On the value of eye symptoms in the localisation of cerebral disease : being the Bowman lecture, delivered before the ophthalmological society of the United Kingdom, on Friday, 9th November, 1888. / by Henry R. Swanzy.

  • Swanzy, Henry R. (Henry Rosborough), 1843-1913.
Date:
1888
Catalogue details

Licence: Public Domain Mark

Credit: On the value of eye symptoms in the localisation of cerebral disease : being the Bowman lecture, delivered before the ophthalmological society of the United Kingdom, on Friday, 9th November, 1888. / by Henry R. Swanzy. Source: Wellcome Collection.

Provider: This material has been provided by King’s College London. The original may be consulted at King’s College London.

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    their motions, it is only these associated motions which are represented in the cortex. By far the most common derangement of these asso- ciated ocular movements, as the result of cortical lesions, is the Conjugate Lateral Deviation of the eyes to one side, i. e. abnormal function of the internal rectus of the one eye, and of the external rectus of the other eye; in para- lysis the deviation being, of course, towards the side of the lesion—the eyes look at the cerebral lesion, as Prevost has expressed it—and in spasm from the side of the lesion. In many of these cases, if the patient’s intelli- gence be not impaired, the eyes can be moved as far as the middle line, or even further, by an effort of the will. We are not able, as yet, to say where the cortical centre for these motions resides in man, for Grrasset’s statement* that it is situated in the supramarginal and angular gyrus has not been verified. But were we to know its position, it is not likely that much would be gained, so far as clinical localisation is concerned, for this centre seems to be extremely sensitive, and to be easily thrown out of gear by lesions of many different parts of the cortex. Conjugate deviation is, in short, very apt to be a distant symptom, especially in cerebral haemorrhage, when it is often accompanied by a rotation of the head in the corresponding direction, and lasts only a brief time. Moreover, it is thought that, when this centre may happen to be actually involved in the lesion, its function, being largely bilateral, is rapidly taken up by the opposite hemisphere, and hence, even when conjugate lateral deviation plays the part of a direct cortical symptom, it can never be recognised as such, owing to its evanescent character. Again, conjugate lateral deviation, similar in character to that caused by a cortical lesion, may proceed from a lesion of the internal capsule. This same symptom, finally, may be caused by a lesion of the pons, involving the special nucleus for the asso- * ‘ De la deviation conjugee/ Paris, 1879.