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and, unhke the subject of true bulbar paralysis, he is generally
somewhat deficient mentally. There is usually a history of
successive (more rarely of simultaneous) attacks of hemiplegia
on opposite sides of the body.

Bilateral athetosis is a disease which is usually congenital, although
the symptoms do not necessarily appear at birth, but may begin
in childhood or even in adolescent life. The disease gradually
increases in severity. It is characterised by wild wriggHng and
twisting movements of all the limbs, chiefly on attempted voluntary
movements (but sometimes spontaneously, when no effort is being
made), and by grimacing of the face, together with spastic rigidity
of the affected muscles (see Figs. 54 and 55). There is generally
a certain degree of mental deficiency. The pyramidal tracts are
not necessarily affected, and the plantar reflexes are usually of the
normal flexor type. In this disease articulation is often affected.
The grimaces of the face and of the tongue muscles interfere con-
siderably with articulation. Moreover, irregular spasmodic con-
tractions of the diaphragm and other respiratory muscles give
the voice a curiously jerky or groaning character, due to sudden
interruptions of breathing.

^ Mingazzini, Sulla sintomatologia delle lesione del nucleo lenticolare, 1902.
2 Wilson, " Progressive Lenticular Degeneration," Brain, 1912.



124



NERVOUS DISEASES



Patients suffering from disseminated sclerosis frequently liave
a peculiar so-called " staccato " speech, in which, the words are
enunciated in a jerky mincing fashion, very difl6.cult to describe,
but easy to recognise once it has been heard. This is sometimes
called the " scanning " speech, from its fancied resemblance to
the scansion of Latin or Greek verse.

In paralysis agitans, as the disease advances, the patient's
voice becomes thin, feeble and reduced almost to a monotone,





Fig. 54.



Fia. 55.



Figs. 54 and 55.
months' child.



—Double athetosis in a girl of 17. The patient was a 7^
She had also signs of stenosis of the pulmonary artery.



whilst his articulation, hke his gait, acquires a " festinant " char-
acter. When speaking, he begins slowly, but towards the ends
of sentences or long words he tends to hurry, so that the final
syllables are pronounced hastily. Together with this we have the
characteristic " starched," expressionless face, the Parkinsonian
mask, commencing unilaterally and ultimately becoming bilateral.

In severe cases of chorea the articulation may be interfered
with, owing to sudden violent movements of the face, tongue, and
respiratory muscles. Speech becomes hesitating and jerky, and
in very bad cases the voice may be reduced to a whisper.

There are also affections of articulation due to functional
cortical disturbances. Of these the most familiar is stammering,



DISORDERS OF ARTICULATION 125

commonest in individuals who, whilst usually above the average
intelligence, have a congenital psychasthenic tendency. Stanmaer-
ing consists in a want of co-ordination between the vocal
(laryngeal) and consonantal (oral) mechanisms of speech, so that,
in the common type, the patient sticks at a consonant, which he
often continues to repeat, over and over again, before he finally
succeeds in. enunciating the rest of the word. He misdirects
his energy on the consonants, instead of touching them hghtly
and passing on to the vowel sounds. Most stammerers lose their
stammer when they sing, their attention being then directed to
the vocal part of speech. The vast majority of stammerers are
males.

A rarer variety of stammering is that in which the patient sticks
at initial vowels. This is due to temporary spasm of the false
vocal cords, and the patient remains with his mouth wide open
until the spasm relaxes, when his words suddenly rush forth in a
hurried stream until he has no breath left. He then takes another
breath and the precipitate rush again occurs.^

Many stammerers acquire various tricks, chiefly through their
efforts to overcome the stammer. Thus extra noises may be thrown
in, e.g. sudden inspiratory grunting or whooping noises, or the
patient may make grimaces or curious contortions of the limbs.

This leads us to recall the various articulation tics or habit-spasms
which are met with in psychasthenic patients, either in conjunction
with stammering or independently of it, and these may be of the
most varied character. The patient's speech may be interrupted
by weird pharyngeal barking or grunting noises. Or the articulation
may be monosyllabic, a whole breath being taken for each syllable.
Or, again, it may be jumbled up in the most extraordinary ways,
though the " tiqueur " usually interpolates, now and then, a
clearly articulated sentence or phrase amongst other uninteUigible
ones. Hysterical aphonia is fairly common, and can usually be
recognised by the history, together with the characteristic laryngeal
appearances. We also meet with cases of hysterical mutism, in
which the patient does not utter even a whispered word.

^ Cathcart has pointed out that this variety of stammering is described
in Shakespeare's As You Like It (Act iii. Scene 2) as follows: —

" I would thou couldst stammer, that thou mightst pour out this con-
cealed man out of thy mouth, as wine comes out of a narrow-necked bottle,
either too much at once, or none at all. I prithee, take the cork out of thy
mouth that I may drink thy tidings."



126 NERVOUS DISEASES

Deaf-mutes are the patients wlio are popularly known as
" deaf and dumb." A normal child learns to speak by imitating
words which he hears, but if a child be congenitally deaf, he
does not learn to speak, but remains deaf and dumb. Moreover,
if he is born with normal hearing, but subsequently becomes
deaf, e.g. from middle ear disease or from meningitis, before
the age of about six years, he usually loses his power of speech.
Such deaf-mutes can generally be taught to speak again by
the oral or " lip-reading " method, where the child imitates the
movements of his teacher's muscles of articulation and also learns
to phonate, though usually with a harsh, discordant voice. But
even deaf-mutes who have never been taught to speak usually
make noises of some sort or other, often pharyngeal snorts and
grunts, or spluttering labial noises, and less frequently laryngeal
sounds. They do this especially when excited. This was the case
with a deaf-mute who used to make weird snorting noises when
playing football. These doubtless helped to smite terror into the
hearts of the opposite side. The congenital deaf-mute is usually
brighter and more clever than the deaf-mute whose deafness was
acquired. Deaf-mutes generally have a wonderful command of
gestures and signs.

Deaf-mutism constitutes a common variety of war-neurosis
after shell-explosions. The soldier is flung to the ground, or
perhaps even partially buried, by a bursting shell, and may be
rendered unconscious, although this latter is not essential. He
immediately finds himself mute or deaf-mute. A considerable
proportion of such patients can be rapidly cured by suggestion,
sometimes aided by the administration of a general anaesthetic.

The dumbness which is present in profound degrees of idiocy
is not an articulative difficulty, but a true speech affection due
to mal-development of the cortical speech-centres. An imbecile
child is speechless because he has no ideas to express ; in this
respect he differs from the deaf-mute, who is often bright and
intelligent.

Certain varieties of deficient articulation are met with in
children or in adults who are mentally more or less childish. The
condition known as lalling consists m a want of precision in the
pronunciation of certain consonants. Thus a patient may substitute
the uvular R for the ordinary linguo -palatal R., or he may sub-
stitute V for Th or W for R, so that " broken reed " becomes



DISORDERS OF ARTICULATION 127

" bwoken weed." Or, again, the patient may substitute Th for S
and is then said to lisp. These last two varieties are sometimes
voluntarily assumed, as a fashionable affectation, by young men
not overburdened with brain power. More serious varieties of lalling
are where the letter L is replaced by some other consonant, so
that " elephant " may be pronounced as " edephant," " esephant,"
" enephant," " erephant," &c. Still worse is it when the patient
has difficulty with K or G, their places being taken by T and D
respectively.

As a general rule, it may be stated that lalhng on a single
consonant does not necessarily indicate defective intellect, whereas
lalling on many consonants, if the patient has passed the age
of childhood, should arouse the suspicion of mental deficiency,
although lalHng is a normal stage in the process of learning to
speak.

Finally, there is the condition known as idioglossia, in which
from difficulty in pronouncing his consonants a child retains the
correct vowels, but substitutes other consonants and seems to
speak a new language of his own. The child is usually mentally
bright and understands all that is said to him. He talks volubly
but unintelhgibly. As a rule he completely outgrows the weak-
ness in course of time.



CHAPTER IX

CRANIAL NERVES

I'he recognition of cranial nerve palsies is, diagnostically, of the
utmost importance, nor is it a matter of such, difficulty as is
commonly imagined.

First, or Olfactory Nerves. —

From the under-surface of the olfactory bulb on each side there
arise some twenty minute nerves which perforate the cribriform
plate of the ethmoid to be distributed to the upper part of the
nose.

To test the sense of smell, we direct the patient to close his
eyes. We then hold aromatic substances, such as oil of cloves,
peppermint, turpentine, or asafoetida, in front of each nostril in
turn, closing the other nostril with the finger. Ammonia or
acetic acid must not be used to test the sense of smell, since
these stimulate the fifth nerve (common sensation), and may
produce a pungent sensation in the nose, even when the sense
of smell is lost.

Anosmia, or loss of the sense of smell, is sometimes of
diagnostic value. It may occur, for example, in congenital absence
of the olfactory nerves, in lesions of the olfactory bulb or olfactory
tract, in some frontal tumours, in injuries of the anterior fossa
of the skull, and in tabetic atrophy of the olfactory nerves.
It also very often occurs unilaterally in hysterical hemiplegia and
is then associated with diminution of the other special senses on
the hemiplegic side. But the value of anosmia as a symptom is
lessened by the fact that numerous local obstructive conditions
in the nose also produce loss of smell, e.g. nasal polypi or even a
simple cold in the head.

Paros7nia, or perverted sense of smell, is always cortical in
origin. Various subjective hallucinations of smell occur not only
in mental disease but also in gross lesions of the uncinate gyrus,
which is the cortical olfactory centre. But here again local nasal
conditions may also cause olfactory sensations, e.g. the unpleasant

128



CRANIAL NERVES



129



odour perceived by a patient suffering from empyema of the
antrum of Highmore, from which horribly offensive pus is escaping
into the nose. On the other hand, in ozsena from chronic atrophic
rhinitis the offensive smell Ls not perceived by the patient, although
painfully evident to his neighbours.

Paroxysmal parosmia, preceded by a disagreeable sensation of
irritation at the root of the nose, and sometimes followed by
violent sneezing and sudden secretion of nasal mucus, may occur
as a nasal crisis in tabes/

Second, or Optic Nerve. — This contains not only visual fibres,
but also the afferent fibres for the pupillary reflex.




Fig. 56. — Diagram of pons and medulla, showing cranial nerves.

We have already referred to the course of the visual path from
retina to cortex (Fig. 29, p. 46), In testing vision we should
determine visual acuity by means of test types at a fixed distance,
such as six metres. Using Snellen's types, of which the largest
should be readable at sixty metres, and the smallest at six metres,
we direct the patient to read the letters from above downwards.
If his vision is normal he will be able to read the smallest type at
six metres. His visual acuity is then represented as V = f . But if
he can only read down as far as the type which ought to be visible at
thirty metres, then V = y*^. Each eye should be tested separately,
the test types being well illuminated and the patient standing
with his back to the light. When the visual acuity is much im-
paired, the patient may not see even the largest type, but can only

' Klippel and Lhermitte, Semaine Medicah, Feb. 17, 1909.



130



NERVOUS DISEASES



count fingers at a short distance, or perhaps can only tell Hght
from darkness. Temporary diminution of visual acuity may
occur in myasthenia gravis.-^

Hemeralopia, or day-blindness, is a condition in which the
power of vision is bad during the day or in a bright light, whilst
the patient sees better in a dim light. The phenomenon is not
uncommon in tobacco amblyopia, where there is usually present
a central scotoma for green and red. The hemeralopia is pro-
bably due to the fact that a bright light rapidly fatigues the
retina and also, by producing pupillary
contraction, causes the peripheral part of
the retina to be less in use than the
central, whereas in a dim light the pupil
dilates and the unaffected peripheral por-
tion of the retina comes into play.

A patient with nyctalopia, or night-
blindness, becomes almost blind at dusk or
in a dim light. This occurs in association
with various conditions, of which the most
interesting is congenital retinitis figmentosa,
a disease easily recognised on ophthalmo-
scopic examination. It also occurs to a
lesser degree in certain cases of " cortical "
cataract, when the lenticular opacity acts
as a permanent diaphragm.

Colour vision is most conveniently tested
by means of Holmgren's wools. These are
thrown on a table weU lit by daylight, and
the patient is given one particular test-skein of wool which is kept
separate from the heap, and told, not to name the colour, but to
match it, selecting from the heap of coloured skeins all those which
are like the test-skein, whether lighter or darker in shade. The
patient is given a pale green test-skein. If his colour vision is
normal, he will pick out all the pale greens correctly, but if he is
red-green colour-blind he will select a grey or straw-coloured skein.
Congenital red-green colour-blindness is the commonest variety.
Yellow-blue colour-blindness is less common. If a patient be
totally colour-blind he will confuse with the test-skein all those
of similar brightness, no matter what their colour may be.
^ Tilney and Mitchell Smith, Neurographs, 1911, vol. i. p. 178.




Fig. 57. — Lateral view of
brain-stem with cra-
nial nerves.



CRANIAL NERVES 131

The size of the field of vision in each eye is of great importance,
and for its accurate measurement a perimeter is required. This,
however, is a large and expensive piece of apparatus. For clinical
purposes the following method is sufficient, presuming that the
physician's own visual fields are normal. The physician sits exactly
opposite the patient, about a yard away from him, and tests each
eye separately. To test the patient's right eye direct him to cover up
his left and to gaze steadily at the physician's left eye. Meanwhile
the physician closes his own right eye and looks steadily at the
patient's pupil, watching that the patient's eye does not wander
from the fixation point. Then, holding his own left hand in
a plane midway between himself and the patient, and beginning
almost at arm's-length, he brings his hand inwards from the
patient's ear towards the middle Hne, meanwhile moving
his own fingers. If the patient's visual field is normal, he
will catch sight of the moving fingers at the same time that
the physician does so. If he does not, that visual field is
contracted and the physician then brings his moving fingers
inwards until the patient does catch sight of them. In this
way we test both the upper and lower quadrants of the
field on the temporal and nasal sides, in turn. If we find
the visual field diminished in one or other eye, it is well to
take a careful perimetric chart.

We may find a central scotoma or blind patch in one or both
visual fields. This is detected by attaching a small white object
to the end of a thin rod and holding it in the centre of the visual
field, midway between one's own and the patient's eye. In this
situation it is not seen by the patient. We gradually move the
white object radially outwards in various directions until the
patient catches sight of it. Central scotoma may occur in various
organic diseases of the optic nerve or retina, such as early optic
atrophy, central retinal haemorrhage, &c., or it may result, in a
minor degree, from obstruction to central vision, e.g. by central
opacities in the lens or cornea. It may also occur, as a temporary
phenomenon, in some cases of migraine. Such conditions are easy
of recognition. Central colour scotoma to red and green (detected
in a similar fashion with coloured objects) together with deficient
visual acuity, is highly suggestive of tobacco amblyopia. In such
cases, besides a history of chronic excess in tobacco, we look for
corroborative signs such as fine tremor of the hands, cardiac



132 NERVOUS DISEASES

irregularity, cardiac pain, &c. An almost identical amblyopia may
also occur from chronic alcoholism.

The visual field may be concentrically contracted. This con-
dition is sometimes due to optic atrophy, the field being reduced
to a small area surrounding the fixation-point, so that the patient
looks at the outer world as though through a narrow tube. Con-
centric contraction of the field of vision for blue, sometimes actually
amounting to blue-blindness, may occur in cases of increased
intra-cranial pressure, especially from cerebral tumours.^ More
commonly concentric contraction of the visual field occurs in
hysteria, the field on the hemiplegic side of the body being more
contracted than that on the other side (Fig. 58), Temporary
contraction of the visual field may occur in myasthenia gravis.
Less frequently a cortical lesion of the angular gyrus, not impli-
cating the subjacent optic radiation (Fig. 29), causes a similar
concentric contraction of both fields, more marked in the eye of
the side opposite to that of the brain lesion. This is somewhat
clumsily named crossed amblyopia, but, as previously observed,
it is much commoner in hysteria than in organic brain disease,
and in hysteria it is frequently associated with diminution or loss
of other special senses on the side of the more contracted j&eld
whose colour sense is frequently lost (achromatopsia). Hysterical
amblyopia is unknown to the patient, and is only discovered on
examination by the physician.

Hemianopia (Fig. 59) means bhndness of half the visual field,
right or left as the case may be, from causes other than retinal
disease. It usually afEects the visual field of both eyes, and is due
to a lesion of the visual fibres at or behind the optic chiasma.
Such chiasmatic lesions may result from pressure by tumours,
syphihtic or inflammatory affections of the basi-sphenoid, from
tumours of the brain or of its membranes, and especially from
pituitary tumours, as in acromegaly. We have already considered
the signs of lesions of the optic tracts, and it is convenient here
to recall the effects of lesions of the optic chiasma.

(A) If the lesion be in the central part of the chiasma, inter-
rupting the decussating optic fibres (belonging to the nasal halves
of both retinae), there is blindness in the outer half of each
visual field : — bi-temporal hemianopia (Fig. 60). This sometimes
occurs in pituitary tumours.

1 Gushing, Johns Hopkins Hosp. Bull., 1909, xx. p. 95.



CRANIAL NERVES



133



(B) If the lesion be situated at one or other lateral extremity
of the chiasma, it will interrupt merely the non-decussating fibres
of the optic nerve and optic tract on that side, causing unilateral
nasal hemianopia in the corresponding eye. To produce bilateral
nasal hemianopia there must be two separate lesions, one at each



/,,/? /Tj




Fig. 58. — Crossed amblyopia, in a case of hysteria.



/iil/he £y^




,80 80;




Fig. 59. — Eight homouymous hemianopia, in a case of softening of the left
occipital lobe.

end of the chiasma, a condition which very seldom occurs. A
lesion involving the central part of the chiasma and extending to
one or other side (Fig. 60, A flus B) will produce the sum of these
two, namely bi-temporal hemianopia flus unilateral nasal hemi-
anopia, i.e. total blindness of one eye with temporal hemianopia
of the other.



134 NERVOUS DISEASES

(C) A lesion of the left optic tract behind the chiasma produces,
as already seen, hemianopia in the right halves of both fields
of vision.

(D) A lesion of one optic nerve simply causes blindness in the
corresponding eye.

In rare cases we may have a quadrantic hemianopia in which
only one quadrant (instead of one-half) of both visual fields is blind.
This is generally due to a lesion limited to part of the cortical half-
vision centre in the cuneate lobule and lingual gyrus. The calcarine
fissure divides the half-vision centre into an upper and a lower part.

R. Optic Tract L. Optic Tract.




R. Eye. L. Eye.

Fig. 60. — Diagram of course of visual fibres in optic chiasma.
(Hamilton.)

A lesion above the calcarine fissure, i.e. in the cuneate lobule,
causes blindness of the lower quadrant, whilst a lesion below the
calcarine fissure, i.e. in the lingual gyrus, causes blindness of the
upper quadrant of the corresponding half -fields.-^

The optic discs and retinae should be examined with the
ophthalmoscope in every case of nervous disease. Every neur-
ologist must be able to use the ophthalmoscope. The most im-
portant conditions to look for are optic neuritis and optic atrophy.
Optic neuritis occurs in numerous pathological conditions within
the skull, especially in intra-cranial tumours and in tuberculous
meningitis. But it also occurs in nephritis, in lead poisoning, in

^ Henschen, Le Centre cortical de la Vision. Internat. Med. Congress,
Paris, 1900.



CRANIAL NERVES 135

diabetes, and in severe anaemia ; and these four common conditions
must always be excluded before we diagnose gross intra-cranial
disease. We may also meet with optic neuritis in certain cases of
cervical myelitis. Optic atrophy may occur primarily, as in tabes
and disseminated sclerosis, or it may be a secondary post-neuritic
process. Sometimes it follows a retro-hulhar neuritis, which is due
most frequently to the toxin of disseminated sclerosis, less com-
monly to chronic alcohol or tobacco poisoning. Pallor of the
temporal halves of the optic discs is often an early sign of dissemi-
nated sclerosis. The combination of optic atrophy, blindness, and
mental deficiency occurs in the amaurotic family idiocy of Tay and
Sachs, an affection of certain Jewish children, coming on in infancy.
In these cases, on ophthalmoscopic examination there is a char-
acteristic cherry-red spot seen at the macula lutea, due to local
oedema and atrophy of the retina, whereby the vascular choroid
shines through. Apart from optic neuritis and optic atrophy, we
must be on the look-out for other pathological conditions of the
fundus, such as choroiditis, albuminuric retinitis, tubercle of the
choroid, occlusion of the central retinal artery, retinal haemor-
rhage, &c.

It must be remembered that a patient may have severe optic
neuritis without any impairment of vision. Optic atrophy, on the
other hand, causes the visual field to contract concentrically to a
greater or less extent, whilst the visual acuity diminishes and
ultimately the eye becomes blind. The atrophy of retro-bulbar
neuritis often produces central scotoma from affection of the papillo-
macular bundle of optic nerve fibres. Scotoma is often the first
sign of retro-bulbar neuritis, long before atrophy is visible by
the ophthalmoscope.

Third, Fourth, and Sixth Nerves. — It is convenient to study
together these three nerves which, between them, innervate all
the voluntary muscles of the eye. The distribution of each is as
follows : — The third nerve (oculo-motorius) suppHes all the external
ocular muscles except two : — the superior oblique suppUed by the
fourth nerve, and. the external rectus supplied by the sixth. It



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