Neurotization of oculomotor, trochlear and abducent nerves in skull base surgery.
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OBJECTIVE: To anatomically reconstruct the oculomotor nerve, trochlear nerve, and abducent nerve by skull base surgery. METHODS: Seventeen 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. RESULTS: Functional 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. CONCLUSIONS: Complete 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. (+info)
Incomplete oculomotor nerve palsy caused by an unruptured internal carotid-anterior choroidal artery aneurysm--case report--.
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A 59-year-old woman visited our institute with the chief complaint of dizziness which persisted whenever she tried to focus on objects. She had not experienced apparent double vision and had no history of intracranial bleeding. Neurological examination revealed no abnormality except for exotropia at the mid-position and at upper gaze. Cerebral angiography revealed that the intracranial portion of the left internal carotid artery ran more horizontally and also identified an unruptured left internal carotid-anterior choroidal artery (IC-AChA) aneurysm of 3.0 mm diameter. The aneurysm at the origin of the AChA was confirmed during surgery. The proximal lateral wall of the aneurysm was in contact with the oculomotor nerve. This contact was released after complete obliteration of the aneurysm. The exotropia resolved 3 months later. Oculomotor nerve palsy usually indicates the presence of internal carotid-posterior communicating artery (IC-PcomA) aneurysm. Since sacrifice of the AChA will result in severe neurological deficits, accurate neuroimaging information is needed prior to the operation. Conventional angiography and/or three-dimensional computed tomography angiography should be performed to ascertain whether the aneurysm is an IC-PcomA or IC-AChA aneurysm, even if some neurosurgeons insist that conventional angiography is not always needed before surgery for an unruptured aneurysm. (+info)
Comparison of the risk of oculomotor nerve deficits between detachable balloons and coils in the treatment of direct carotid cavernous fistulas.
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Retrograde horseradish peroxidase transport after oculomotor nerve injury.
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We studied the distribution of somatic motor neurons innervating the cat superior rectus 3-6 months after oculomotor nerve injury using intramuscular horseradish peroxidase (HRP). In normal cats, 98% or more of the labelled superior rectus motoneurons were in the contralateral oculomotor subnucleus. Two experimental cats who exhibited little or no evidence of recovery showed few labelled cells (4% of controls) which were distributed in both the ipsilateral and contralateral oculomotor nucleus. The other three experimental cats demonstrated definite signs of recovery, and HRP injections labelled more cells (20% of controls) also distributed in the ipsilateral and contralateral oculomotor subnuclei. This study shows that, after sectioning, the oculomotor nerve regenerates and anomalous connections develop between the somatic motoneurons of the ipsilateral oculomotor nucleus and the superior rectus. These findings support the hypothesis that acquired oculomotor synkinesis developing after third nerve injury results from misdirection of regenerating axons. (+info)
Traumatic third nerve palsy.
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Twenty patients with a traumatic third nerve palsy had sustained a closed head injury with prolonged loss of consciousness in a high-speed deceleration accident. Sixteen were male, and the average age was 25 years. Seven had skull or facial fractures, 15 damage to the anterior visual pathways, and 16 other permanent neurological damage. Nineteen developed the misdirection/regeneration syndrome. Thirteen had strabismus surgery, and an area of binocular single vision was enlarged or achieved in three. (+info)