Studies on motor cyclofusion. Part 2. Analysis of motor cyclofusion in patients with unilateral superior oblique palsy
Nakayama, M.
Nippon Ganka Gakkai Zasshi 91(2): 286-292
1987
ISSN/ISBN: 0029-0203 PMID: 3604818 Document Number: 289592
Motor cyclofusion (mcf) was objectively measured in 12 cases (4, congenital; 8, acquired) with unilateral superior oblique palsy by means of photographic method using the modified Aulhorn's Phase Difference Haploscope with newly devised equipments for changing head positions (head erect position (HE), 15.degree. chin elevated position (CE), 15.degree. chin depressed position (CD), or 30 head tilted positions-to either of both sides-, RT or LT). A figure of a doll face, 10.degree. of visual angle in size, was used as the figure of fusional stimulus. The obtained data were analyzed with special reference to the data of normal subjects reported previously by the author using the same method. The results were as follows: 1) The mcf movements were divided into 4 types in the previous report. Because of lack of equilibria of cyclomotorial components of the extraocular muscles in unilateral superior oblique palsy, a few cases of cyclovergence type and no cases with cycloduction type were found in this study. 2) In comparison with the amount of the mcf of unilateral superior oblique palsies to that of normal subjects, (a) a smaller mcf was noted in both ex- and incyclodirectional simuli (3.degree., 6.degree.) in CE (p < 0.05). In the paretic eye, an increasing of the amount of excyclodeviation in this head position was revealed mainly due to a palsy of the superior oblique, one of the intorters. (b) In CD, in half of the cases without overaction of the IO of the paretic eye, a smaller mcf was noted in excyclofusinal stimuli (3.degree., 6.degree.), however, no significant differences in mcf in the other half of the cases with overaction of the IO Of the involved eye and in normal cases were found (p < 0.05). (c) There was also a smaller mcf in excyclofusional stimuli (3.degree., 6.degree.) in the head tilted position to the affected side (p < 0.05). In this head position, a small amount of additional excycloduction of both eyes could be allowed beyond the eye position of excycloduction where there was a disturbance of counterrolling of the paretic eye and a normal size of counterrolling of the non-paretic eye. (d) No significant differences were found between the amount of mcf in HE and that in the head tilted position to the non-affected side. This fact would indicate that no prominent influences of unilateral superior oblique palsy to ocular movement were found in these head positions.