OBJECTIVETo anatomically reconstruct the oculomotor nerve, trochlear nerve, and abducent nerve by skull base surgery.

METHODSSeventeen cranial nerves (three oculomotor nerves, eight trochlear nerves and six abducent nerves) were injured and anatomically reconstructed in thirteen skull base operations during a period from 1994 to 2000. Repair techniques included end-to-end neurosuture or fibrin glue adhesion, graft neurosuture or fibrin glue adhesion. The relationships between repair techniques and functional recovery and the related factors were analyzed.

RESULTSFunctional recovery began from 3 to 8 months after surgery. During a follow-up period of 4 months to 6 years, complete recovery of function was observed in 6 trochlear nerves (75%) and 4 abducent nerves (67%), while partial functional recovery was observed in the other cranial nerves including 2 trochlear nerves, 2 abducent nerves, and 3 oculomotor nerves.

CONCLUSIONSComplete or partial functional recovery could be expected after anatomical neurotization of an injured oculomotor, trochlear or abducent nerve. Our study demonstrated that, in terms of functional recovery, trochlear and abducent nerves are more responsive than oculomotor nerves, and that end-to-end reconstruction is more efficient than graft reconstruction. These results encourage us to perform reconstruction for a separated cranial nerve as often as possible during skull base surgery.

Abducens Nerve ; surgery ; Adolescent ; Adult ; Female ; Humans ; Male ; Middle Aged ; Nerve Regeneration ; Nerve Transfer ; methods ; Oculomotor Nerve ; surgery ; Oculomotor Nerve Injuries ; Skull Base Neoplasms ; surgery ; Trochlear Nerve ; surgery ; Trochlear Nerve Injuries

PURPOSE: To define the clinical characteristics of acute vertical strabismus in adults strabismus without known ocular and cranial external factors. METHODS: We performed a retrospective study of 72 adult patients who developed acute vertical strabismus without known ocular and cranial external factors such as trauma or operation and were followed up for at least 6 months. RESULTS: Undetermined cause (n = 41, 57%) was the most common etiology of acute vertical strabismus, followed by fourth cranial nerve palsy (n = 15, 20.8%), myasthenia gravis (n = 7, 9.7%), third cranial nerve palsy (n = 6, 8.3%), brain tumor (n = 2, 2.7%), and carotid-cavernous fistula (n = 1, 1.3%). The average vertical deviation at primary position was 7.2 prism diopter at initial visit. Thirty-eight (62.3%) patients recovered to orthophoria and 13 (21.3%) patients showed decreased level of diplopia. The average recovery period was 2.9 months. Ten cases remained as strabismus and 5 underwent surgery upon patient's request. CONCLUSIONS: Unknown cause was the most common diagonosis of adult acute vertical strabismus without known ocular and cranial external factors. In the present study, 62.3% of patients recovered to orthophoria and 83.6% recovered without surgical procedures.
Adult* ; Brain Neoplasms ; Diplopia ; Fistula ; General Surgery ; Humans ; Myasthenia Gravis ; Oculomotor Nerve ; Paralysis ; Retrospective Studies ; Strabismus* ; Trochlear Nerve Diseases ; Wounds and Injuries