SENSORY APHASIA. — Cortical word deafness is usually caused by a lesion of the middle or posterior portion of the first and second left temporal convolu tion, chiefly the first. Auditory speech is not, however, so exclusively a left brain function as is motor speech; hence the fact of incomplete and more tran sient types of speech-defect from uni lateral lesions of this region. Lesions affecting the subcortical white fibres from this area give rise to the subcortical type of word-deafness, as it is termed.
Case of lesion of the left temporal lobe in a left-handed man without word deafness. Seppili (Alienist and Neurolo gist, Apr., '93).
Case of lesion cf the first, second, and third right temporal lobes, with word deafness. Many similar cases are re ported in literature; two cases of lesion of the left lobe in left-handed persons, without deafness, and thirty cases with word-deafness from lesions of the left temporal lobe in right-handed persons. Scavano (Revue Inter. de Bibliographic, June 10, '03).
Case of deaf-mutism, in an adult, due to symmetrical lesions in the two tem poral lobes. The first and second tem poral convolutions were replaced by cicatricial tissue; the third was atrophied and sclerosed. Seppili (Alienist and Neurologist, Apr., '95).
Three autopsies in patients with sen sory aphasia. There were softening and atrophy of the left first temporal con volution. Case of subcortical aphasia noted. The patient could not speak and had no comprehension of spoken lan guage. IIe had right hemiplegia. Soften ing of the external capsule and lenticular muscles was found at autopsy. W. T. Worcester (N. Y. Med. Jour., Jan. 8, '9S).
Cortical word-blindness is caused by a lesion of the postero-inferior portion of the second left parietal convolution (angulo-occipital region).
Lesions affecting the optic radiations of Gratiolet cause the subcortical variety of alexia. Interruptions of relations through commissural fibres with any of the associated speech-areas will, of course, result in one of the mixed forms of aphasia or in subcortical alexia.
Fifty cases of sensory aphasia in which Broca's centre was not found diseased. In all some form of sensory aphasia was present, and in all the lesion lay in the lower posterior third of the brain. The convolutions were found affected in the following order: The first temporal in 38, the second temporal in 27, the in ferior parietal in 21, the angular gyrus in 25, the supramarginal gyrus in 12, the occipital lobe in 12. Paraphasia may be caused by lesions in various locations. Word-deafness due to a lesion of the first and second temporal convolutions, and word-blindness may be produced by lesions lying in the region of the inferior parietal lobule, or extending over, an teriorly from it, into the temporal region, or, posteriorly, into the angular gyrus and occipital lobe. Failure to recognize
a word heard implies destruction of the temporal cortical arca; failure to recall the name of an object seen implies the destruction of the temporo-occipital asso ciation tract in the subcortical white matter.
If the lesion be extensive enough to involve the cutler's, or deep enough to reach the visual tract to the cuneus as it passes beneath the angular gyrus and convexity of the occipital lobe, it will produce hemianopsia; if not, actual blindness may not accompany psychical blindness. In either case it is found that when things are not recognized they can not be named when seen. The visual memory-pictures lie in the angular gyrus and inferior parietal lobule. 31. Allen Starr (Brain, July, '89).
Case of word-blindness with agraphia, due to a spot of softening as large as a five-franc piece, occupying the whole of the inferior parietal lobe. Neither motor aphasia nor word-deafness was present. &rieux (Bull. de la Soc. de Med. Men tale de Belgique, Mar., '92).
Case of alexia, agraphia, amnesic aphasia, and word-deafness, due to tumor in the occipital lobe, having largely destroyed the subcortical commissural fibres in the angular gyrus. Weisseu burg (Archives de Neurol., July. Case of pure word-blindness for letters. words, musical signs, with retained ability to read figures and calculate. No word-deafness nor difficulty in articula tion nor any impairment of motor power or sensation. Four years later sudden seizure and death. For two days before death there were paraphasia and agra phia, resulting from the seizure, which was found at the autopsy to have in volved the left inferior parietal convolu tion and angular gyros. Old yellowish areas of softening with atrophy found in the lingual and fusiform lobules, the miens, and the apex of the occipital lobe; secondary degeneration in the splenium of the corpus callosum; and pronounced atrophy in the optic radia tions. The right hemisphere was intact. Histologically, lesion least pronounced at level of lower lip of calcarine fissure and especially localized in the fusiform and lingual lobules, the tapitum, and the radiations of Gratiolet, and the inferior longitudinal fasciculus of Burdach were entirely destroyed. All of the structures in the descending branch of the calcarine fissures were involved in the softening. Conclusion that the lower portion of the inferior longitudinal fasciculus of Bur clack contains fibres that connect the visual centre with the centre for lan guage. Menne and Vialet (Comptes liendus Heb. des Seances et Memoires de la Soc. de Biol., No. 28, p. 790, '93).