Abstract
Using the test for the convergence reflex and the test for the righting reflex and convergence reflex (Ushio and Hinoki, 1971), effects of a prismatic lens over the paralytic eye were examined in 33 patients with head and neck injuries, in connection with the disturbance of the convergence reflex and the convergence-induced disturbances of the righting reflex. In the test for the righting reflex and a convergence reflex, the subject is asked to maintain Romberg's position daring which the convergence reflex is induced. The results obtained were as follows:
(1) Disturbance of the convergence reflex was alleviated in 24 of the 33 patients (73%), unchanged in 9 (27%), aggravated in 6 (18%), when a prismatic lense was placed over the paralytic eye with the apex of the lens toward the nose.
(2) Convergence-induced disturbance of the righting reflex was alleviated in 18 of the 33 patients (55%), unchanged in 9 (27%), aggravated in 6 (8%) when a prismatic lens was placed over the paralytic eye.
(3) There was a positive correlation between the results from the test for the convergence reflex and those from the test for the righting reflex and convergence reflex when a prismatic lens was placed over the paralytic eye.
(4) Fourteen patients who fell backward on Romberg's position and had cerebellar symptoms were examined using the test for the righting reflex and convergence reflex and the tests for cerebellar ataxia of the upper limbs. Both kinds of tests were carried out while placing a prismatic lens over the paralytic eye.
Through these examinations, it was found that the above-mentioned falling backward was significantly ameliorated, i. e., at the rate of 85.7% when the former test was carried out. In contrast, improvement in cerebellar ataxia of the upper limbs was less obvious, i. e., at the rate of 28.5% when the latter test was performed.
From a series of examinations, the following conclusions were drawn:
(1) Disturbances of the convergence reflex can be a factor in inducing and/or aggravating bodily disequilibrium due to post-concussion states.
(2) Disturbance of the convergence reflex can induce and/or increase bodily disequilibrium in collaboration with the cerebellar vermis. In contrast, such disturbance does not significantly correlate with the cerebellar hemispheres, with regard to the development and/or increase of bodily disequilibrium.
