Diagnosis of disorders of the cerebellar apparatus / by Tom A. Williams.

  • Williams, Tom A. (Tom Alfred), 1870-
Date:
1910
Catalogue details

Licence: In copyright

Credit: Diagnosis of disorders of the cerebellar apparatus / by Tom A. Williams. 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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    a sensation of surrounding objects being displaced towards the posi- tive pole. If either labyrinthine apparatus or center is interfered with this phenomenon does not occur when the positive pole is placed on the diseased side. These sensations and movements are accom- panied by nystagmus towards the positive pole. Other means of exploring the vestibular function are the irriga- tion test of Barany^^ and the rotation platform, in which nystagmoid movements occur long before vertigo is produced. When a person is seated on a platform revolving towards the right, the eyes will be observed, or better felt, to make a series of rapid rhythmical move- ments in the same direction as that in which he is turning, after each jerk returning more slowly to the mid position. After a few sec- onds, these movements cease until the platform ceases to turn, when they recommence, but in the opposite direction. These movements are dependent upon the inertia of the endolymph, as was shown ex- perimentally by Ewald.-^^ Their non-occurrence signifies interfer- ence with vestibular function, provided of course the oculo-motor apparatus is intact. The right labyrinth is the main controller of rotation to the right and vice versa, as the following case shows: After an accident, a workman felt out of sorts, but had only slight pain on side of head; but on ciuestioning, he admitted sounds in the ear and vertigo when upright, objects seeming to turn from left to right. On testing, there was very little nystagmus in rotation to the right, but much more after rotation to the left. The confirma- tion of the lesion of the left vestibule was gained by a demonstration of diminished perception of sound in the left ear, both to aerial and cranial conduction^® (Goldman of Cairo). The irrigation m’ethod does not depend upon pressure, but on temperature. Cold water causes nystagmus towards the opposite side, but the test is less responsive than that with hot water at 40° C. unless the tympanum is perforated. These effects are explained by the induction of currents in the endolymph by the change of tempera- ture. Thus, cold water causes a current from the top of the anterior semicircular canal to the ampulla below; and hence when the right ear is injected, a rotation nystagmus to the left is produced. It is only when the head is leant on the shoulder so as to tilt the horizontal canal into a more vertical plane that this test causes lateral nystag- mus : because in the horizontal plane gravity does not displace