A physician's notes on ophthalmology. 2nd series / by J. Hughlings Jackson.

  • Jackson, John Hughlings, 1834-1911.
Date:
[1875]
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Licence: Public Domain Mark

Credit: A physician's notes on ophthalmology. 2nd series / by J. Hughlings Jackson. 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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    ON OCULAR VERTIGO ; ITS BEARING ON THE INTERPRETATION OF THE GAIT OF LOCOMOTOR ATAXY, AND THE REEL OF DISEASE OF THE CEREBELLUM. Dr. Hughlings Jackson thinks that from consideration of certain symptoms in cases of palsy of ocular muscles we obtain a clue to the interpretation of the real nature of disorders of co-ordination, such as the reel in disease of the cerebellum and locomotor ataxy. He finds that this has in effect been already stated by Wundt. In the “ Medical Press and Circular,” May 12, 1875, Dr. Jackson writes:— “ The term disorder of co-ordination is frequently used ; but it is applied to diseases which are fundamentally different; for example, it is applied to chorea and to locomotor ataxy. Of course, both these are disorders of co-ordination; but the term is used without qualification, and this leads to the two different, indeed opposite, states being considered as alike in their physio- logical or functional causation. Chorea and locomotor ataxy are not only unlike in that different parts of the body are affected, but unlike in the functional affection. In the former there is ‘ over-function in the latter there is loss of function. In view of the active motor disorder of the ataxic patient, the statement that there is loss of function of the nervous centres for loco- motion seems, at first glance, absurd. But is there not wasting of nerve fibres in the posterior column of the cord ? And what could this 1 cause ?’ It would ‘ cause ’ nothing active. It could not ‘ cause ’ the disorderly gait—in fact, it could ‘ cause ’ nothing. The disorder of co-ordination in. locomotor ataxy and in some other affections is owing to a double difficulty consequent on loss of function of nerve tissue; there is really paralysis. There is (1) over-estimate of a movement intended to be executed by the centre diseased, but not accomplished, and (2) by healthy centres, increased action of associated movements in accordance with the over-estimate. The explanation given of the disorder of co-ordination in locomotor ataxy applies mutatis mutandis to the reel from disease of the cerebellum.” The following is a quotation from the Mirror of the Lancet, January 30, 1875 :— “ At first glance it seems absurd to speak of there being loss of power in locomotor ataxy, at any rate in an early stage of this disease. The patient has great power in his legs. Dr. Hughlings Jackson believes that there is paresis, and this only of certain highly special movements. As a centre (the posterior column of the cord) is affected, there could not be loss of power in single muscles or groups of muscles, but loss or defect in movements, in which several muscles co-operate. Dr. Hughlings Jackson believes that the first movement to fail in cases of loco- motor ataxy is that in which the peroneus longus is the muscle