Abstract
The blindfolded vertical writing test with changes in head position was applied to examine the vestibular function in cases of unilateral peripheral Labyrinthine diseases: e.q. Meniere's disease, Sudden deafness, traumatic deafness, postoperative state of fenestration operation, toxic Vertigo due to streptmycin and salcylic acid, and supprative labyrinthitis.
The results were as follows.
1. Marked deviation in writing was observed not only in case of Meniere's disease but also in cases of unilateral peripheral labyrinthine diseases above descrived.
To be noted, however, were the facts that the majority cases of peripheral labyrinthine diseases showed pronounced positional deviation in writting in a certain constant direction and this phenomenon was apt to be especially marked when the head inclined to the side of the lesion, as compared with the head inclination to the intact side.
2. When the results of this test were compared with those of examination of positional nystagmus, the high sensitiveness of the former for detection of abnormality was more impressive. Namely, the marked positional deviation in writing was observed in the majority cases in which positional nystagmus was absent. As to the mechanism of apparance of positional deviation in writing, though details of the mechanism of this phenomenon is still obscure, it may be allowed for us to conclude that this phenomenon is induced by abnormal impulses generated in the labyrinth by changes in head position and passing through the vestibulo-spinal pathway.
However, it should be taken into consideration that the tonic neck reflex may have something to do with deviation in writing in association with changes in head position in cases of peripheral labyrinthine diseases.
