| OCR Text |
Show ]. Clin. Neuro-ophthalmol. 1: 209-211, 1981. Fourth Nerve Palsy Opposite a Black Eye Two Patients Simulating Orbital Blowout Fractures JAMES R. KEANE, M.D. Abstract Two patients with ocular ecchymosis and vertical diplopia following face and head trauma were initially thought to have orbital floor fractures. Subsequent evaluation failed to demonstrate blowout fractures and revealed opposite fourth nerve palsies as the cause of diplopia. Introduction Hypotropia accompanying traumatic lid ecchymoses suggests an orbital floor fracture .1.2 Accordingly, the following two patients were thought to have orbital blowout fractures until further examination revealed an opposite fourth nerve palsy as the cause of post-traumatic vertical diplopia. Case 1 A 35-year-old man was admitted, lethargic and intoxicated, to the neurosurgery service following a beating about the face and head. Aside from swelling and reddish ecchymosis of the right eyelids, his ocular and neurologic examinations were considered nonnal. CT scan showed no intracranial or orbital abnonnalities. The next day, upon awakening, he complained of vertical double vision. Right hypotropia accompanying his black eye suggested a right orbital floor fracture (Fig. 1). On further examination, however, his diplopia was greatest on gaze down and to the right with obvious limitation in the direction of the left superior oblique muscle (Fig. I). A subjective Bielschowsky head tilt test and Lancaster diplopia fields confinned the left fourth nerve paresis. Orbital x-rays showed no evidence of a fracture. From the Department of Neurology, Los Angeles County-University of Southern California Medical Center, Los Angeles, California. September 1981 Case 2 A 17-year-old man was admitted in stupor to the neurosurgery service following an assault. Examination revealed a supraorbital bruise, eyelid ecchymoses, and subconjunctival hemorrhage on the right side. Aside from stupor and symmetric horizontal gaze-evoked nystagmus, his neurologic examination was nonnal. A CT scan showed no intracranial or orbital abnonnalities. Several days later, he was still lethargic but sufficiently alert to complain of vertical double vision. Examination on the fifth hospital day showed bilateral lower lid ecchymoses-greater on the right side, right hypotropia, mild right infraorbital hypesthesia, and upward-as well as lateralgaze- evoked nystagmus. While his initial appearance suggested the likelihood of a right orbital floor fracture, the bilateral, "raccoon eyes" lid ecchymoses indicated a basal skull fracture. Further examination, over the next 2 days as his cooperation improved, revealed a spontaneous right head tilt, paresis of the left superior oblique muscle (Fig. 2), and a positive Bielschowsky head tilt test. Orbital x-rays showed clouding of the right frontal and maxillary sinuses but no orbital fractures were detected. The right infraorbital numbness was tentatively ascribed to nerve damage at the foramen, but it was possible that a cryptic right orbital floor fracture was present. Discussion Closed-head trauma is the most common cause of an acquired fourth nerve palsy.:l.~ The correct diagnosis usually requires a moderate degree of patient cooperation and is difficult, if not impossible, to establish while the patient is stuporous. After the patient becomes alert and complains of vertical double vision, the diagnosis of unilateral trochlear nerve paresis is usually straightforward. Initially, lethargy and physical signs suggesting an opposite blowout fracture combined to delay diagnosis in the two patients presented here. Confusion between these two common causes of posttraumatic vertical diplopia is not surprising. The 209 Traumatic Trochlear Palsy Figure 1. (Keane) (patient #1) Right palpebral ecchymoses and swelling accompanying a left fourth nerve paresis. rj~l"~ 2. (K,·.lJll·) (pati"nt #2) Right periorbit,,1 "brasion "nd subconjunctional hemorrhage. right greater than left palpebral ('cchvrnoses, and left fourth nerve paresis. 210 Journal of Clinical Neuro-ophthalmology combination of a blowout fracture with both bilateral 5 and contralateral6 . 7 fourth nerve palsy has been described. An oblique frontal blow has been suggested as a common cause of opposite trochlear nerve trauma. 4 Similar vectors of force can be involved in the direct ocular blow that produces a blowout fracture of the orbit. In the past, some authorities have recommended prompt surgical repair of presumed orbital floor fractures in the presence of typical clinical signs, even when detailed radiographic studies fail to demonstrate a fracture.Il·!· The present cases suggest some caution in accepting the "typical signs" of a blowout fracture. Hypocycloidal tomography and coronal orbital CT studies should now be able to delineate floor fractures prior to surgery. Even when a blowout fracture is confirmed, the possibility that vertical diplopia may be the result of an associated fourth nerve palsy should be considered. References 1. Putterman, M., Stevens, T., and Urist, J.: Nonsurgical management of blow-out fractures of the orbital floor. Am. ]. Ophthalmol. 77: 232-239, 1974. September 1981 Keane 2. Greenwald, S., Keeney, H., and Shannon, M.: A review of 128 patients with orbital fractures. Am. ]. Ophthalmol. 78: 655-664, 1974. 3. Khawam, E., Scott, A., and Jampolsky, A.: Acquired superior oblique palsy. Arch. Ophthalmol. 77: 761768, 1967. 4. Burger, J., Kalvin, H., and Smith, J.: Acquired lesions of the fourth cranial nerve. Brain 93: 567-574, 1970. 5. Chapman, I., Urist, J., Folk, R., et al.: Acquired bilateral superior oblique muscle palsy. Arch. Ophthalmol. 84: 137-142, 1970. 6. Cantillo, N.: A case of superior oblique palsy in an orbital floor fracture. Am. Orthop. ]. 28: 124-126, 1978. 7. Knapp, P.: Blow-out fractures. In Symposium on Strabismus. C. V. Mosby, St. Louis, 1978, pp. 285291. 8. Lerman, S.: Blowout fracture of the orbit: Diagnosis and treatment. Br. ]. Ophthalmol. 54: 90-98, 1970. 9. MacDonald, R., Jr.: Head trauma-Orbital fractures. In Industrial and Traumatic Ophthalmology. C. V. Mosby, St. Louis, 1964, pp. 82-99. Write for reprints to: James R. Keane, M.D., 1200 N. State Street, Los Angeles, California 90033. 211 |
