Postoperative Oculomotor Nerve Palsy Research Articles

Resection of Oculomotor Nerve Lesions Using Continuous Stimulation of the Oculomotor Nerve Proximal to the Lesion: A Technical Report

We describe a continuous monitoring method aimed at preserving nerve function during biopsy of lesions on the oculomotor nerve using stimulation of the oculomotor nerve proximal to the lesion. A 5-year-old girl with a recurrent left oculomotor nerve palsy and contrast-enhancing left oculomotor nerve mass on magnetic resonance imaging underwent a biopsy of the lesion to aid in its diagnosis. At the time of surgery, needle electrodes were inserted into the superior and inferior rectus muscles percutaneously, and cotton-covered electrodes were implanted into the oculomotor nerve proximal to the lesion. Compound muscle action potentials of the oculomotor nerve were measured continuously by monopolar stimulation. The lesion was mapped by direct stimulation, and the unresponsive area was excised. The amplitude of the compound muscle action potentials decreased during the resection but recovered postoperatively. After resection of the lesion, the compound muscle action potentials remained the same as they were preoperatively. No obvious postoperative oculomotor nerve palsy was observed. This method of continuous monitoring of the function of the oculomotor nerve is simple to use and is suitable for lesions in close proximity to the oculomotor nerve.

Resection of Mesencephalic Cavernoma Using the "Half-and-Half" Approach: 2-Dimensional Operative Video.

Brainstem cavernous malformations present a particular challenge to neurosurgeons. Their deep location and proximity to critical brainstem nuclei and fiber tracts make surgical access challenging. Despite this, microsurgical resection of brainstem cavernomas has been associated with good long-term neurological outcome, albeit with notable (but temporary) perioperative morbidity. Here, we demonstrate the microsurgical resection of a mesencephalic cavernoma via a "half-and-half" approach. Described as the temporopolar approach by Sano in 1980,1 this approach centers on the oculomotor nerve and combines the transsylvian and pre-/subtemporal corridors. A wide opening of the Sylvian fissure and posterior mobilization of the temporal lobe permits access to the interpenducular cistern, mesencephalon and rostral pons. In this way, the "half-and-half" ideally suited for lesions of the anterior and antero-lateral brainstem. While temporary postoperative oculomotor nerve palsy is not uncommon, rapid resolution is expected. Verbal consent was provided by the patient for reproduction and publication of her case.

Endoscopic endonasal anterior clinoidectomy: surgical anatomy, technique nuance, and case series.

Advances in endoscopic technique allow for resection of the anterior clinoid process (ACP) via an endoscopic endonasal approach. The authors discuss the endoscopic endonasal anterior clinoidectomy (EEAC) and demonstrate the relevant surgical anatomy and technical nuances. The approach was simulated in 6 cadaveric heads. From a technical point of view, the lateral optic carotid recess was used as the landmark in the proposed technique. The superomedial, superolateral, and inferior vertices of this recess are the main operative points. The EEAC approach was achieved by disconnecting the ACP tip from the base by drilling the 3 vertices. The proposed approach was successfully performed in all cadaveric specimens. Then, in a case series involving 6 patients in whom the EEAC approach was used, there were no vascular injuries; 2 patients had postoperative oculomotor nerve palsy, which improved in one and resolved in the other by 1 month.The EEAC approach for tumors and vascular lesions in the parasellar region is technically feasible. The surgical corridor is increased by ACP resection, although to a lesser extent than the transcranial anterior clinoidectomy. Based on the authors' initial anatomical and surgical results, resection of the ACP via the endonasal endoscopic approach is a novel technique worth exploring in suitable cases.

Multimodality Techniques in Microsurgical Clipping as the Gold Standard Treatment in the Management of Basilar Tip Aneurysm: A Case Series.

Introduction:Basilar aneurysms represent 5%–7% of all intracranial aneurysms. The main goal of open surgery is to achieve complete obliteration of the aneurysmal sac using minimal invasive technique while emphasizing on avoidance of complication.Materials and Methods:We performed a retrospective cohort study of nine cases of unruptured basilar tip aneurysm referred to the Fujita Health University Banbuntane-Hotokukai Hospital, Japan. The objective of the study was to analyze the surgical outcomes of unruptured basilar tip aneurysm.Results:Nine patients with unruptured basilar tip aneurysm were referred to our hospital between 2015 and 2017. The median size of the aneurysm and age were 4.00 mm (interquartile range [IQR] = 3.25–6.75 mm) and 58 years (IQR = 54–70 years), respectively. Five patients (55.6%) were presented with multiple intracranial aneurysms. Surgical adjuncts such as intraoperative neuromonitoring, intraoperative indocyanine green (ICG) angiography with dual-image videoangiography (DIVA), and neuroendoscope were used. Two patients developed transient postoperative oculomotor nerve palsy which resolved spontaneously. The median duration of surgery and days of hospitalization were 292 min (IQR = 237.5–350.5 min) and 12 days (IQR = 12–25 days), respectively. There was no mortality recorded in this case series.Conclusion:Microsurgical clipping of basilar tip aneurysm is safe in unruptured basilar tip aneurysm with a low risk of postoperative mortality or morbidity. All complications reported in this case series were transient with no long-term sequalae. The improved safety profile of microsurgical technique is due to the availability of intraoperative neuromonitoring, neuroendoscope, ICG, and DIVA. The application of multimodality technique in neurovascular surgery has also helped to achieve complication avoidance. The obliteration of the aneurysmal sac helps to restore the laminar blood flow in the bifurcation and distal blood vessels and improves the brain perfusion.

Pressure-Lowering Effect of Fistula Occlusion in a Patient with Secondary Glaucoma Due to an Intracranial Arteriovenous Fistula.

IntroductionThis case report presents the pressure-lowering effect of transluminal fistula occlusion in a patient suffering from secondary glaucoma due to carotid cavernous fistula (CCF).Case ReportA 76-year-old Caucasian woman presented with dilated epibulbar vessels with elevated intraocular pressure (IOP, >30 mmHg) as well as glaucomatous excavations of the optic disc in both eyes. Cerebral digital subtraction angiography revealed a CCF with bilateral orbital communication. Preoperative diurnal pressure profiling showed an average IOP of 25.8 mmHg (right eye) and 26.6 mmHg (left eye). Transluminal intervention and fistula occlusion led to a decrease in IOP of about 9 mmHg. A post-operative oculomotor nerve palsy regressed spontaneously.ConclusionSecondary glaucoma due to CCF might be affected by fistula occlusion. Therefore, it should be considered before any surgical glaucoma interventions are performed. Diurnal pressure profiling is an effective tool for monitoring therapeutic success.Electronic supplementary materialThe online version of this article (doi:10.1007/s40123-015-0036-0) contains supplementary material, which is available to authorized users.

Mobilization of the Transcavernous Oculomotor Nerve During Basilar Aneurysm Surgery

The transcavernous approach adds a significant exposure advantage in basilar aneurysm surgery. However, one of its frequently reported side effects is postoperative oculomotor nerve palsy. To present the technique of mobilizing the oculomotor nerve throughout its intracranial course and to analyze its consequences on the nerve tension and clinical outcome. The oculomotor nerve is mobilized from its mesencephalic origin to the superior orbital fissure. Its degree of mobility, related to the imposed pulling force, was measured in 11 cadaveric nerves. Tension was mathematically deduced and compared before and after mobilizing of the cavernous segment. One hundred four patients treated for basilar aneurysms with the orbitozygomatic pretemporal transcavernous approach were followed up for a 1-year period and evaluated for postoperative oculomotor nerve palsy. Releasing the transcavernous segment compared to cisternal mobilization alone resulted in a significant increase in freedom of mobility from 4 to 7.9 mm (P < .001) and in a significant decrease in tension from 0.8 to 0.5 N (P = .006). Ninety-nine percent of aneurysms treated with this technique were amenable to neck clipping, and a total of 84% of patients had a good postoperative outcome (modified Rankin Scale score, 0-2). All patients showed direct postoperative palsy; however, 97% had a complete recovery by 9 months. Only 3 patients had a persistent diplopia on medial gaze, which was corrected with prism glasses. Mobilization of the transcavernous oculomotor nerve results in better maneuverability and less tension on the nerve, which lead to successful surgical treatment and favorable oculomotor outcome.

Clinical manifestation and endovascular treatment of cavernous dural arteriovenous fistula

Objective To explore the clinical symptoms, performance and efficacy of endovascular treatment of cavernous sinus dural arteriovenous fistula. Method 16 cases of cavernous dural arteriovenous fistula admitted in our department from January 2006 to May 2009 and the retrospective analysis of clinical data and symptoms, vascular intervention and curative effects were analyzed. Result There were 13 patients with congestive eyes (or the merger exophthalmos), one with exophthalmos, two with temporal noise, one with subarachnoid hemorrhage. Six patients were treated by NBCA embolization through arterial approach. Immediate embolization was achieved in 3 cases after fistula occlusion. There was residual fistula in 1 case but the symptoms disappeared after 2 months. And there was residual fistula in another 2 cases, but notable improvements in symptoms were observed. 8 cases were treated through a simple approach of vein thrombosis. 2 cases in which were treated by ONYX and coil embolization and complete fistula occlusion was observed. These 2 cases were associated with postoperative oculomotor nerve palsy and outreach, the symptoms were better after 1 month. 5 cases were treated through simple ONYX embolism. 1 case was performed through combined arterial and venous approach for embolization and complete fistula occlusion was achieved. 1 cases of a small fistula was performed by carotid artery compression and the fistula was observed to be smaller after 2 month. The postoperative complications of eyes were found in 3 patients: 1 ocular and oculomotor nerve palsy, 1 diplopia and outreach nerve palsy, 1 conjunctival hyperemia and eye pain. All the complications of eyes were all alleviated. Conclusions The clinical manifestations of cavernous sinus dural arteriovenous fistula are varied. Endovascular treatment is safe and effective. Through arterial embolization approach, the possibility rate of fistula occlusion is lower than that of the intravenous approach. But the incidence of postoperative complications of eyes of arterial approach is also lower. A higher rate of fistula occlusion is observed in intravenous approach, hut it should be paid attention to the prevention of eye complications. Key words: Arteriovenous fistula; Cavernous sinus; Postoperative complication

Posterior Clinoidectomy: Dural Tailoring Technique and Clinical Application

The posterior clinoid process, a bony prominence at the superolateral aspect of the dorsum sellae, has a strategic importance in a transcavernous approach to basilar tip aneurysms. To further optimize this microsurgical technique during posterior clinoidectomy, we performed a cadaveric study of this regional anatomy, describe a technique called dural tailoring, and report initial results in the surgical treatment of upper basilar artery (BA) aneurysm. After 10 adult cadaver heads (silicone-injected) were prepared for dissection, a posterior clinoidectomy with dural tailoring was performed. The dura overlying the upper clivus was coagulated with bipolar electrocoagulation and incised. Stripping dura off the clivus and lateral reflection then exposed the ipsilateral posterior clinoid process and dorsum sellae, thus creating a dural flap. Posterior clinoidectomy with dural tailoring was then used in seven patients with upper BA aneurysms. Our stepwise modification of the posterior clinoidectomy with dural tailoring created a flap that afforded protection of the cavernous sinus and oculomotor nerve. During surgery, there were no recorded intraoperative injuries to neurovascular structures. One patient died postoperatively from morbidity related to severe-grade subarachnoid hemorrhage. Postoperative oculomotor nerve palsy occurred in 3 patients (43%). In all cases, the nerve was anatomically preserved and partial to complete recovery was recorded during the first postoperative year. This technique effectively provided exposure of retrosellar upper basilar aneurysms in seven patients (basilar tip 43% and superior cerebellar artery aneurysms 57%). Outcomes and safety are at least equivalent to or better than basilar aneurysm surgery performed without surgical adjuncts, presumably a less complex subset.

Upper basilar artery aneurysms: oculomotor outcomes in 163 cases

The purpose of this study was to identify factors predictive of postoperative oculomotor nerve palsy among patients who undergo surgery for distal basilar artery (BA) aneurysms. The data can be used to estimate preoperative risk in this population. The natural history of oculomotor nerve palsy in patients with good outcomes is also defined. The cases of 163 patients with distal BA aneurysms, who were treated surgically between 1996 and 2002, were retrospectively studied to identify factors contributing to oculomotor nerve palsy. After the data had been collected, stepwise logistic regression procedures were used to determine the predictive effects of each variable on the development of oculomotor nerve palsy and to create a scoring system. Factors that interfered with resolution of oculomotor dysfunction in patients with good outcomes were also studied. Postoperative oculomotor nerve palsy occurred in 86 patients (52.8%) with distal BA aneurysms. The following factors were associated with postoperative oculomotor dysfunction, as determined by a categorical data analysis: (1) younger patient age (p < 0.001); (2) poor admission Hunt and Hess grade (p < 0.001); (3) use of temporary arterial occlusion (p < 0.001); 4) poor Glasgow Outcome Scale score (p < 0.001); and (5) the presence of a BA apex aneurysm that projected posteriorly (p < 0.001). For patients with good outcomes, postoperative oculomotor nerve palsy resolved completely within 3 months in 31 patients (52%) and within 6 months in 47 patients (80%). The projection of the BA aneurysm was associated with incomplete oculomotor recovery at 6 months postoperatively (p = 0.019). The results of this study can help identify patients with a high risk for the development of oculomotor nerve palsy. This may help neurosurgeons in preoperative planning and discussions.

Oculomotor nerve palsy after surgery for upper basilar artery aneurysms.

The goals of this study were to evaluate the relationship between postoperative oculomotor nerve palsy and other clinical factors and to improve preoperative estimations of the risk. Such an evaluation has not been previously described in the literature. Patient records for 77 basilar tip aneurysm cases and 28 basilar superior cerebellar artery aneurysm cases treated between 1981 and 1997 were reviewed. Clinical and radiological parameters were separately analyzed using the chi2 test, and then multiple-regression analysis was used. Postoperative oculomotor palsy occurred in 25 (32%) patients with basilar tip aneurysms and 11 (39%) patients with basilar superior cerebellar artery aneurysms, in addition to 2 patients with basilar tip aneurysms and 3 patients with basilar superior cerebellar artery aneurysms who exhibited oculomotor palsy before surgery. For both type of aneurysms, the size and direction of the aneurysms were closely related to oculomotor nerve palsy. The complication also tended to occur in early surgery cases, in younger patients, and in patients of poor-clinical grade status. In this study, some clinical and radiological factors were found to be associated with postoperative oculomotor nerve palsy.