Copyright
James Ross.

On aphasia, being a contribution to the subject of the dissolution of speech from cerebral disease online

. (page 11 of 15)
Online LibraryJames RossOn aphasia, being a contribution to the subject of the dissolution of speech from cerebral disease → online text (page 11 of 15)
Font size
QR-code for this ebook


ideational centre I C, and this in its turn becomes connected with the
motor centre for the regulation of the movements of the hand in writing,
CLE. The arrows indicate the direction of the conduction, and it will



91



be observed that on the lines which connect the mouth and the hand with
the centres for the regulation of the movements of articulation C L A, and
of wi'iting CLE, respectively, and the lines connecting these centres with
the ideational centre I C, the arrows point both upwards and down-
wards. This is to show that when a person utters or writes a word he
becomes conscious of the operation through, the nerves of muscular
sense, without the aid of the special senses. It is unnecessary to give
a further description of this diagram, inasmuch as the reader who
has mastered our discussion of Kussmaul's scheme will readily interpret
for himself the kind of speech disorder that will be caused by disease of
pai'ticular centimes and conducting paths.

In a very elaborate and able paper on aphasia by Lichtheim,
translated into English by de Watteville,^ several diagrams, or rather




Fig. 7.

several modifications of the same diagram, are given to illustrate the
various speech disorders, and of these we select Fig. 7 as being the
simplest, if not the most complete. In this diagram B represents the
centre for conceptions, or the ideational centre. A is the centre of
acoustic, that of visual, word-images ; M is the motor centre for
the regulation of the movements of articulatipn, and E for the regulation
of the movements of the hand in writing. The commissural fibres
connecting these centres will be readily intelligible without fui-ther
description. The author believes that the different clinical forms of
aphasia may be reduced to seven types, and that each of them is caused
by lesion of one of the centres, A and M, or of one of the five conducting
paths, A M, B M, M m, A B, and a A,

1 Lichtheim (Prof. L.). "Ueber Aphasie." Aus der medicinischen Khnik in Bern. Deutsches
Archiv f. Bin. Med., Bd. XXXVL, Leipzig, 1SS5, p. 204. De Watteville (Dr. A.) "On aphasia."
Brain, VoL VII., Lond., 1SS5, p. 433.



92



The annexed table, borrowed from a very excellent abstract of
Lichtheim's paper by Thomsen/ gives at a glance the author's seven
types of aphasia, with the centre or conducting path injured in each : —









•«


tj


-d








nS rQ








a>


<L>


0)








03 d)






03




a


•J


-+3

1


o


o


a a

3 J

4) cU








P5


^


P^








P5 P^


<1






















_cS


d


*


*.


*






O






02


S


d


n3


d




'd






1

'1'
g


1


0)


ID

a


a


-ij

o
1-:!


l-< 03


o






Ah


p-i


p:3


Ph


P5




P^
























•id






'^*


nS


n3 r^


IJ)








<u






O)


a>


<U 03


o




-J






o


-p3

o


.a

'c3


•i


a a
'3 "cs




g


kI




^A


1-^




^


HJ -li
03 03


m ■
W E2








P5






P^


P^


P? P^








































o Ph










TS


TJ


TJ


TJ


'd 13












a>


OJ


a>


<u


03 03






^^"


-ti


+=


fl


.a


a

• rH


.a


•§ -2




O


o


"3


"3


CS


"3


o3 <A






pq


1-1


ij






03


<o


OJ (B


-5 g










Ph


P^


Ph


Ph


P5 P?


. P




















n o
























.S


A

.^


.2


.2

02


^
S


-s


-d rd


CO




^^


i




,i3


t


.a


03 03

,a a


D




CO


Ph


1


-' Ph


p.


Ph


'3


'cs '3






->i


OS


Ph


2


®


-4J -p

03 0)


CQ






Ah


Ph


P5


« P^


















s






■d


tJ










n3


p-l






0)


dj










03


<J




(M-^




.3


o


-+=


o


1i

o


-P d

o 3


O






■s


03


hJ


h^


i-:i


i-:i


^ ^


TO






P5


P^










p^


P3


































■^


o




















Pm


















^6 'd

03 03








-|i


-t^


-(j


-ti


^


sa


a a






-^^


O


O


o


O


o


"3










^^


J


>A


h:i


1-q


<A


03 <D

Ph P^


w


|H £ ai
M W ^ g;
^ W w o

S ^ H S
i P3 S o

R § 6 ^

w to i? P
» fife


a

pq


pq


a


a


H
S
^


pq
<!

eS


2" «■








o


C3


c3
















»


q


,


,
















'd


o


CHH


^ " ^






rfs


.s




o


1

.2

O
bJO

_a


o :


°„=.a




to

1 g

EH fi, H

g ° ?

^ Oh


o

<v

(Ll

H


h3

a
o


bo

a


o
a
.2


60 ITS

IS


.9 P o










Pi

a>

P^


'■+3


m o 03 -r; 'Th

a « a ^ §
t> 1:3 fe



A careful study of this

> Thomsen. " Ueber Aphasie.
1885, p. 417.



table will show that the clinical analysis of

" — CmtralblaU fur Hinische Medicin, Bd. VI., Leap2dg,



93

cases is carried out only to a very imperfect degree. It will be at once
seen that the first and fourth types are only different degrees of aphemia
in association with motor agraphia, while the fifth represents aphemia
without motor agraphia. The seventh type represents a moderate
degree of word-deafness, while the second and sixth represent word-
deafness and word-blindness variously combined. The third type now
remains for consideration. In the example which Lichtheim gives,
the patient on being asked "' What was there for supper?' answered,
' Bread, meat, potatoes,' with only two mistakes."^ On being asked to
i-elate his history he strung together numerous words, of which only one
now and then could be made out, such as " evening, five and twenty
and." The patient could understand spoken and written language, and
could also repeat correctly short words uttered in his hearing, but in the
repetition of words generally and in loud reading he committed the
same kind of mistakes as in voluntary speech. This case is doubtless
allied to our first degree of aphemia, a condition in which the patient
comprehends both spoken and written speech, and is able to utter a great
many words, but cannot complete a sentence. The fact, however, that
at the autopsy the lesion was found chiefly in the area of distribution of
the posterior branches of the Sylvian artery, shows that the sensory
mechanism of speech was injured. It will suffice at present to say that
Lichtheim's third type corresponds with the disorder of speech which
Dr. Broadbent has named "inability to express the relations between
things," and which he believes to be caused by disease of an assumed
propositionising centre. Such cases are believed by Wernicke^ to be
caused by injury of the fibres which connect the sensory with the
motor centres of speech, and he has consequently named them commis-
sural aphasia. But we shall return to the consideration of these cases
after giving a brief account of Dr. Broadbent's views of the sensory
disorders of speech.

Dr. Broadbent^ sets out in his explanation of speech disorders with
the proposition that all muscular movements are performed under the
direction of a "guiding sensation." If, for example, the palm of the
hand of a person asleep be tickled, impulses are conducted inwards to a
particular level of the spinal cord, and thence are reflected outwards to
the muscles which close the hand. When, however, the individual is

' Lichtheim, Brain, loc. cit, p. 4.45.

^ See Wernicke (0), Lehrbuch der Gehinih-ankheite-n filr Aei-zte VMcl Sfudirende, Bd. II. , 1S81, p. 205.

^ Broadbent (W. H.) "A case of peculiar affection of speech with commentary." Brain,
Vol. I., London, 1879, page 484 et seq. ; see also, "On a case of amnesia, with post-mortem
examination." Medico-Chirurgical Transactions, Vol. LXI., 1878, p. 147 ; ' On a particular form
of amnesia ; loss of novms." Ibid, Vol. LXVIL, 1884, p. 249.



94

awake, the outgoing portion of the reflex arc can be utilised by the
cortex of the brain, and then voluntary closure of the hand takes place.
The nuclei of the motor fibres of the peripheral nerves in the spinal cord
are, therefore, subservient both to centripetal impulses coming from tha
periphery, and to centrifugal impulses from the cortex of the brain.
But the centrifugal impulses from the cortex are initiated and
controlled by centripetal impulses going from the periphery to
the cortex. It thus appears that each movement is represented
in the anterior grey horns of the cord by a group of con-
nected cells, and that this group may be called into activity
either by centripetal impulses going from the periphery to that
level of the spinal cord in which these cells are situated, or by centri-
fugal impulses descending to this level from a higher nerve centre. In
Dr. Broadbent's words, " a motor cell-group is formed under the guidance
of a sensory cell-group on the same level, and when formed is made use
of by a higher centre." In the case of speech the " motor cell-group "■
must combine into orderly action — the thoracic muscles to obtain an
expiratory current of air, the laryngeal muscles for phonation, and the
muscles of the lips and tongue for articulation. This motor cell-group
Dr. Broadbent names for convenience the word group, and he believes-
that it is organised in the corpus striatum. When the cells of the word-
group are called into activity by centripetal impulses on the same level
the action is reflex, and the resulting contractions simply represent a
complicated muscular adjustment without any reference to intellectual
expression ; but on the activity of the group being evoked from the
cortex, then the movement becomes subservient to speech. The cortical
outlet for speecb is situated in the third left frontal convolution, and the
cortical guiding sensory centre for spoken language is situated in the
superior temporo-sphenoidal convolution (auditory centre). In accord-
ance with the annexed diagram, lesion of S (the motor centre for speech)
will cause motor aphasia, while lesion of A (the auditory perception
centre), or of a s (the fibres which connect the inlets and outlets) will
cause different forms of sensory aphasia. A hypothetical explanation is
thus afforded for three disorders of speech. In lesion of S, the "way
out" for all the muscular adjustments concerned in intellectual expression
is destroyed. In lesion of a s, the line of communication between the
guiding sensory centre and the motor outlet is damaged, and mistakes in
words recognisable by the patient occur; while in lesion of the sensory
centre A, mistakes in words occur of which the speaker remains uncon-
scious. But still higher centres than those named are brought into use
in intellectual expression, and disease of these produces various compli-
cated disorders of speech. " The formation of an idea of any external



95

object," says Dr. Broadbent,^ " is tbe combination of the evidence respect-
ing it received through all the senses ; for the employment of this idea in
intellectual operations it must be associated with and symbolised by a
name. The structural arrangement corresponding to this process I have
supposed to consist in the convergence from all the ' perceptive centres '




of tracts of fibres to a convolutional area (not identified), which may
be called the 'idea centre' or 'naming centre.' This will be on the
sensory, afferent, or upward side of the nervous system ; its correlative
motor centre will be the propositionising centre, in which names or nouns,
are set in a framework of other words for outward expression, and in




which a proposition is realised in consciousness or mentally rehearsed.
If we are to have a seat of the faculty of language, it would be here
rather than in the third left frontal convolution, with which, however, it
may possibly be in close proximity. Expressing this by a diagram, we



I Broadbent (W. H.) Brain, Vol. I., 1879, p. 494.



96

have V, A, and T, the visual (angular gyrus, Ferrier), auditory (infra-
marginal Sylvian gyrus), and tactual (uncinate gyrus), perceptive centres,
sending converging tracts of fibres, v n^ an, t n, to N, the ' naming
centre.' Here the perceptions, from V and T (smell and taste are
omitted for the sake of simplicity), are combined with an idea, which
idea is symbolised by the name reaching N through A, which has always,
in the experience of the individual, been associated with the object. P
is the propositionising centre, in which the phrase is formed, its relations
with N and S being sufficiently clear."

According to this scheme, lesion of the naming centre N would
cause loss of the memory of names or nouns, leaving the patient able to
express himself imperfectly in words indicative of relations and attributes.
Lesion of P, the propositionising centre, would render the patient unable
to construct a sentence, although retaining the use of names. This
condition Dr. Broadbent^ illustrates by the case of a patient, who, in
endeavouring to explain that he had two brothers in America, said —
" Brother — New York — brother — "Merica — letter — two brothers in
America — letter." The patient could understand spoken and written lan-
guage, but his attempts at reading aloud ended in gibberish. He was
unable to write to dictation, and, with the exception of his own name and
the names of his brothers — which he wrote quite well — he was also unable
to write spontaneously. He could copy short words quickly and
correctly, but a long word he took down slowly and in schoolboy
characters, and as he wrote each letter he named it aloud, and always
wrongly. This form of speech disorder Dr. Broadbent regards as an
" inability to express the relations between things " ; it corresponds with
Lichtheim's third type, and with Wernicke's commissural aphasia, but we
reserve further consideration of it at present.

Lesion of the visual perceptive centre V, or of its channel of com-
munication V n with the naming centre N, would explain cases of word-
blindness, while lesion of the auditory perceptive centre A, or of its
channel of communication a n with the naming centre would explain
word-deafness.

A very good diagram illustrative of the disorders of speech is given
by Professor Grainger Stewart,^ and although I believe that he postulates
too many centres both on the ingoing and on the outgoing side of the
speech mechanism, his scheme, taken in conjunction with his remarks on
aphasia, is well worthy of careful study. No good, however, would result
from dwelling at greater length on this part of our subject.

1 Broadbent (W. H.), Brain, Vol. I., 1879, p. 486.

2 Stewart (T. Grainger). An introduction to the study of the diseases of the nervous system."
Edin. 1884, page 181 et acq.



97

Instead of entering upon a criticism of the diagrams figured and
described in the foregoing pages, we prefer to indicate briefly our own
views of the nature of the connection existing between the various
speech disorders and the lesions which underlie them. In the first place
we shall deal Avith motor aphasia, because it is more simple, and conse-
quently more easily handled, than the sensoiy forms of the affection.

The first and most important proposition which we will endeavour to
establish is that motor aphasia is the result of a genuine paralysis. Some
pathologists have offered much opposition to this view. They assert, and
with truth, that the subject of a pure motor aphasia is often capable of
moving his lips freely, of protruding his tongue and employing it in
the act of deglutition, and of using his vocal apparatus in singing,
without giving evidence that the muscles engaged in these actions are
suffering from any degree of paralysis. They also point to the well-
ascertained fact that in cases of pure motor agraphia all the other move-
ments of the hand may be effected with ease, and without the gross
strength of the grasp being diminished. Those who urge these objections
believe aphemia to be caused by a want of motor co-ordination, and
they have consequently named the affection ataxic aphasia. That
aphemia is due to a motor inco-ordination we do not deny ; so is
diplopia, but in most cases it is paralytic also. In paresis or paralysis
of the sixth nerve, for instance, the patient is unable to direct the axes
of vision to one object, and he consequently sees two objects instead of
one, and so far there is an inco-ordination of the ocular muscular
movements, but it is caused by paralysis of one of the muscles
of the eyeball. And to call aphemia by the name of ataxic aphasia is only
less absurd than it would be to call cases of double vision from paralysis
of one or more of the ocular muscles by the name of ataxic diplopia,
because the paralysis is not always so easily discovered in the former as
in the latter affection. The brain is, indeed, so far as its motor functions
are concerned, an organ by means of which the simple movements which
are regulated by the spinal cord are variously combined and co-ordinated
so that complex bodily adjustments are produced, and when the cerebral
motor organisation is "wholly destroyed by disease the co-ordination is
altogether lost, or when it is partially destroyed the co-ordination is so
disordered that the balanced muscular contractions which are requisite
for effecting delicate movements fail to take place. In every case of
partial paralysis from cerebral disease, therefore, there is a want of
motor co-ordination ; but this motor disorder is in no way comparable
with the genuine ataxia of tahes clorsalis, in which not a trace of
paralysis is to be discovered.

In order to illustrate the theory that aphemia is a paralytic
disorder, let us attend to the course of the development of the

G



98

movements of the hand. In the infant at birth the hand closes
on anything that touches lightly the palm, this movement being
altogether reflex and regulated by the spinal cord. When the
infant is a little older he begins to use the hand as an organ of prehen-
sion, and the acquired movements, which are now voluntary and
regulated from the brain, become more and more complicated by use,
each complication of movement being represented by a new complica-
tion of structure in the cerebrum. Let us now suppose that the faculty
of writing is not developed until after the infant has reached adult age
and has acquired the full strength of manhood. This supposition is
made in order to show that the delicate muscular adjustments which
have to be acquired in learning to write have added nothing to the
strength of the hand as an ordinary prehensile organ, and it is easily
conceivable that disease may destroy the new organisation in the brain
which is the structural correlative of those delicate movements, without
diminishing in the slightest degree the strength of the hand for ordinary
purposes. Now this is what occurs in pure cases of motor agraphia. In
most cases loss of the faculty of writing is accompanied by impairment
of the power of the hand as an organ of prehension, and it is then said
that the agraphia is accompanied by more or less of |iemiplegia, but it
is important to recognise that motor agraphia is itself an indication of a
slight degree of hemiplegia, even in those rare cases in which the gross
strength of the hand is not perceptibly diminished. Similar remarks
apply to aphemia ; it is of itself an indication of hemiplegia even in the
rare cases in which it is unaccompanied by any perceptible paralysis of
the face or tongue.

If further proof be required of the paralytic nature of aphemia and
motor agraphia, it is found in the fact that these speech disorders are
accompanied, except in the rarest instances, by some degree of hemi-
plegia. And again, in experiments on animals, electrical excitation of
the posterior part of the third frontal convolution, which is the seat of
the lesion in aphemia, gives rise to opening of the mouth, with protru-
sion and retraction of the tongue, thus showing the essential identity of
function of this part of the brain with the other motor centres of the
cortex. The phenomena which attend unilateral convulsions teach the
same lesson. It is now well recognised that an attack of unilateral
epilepsy is followed by some degree of paralysis of the parts which
were the seat of the spasm. When the spasm begins in the foot, the
leg, and when it begins in the hand, the upper extremity, are found
to be more or less paralysed for some time after the cessation of
the spasm ; and when the spasm begins at the angle of the mouth,
the attack, when right-sided, is not only followed by a considerable



99

loss of expression on the side of the face that was the subject of
spasm, but also by a decided aphemia. From these considerations it
may be concluded that aphemia and motor agraphia are a paralysis of
highly specialised movements ; that in rare cases the special movements
of articulation, and of the hand in writing, are paralysed without the
general movements of the respective organs being interfered with ; but
that in most cases not only the special but the general movements also
suffer to some extent, and then only is it popularly recognised that the
speech disorder is accompanied by, or is a part of, hemiplegia. Before
proceeding further, therefore, it is desirable for us to study somcAvhat
minutely the mechanism by which hemiplegia is produced, and the
phenomena which attend it, for it is in this way alone that we can hope
to throw light upon several obscure problems connected with aphasia
and motor agraphia, which still remain unconsidered.

It may be stated as a general proposition that the muscles of one
lateral half of the body are regulated from the cerebral hemisphere of
the opposite side. The centres for the regulation of the movements of
the opposite side of the body are situated on the outer convex surface of
the cerebral hemisphere — the so-called motor area of the cortex. These
centres are connected with the anterior grey horn of the spinal cord of
the opposite side, and to a less extent with that of the same side by the
long fibres of the pyramidal tract. Now hemiplegia of the opposite side
of the body may be caused by extensive disease of the motor centres
themselves, but the ordinary form of hemiplegia is usually caused by
compression or rupture of the fibres of the pyramidal tract, as they come
together to form one bundle between the basal ganglia in the internal
capsule. It is found, however, that interruption of conduction through
the whole of the fibres of the pyramidal tract of one hemisphere does
not paralyse all the muscles of the opposite side of the body. In pro-
found hemiplegia some of the muscles are completely paralysed, while
others are scarcely, if at all, affected. It was first pointed out by
Dr. Broadbent^ that the muscles which remain comparatively unaffected
by paralysis in hemiplegia are those which, like the muscles of respira-
tion, are associated in their actions with the corresponding muscles of
the opposite side. In cases of severe hemiplegia the muscles of the
hand, the actions of which are independent of the muscles of the other
hand, remain persistently paralysed, while the muscles of respiration,
which always act in conjunction with the corresponding muscles of the
opposite side, may show a slight degree of feebleness at first, but recover
completely in a few days. The explanation offered by Dr. Broadbent for
the fact that the muscles which are bilaterally associated in their actions

' Broadbent (W. H.), British and Foreign Medico-Chir. Review, 1S66, p. 477.



100

have a relative imnmnity from paralysis is that these muscles are inner-
vated from both cerebral hemispheres, and consequently vi^hen the motor
centres or conducting paths of the one hemisphere are injured, the
muscles in question receive their impulses to action from the uninjured
hemisphere. He believes that the connection between the motor nervous
mechanisms of the two sides of the body is effected by means of com-
missural fibres in the medulla oblongata and spinal cord.

In the annexed diagram B and B' represent the cortices of the right
and left hemispheres of the brain, M M' represent motor centres, and
N and N' nerve nuclei in the medulla oblongata or spinal cord. P and P'
represent the conducting paths in the pyramidal tracts which form a
crossed connection between the cortical motor centres and the spinal
nuclei, while m and m represent the nerves which pass out to the
muscles. 1, 2, 3, 4, and 5 represent lesions in different situations. When




the muscles of the one side of the body, as those of the hand, act inde-


1 2 3 4 5 6 7 8 9 11 13 14 15

Online LibraryJames RossOn aphasia, being a contribution to the subject of the dissolution of speech from cerebral disease → online text (page 11 of 15)