Various Deviations
Also due to want of the cerebella check element (and hypotonic), the knee jerk become pendulous swinging back and forth instead of stopping after one or two kicks. Finally, ataxia is brought out with the patient in the recumbent position by the heel to knee test. With eyes open and closed he is asked to raise the foot high, touch the knee and carry the heel along the shin. The ataxia can also be demonstrated by asking the patient to touch an object with his toes.
Obviously all tests for in coordination are made bilaterally, all cerebella ataxia is gipsy lateral; most cerebral forms are contra lateral.
Pointing and past-pointing which really are vestibular and not pure cerebella tests, may be briefly considered here. The patient is asked to extend his arm and perform the movement at the shoulder. The examiner stands in front of him and the patient touches with the extended index finger the examiner’s two index fingers, which are held together in a fixed position. Normally with eyes open, there is no deviation. On closing the eyes and knowing the position of the examiner’s fingers, the patient should be able to touch the same spot every time. If he deviates to the right or the left there is said to be past pointing. Without entering here into a discussion of the meaning of the various deviations the following may be said:
- Normally there is no deviations
- In cases of irrigative labyrinthine lesions there is spontaneous deviation
- Normally if the vestibular apparatus is stimulated by rotation or irrigation of the ears with cold or hot water, there is deviation or past pointing
- In total or destructive lesions of the vestibular apparatus there is no past pointing on stimulation
- The plan of past pointing is influenced by the position of the head during the tests.