The functions of the cerebrum / by Shepherd Ivory Franz.

  • Shepherd Ivory Franz
Date:
1914
Catalogue details

Licence: In copyright

Credit: The functions of the cerebrum / by Shepherd Ivory Franz. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    *32 the aphasia was associated with lesions of the second and third frontal convolutions, of the island of Reil, of the internal capsule, and of the surrounding regions in the left hemisphere. The reason for an association of such contralateral lesions (i. e., not corre- sponding to the hemisphere of greater voluntary control) with the speech disturbances is not plain, but it is apparent that in this case, and probably in others, there may be an anomaly in the motor and sensory association functions of the cerebrum, or, which seems to the reviewer more probable, that we have in this case only an example of the normal variation in function in different individuals. The symptom variations which are found in individuals with lesions in the occipital lobes are also very great. Certain cases have been described in which very extensive lesions have not been accompanied by a complete loss of vision, while in other cases com- paratively small lesions resulted in almost complete loss. At other times it is found that even in apparently complete bilateral lesions some visual ability f'emains. In extensive calcarine lesions, and especially in those cases in which there are visual defects for special retinal segments, it is not unusual to find that patients still retain certain visual ideas and have visual experiences which are of the nature of hallucinations. In the case which has been de- scribed by Josefson (5), this was found. In this patient, in addition to the general mental changes associated with the pressure, etc., due to the cerebral lesion, which was produced by a glioma or a sarcoma in the left occipital lobe, there were found homonymous hemianopsia with optical aphasia and alexia, but the patient had marked visual hallucinations in the right visual field corresponding to the hemianopic area, and the hallucinatory figures were at times larger than normal. Such cases have more than the particular interest for the purpose of localization of cerebral function, for they indicate that even though there be large amounts of destruction of cells and fibres, the mental functions, supposedly connected with the activity of these cells and fibres, may still persist. They also indicate how little we know at present of the relations of cere- bral cell activity and such mental things as ideas. Minkowski (9), after extirpating the occipital regions of the cat’s brain, and in certain cases the eyes, has determined the paths of degeneration, and especially the relation of the degenerations in the external corpus geniculatum due to lesions of the striate area (calcarine cortex). His results indicate that the external genic- ulate body is the only subcortical structure in which, following
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