712 



APHASIA. 



represented in the scheme. We must assume the existence of a higher centre (B), " in which 

 concepts are elaborated," where these sounds become intelligible. \ ohtional language requires 

 i connection between B and M, as well as between A and M. But we have also reading and 

 writing. Suppose O to represent a centre for visual impressions (printed words or writing) : 

 these we can understand through the connection between such visual impressions and auditory 

 impression*, whercbv a path is established through OA (fig. 495). In reading aloud, however, 

 the oro-lingual muscles must be co-ordinated, so we have the path OAM opened up. In 

 writing, or copying written characters, the movements of the hand are special, and perhaps 

 require a special centre, or at least a special arrangement of the channels for impulses in the 

 centre ; the movements are learned under the guidance of ocular impressions, so we connect O 

 ami K. E being the centre guiding the movements in writing. As to volitional writing, the 

 impulse passes through M but does it pass directly to E, or indirectly through A ? Lichtheim 

 assumes that it goes direct from M to E. It is evident that there are seven channels which 

 may be interrupted, each one giving rise to a different form of aphasia (1 to 7).] 



[Looked at from another point of view, either the ingoing (a) or outgoing (m) channels or 

 centres, or the commissural fibres between both, may be affected. If the motor centre is 

 affected, we have Wernicke's " motor aphasia" ; if the sensory, his "sensory aphasia."] 



[In the most common form, or ataxic aphasia (Kussmaul), which was that described by 

 Broca, or the "motor aphasia" of Wernicke, the lesion is in fig. 494, in M, i.e., in the motor, 

 or what Ross calls the emissive department. In such a case, it is obvious that there will be 

 loss of (1) volitional speech, (2) repetition of words, (3) reading aloud, (4) volitional writing, 

 and (5) writing to dictation ; while then; will exist (a) understanding of spoken words, (b) also 



of written words, (c) and the faculty of copying. 

 If the lesion be in A,' we have the "sensorial aphasia" 

 of Wernicke, i.e., in the acoustic word-centre; we 

 find loss of (1) understanding of spoken language, 

 (2) also of written language, (3) faculty of repeating 

 words, (4) and of writing to dictation, (5) and of 

 reading aloud ; there will exist (a) the faculty of 

 writing, (b) of copying words, and (c) of volitional 

 speech, but the volitional speech is imperfect, the 

 wrong word being often used, so that there is the 

 condition of f" paraphasia." If the connection be- 

 tween A and M be destroyed, other results will 

 follow, and such cases of "commissural" aphasia 

 have been described by Wernicke. If the interrup- 

 tion be between B and M, we have a not uncommon 

 variety of motor aphasia (4), where there is loss of 

 (1) volitional speech, and (2) volitional writing, and 

 there exist (a) understanding of spoken language, (b) 

 of written language, (c) and the faculty of copying; 

 but it differs from Broca's aphasia in that there also 

 exists the faculty (d) of repeating words, (e) of writ- 

 ing to dictation, (/), and of reading aloud. If the 

 lesion is in Mm (5), the symptoms will be those of 

 Broca's aphasia, but there will exist (1) the faculty of 

 volitional writing, and (2) of writing to dictation. 

 Many examples of this occur where patients have 

 lost the faculty of speaking, but can express their 

 thoughts in writing. In lesions of the path AB (6), 

 there will be loss of (1) understanding of spoken 

 language, and (2) of written language, and there will 

 exist (a) volitional speech (but it will be para- 

 phasic), (b) volitional writing (but it will have the 

 characters of paragraphia), (c) the faculty of repeat- 

 ing words, (d) reading aloud, (e) writing to dictation, 

 nnd {/) power of copying words. The person will be quite unable to understand what he 

 repeat*, reads aloud, or copies.] 



[Fig. 496 shows diagrammatically the conditions in motor and sensory aphasia. From 

 the eye and ear centripetal fibres (v and a) ascend to terminate in the visual (V) and auditory 

 centres (A), in the cortex, while afferent fibres (s, s\ s"), indicated by dotted lines, also pass 

 from the articulations, muscles of the hand, and orbit to the cerebrum. The dotted lines on the 

 surface of the cortex represent the association system of fibres which connects the centres 

 with each other. The centres for vocal (V) and written expression (W) are connected by centri- 

 fugal fibres, m and in', with the hand and larynx respectively (Boss).] 



lU. The thermal centre for the extremities is associated with the motor areas ( 377). Injury 

 or degeneration of these areas causes inequality of the temperature on both sides (Bechterew). 



Fig. 496. 



