Small unruptured cerebral aneurysms presenting with oculomotor nerve palsy

Recovery of Oculomotor Nerve Palsy After Surgical and Endovascular Repair of Unruptured Internal Carotid-Posterior Communicating Artery Aneurysms

OBJECTIVE

Unruptured posterior communicating artery (Pcom) aneurysms cause oculomotor nerve palsy (ONP). However, the time course of recovery after aneurysm repair remains unclear. We aimed to evaluate the ONP course after clipping and coiling for unruptured Pcom aneurysms.

METHODS

We retrospectively reviewed the medical records of 25 consecutive patients with ONP due to unruptured Pcom aneurysms, undergoing aneurysm repair at our institution during 2010-2022. We analyzed the clinical data, angiographic results, and surgical complications. The time to ONP recovery was evaluated using the Kaplan-Meier method.

RESULTS

This study included 14 patients undergoing surgical clipping and 11 undergoing endovascular coiling. The two groups exhibited no significant differences in complete or partial ONP percentage or in symptom presentation (ptosis, diplopia, ocular paralysis, pupillary light reflex disorder, or mydriasis). All patients achieved complete or partial recovery during the follow-up period. The median time to partial or complete improvement in ONP was significantly shorter for clipping compared to coiling (2 days vs. 33 days; P = 0.009). Preoperative partial and complete ONP were stratified; clipping improved significantly earlier than coiling in the complete ONP group (P = 0.010). In the early treatment group (based on the median duration of treatment), clipping resulted in earlier improvement than coiling (P = 0.014). In the small aneurysm group (based on the median of the aneurysm maximum diameter), clipping resulted in earlier improvement than coiling (P = 0.005).

CONCLUSION

In ONP caused by an unruptured Pcom aneurysm, clipping may provide faster recovery than coiling, particularly in cases of early onset, complete palsy, and small aneurysms.

An understimated maneuver for oculomotor nerve palsy due to posterior communicating artery aneurysm: the opening of the anterior petroclinoid ligament. A technical note

Posterior communicating artery aneurysms (PcomAs) present with oculomotor nerve (OMN) palsy in 20-30% of cases, and the sudden onset of OMN palsy has to raise the suspicion of rupture, until proven otherwise. The surgical technique is described in a stepwise fashion. An illustrative case is reported: a 57-year-old female was admitted to our department with the diagnosis of a right sided-PcomA. Three months before the admission, when she harbored with the acute onset of complete ptosis, diplopia, orbital pain, impairment of the medial, upward, and downward gaze, with no pupil dysfunction. The origin of the Pcom and the neck of the aneurysm were easily identified and the aneurysm was clipped. Then, we followed the OMN and cut for less than 4 mm the above-lying anterior petroclinoid ligament (APL) to obtain nerve release. Although few cases are described in the literature, and ours represents a single case, we support that this maneuver should be introduced in the clinical practice of expert neurosurgeons dealing with vascular pathologies, such as the opening of the falciform ligament occurs for the decompression of the optical nerve.

Factors affecting resolution of oculomotor nerve palsy following endovascular embolization of posterior communicating artery aneurysms

PURPOSE

To investigate the effect of endovascular embolization of posterior communicating artery (Pcom) aneurysms on concomitant oculomotor nerve palsy (OMNP) and factors affecting the effect of treatment.

MATERIALS AND METHODS

Patients with the Pcom aneurysms concomitant with OMNP were retrospectively enrolled for endovascular treatment of the aneurysms. All patients had the endovascular management. The clinical effect, degree of OMNP, size of the aneurysm, type of treatment, subarachnoid hemorrhage (SAH), and time from onset to treatment were analyzed on the resolution of OMNP.

RESULTS

Ninety-six patients with 99 Pcom aneurysms were enrolled and treated endovascularly, with the success rate of 100%. Immediately after endovascular treatment, 75 aneurysms (75.75%) got complete occlusion, and 24 (24.24%) nearly complete occlusion. Followed up for 3-18 (mean 8.52±0.56) months, complete resolution of the OMNP was achieved in 63 patients (65.63%), partial resolution in 21 (21.88%), and non-recovery in the other 12 (12.50%). The degree of OMNP at onset, SAH, and time from onset to treatment were significantly (P<0.05) correlated with the resolution of OMNP. Univariate analysis revealed that younger age of the patient, degree of OMNP at onset, presence of subarachnoid hemorrhage, and time from disease onset to treatment were significantly (P<0.05) associated with the recovery of OMNP. Multivariate analysis revealed that the younger age, degree of OMNP at onset, and time from disease onset to treatment were significantly (P<0.05) associated with the recovery of OMNP.

CONCLUSION

Endovascular embolization of Pcom aneurysms concomitant with OMNP can effectively improve the OMNP symptoms, especially for patients with moderate and a shorter history of OMNP. Younger age, degree of oculomotor nerve palsy at onset, and time from onset to treatment may significantly affect recovery of oculomotor nerve palsy.

Serum Interleukin-1 Levels Are Associated with Intracranial Aneurysm Instability

Serum interleukin-1 (IL-1) are possibly indicative of the inflammation in the intracranial aneurysm (IA) wall. This study aimed to investigate whether IL-1 could discriminate the unstable IAs (ruptured intracranial aneurysms (RIAs) and symptomatic unruptured intracranial aneurysms (UIAs)) from stable, asymptomatic UIAs. IA tissues and blood samples from 35 RIA patients and 35 UIA patients were collected between January 2017 and June 2020 as the derivation cohort. Blood samples from 211 patients with UIAs were collected between January 2021 and June 2022 as the validation cohort (including 63 symptomatic UIAs). Blood samples from 35 non-cerebral-edema meningioma patients (non-inflammatory control) and 19 patients with unknown-cause subarachnoid hemorrhage (hemorrhagic control) were also collected. IL-1β and IL-1.ra (IL-1 receptor antagonist) were measured in serum and IA tissues, and the IL-1 ratio was calculated as log10 (IL-1.ra/IL-1β). Based on the derivation cohort, multivariate logistic analysis showed that IL-1β (odds ratio, 1.48, P = 0.001) and IL-1.ra (odds ratio, 0.74, P = 0.005) were associated with RIAs. The IL-1 ratio showed an excellent diagnostic accuracy for RIAs (c-statistic, 0.91). Histological analysis confirmed the significant correlation of IL-1 between serum and aneurysm tissues. IL-1 ratio could discriminate UIAs from non-inflammatory controls (c-statistic, 0.84), and RIAs from hemorrhagic controls (c-statistic, 0.95). Based on the validation cohort, the combination of IL-1 ratio and PHASES score had better diagnostic accuracy for symptomatic UIAs than PHASES score alone (c-statistic, 0.88 vs 0.80, P < 0.001). Serum IL-1 levels correlate with aneurysm tissue IL-1 levels and unstable aneurysm status, and could serve as a potential biomarker for IA instability.

Internal carotid artery aneurysm with incomplete isolated oculomotor nerve palsy: a case report

BACKGROUND

Oculomotor nerve palsy is a common and well-described disease with diverse etiologies. Clinicians should quickly and correctly diagnose and treat oculomotor nerve palsy according to its characteristics and the accompanying symptoms and signs. Intracranial aneurysm is an important and frequent cause of oculomotor nerve palsy. Considering the catastrophic consequences of rupture, the possibility of an urgent, life-threatening disease should always be considered.

CASE PRESENTATION

A 63-year-old Chinese woman presented with intermittent left ptosis and diplopia and painless incomplete oculomotor nerve palsy without pupil involvement. She manifested no mydriasis or extraocular muscle weakness, and the light reflex was normal. Other cranial nerves and somatosensory and somatomotor examinations were normal. The neostigmine experiment and electromyography were normal, so the diagnosis of myasthenia gravis was excluded. Brain magnetic resonance angiography showed a 4-mm aneurysm located at the cavernous segment of the left internal carotid artery. Unfortunately, the patient refused digital subtraction angiography and was discharged home without further treatment.

CONCLUSION

Neuroimaging must be performed to exclude intracranial aneurysms in oculomotor nerve palsy regardless of whether the pupils are involved, as aneurysm rupture carries substantial morbidity and mortality.

Nomogram model for predicting oculomotor nerve palsy in patients with intracranial aneurysm

AIM

To explore the risk factors of oculomotor nerve palsy (ONP) in patients with intracranial aneurysm (IA) and develop a nomogram model for predicting ONP of IA patients.

METHODS

A total of 329 IA patients were included. Logistic regression analysis was applied to identify independent factors, which were then integrated into the nomogram model. The performance of the nomogram model was evaluated by calibration curve, receiver operating curve (ROC), and decision curve analysis.

RESULTS

Univariate and multivariate logistic regression analysis indicated posterior communicating artery (PCoA) aneurysm [hazard ratio (HR)=17.13, P<0.001] and aneurysm diameter (HR=1.31, P<0.001) were independent risk factors of ONP in IA patients. Based on the results of logistic regression analysis, a nomogram model for predicting the ONP in IA patients was constructed. The calibration curve indicated the nomogram had a good agreement between the predictions and observations. The nomogram showed a high predictive accuracy and discriminative ability with an area under the curve (AUC) of 0.863. The decision curve analysis showed that the nomogram was powerful in the clinical decision. PCoA aneurysm (HR=3.38, P=0.015) was identified to be the only independent risk factor for ONP severity.

CONCLUSION

PCoA aneurysm and aneurysm diameter are independent risk factors of ONP in IA patients. The nomogram established is performed reliably and accurately for predicting ONP. PCoA aneurysm is the only independent risk factor for ONP severity.

Complex Intracranial Aneurysms

Complex intracranial aneurysms remain challenging to treat using standard microsurgical or endovascular techniques. These aneurysms often require a combination of deconstructive and reconstructive procedures, such as parent artery occlusion, flow alteration, and blind-alley formation with or without bypass surgery, for effective and enduring therapeutic effects. It is important to determine the type of bypass based on the site of occlusion of the patent artery, anatomical features of the distal vessels, and expected adequate blood flow. In this chapter, we describe the "Standards," "Advances," and "Controversies" in the context of a microsurgical treatment strategy for complex intracranial aneurysms. "Standards" include a combination of frequent and commonly used procedures that have been gathering a certain consensus on their effectiveness. "Advances" include infrequent, demanding, and/or uncertain surgical procedures that are currently under debate. Finally, "Controversies" discuss a number of unsolved issues.

Factors affecting resolution of oculomotor nerve palsy following endovascular embolization of posterior communicating artery aneurysms

PURPOSE

To investigate the effect of endovascular embolization of posterior communicating artery (Pcom) aneurysms on concomitant oculomotor nerve palsy (OMNP) and factors affecting the effect of treatment.

MATERIALS AND METHODS

Patients with the Pcom aneurysms concomitant with OMNP were retrospectively enrolled for endovascular treatment of the aneurysms. All patients had the endovascular management. The clinical effect, degree of OMNP, size of the aneurysm, type of treatment, subarachnoid hemorrhage (SAH), and time from onset to treatment were analyzed on the resolution of OMNP.

RESULTS

Ninety-six patients with 99 Pcom aneurysms were enrolled and treated endovascularly, with the success rate of 100%. Immediately after endovascular treatment, 75 aneurysms (75.75%) got complete occlusion, and 24 (24.24%) nearly complete occlusion. Followed up for 3-18 (mean 8.52±0.56) months, complete resolution of the OMNP was achieved in 63 patients (65.63%), partial resolution in 21 (21.88%), and non-recovery in the other 12 (12.50%). The degree of OMNP at onset, SAH, and time from onset to treatment were significantly (P<0.05) correlated with the resolution of OMNP. Univariate analysis revealed that younger age of the patient, degree of OMNP at onset, presence of subarachnoid hemorrhage, and time from disease onset to treatment were significantly (P<0.05) associated with the recovery of OMNP. Multivariate analysis revealed that the younger age, degree of OMNP at onset, and time from disease onset to treatment were significantly (P<0.05) associated with the recovery of OMNP.

CONCLUSION

Endovascular embolization of Pcom aneurysms concomitant with OMNP can effectively improve the OMNP symptoms, especially for patients with moderate and a shorter history of OMNP. Younger age, degree of oculomotor nerve palsy at onset, and time from onset to treatment may significantly affect recovery of oculomotor nerve palsy.

Importance of the "Rule of the Pupil" in the Modern Neuroimaging Era

ABSTRACT

The "Rule of the Pupil" states that when aneurysms compress the oculomotor nerve, a dilated or sluggishly reactive pupil will result. In previous decades, when cerebral angiography was required to detect an intracranial aneurysm, the "Rule of the Pupil" was used to determine the relative risk of angiography and the likelihood of aneurysmal compression in patients with third nerve palsies (3NPs). Noninvasive imaging including computed tomography angiography (CTA) and magnetic resonance angiography has become readily accessible and can detect all aneurysms large enough to cause 3NPs. It is therefore recommended that all patients with 3NP undergo neuroimaging regardless of pupil status because the consequences of missing an aneurysm are high. The question therefore remains as to whether the "Rule of the Pupil" still has relevance in today's era of modern neuroimaging. We describe a 73-year-old man who developed a left complete, pupil-sparing 3NP and was found to have a paraclinoid meningioma in the left cavernous sinus. As compressive lesions are expected to impair the iris sphincter muscle, no intervention was recommended and his 3NP spontaneously improved within 3 months. We also describe a 54-year-old woman with diabetes and a complete 3NP with a dilated, nonreactive pupil. Initial CTA was reported as normal, but re-review of imaging revealed a posterior communicating artery aneurysm and immediate intervention to coil the aneurysm occurred. The "Rule of the Pupil" is still important in the modern neuroimaging era as demonstrated in cases of incidentally found lesions along the course of the oculomotor nerve and missed radiological findings.

Clipping versus coiling for the treatment of oculomotor nerve palsy induced by posterior communicating artery aneurysms: A comparison of effectiveness

BACKGROUND

A long debate has been going on in the clinical effectiveness to determine whether surgical clipping or coiling more favorable for oculomotor nerve palsy (ONP) caused by PcomAA. We aimed to perform a study, focusing on the effectiveness of ONP induced by PcomAA after treatment of surgical clipping and endovascular coiling.

METHOD

Potential studies were searched on PubMed, EMBASE, Web of Science, and Cochrane Library from database inception to February 2021, and STATA version 12.0 was exerted to process the pooled data.

RESULTS

A total of 16 articles are included in the study, hailing from the United States, South Korea, the United Kingdom, France, Germany, Korea, China, Japan, Britain, and Singapore. The results showed that the clipping group was related to a higher incidence of complete ONP recovery at follow-up (OR = 5.808, 95% CI 2.87 to 11.76, p < 0.001), the lower rates of partial ONP recovery (OR = 0.264, 95% CI 0.173 to 0.402, p < .001) and no improvement of ONP at follow-up (RD = -0.149, 95% CI -0.247 to -0.051, p = .003). In the subgroup of complete ONP recovery based on the condition of patients, clipping was associated with a higher incidence of complete ONP recovery in patients with the incomplete initial ONP (OR = 3.579, p = .020) and ruptured aneurysm (OR = 5.38, p = .020). Regarding the subgroup of complete ONP recovery based on the quality of studies, similar results also appeared.

CONCLUSION

Surgical clipping was more favorable to the recovery from ONP caused by PcomAA endovascular coiling due to a higher rate of recovery and recovery degree of ONP. Besides that, more evidence-based performance is necessary to supplement this opinion.

Third Nerve Palsy Due to Intracranial Aneurysms and Recovery after Endovascular Coiling

INTRODUCTION

The modality of treatment of third nerve palsy (TNP) associated with intracranial aneurysms remains controversial. While treatment varies with the location of the aneurysm, microsurgical clipping of PComm aneurysms has generally been the traditional choice, with endovascular coiling emerging as a reasonable alternative.

METHODS

Patients with TNP due to an intracranial aneurysm who subsequently underwent treatment at a mid-sized Canadian neurosurgical center over a 15-year period (2003-2018) were examined.

RESULTS

A total of 616 intracranial aneurysms in 538 patients were treated; the majority underwent endovascular coiling with only 24 patients treated with surgical clipping. Only 37 patients (6.9%) presented with either a partial or complete TNP and underwent endovascular embolization; of these, 17 presented with a SAH secondary to intracranial aneurysm rupture. Aneurysms associated with TNP included PComm (64.9%), terminal ICA (29.7%), proximal MCA (2.7%), and basilar tip (2.7%) aneurysms. In general, smaller aneurysms and earlier treatment were provided for patients for ruptured aneurysms with a shorter mean interval to TNP recovery. In the endovascularly treated cohort initially presenting with TNP, seven presented with a complete TNP and the remaining were partial TNPs. TNP resolved completely in 20 patients (55.1%) and partially in 10 patients (27.0%). Neither time to coiling nor SAH at presentation were significantly associated with the recovery status of TNP.

CONCLUSION

Endovascular coil embolization is a viable treatment modality for patients presenting with an associated cranial nerve palsy.

Delayed oculomotor nerve palsy associated with a ruptured anterior communicating aneurysm: Case report

BACKGROUND AND IMPORTANCE

Oculomotor nerve palsy (ONP) is usually associated with posterior communicating (PCOM) aneurysms. ONP in patients with anterior circulation aneurysms are extremely rare, with only a handful of such published cases to date. There is currently no accepted mechanism to explain this clinical finding.

CLINICAL PRESENTATION

We describe a case of a 60-year-old female that benefitted from endovascular coiling of a ruptured anterior communicating (ACOM) aneurysm. In the following days, she clinically deteriorated and benefitted from another digital subtraction angiography (DSA) with intravascular verapamil for suspected vasospasm, and subsequently developed a right ONP.

CONCLUSION

Although classically related to PCOM aneurysm, ONP may be associated with ACOM aneurysms. The causative mechanism is unclear, but vasospasm may alter the microvascularisation of the oculomotor nerve, leading to ischemia.

Clipping versus coiling in the treatment of oculomotor nerve palsy induced by unruptured posterior communicating artery aneurysms: A meta-analysis of cohort studies

BACKGROUND

Although the superiority of clipping compared to coiling on the oculomotor nerve palsy (ONP) recovery for ruptured posterior communicating artery aneurysms (PcomAAs) has been widely accepted, which treatment modality is better in the treatment of ONP induced by unruptured PcomAAs still remains unclear.

METHODS

A meta-analysis of studies that compared clipping with coiling was performed after a literature search. Perioperative data and clinical outcome were extracted. Analysis on the effect of the two treatment modalities was then performed.

RESULTS

Nine eligible studies with a total of 136 patients met the inclusion criteria. There was a significant difference in the total efficiency (any degree of improvement) on ONP favoring clipping [RR= 1.21, 95%CI (1.01, 1.44), p = 0.04], the effect was most notable for complete recovery of ONP after having suffered preoperative partial palsy [RR= 0.72, 95%CI (0.55, 0.95), p = 0.02]. There was neither a significant difference regarding the complete recovery of ONP [RR= 1.11, 95%CI (0.77, 1.61), p = 0.58] nor the frequency of complications [RR= 0.07, 95%CI (0.00, 1.10), p = 0.06]. Also when subdividing there was no significant difference in complete recovery of ONP in patients who had initially suffered a complete ONP [RR= 0.79, 95%CI (0.38, 1.64), p = 0.53] and partial ONP [RR= 1.16, 95%CI (0.65, 2.08), p = 0.61] between clipping and coiling.

CONCLUSIONS

A superiority of clipping over coiling for the improvement of ONP secondary to unruptured PcomAAs was found. Patients with partial ONP were more likely to attain a complete resolution of ONP, as compared to complete ONP.

Cavernous internal carotid artery aneurysm presenting with ipsilateral oculomotor nerve palsy: A case report

The oculomotor nerve palsy is a rare neurological deficit, it is associated with numerous underlying pathologies. Including stroke, neoplasms, trauma, post-surgical inflammation, and microvascular damage from chronic disease. It can cause a set of neurological deficits, including diplopia from oculomotor nerve involvement, decreased visual acuity from optic neuropathy, facial hypoesthesia from involvement of the trigeminal nerve, and less frequently facial pain. We present a case of 52 years old female patient who presented with a history of lateral divination of the left eye associated with ipsilateral drooping of upper eyelid, visual disturbance, and ‏pupil dysfunction. MRI and MRA were performed and in conventional sequences plus 3D FIESTA sequence and it shows a signal void structure, compressing the left oculomotor nerve after passing through left chiasmatic cistern and upon entrance to cavernous sinus. Reformatted images demonstrate that this structure arising from distal left internal carotid artery at lateral part of cavernous sinus represents a saccular aneurysm in the cavernous part of the internal carotid. Aneurysms can cause direct compression of the third cranial nerve either by the enlargement of an unruptured aneurysm or by rupture of the aneurysmal sac resulting in third cranial nerve palsy.

Qualitative and Quantitative Wall Enhancement on Magnetic Resonance Imaging Is Associated With Symptoms of Unruptured Intracranial Aneurysms

BACKGROUND AND PURPOSE

Aneurysmal wall enhancement (AWE) on vessel wall magnetic resonance imaging (VW-MRI) has been described as a new imaging biomarker of unstable unruptured intracranial aneurysms (UIAs). Previous studies of symptomatic UIAs are limited due to small sample sizes and lack of AWE quantification. Our study aims to investigate whether qualitative and quantitative assessment of AWE can differentiate symptomatic and asymptomatic UIAs.

METHODS

Consecutive patients with UIAs were prospectively recruited for vessel wall magnetic resonance imaging at 3T from October 2014 to October 2019. UIAs were categorized as symptomatic if presenting with sentinel headache or oculomotor nerve palsy directly related to the aneurysm. Evaluation of wall enhancement included enhancement pattern (0=none, 1=focal, and 2=circumferential) and quantitative wall enhancement index (WEI). Univariate and multivariate analyses were used to identify the parameters associated with symptoms.

RESULTS

Two hundred sixty-seven patients with 341 UIAs (93 symptomatic and 248 asymptomatic) were included in this study. Symptomatic UIAs more frequently showed circumferential AWE than asymptomatic UIAs (66.7% versus 17.3%, P<0.001), as well as higher WEI (median [interquartile range], 1.3 [1.0-1.9] versus 0.3 [0.1-0.9], P<0.001). In multivariate analysis, both AWE pattern and WEI were independent factors associated with symptoms (odds ratio=2.03 across AWE patterns [95% CI, 1.21-3.39], P=0.01; odds ratio=3.32 for WEI [95% CI, 1.51-7.26], P=0.003). The combination of AWE pattern and WEI had an area under the curve of 0.91 to identify symptomatic UIAs, with a sensitivity of 95.7% and a specificity of 73.4%.

CONCLUSIONS

In a large cohort of UIAs with vessel wall magnetic resonance imaging, both AWE pattern and WEI were independently associated with aneurysm-related symptoms. The qualitative and quantitative features of AWE can potentially be used to identify unstable intracranial aneurysms.

Quantifying asymmetry of anterior cerebral arteries as a predictor of anterior communicating artery complex aneurysm

OBJECTIVES

The aim of this study was to establish an anatomical index for early prediction of the risk of development of aneurysms in anterior communicating arterial complex (AcomAC). The asymmetric diameter of one anterior cerebral artery (ACA) to other could alter haemodynamics and may contribute to formation of aneurysms in AcomAC and be a reliable predictor of the risk of development of aneurysms.

DESIGN AND SETTING

This is a retrospective, observational and quantitative study, which used cerebral computed tomography angiography (CCTA) scans in South Australia.

PARTICIPANTS

CCTA scans of 166 adult patients of both sexes were studied.

MAIN OUTCOME MEASURES

The internal diameters of the proximal segments of ACAs (A1s) were measured. Position and presence or absence of aneurysms in AcomAC were determined. The ratio of A1 diameters was taken as a measure of A1 asymmetry.

RESULTS

The ratio of diameters of A1s correlated with the occurrence of AcomAC aneurysms. The risk of development of aneurysms in AcomAC was much greater (80%, OR=47.3) when one A1 segment's radius was at least 50% larger (ie, 2.25 times cross-sectional area) than the other.

CONCLUSION

The general information on asymmetric A1 has been published previously. The present findings have significant contribution since the A1s asymmetry ratios have been categorised in ascending order and matched with the presence of AcomAC aneurysms. The asymmetry ratio of the A1 is a good predictor for the development of AcomAC aneurysms. Reconstruction of the asymmetric A1 could be done if the technology gets advanced.

Recovery of oculomotor nerve palsy after endovascular management of posterior communicating artery aneurysms

BACKGROUND

Oculomotor nerve palsy (ONP) is a common clinical presentation of posterior communicating artery (PcomA) aneurysms. It remains unclear if patients have a better rate of recovery after surgical clipping or endovascular coiling.

OBJECTIVES

The main objectives of this study were to assess the overall rate of ONP recovery after endovascular coiling of PcomA aneurysms, as well as to determine the associated predictive factors of oculomotor nerve recovery.

METHOD

We retrospectively evaluated the demographic, clinical, and radiological characteristics and the outcome of consecutive patients presenting with PcomA aneurysms treated by endovascular coiling from January 2012 to November 2016 with at least 1 year clinical and radiological follow-up. Statistical analysis was applied to determine the association between ONP recovery and the demographic, clinical and radiological variables.

RESULTS

A total of 91 patients with PcomA aneurysms were treated endovascularly. Thirty-four patients (22 women and 12 men) with ONP related to PcomA aneurysms were included. The mean age of the patients was 49.8 years. Subarachnoid haemorrhage was present in 27 patients. The mean aneurysm size was 6.7 mm. The overall rate of recovery was 88.2%. Complete nerve recovery was seen in 16 (47%) patients and partial recovery was observed in 14 (41.2%) patients, whilst 4 (11.8%) patients remained unchanged after treatment. The non-posterolateral direction of the aneurysm showed a tendency towards better recovery compared to the posterolateral projection (p = 0.06).

CONCLUSION

Endovascular coiling of PcomA aneurysms in patients with ONP resulted in a cure or improvement of oculomotor nerve dysfunction in the majority of patients.

Microvascular Decompression for Oculomotor Nerve Palsy due to Nonaneurysmal Vascular Compression

BACKGROUND

Diabetes mellitus and aneurysmal compression are well-known causes of oculomotor nerve palsy (ONP), but nonaneurysmal vascular compression of the oculomotor nerve has rarely been reported.

CASE DESCRIPTION

A 70-year-old nondiabetic man presented with left ONP for the past 2 days. Magnetic resonance imaging revealed the left posterior communicating artery to be compressing the left oculomotor nerve. Microvascular decompression of the offending artery from the nerve via a left frontotemporal craniotomy was performed; the nerve showed a color change suggestive of degenerative alteration. ONP was fully resolved within 1 month of surgery.

CONCLUSIONS

Whether nonaneurysmal vascular compression of the oculomotor nerve is a true cause of ONP is sometimes controversial. However, recent developments in magnetic resonance imaging can clearly demonstrate the spatial relationship between the oculomotor nerve and vessels. Detailed magnetic resonance imaging should be used to diagnose compression of the oculomotor nerve by blood vessels. Microvascular decompression is the treatment of choice in this situation.

Endovascular Treatment of Patients with Oculomotor Nerve Palsy Induced by Posterior Communicating Artery Aneurysms

Objective

Whether coiling is the best treatment option for oculomotor nerve palsy (ONP) induced by posterior communicating artery (PComA) aneurysms remains controversial. In this study, we retrospectively analyzed the recovery of ONP caused by PComA aneurysms.

Methods

Between 2007 and 2019, 8 patients with PComA aneurysms and ONP underwent coiling at our institution. We retrospectively reviewed ONP recovery, duration from onset of ONP to treatment, and complications of procedures.

Results

At the last available clinical follow-up, ONP recovery was complete in 4 patients (50%) and partial in 4 patients (50%). Patients with partial recovery of ONP had sequelae of eye movement impairment that did not affect daily life. In 1 patient, hemiplegia developed due to cerebral infarction of the corona radiata the day after coiling, but it fully recovered 1 year after operation. The delay from the onset of ONP to coiling was significantly related to partial ONP recovery (r = -0.83, p = 0.01).

Conclusion

Endovascular treatment is a relatively safe and satisfactory treatment for PComA aneurysms with ONP.

Surgical Management of Posterior Communicating Artery Aneurysms in the Presence of a Low-Coursing Internal Carotid Artery and Narrowed Retrocarotid Window

BACKGROUND

Anatomical variations of the course of the internal carotid artery (ICA) may complicate surgical clipping of posterior communicating artery (PCoA) aneurysms by narrowing the retrocarotid window. We evaluated the efficacy of the periclinoid surgical maneuvers for expanding the retrocarotid window and analyzed computed tomography angiography (CTA) data from patients with PCoA aneurysms to define parameters for low-coursing ICAs.

METHODS

Using cadaveric specimens, standard pterional craniotomies were fashioned and extradural or intradural periclinoid surgical maneuvers-cutting of the meningo-orbital band, anterior clinoidectomy, and cutting of the distal dural ring (DDR)-were performed, and their relative advantages for expanding the retrocarotid window were assessed. Additionally, preoperative CTA data from 24 patients with PCoA aneurysms used to calculate the angles of the ICA relative to the skull base.

RESULTS

Periclinoid maneuvers, especially the anterior clinoidectomy, provided additional exposure of the retrocarotid space. Cutting of the DDR allowed for partial mobilization of the ICA and widened the retrocarotid surgical window, enhancing maneuverability. The anterior clinoidectomy with cutting of the DDR allowed for enhanced exposure of the medial, middle, and posterolateral aspects of the retrocarotid space. Cutting the anterior petroclinoid fold and mobilizing cranial nerve III provided wide exposure of the lateral aspect of retrocarotid space.

CONCLUSION

When clipping PCoA aneurysms in the presence of normal-coursing ICAs (approximately ≥30° ICA angle), a standard pterional craniotomy with anterior clinoidectomy and cutting of the DDR allows for substantial expansion of the retrocarotid window.

Endovascular versus surgical treatment for improvement of oculomotor nerve palsy caused by unruptured posterior communicating artery aneurysms

Background

There is no consensus regarding the best treatment option for unruptured aneurysms of the posterior communicating artery (PCom) presenting with oculomotor nerve palsy (ONP). We aimed to assess predictors of ONP recovery in a multicenter series of consecutive patients.

Materials and methods

A retrospective review of prospective databases in three tertiary neurosurgical centers was carried out, selecting patients with ONP caused by unruptured PCom aneurysms, treated by surgical clipping or embolization, between January 2006 and December 2013. Patient files and imaging studies were used to extract ophthalmological assessments, treatment outcomes, and follow-up data. Predictors of ONP recovery during follow-up were explored using univariate and multivariate analyses.

Results

We identified 55 patients with a median ONP duration before treatment of 11 days (IQR 4.5–18); the deficit was complete in 27 (49.1%) and incomplete in 28 (50.9%) cases. Median aneurysm size was 7 mm (IQR 5–9). Twenty-four (43.6%) patients underwent surgical clipping and 31 (56.4%) embolization as the primary treatment. Overall, ONP improved in 40 (72.7%) patients and persisted/recurred in 15 (27.3 %). Surgery, interval to complete treatment <4 weeks, aneurysm recurrence during follow-up, and retreatment during follow-up were significantly correlated with ONP outcome in the univariate analysis. In the multivariate analysis, independent predictors of ONP improvement were interval to complete treatment <4 weeks (OR 5.15, 95% CI 1.37 to 23.71, p=0.015) and aneurysm recurrence during follow-up (OR 0.1, 95% CI 0.02 to 0.47, p=0.003).

Conclusion

There was no significant difference in ONP recovery between surgical clipping and embolization. The best predictor for ONP recovery was timely, complete, and durable aneurysm exclusion.

An unruptured posterior communicating artery aneurysm ruptured during angiography: A case report

INTRODUCTION

Cerebrovascular imaging is the gold standard for diagnosis of intracranial aneurysms. Rupture of intracranial aneurysm is rare in cerebrovascular angiography, especially in unruptured intracranial aneurysm.

PATIENT CONCERNS

A 74-year-old woman was admitted to the hospital for sudden onset of left eyelid ptosis for 1 day with no obvious inducement. The patient had a history of hypertension. Physical examination revealed that she had clear consciousness and normal speech, but the left eyelid drooped. The left pupil diameter was 5 mm and light reflex was absent. The left eyeball could not move, and the right eye examinations were normal. The limb muscle strength and muscle tension were normal.

DIAGNOSIS

Bilateral internal carotid artery posterior communicating aneurysm, severe stenosis of the origin of left carotid artery, and right oculomotor nerve palsy.

INTERVENTIONS

After the hospital, the aneurysm ruptured and hemorrhaged during radiography, and the patient improved after immediate rescue and treatment. On the third day after angiography, the patient's the condition gradually stabilized. Under the general anesthesia, left carotid artery stenosis stent implantation and left posterior communicating artery aneurysm stent assisted coil embolization were performed successfully. On the second day after embolization, the patient's head computed tomography (CT) showed subarachnoid hemorrhage with hydrocephalus. The patient underwent external ventricular drainage. A month later, the patient underwent ventriculoperitoneal shunt.

OUTCOMES

Six months later, the patient visited our hospital for a follow-up, and she was clear-headed, aphasia, right limb hemiplegia with muscle strength grade II, left side autonomous activities, and the GOS score was 2 points. Head CT showed the ventricles were normal.

CONCLUSIONS

Acute oculomotor palsy may be a risk factor for rupture of ipsilateral unruptured aneurysms, but more basic research and clinical trial evidence of intracranial aneurysms are needed to confirm this.

Ruptured aneurysm in the posterior communicating segment of carotid artery presenting with contralateral oculomotor nerve palsy

Background:

Brain aneurysms are mostly discovered during the investigation of subarachnoid hemorrhage (SAH). Some patients present neurological signs that may suggest the aneurysm’s topography, and the oculomotor nerve palsy (ONP) of the same side of the aneurysm is the most common sign. Only one case report of contralateral palsy was previously described in the medical literature.

Case Description:

Authors describe a patient who presented a classic manifestation of SAH associated with complete ONP, whose vascular investigation demonstrated a brain aneurysm located in the contralateral intracranial carotid. The patient was surgically treated with great neurologic outcome, and late angiography did not evidence other vascular abnormalities.

Conclusion:

The ipsilateral ONP is a common sign found in posterior communicating artery aneurysms; however, such aneurysm can have different presentations due to the elevation of intracranial pressure, and, in rarer cases, the ONP cannot be operated as a localizing sign.

The aetiologies of the unilateral oculomotor nerve palsy: a review of the literature

Oculomotor nerve palsy (ONP) is an important and common clinical diagnosis. Its main features are diplopia and ptosis. Its aetiologies are various and complex. A number of different conditions have been reported to cause ONP, such as diabetes mellitus, aneurysm, tumours, painful ophthalmoplegia, pituitary lesions, cavernous sinus lesions, central nervous system infections, and subarachnoid haemorrhage. A patients needs to undergo several tests in order to establish the correct underlying pathology. In this review, we have summarized the aetiologies of the unilateral ONP, and discussed their relative clinical features, pathogenesis, diagnostic criteria, treatment options, and prognosis. We searched PubMed for papers related to ONP and its aetiologies, and selected the publications, which seemed appropriate.

Bleb formation in small unruptured intracranial aneurysm as a predictor of early rupture

Small unruptured aneurysms are thought to have a low risk of rupture, but the management of such lesions is still controversial. A 73-year-old man with a small anterior communication artery aneurysm, 4 mm in diameter, while on follow-up, developed an aneurysmal subarachnoid hemorrhage 2 weeks after the detection of a newly emerged bleb on the surface of the aneurysm. In conclusion, the formation of a bleb should be considered as a warning sign of an impending rupture, and treatment should be provided even for patients with small aneurysms.

Flow-diverter stents for endovascular management of non-fetal posterior communicating artery aneurysms-analysis on aneurysm occlusion, vessel patency, and patient outcome

Background Use of flow-diversion technology in the treatment of incidental and recanalized posterior communicating artery (PComA) aneurysms. Methods Patients treated with the Pipeline embolization device (PED) for PComA aneurysms were identified and included in our retrospective analysis. We evaluated aneurysm characteristics, modified Rankin Scale score (mRS) on admission, angiography follow-up, and patient clinical outcome at discharge, at three to nine months, and at 12-18 months. Results We included 56 patients with a mean age of 56 years. Median mRS on admission was 0. All aneurysms involved the PComA and were either new findings or found to have shown recanalization at angiography follow-up from previous coil embolization or surgical clipping. Intraprocedural device foreshortening was observed in one case requiring additional placement of a self-expanding stent. One intraprocedural aneurysm rupture occurred because of a broken distal wire. This patient had an mRS of 4 after the procedure. Three- to nine-month and 12- to 18-month follow-up angiography showed near complete or complete aneurysm occlusion in most cases. Minimal to mild intimal hyperplasia was seen in five cases at three to nine months. PComA patency over time showed 29 of 46 initially patent vessels still patent at six months. Thirteen and seven PComAs showed progressive decrease in flow at three to nine months and 12-18 months, respectively. Median mRS remained 0 for all patients at three- to nine-month and 12- to 18-month follow-up. Conclusions Our preliminary results show that flow-diversion technology is an effective and safe treatment option. Larger studies with long-term follow-up are needed to validate our promising results.

Intracranial Aneurysms of Neuro-Ophthalmologic Relevance

BACKGROUND

Intracranial saccular aneurysms are acquired lesions that often present with neuro-ophthalmologic symptoms and signs. Recent advances in neurosurgical techniques, endovascular treatments, and neurocritical care have improved the optimal management of symptomatic unruptured aneurysms, but whether the chosen treatment has an impact on neuro-ophthalmologic outcomes remains debated.

EVIDENCE ACQUISITION

A review of the literature focused on neuro-ophthalmic manifestations and treatment of intracranial aneurysms with specific relevance to neuro-ophthalmologic outcomes was conducted using Ovid MEDLINE and EMBASE databases. Cavernous sinus aneurysms were not included in this review.

RESULTS

Surgical clipping vs endovascular coiling for aneurysms causing third nerve palsies was compared in 13 retrospective studies representing 447 patients. Complete recovery was achieved in 78% of surgical patients compared with 44% of patients treated with endovascular coiling. However, the complication rate, hospital costs, and days spent in intensive care were reported as higher in surgically treated patients. Retrospective reviews of surgical clipping and endovascular coiling for all ocular motor nerve palsies (third, fourth, or sixth cranial nerves) revealed similar results of complete resolution in 76% and 49%, respectively. Improvement in visual deficits related to aneurysmal compression of the anterior visual pathways was also better among patients treated with clipping than with coiling. The time to treatment from onset of visual symptoms was a predictive factor of visual recovery in several studies. Few reports have specifically assessed the improvement of visual deficits after treatment with flow diverters.

CONCLUSIONS

Decisions regarding the choice of therapy for intracranial aneurysms causing neuro-ophthalmologic signs ideally should be made at high-volume centers with access to both surgical and endovascular treatments. The status of the patient, location of the aneurysm, and experience of the treating physicians are important factors to consider. Although a higher rate of visual recovery was reported with neurosurgical clipping, this must be weighed against the potentially longer intensive care stays and increased early morbidity.

Long-Term Functional Outcome of Symptomatic Unruptured Intracranial Aneurysms in an Interdisciplinary Treatment Concept

OBJECTIVE

In symptomatic unruptured intracranial aneurysms (UIAs), data on long-term functional outcome are sparse in the literature, even in the light of modern interdisciplinary treatment decisions. We therefore analyzed our in-house database for prognostic factors and long-term outcome of neurologic symptoms after microsurgical/endovascular treatment.

METHODS

Patients treated between 2000 and 2016 after interdisciplinary vascular board decision were included. UIAs were categorized as symptomatic in cases of cranial nerve or brainstem compression. Symptoms were categorized as mild/severe. Long-term development of symptoms after treatment was assessed in a standardized and independent fashion.

RESULTS

Of 98 symptomatic UIAs (microsurgery/endovascular 43/55), 84 patients presented with cranial nerve (NII-VI) compression and 14 patients with brainstem compression symptoms. Permanent morbidity occurred in 9% of patients. Of 119 symptoms (mild/severe 71/48), 60.4% recovered (full/partial 22%/39%) and 29% stabilized by the time of last follow-up; median follow-up was 19.5 months. Symptom recovery was higher in the long-term compared with that at discharge (P = 0.002). Optic nerve compression symptoms were less likely to improve compared with abducens nerve palsies and brainstem compression. Prognostic factors for recovery were duration and severity of symptoms, treatment modality (microsurgery) and absence of ischemia in the multivariate analysis.

CONCLUSIONS

This recent study presents for the first time a detailed analysis of relevant prognostic factors for long-term recovery of cranial nerve/brainstem compression symptoms in an interdisciplinary treatment concept, which was excellent in most patients, with lowest recovery rates in optic nerve compression. Symptom recovery was remarkably higher in the long-term compared with recovery at discharge.

Clipping Versus Coiling in the Management of Posterior Communicating Artery Aneurysms with Third Nerve Palsy: A Systematic Review and Meta-Analysis

OBJECTIVE

To compare surgical clipping with endovascular coiling in terms of recovery from oculomotor nerve palsy (ONP) in the management of posterior communicating artery (PCoA) aneurysms causing third nerve palsy.

METHODS

We conducted a systematic review of the literature and meta-analysis.

RESULTS

The meta-analysis included 11 relevant studies involving 384 patients with third nerve palsy caused by PCoA aneurysms at baseline, of whom 257 (67.0%) were treated by clipping and 127 were treated by coiling (33.0%). Pooled odds ratios of the impact of clipping or coiling on complete ONP recovery, lack of ONP recovery, and procedure-related death were calculated. The overall complete ONP recovery rate was 42.5% in the coiling group compared with 83.6% in the clipping group. The increase in complete ONP recovery in the clipping group corresponds to an overall pooled Mantel-Haenszel odds ratio of 4.44 (95% confidence interval = 1.66-11.84). Subgroup analysis revealed a clear benefit of clipping over coiling in patients with ruptured aneurysms, but not in patients with unruptured aneurysms. No procedure-related deaths were reported by any of the 11 studies.

CONCLUSIONS

Surgical clipping of PCoA aneurysms causing third nerve palsy achieves better ONP recovery than endovascular coiling; this could be particularly true in the case of ruptured aneurysms. In view of the purely observational data, statements about this effect should be made with great caution. A randomized trial would better address the therapeutic dilemma, but pending the results of such a trial, we recommend treating PCoA aneurysms causing ONP with surgery.

Outcomes of Oculomotor Nerve Palsy Caused by Internal Carotid Artery Aneurysm: Comparison between Microsurgical Clipping and Endovascular Coiling

The purpose of this study was to compare the clinical outcomes of microsurgical clipping and endovascular coiling in patients with oculomotor nerve palsy (ONP) caused by internal carotid artery (ICA) aneurysm. Among 17 patients with ICA aneurysms presented with ONP, 9 (52.9%) underwent microsurgical clipping and 8 (47.1%) underwent endovascular coiling. Outcomes of functional recovery of ONP were investigated and compared between surgical group and endovascular group. Mean intervals between the onset and treatment were significantly longer in microsurgical group (18.2 days) than in endovascular group (3.5 days). In microsurgical group, complete resolution (CR) of ONP was obtained in 7 of 9 patients (77.8%) and partial resolution (PR) was seen in 2 patients (22.2%). In endovascular group, CR was obtained in 5 of 8 patients (62.5%) and PR was seen in 3 patients (37.5%). The optimal treatment of aneurysm-induced ONP remains controversial; however, present study suggests both procedures are beneficial for achieving functional recovery of ONP. The treatment strategy should be decided primarily considering the general risks of the two procedures, and presence of ONP is not a disadvantageous factor for either procedure.

Resolution of Oculomotor Nerve Palsy Secondary to Posterior Communicating Artery Aneurysms

BACKGROUND:

Previous studies have attempted to determine the best treatment for oculomotor nerve palsy (ONP) secondary to posterior communicating artery (PCoA) aneurysms, but have been limited by small sample sizes and limited treatment.

OBJECTIVE:

To analyze the treatment of ONP secondary to PCoA with both coiling and clipping in ruptured and unruptured aneurysms.

METHODS:

Data from 2 large academic centers was retrospectively collected over 22 years, yielding a total of 93 patients with ONP secondary to PCoA aneurysms. These patients were combined with 321 patients from the literature review for large data analyses. Onset symptoms, recovery, and time to resolution were evaluated with respect to treatment and aneurysm rupture status.

RESULTS:

For all patients presenting with ONP (n = 414) 56.6% of those treated with microsurgical clipping made a full recovery vs 41.5% of those treated with endovascular coil embolization (P = .02). Of patients with a complete ONP (n = 229), full recovery occurred in 47.3% of those treated with clipping but in only 20% of those undergoing coiling (P = .01). For patients presenting with ruptured aneurysms (n = 130), full recovery occurred in 70.9% compared with 49.3% coiled patients (P = .01). Additionally, although patients with full ONP recovery had a median time to treatment of 4 days, those without full ONP recovery had a median time to treatment of 7 days (P = .01).

CONCLUSION:

Patients with ONP secondary to PCoA aneurysms treated with clipping showed higher rates of full ONP resolution than patients treated with coil embolization. Larger prospective studies are needed to determine the true potential of recovery associated with each treatment.

A Retrospective Comparison of the Influence of Surgical Clipping and Endovascular Embolization on Recovery of Oculomotor Nerve Palsy in Patients With Posterior Communicating Artery Aneurysms

BACKGROUND:

Oculomotor nerve palsy (ONP) is a common symptom of posterior communicating artery aneurysms (PcomAAs). Surgical clipping and endovascular embolization are used to treat PcomAAs with ONP.

OBJECTIVE:

To analyze the impact of these 2 techniques on recovery of ONP caused by PcomAAs.

METHODS:

The clinical data for 176 patients with intracranial PcomAAs with ONP admitted to the Department of Neurosurgery, Sichuan Provincial People's Hospital, between June 2008 and May 2013 who undergone surgical clipping or endovascular embolization were studied retrospectively. The 2 treatment groups were compared with respect to age, sex, aneurysm size, levels of hypertension and hyperlipidemia, preadmission ONP duration, subarachnoid hemorrhage (SAH), complete ONP, postoperative recovery time from ONP symptoms, and degree of recovery. The follow-up duration was a minimum of 12 months. Multivariate Cox regression was used for analysis.

RESULTS:

A total of 132 patients were treated by surgical clipping, and 44 were treated by endovascular embolization. Significant differences were found in postoperative recovery time (83.87 ± 34.70 days for clipping and 137.45 ± 44.94 days for embolization, P &lt; .001) and recovery rates (130 [98.5%] for clipping and 30 [68.2%] for embolization, P &lt; .001). The period between ONP onset and admission was associated with recovery. Postoperative complications included significant cerebral vasospasms (6 in the clipping group and 2 in the embolization group) and hydrocephalus (16 in the clipping group and 9 in the embolization group).

CONCLUSION:

Simultaneous elimination of 2 injury mechanisms, compression and pulsation, when treating the oculomotor nerve by surgical clipping may be more advantageous than endovascular embolization to treat ONP caused by PcomAA.

A Case of the Internal Carotid Artery-Posterior Communicating Artery Aneurysm Mimicking Tolosa-Hunt Syndrome

A 53-year-old woman experienced a right retrobulbar pain followed by ipsilateral extraocular palsies in all directions without dilated pupils or ptosis. Because a plain head computed tomography (CT) scan obtained on her initial visit showed no abnormal findings, such as subarachnoid hemorrhage or a giant cavernous aneurysm, her condition was provisionally diagnosed as Tolosa–Hunt syndrome and elective magnetic resonance (MR) imaging was scheduled. The day after her initial visit, however, she suddenly developed complete ptosis and a dilated pupil on the right side. Emergency MR imaging and angiography revealed a clover leaf-shaped aneurysm projecting to the cavernous sinus at the junction of the internal carotid artery and the posterior communicating artery. Her condition was diagnosed as impending rupture of the aneurysm, and she underwent emergency open surgery. Her symptoms completely resolved within the following 2 weeks. Our case demonstrated that a medium-sized internal carotid artery–posterior communicating artery aneurysm can cause simultaneous oculomotor and abducens nerve palsies with retrobulbar pain if the shape of the aneurysm is complicated. Although these symptoms are very similar to those of Tolosa–Hunt syndrome, we believe that prompt radiological examinations such as MR or 3D CT angiography should be performed to prevent subsequent rupture of the aneurysm.

Resolution of Diminished Olfactory Sensation After Treatment of Bilateral Ophthalmic Segment Aneurysms With Flow Diversion

BACKGROUND AND IMPORTANCE:

Olfactory tract dysfunction due to an unruptured intracranial aneurysm is rare. We present a case in which a patient with impaired olfaction related to bilateral internal carotid artery aneurysms experienced subjective and quantitative objective improvement of olfactory sensation after treatment of ophthalmic segment aneurysms with flow diversion.

CLINICAL PRESENTATION:

A 44-year-old woman presented with hyposmia and bilateral ophthalmic segment internal carotid artery aneurysms. The symptom of hyposmia, worsening over a period of several months, was suspected to be due to mass effect from bilateral unruptured ophthalmic segment aneurysms pressing on the olfactory tracts. Each aneurysm was treated with a Pipeline embolization device (PED). Follow-up angiography at 5 months showed occlusion of both aneurysms. The patient experienced subjective improvement in olfaction and complete objective resolution of her hyposmia as measured by the validated University of Pennsylvania Smell Identification Test (UPSIT).

CONCLUSION:

Intracranial aneurysms causing dysfunction of olfactory sensation due to mass effect upon the olfactory tract can be successfully treated with flow diversion. Flow diversion should be considered as one of the treatment options for patients with cranial nerve dysfunction due to unruptured intracranial aneurysms.

Morphological and clinical risk factors for posterior communicating artery aneurysm rupture

OBJECT

Recent studies have shown that posterior circulation aneurysms, specifically posterior communicating artery (PCoA) aneurysms, are more likely to rupture than other aneurysms. To date, few studies have investigated the factors contributing to PCoA aneurysm rupture. The authors aimed to identify morphological and clinical characteristics predisposing to PCoA aneurysm rupture.

METHODS

The authors retrospectively reviewed 134 consecutive patients with PCoA aneurysms managed at their facility between July 2003 and December 2012. The authors divided patients into groups of those with aneurysmal rupture (n = 39) and without aneurysmal rupture (n = 95) and compared morphological and clinical characteristics. Morphological characteristics were mainly evaluated by 3D CT angiography and included diameter of arteries (anterior cerebral artery, middle cerebral artery, and internal carotid artery), size of the aneurysm, dome-to-neck ratio, neck direction of the aneurysmal dome around the PCoA (medial, lateral, superior, inferior, and posterior), aneurysm bleb formation, whether the PCoA was fetal type, and the existence of other intracranial unruptured aneurysm(s).

RESULTS

Patients with ruptured PCoA aneurysms were significantly younger (a higher proportion were < 60 years of age) and a significantly higher proportion of patients with ruptured PCoA aneurysms showed a lateral direction of the aneurysmal dome around the PCoA, had bleb formation, and the aneurysm was > 7 mm in diameter and/or the dome-to-neck ratio was > 2.0. Multivariate logistic regression analysis showed age < 60 years (OR 4.3, p = 0.011), history of hypertension (OR 5.1, p = 0.008), lateral direction of the aneurysmal dome around the PCoA (OR 6.7, p = 0.0001), and bleb formation (OR 11, p < 0.0001) to be significantly associated with PCoA aneurysm rupture.

CONCLUSIONS

The present results demonstrated that lateral projection of a PCoA aneurysm may be related to rupture.

Oculomotor nerve palsy by posterior communicating artery aneurysms: influence of surgical strategy on recovery

OBJECT

Resolution of oculomotor nerve palsy (ONP) after clipping of posterior communicating artery (PCoA) aneurysms has been well documented. However, whether additional decompression of the oculomotor nerve via aneurysm sac dissection or resection is superior to pure aneurysm clipping is the subject of much debate. Therefore, the objective in the present investigation was to analyze the influence of surgical strategy--specifically, clipping with or without aneurysm dissection--on ONP resolution.

METHODS

Between June 1999 and December 2010, 18 consecutive patients with ruptured and unruptured PCoA aneurysms causing ONP were treated at the authors' institution. Oculomotor nerve palsy was evaluated on admission and at follow-up. The electronic database MEDLINE was searched for additional data in published studies of PCoA aneurysms causing ONP. Two reviewers independently extracted data.

RESULTS

Overall, 8 studies from the literature review and 6 patients in the current series (121 PCoA aneurysms) met the study inclusion criteria. Ninety-four aneurysms were treated with simple aneurysm neck clipping and 27 with clipping plus aneurysm sac decompression. The surgical strategy, simple aneurysm neck clipping versus clipping plus oculomotor nerve decompression, had no effect on full ONP resolution on univariate (p = 0.5) and multivariate analyses. On multivariate analysis, patients with incomplete ONP at admission were more likely to have full resolution of the palsy than were those with complete ONP at admission (p = 0.03, OR = 4.2, 95% CI 1.1-16).

CONCLUSIONS

Data in the present study indicated that ONP caused by PCoA aneurysms improves after clipping without and with oculomotor nerve decompression. The resolution of ONP is inversely associated with the initial severity of ONP.

Intraoperative oculomotor nerve monitoring predicts outcome following clipping of posterior communicating artery aneurysms

Valid parameters do not exist to predict oculomotor nerve palsy (ONP, ptosis and/or diplopia) intraoperatively. In 49 operations involving 46 patients with posterior communicating artery aneurysms, the oculomotor nerves were stimulated after the aneurysms were clipped. A quantitative analysis of evoked compound muscle action potential (CMAP) parameters (stimulus threshold, amplitude and latency) from the levator palpebrae superioris (LPS) muscle was performed. Absolute values of CMAP amplitude statistically correlated with initial and long-term oculomotor nerve function (ONF) after surgery (p<0.05). In addition, subarachnoid hemorrhage (SAH) significantly influenced the CMAP threshold (p<0.05). Monitoring of LPS muscle activity is valuable in the assessment of ONF, and the CMAP amplitude of LPS may be a reliable predictor of ONF. Moreover, SAH has an impact on the parameters of the LPS CMAP.