
sclesj, and quite a number of the large black cells above de- 
scribed, as existing in such quantities in the pia mater. Their ANATOMY OF TETANUS. 
11 
relations to the blood-vessels are thus pretty clearly set forth 
for they are not seen in the fissures, where the pia mater ex- 
tends without large blood-vessels. 
The central gray matter around the enlarged perivascular 
space and also around the central canal, (the lumen of which 
was occluded), was thickened and infiltrated with granular 
matter, (See Fig. 8). 
Among the ascending bundles of the accessory root-fibres 
existed also the same lesions here and there. The fibres 
traversing the lateral columns were also accompanied for 
long distances, and crossed here and there by stuffed blood- 
vessels, enlarged perivascular spaces and cell exudations. 
These lesions, of themselves, would be of little moment 
did they appear elsewhere in the section, but the fact of their 
being almost exclusively confined to the spinal accessory 
tract, renders them objects of suspicion. (See dotted line 
Fig- ;)• 
The inflamed pia mater affects, as was before stated, the 
spinal accessory as well as the other nerve-roots. 
In sections higher up in the decussation of the pyramids 
there is quite general distention of blood-vessels, but the 
gross vascular lesions and vacuoles are almost exclusively 
confined to the spinal accessory tract. Here and lower 
down the central canal is filled with desquammated epithelium 
and the gray matter around it has a dense, granular look. 
The next group of sections show the central canal just 
opening out into the fourth ventricle. 
There was- seen in the origin and course of the hypoglossal 
nerve very marked vascular lesions, (see Fig. 9), and, in 
its course through the olivary bodies, large vacuoles and 
areas of disintegration. 
In the origin and course of the vagus numerous small 
vascular lesions exist, but no changes of magnitude. 
In sections higher up when the glosso-pharyngeal and 12 
R. IV. A MID ON. 
higher still, the auditory nerves occupy the posterior and 
lateral regions of the medulla, occupied lower down by the 
vagus, the lesions were chiefly confined to the hypoglossal 
tract, whose long nucleus traverses the whole of this space. 
In the course of its fibres through the olivary bodies, the 
lesions were of more magnitude and consisted of immense 
perivascular spaces and large vacuoles. 
In the glosso-pharyngeal tract the minor vascular lesions 
were quite abundant, as they were also in the lower facial 
nucleus. Higher than this, at the lower margin of the pons, 
in sections bringing the common nucleus of the abducens 
and facial into view, very few lesions are detected and these 
are of a vascular nature. 
In these sections, the commencement of the motor nucleus 
of the fifth nerve comes into view. 
No marked lesion exists here except a rather granular 
condition of the large motor cells forming the nucleus. 
Higher than this, sections begin to disclose more serious 
lesions. 
In the ascending branch of the fifth pair, there are few 
lesions except occasional over-distension of the blood-vessels 
and a few small areas of disintegration. In the course of 
the descending branch, and among the bladder-shaped cells 
from which it arises, many vacuoles appear. 
In the locus cseruleus many excavations appear among 
the large, pigmented cells, and also where these cells merge 
by losing their pigment and acquiring processes, into the 
motoi nucleus of the fifth, occupying an anterior position. 
In the couise of these fibies emerging from and crossing 
the raphe fiom the opposite locus cmruleus, large vascular 
lesions exist. (See Fig 5). 
Having passed the nucleus of the sixth and seventh sec- 
tions begin to disclose more serious lesions. In the lower 
region of the trigeminus there begin to appear here and ANA TOM V OF TE TA N US. 
13 
there small and large cavities Riled with a clear, colloid 
material. (Figs. 4 and 1). 
These are visible to the naked eye, occupy the central 
motor region of the pons, and increase in number and size 
till the region of the fifth nerve is reached. They were over 
twenty in number, one of them being 5 mm. in its longer 
diameter. 
This large vacuole lay in close proximity to the root of 
the fifth, as it passed from its nucleus forwards through the 
pons and still nearer the motor nucleus of the fifth. 
Many of these large vacuoles lay just in front of, and some 
in the region of the pons occupied by the motor nucleus, 
and the scattered large cells giving origin to the motor root 
of the fifth. 
These cavities were formed between the transverse bands 
(arciform fibres) which pass from the raphe outward, and did 
not destroy them, but put them on the stretch. 
It is in these bands also, that the nuclear proliferation of 
the connective-tissue is most distinctly shown. 
The raphe, too, here presents gross lesions chiefly of a 
vascular nature. 
Higher in the pons the lesions were, vacuoles in the 
motor tract not going far enough back to implicate the 
nuclei of the third and fourth nerves, which were perfectly 
normal. 
To summarize then, lesions of various magnitude and 
nature have been found in the tracts occupied by the tri- 
geminus, part of the facial, spinal accessory and hypoglossal, 
while slight departures from the normal structure appear in 
the glosso-pharyngeal and pneumogastric tracts. 
These lesions were, let it be understood, of a peculiar 
nature. 
Take for example the lesions found in the whole hypo- 
glossal tract. At no one point do we find the whole or a 14 
D. W. A MID ON. 
large part of the nucleus destroyed, or the course of a great 
number of fibres interrupted, but throughout the entire tract 
we find lesions varying in severity from simple vascular en- 
gorgement, to areas of disintegration and vacuoles. These, 
moreover, are scattered here and there among the cells of 
the nucleus, (see Fig. 9), and along and across the 
course of the fibres, not causing the destruction of much 
nerve-tissue, but yet, by their topographical distribution and 
their proximity to important parts, rendered objects of sus- 
picion. 
With one exception the gross lesions were confined to the 
motor nerves. In the origin and course of the sensory root 
of the trigeminus many severe lesions were found. 
The lesions are, moreover, of such a nature and distribu- 
tion, that an excitation not an abolition of the functions of 
a nerve would most likely ensue. 
Let it now be seen how far a correlation of lesions and 
symptoms will carry out this supposition. 
In the first place the inflamed pia mater, surrounding the 
cord and including the anterior, posterior and spinal acces- 
sory nerve-roots, claims the attention. 
Looking over the symptoms in the present case, those, 
which will strike the reader as possibly caused by this 
are pain and stiffness in the back of the neck, and as these 
are put down in all text-books as symptoms of cervical 
spinal meningitis, they can plainly be attributed in this case 
to the meningeal lesions above mentioned. 
In the second place there have been demonstrated vascular 
and cavernous lesions in the whole spinal accessory tract 
and also inflamed pia mater about the spinal accessory roots. 
The spinal accessory is a motor nerve. It innervates in 
whole or in part the constrictors of the pharynx, (through 
the glosso-pharyngeal and pneumogastric), the muscles of 
the larynx (through the pneumogastric), and, in conjunction ANATOMY OF TETANUS. 
15 
with the cervical nerves, the sterno-rnastoid and trapezius. 
The irritation of its centre and roots might be supposed 
to give rise to signs of irritation at its peripheral distribution. 
What is there among the symptoms to point to this? On 
looking them over there are seen dysphagia, spasm of the 
sterno-mastoid and trapezius, and spasm of the glottis. 
Dysphagia is due largely to spasm of the constrictors of 
the pharynx, while the other two are due to spasm of muscles 
almost wholly under spinal accessory control. 
The unimportant lesions described as occurring in the 
pneumogastric and glosso-pharyngeal tracts may also have 
played a reflex part in the causation of spasm of the glottis 
and dysphagia. 
In the third place the excited state of the hypoglossal 
nerve must find some outward manifestation. 
It too, is a motor nerve, and besides the lingual, supplies 
other muscles brought into play in the first act of delutition. 
The spasmodic action of these, too, finds its manifestation 
in the dysphagia. 
The lesions in the lower facial nucleus now demand atten- 
tion. 
1 here is a well-known disease called labio-glosso-pharyn- 
goal paralysis. In this disease there is developed, some- 
times suddenly, more often slowly, paralysis of the muscles 
of the mouth, tongue and pharynx causing impaired articu- 
lation, and imperfect or impossible deglutition. 
In this disease the lesion is found in that part of the me- 
dulla containing the hypoglossal, glosso-pharyngeal and 
lower facial nuclei. 
The position of this lesion has led many observers to con- 
sider this nucleus the centre for the muscles of the mouth, 
which are the only facial muscles implicated in this disease. 
Reasoning thus, and finding this nucleus and not the 
upper, the seat of lesion in the present case, one is not sur- A\ IV. AMIDON. 
prised to find the muscles about the mouth in a state of ex- 
citement giving rise to the “ risus sardonicus." 
The gross and minute lesions found in the pons are such 
as, by their direct action through the motor tract, and indi- 
rectly through the sensory origin of the fifth pair, would 
tend to keep that nerve in a state of perpetual excite- 
ment. 
This excited state would be outwardly manifested by 
spasm of the muscles of mastication (temporals, pterygoids 
and masseters), and in this we see the trismus or lockjaw, 
the constant, and hitherto unexplained symptom of 
tetanus. 
How much the implication of the respiratory centre in 
the medulla may have had to do with the Cheyne-Stokes’ 
respiration is doubtful. 
This peculiar breathing, although usually attributed to 
irritation or paresis of the respiratory centre in the medulla, 
may also be caused by peripheral irritation or impediment 
which occurred in this case in the form of oedema of the 
lungs. 
The part which the irritated general vaso-motor centre in 
the medulla played in the causation of the fever is hard to 
say, but in it the septicaemic condition, present in this case, 
undoubtedly had its share. 
The field, tempting in the extreme, of pathogeny and 
pathological physiology beckons the investigator on ; but 
the task of the present paper is ended. 
The character and location of the lesions in the present 
case have been pointed out. 
An attempt has been made (how successfully the reader 
may judge) to find the outward expression of each lesion in 
a symptom, thus making the case typical. 
It is earnestly hoped that this method may be more gen- 
erally adopted, particular attention being paid by subse- ANATOMY OF TETANUS. 
quent investigators to the medulla oblongata and pons 
varolii. 
In closing, let an answer be given to those who will say, 
“If such lesions exist in every case, how is it that some re- 
cover ? ” The writer does not think that in non-fatal cases 
lesions as gross as occurred in the present case existed, but 
that in them the pathological change stopped one step short 
of the formation of large exudations and cavities, and was 
limited to vascular engorgements, perivascular dilatations and 
exudations, which, by their topographical distribution, were 
all-sufficient to cause the irritative symptoms occurring in 
cases of tetanus where recovery supervenes. 
EXPLANATION OF PLATE. 
Fig. i. Transverse section of the pons varolii above the point 
of emergence of the trigeminus, and below the nuclei of the third 
and fourth nerves. 
Showing the size and position of the vacuoles. 
Semi-diagrammatic. Enlarged 2 diameters. 
Fig. 2. From transverse section of upper cord. P. c. = Posterior 
column next the posterior root P. r. P. h.=tip of posterior horn 
of gray matter. L. c.=lateral column. P. m. = Pia mater with new 
material on its surface and new cells in its meshes, 120 diam. 
Fig. 3. Granular, pigmented connective-tissue cells teased out 
of pia mater, more highly magnified, 750 diam. 
Fig. 4. Cavity in the motor tract of the pons between the arci- 
form fibres, a. f., and filled with slightly granular, colloid material, 
120 diam. 
Fig. 5. Enlarged perivascular space with oblique section of 
enclosed blood-vessels. 'Phis lesion existed in the floor of the 
fourth ventricle where sensory fibres of fifth pair pass across raphe, 
(200 diam.). 
Fig. 6. Enlarged from Fig. 7. A. h. = Ant. horn. P. h. = Post. 
horn. C. c. = Central canal. S. a. r. = Spinal accessory root, (120 
diam.). 
7- Transverse section of upper cervical cord. Showing 
A. c. = Anterior columns ; L. c. Lateral columns, P. c. = Pos- 
terior columns. Spinal accessory tract enclosed in dotted lines. 
S. a. r. = Spinal accessory root, 10 diams. R. W. AM WON. 
Fig. 8. Trans, sect, central gray substance of upper cervical 
cord. C. c. = Central canal. A. f. = Anterior fissure. P. f. = Pos- 
terior fissure. A. c. = Anterior gray commissure. P. c. = Posterior 
gray commissure. A. h. = Anterior horn. P. h. = Posterior horn. 
C.= Enlarged perivascular space containing A.= Empty artery ; 
V.== Engorged vein. Also other small vessels and large pigmented 
cells, same as in Figs. 2 and 3. 
Fig. 9. Section of hypoglossal nucleus, H. n., low down. 
C. c.= Central canal. H. r.=Hypoglossal roots. R.=Raphe. 
B. v.—Stuffed blood-vessel and enlarged perivascular space in 
hypoglossal nucleus, crossing and accompanying the root-fibres. 
C.