In conjunction with disorders of speech difficulty in reading, in writing, and in communication by gesture may occur; and these conditions are designated respectively alexia, agraphia, and ami

FIG. 12.-Floor of the skull showing the exit of the cerebral nerves (after Henley: 01, olfactory nerve; Op, optic nerve; ocm, oculomotor nerve: tr, trochlear nerve; trg, trigem inal nerve; ab, abducens nerve; fc, facial nerve; ac, auditory nerve: gl, glossopharyngeal nerve; g, vagus; acc, accessory nerve; hp, hypoglossal nerve; ci, internal carotid artery: H, hypophysis; t, apex of the tentorium; feb, falx cerebelli.

hp

mia. All of these disorders together constitute the aphasic symp-
tom-complex. At times the patient has lost all power of commu-
nicating with his fellows by writing, by speech, or by gesture, and
of understanding others through speech, writing, and gesture.

ост

The patient has lost his facultas signatrix, and suffers from asymbolia or asemia. Patients with motor aphasia naturally exhibit also motor alexia. Sensory aphasia bespeaks sensory alexia, in the presence of which the patients do not comprehend the sense of what is read. They therefore fail to comply with written requests. Motor agraphia renders the patient incapable of writing by transcript, while in the presence of amnesic agraphia that which is thought and willed cannot be recorded on paper. Inability to write from dictation would be designated sensory agraphia.

FIG. 13.-Distribution of the artery of the fossa of Sylvius upon the cerebral cortex, partially diagrammatic: Art.f.S, artery of the fossa of Sylvius: ", inferior frontal convolution; Op, operculum; rew, anterior central convolution: her, posterior central convolution: of, superior temporal convolution: mt, middle temporal convolution: JR, island of Reil.

Disorders occur in the mimic field in quite a corresponding manner. Gestures are not imitated-motor amimia-or are not understood-sensory amimia-or they cannot be executed-amnesic amimia.

The aphasic symptom-complex is by no means entirely exhausted by the alterations described. Analogous disturbances may, for instance, occur in the musical faculty, so that the patients are unable to repeat well-known melodies sung to them, or are unable to recognize them; or they are unable to sing a melody with which they had previously been

familiar. Disorders of the power of calculation have also been observed, and the like. At times the patients have lost their comprehension of the use of objects and suffer from apraxia. If they be given some article of clothing, they are incapable of deciding what to do with it. A candle may, for instance, be used for washing the hands, while soap may be introduced into the mouth, and the like.

The doctrine of aphasia, which was first established especially by two French physicians, Dax and Broca, has been subjected to most assiduous investigation up to the present time. Various diagrams have been constructed for the purpose of explaining the mechanism of the aphasic symptom-complex, but some cases will not fit into such explanations; so that a number of problems still remain to be solved in this connection. The strictly aphasic disturbances can be readily comprehended from the accompanying diagrams (Figs. 14 and 15). In order to acquire the power of

speech as a child, it is necessary for the individual to hear spoken words and to attempt their reproduction. Accordingly, the path for the auditory nerve, the cortical auditory center in the superior temporal convolution, the path of communication with the cortical center for the muscles of speech in the inferior frontal convolution, and the peripheral path for the speechmuscles must be intact (Fig. 14). A child first repeats words without comprehending their significance, and only gradually it learns to associate a definite conception or idea with each word. This can take place only by the establishment of a path of communication between the cortical auditory center and the concept-center, and also of a path of communication between the latter and the cortical center for the muscles of speech. The latter is necessary for spontaneous, intelligent speech. Fig. 15 represents a diagram for the comprehension of intelligent speech.

Disorders of speech, or aphasia, will occur either if the cortical auditory center or the cortical center for the muscles of speech is destroyedcortical aphasia; or if the paths of communication between the cortical auditory center or the center for the muscles of speech and the concept

center are interrupted-transcortical aphasia; or if the path for the auditory nerve or for the muscles of speech is injured-subcortical aphasia; or, finally, if an interruption has taken place in the conduction-path between the cortical auditory center and the cortical center for the muscles of speechconduction-aphasia.

Destruction of the cortical auditory center causes sensory aphasia. The patient fails to comprehend spoken words, and is unable to repeat them. On the other hand, spontaneous speech is not interfered with. Naturally, improper words or words with a similar sound are often used in speechso-called paraphasia. Destruction of the path of communication between the cortical auditory center and the concept-center gives rise to transcortical sensory

FIG. 16.-Diagrammatic representation of the entire aphasic symptom complex: B, cortical concept-center; S, cortical center for the muscles of speech; fe, cortical auditory center; 0, cortical optic center; F, cortical center for the movements of writing; a4c, path for the auditory nerve; mS, path for the muscles of speech; Es, path for the movements of writing.

aphasia. The patient fails likewise to comprehend spoken words, but is able to repeat them. Spontaneous speech is not interfered with, and is only modified by paraphasia. Destruction of the path for the auditory nerve gives rise to subcortical sensory aphasia. This entirely resembles cortical sensory aphasia (loss of the comprehension of words and inability to repeat spoken words), although, as will be explained later, other agraphic disturbances are present. Destruction of the cortical center for the muscles of speech induces cortical motor or ataxic aphasia. The patient, in spontaneous speech and on repetition, is capable, at best, of using distorted words. Destruction of the path of communication between the cortical center for the muscles of speech and the concept-center gives rise to transcortical motor aphas The patient comprehends spoken language, and is also capable of it, while the

power of spontaneous speech is lost. Destruction of the path for the muscles of speech gives rise to subcortical motor aphasia. This closely resembles cortical motor aphasia (disturbance of the power of spontaneous speech and of repetition, with preservation of the comprehension of spoken language), although it is attended with other agraphic disturbances. Patients with subcortical motor aphasia are thought to be capable also of designating the number of syllables of which a spoken word is composed, for instance, through pressure with the hands, while this power is lost in the presence of cortical motor aphasia. Destruction of the path of communication between the cortical auditory center and the center for the muscles of speech gives rise to conduction-aphasia. The patient comprehends spoken language and can also speak spontaneously; but the power of repetition is interfered with. The disturbance may be mitigated through the intermediation of the concept-center, although there is frequently confusion of words-paraphasia.

For the comprehension of the alexic and agraphic disturbances that so frequently occur in association with aphasia, diagrams have been constructed that take into consideration the cortical optic centers and their paths of communication, and the cortical center for the movements of writing and their conduction-paths. Fig. 16 represents such a diagram, from which the aphasic symptom-complex may be comprehended in accordance with the seat of the disease.

1. Cortical motor aphasia (Fig. 16, 1).

Loss of the power of spontaneous speech.
Loss of the power of repeating spoken words.
Loss of the power of reading.

Loss of the power of writing from dictation.
Loss of the power of writing spontaneously.

Loss of the power to designate the number of syllables in

words.

Preservation of the power of comprehending speech.

Preservation of the power of comprehending writing.
Preservation of the power of writing by transcript.

2. Transcortical motor aphasia (Fig. 16, 2).

Loss of the power of spontaneous speech.
Loss of the power of writing spontaneously.
Preservation of the power of comprehending speech.
Preservation of the power of repeating spoken words.
Preservation of the ability to read aloud.

Preservation of the power of comprehending writing.
Preservation of the ability to write by transcript.
Preservation of the ability to write from dictation.

3. Subcortical motor aphasia (Fig. 16, 3).

Loss of the power of spontaneous speech.

Loss of the power of repeating spoken words.
Loss of the ability to read aloud.

Preservation of the power of comprehending speech.
Preservation of the power of comprehending writing.
Preservation of the power of writing spontaneously.
Preservation of the ability to write by transcript.
Preservation of the ability to write from dictation.

4. Cortical sensory aphasia (word-deafness) (Fig. 16, 4).
Loss of the power of comprehending speech.
Loss of the power of repeating spoken words.
Loss of the ability to read.