Etiological distribution of isolated oculomotor nerve palsy: analysis of 633 patients and literature review.

BACKGROUND AND PURPOSE: The etiological distribution of oculomotor nerve palsy has varied amongst the studies. This study aimed to define the clinical features and underlying etiologies of isolated oculomotor nerve palsy by recruiting patients from all departments in a referral-based university hospital. METHODS: The medical records of 672 patients who had a confirmed diagnosis of isolated oculomotor nerve palsy at all departments of Seoul National University Bundang Hospital, Seongnam, South Korea, from 2003 to 2020 were reviewed. A proportion of the etiology of isolated oculomotor nerve palsy was also compared with that of patients pooled from the previous studies that were searched on PubMed in May 2022. RESULTS: The most common etiology was microvascular (n = 168, 26.5%), followed by vascular anomalies (n = 110, 17.4%), neoplastic (n = 86, 13.6%), inflammatory (n = 79, 12.5%), idiopathic (n = 60, 9.5%) and traumatic (n = 53, 8.4%). Neurologists were mainly involved in the management of microvascular and inflammatory oculomotor nerve palsies whilst ophthalmologists mainly participated in the care of idiopathic, neoplastic and traumatic palsies. Neurosurgeons mostly took care of oculomotor nerve palsy due to vascular anomalies. CONCLUSIONS: The proportion of etiologies of isolated oculomotor nerve palsy may differ according to the specialties involved in the management. The results of previous studies on the etiological distribution of isolated oculomotor nerve palsy should be interpreted with this consideration.

Successful surgical treatment of oculomotor palsy due to schwannoma of the cavernous sinus in a 7-year-old girl: a case report.

Oculomotor nerve schwannoma in children not associated with neurofibromatosis is a rare disease, with 26 pediatric cases reported so far. There is no established treatment plan. A 7-year-old girl presented with oculomotor nerve palsy. Surgical reduction of the tumor combined with postoperative gamma knife surgery preserved the oculomotor nerve, improved oculomotor nerve function, and achieved tumor control during the observation period of 20 months. The combination of partial surgical resection and gamma knife surgery as a treatment strategy for oculomotor nerve schwannoma resulted in a good outcome.

Analyzing the relationship between cerebral aneurysms and Non-oculomotor cranial nerve palsies: a systematic review.

OBJECTIVES: This study aimed to investigate the association between intracerebral aneurysms and cranial nerve (CN) palsies, focusing on nerves other than the oculomotor nerve. It sought to determine the prevalence, risk factors, and clinical outcomes of these nerve palsies and compare the effectiveness of microsurgical clipping versus endovascular coiling in restoring nerve function. METHODOLOGY: Following PRISMA guidelines, a comprehensive literature search was conducted using databases like PubMed, Scopus, and Google Scholar, covering studies from 1975 to April 2024. The inclusion criteria targeted patients with non-oculomotor nerve palsies diagnosed with cerebral aneurysms. Studies published before 1975 and non-English studies were excluded. Data extraction included study design, patient characteristics, and intervention outcomes. The Joanna Briggs Institute and Newcastle-Ottawa scales were used to assess study quality. Data were synthesized narratively and statistically analysed using SPSS v27. RESULTS: The analysis included 47 patients (53.2% female, mean age 44.8 years). The internal carotid artery (ICA) was the most common aneurysm site (44.7%), and the abducent nerve (CN VI) was most frequently affected. Ruptured aneurysms had better recovery outcomes (88.9%) than unruptured ones (66.7%). Hypertension was present in 9.2%. Unilateral aneurysms were seen in 80.9%, with 76.6% having a single nerve palsy. Non-ruptured aneurysms accounted for 58.1%, and ruptured for 41.9% of associated cranial nerve palsies. Treatment included microsurgical approaches (42.6%), endovascular approaches (34%), combined approaches (6.4%), and conservative management (17%). Recovery of the palsy was observed in 75.6%, with endovascular procedures showing higher recovery (93.3%) compared to conservative treatment (28.6%). CONCLUSION: Intracerebral aneurysms are significantly associated with non-oculomotor CN palsies. Endovascular procedures yield higher recovery rates than conservative management, particularly in ruptured aneurysms. Timely and appropriate treatment is crucial for improving nerve function recovery in these patients.

Oculomotor nerve cavernous malformation: case report and operative video.

BACKGROUND: Cavernous malformations (CMs) are clusters of thin-walled sinusoidal vessels without well-defined walls. Though they can occur anywhere in the neuroaxis, cranial nerve (CN) CMs are rare. METHOD: We report a 47-year-old male with gradual CN III palsy. Initial imaging showed no significant findings, but a follow-up MRI revealed a growing lesion along CN III. Intraoperative findings confirmed a CN III CM. Diagnosing and treating CN III CM are complex. Radiological findings lack specificity, requiring consideration of various diagnoses for patients with isolated CN III palsy and abnormal radiological findings. CONCLUSION: Surgery is the gold standard, aiming for complete lesion removal while minimizing neurological complications.

Recurrent Third Nerve Paresis with Migraine: A Case Report and Review of the Literature.

Ophthalmoplegic migraine (OM), first described by Charcot in 1870, is a disorder characterised by recurrent episodes of migraine associated with ophthalmoplegia. It has been extensively described in children and is rarer in adults. Commonly, the third nerve is affected with pupillary involvement and, more rarely, the fourth or the sixth nerve. OM is now believed to be an inflammatory demyelinating neuropathy. However, in the largest series of OM so far, by Lal et al. it most commonly involved the sixth nerve, started with a crescendo migraine and was accompanied by no enhancement of the cranial nerves. This has led to a rethink about the role of migraine, in the pathogenesis of OM. We describe a 14-year-old boy, with a 10-year history of intermittent headache followed by drooping of right eyelid and diplopia. The current episode started with a migrainous headache, which increased in severity over 3 days, followed by right third nerve paresis with pupillary involvement. Contrast-enhanced magnetic resonance imaging (MRI) of the brain with contrast showed nodular thickening at the root entry zone of the right oculomotor nerve with bright enhancement. The child responded to oral prednisolone, which was tapered over a month. Migraine prophylaxis with propranolol was concurrently added. His repeat MRI brain showed complete disappearance of enhancement of the lesion at 1 year.

Isolated Inferior Division Oculomotor Nerve Palsy as the First Manifestation of Human Immunodeficiency Virus and Syphilis Co-Infection: A Rare Case Report.

Human immunodeficiency virus (HIV) and syphilis are two sexually transmitted diseases that continue to pose significant public health challenges globally. HIV and syphilis can be seen together; individuals with one of these infections are at risk of developing the other. Sharing common risk factors such as sexual transmission or intravenous drug use makes their coincidence likely. Syphilis, an infection caused by a spirochaete (Treponema pallidum), is a great mimicker and can present with a wide variety of clinical manifestations. Syphilis can cause various neurological symptoms including complete oculomotor nerve palsy; however, it is not a common manifestation. Here, we report for the first time a case of persistent incomplete oculomotor nerve palsy with pupillary involvement caused by the involvement of the inferior division of the oculomotor nerve, secondary to HIV and syphilis co-infection.

Identification and characterization of differentially expressed circular RNAs in extraocular muscle of oculomotor nerve palsy.

BACKGROUND: Oculomotor nerve palsy (ONP) is a neuroparalytic disorder resulting in dysfunction of innervating extraocular muscles (EOMs), of which the pathological characteristics remain underexplored. METHODS: In this study, medial rectus muscle tissue samples from four ONP patients and four constant exotropia (CXT) patients were collected for RNA sequencing. Differentially expressed circular RNAs (circRNAs) were identified and included in functional enrichment analysis, followed by interaction analysis with microRNAs and mRNAs as well as RNA binding proteins. Furthermore, RT-qPCR was used to validate the expression level of the differentially expressed circRNAs. RESULTS: A total of 84 differentially expressed circRNAs were identified from 10,504 predicted circRNAs. Functional enrichment analysis indicated that the differentially expressed circRNAs significantly correlated with skeletal muscle contraction. In addition, interaction analyses showed that up-regulated circRNA_03628 was significantly interacted with RNA binding protein AGO2 and EIF4A3 as well as microRNA hsa-miR-188-5p and hsa-miR-4529-5p. The up-regulation of circRNA_03628 was validated by RT-qPCR, followed by further elaboration of the expression, location and clinical significance of circRNA_03628 in EOMs of ONP. CONCLUSIONS: Our study may shed light on the role of differentially expressed circRNAs, especially circRNA_03628, in the pathological changes of EOMs in ONP.

Congenital isolated unilateral third nerve palsy in children: the diagnostic contribution of high-resolution MR imaging.

PURPOSE: To describe the neuroanatomical correlates of unilateral congenital isolated oculomotor palsy by means of high-resolution MRI. METHODS: Children with a clinical diagnosis of congenital isolated oculomotr palsy and with a high-resolution MRI acquisition targeted on the orbits and cranial nerves were selected and included in the study. An experienced pediatric neuroradiologist evaluated all the exams, assessing the integrity and morphology of extraocular muscles, oculomotor, trochlear and abducens nerves as well as optic nerves and globes. Clinical data and ophthalmologic evaluations were also collected. RESULTS: Six children (age range: 1-16 years; males: 3) were selected. All patients showed, on the affected side (left:right = 5:1), anomalies of the III nerve and extraocular muscles innervated by the pathological nerve. One patient had complete nerve agenesis, two patients showed a diffuse thinning of the nerve, from the brainstem to the orbit and 3 patients showed a distal thinning of the oculomotor nerve, starting at the level of the cavernous sinus. In all cases atrophy of corresponding muscles was noticed, but the involvement of the affected muscles varied with the nervous pattern of injury. CONCLUSIONS: High-resolution MRI represents a valuable tool for the diagnosis of III nerve anomalies in unilateral congenital IOP, showing different patterns of nerve involvement and muscular atrophy.

A case report of pituitary neuroendocrine tumor manifesting as severe conjunctival chemosis.

BACKGROUND: Conjunctival chemosis (CC) is an extremely rare symptom of pituitary neuroendocrine tumor (PitNET). We report an extremely rare case of PitNET manifesting as severe CC. CASE PRESENTATION: A 48-year-old male was admitted to our hospital with severe CC, proptosis, and ptosis of the right eye. Magnetic resonance imaging demonstrated the tumor mass invading the cavernous sinus (CS) with cystic lesion. The patient underwent emergent endoscopic transsphenoidal surgery, and the pathological diagnosis was PitNET. CC of the right eye remarkably improved after the surgery. Glucocorticoid therapy was performed for right oculomotor nerve palsy, which rapidly improved. The postoperative course was uneventful and the patient was discharged from our hospital without hormone replacement. CONCLUSIONS: CC caused by CS invasion of PitNET can be cured by early surgical treatment. Therefore, PitNET is important to consider in the differential diagnosis of CC.

Meningioma originating from the oculomotor nerve without dural attachment in a child.

Meningioma originating from the oculomotor nerve without dural attachment in children has been rarely reported. A 6-year-old patient presented ptosis of the right eye for 5 years. MRI indicated an occupying lesion in the right cavernous sinus. A tumor originating from the oculomotor nerve without dural attachment was found during subsequent surgery and confirmed as meningioma by pathology. Subsequently, the tumor was removed completely, and the oculomotor nerve was reconstructed using the sural nerve. The patient's symptoms were relieved partially after 3 months. The findings of this case suggested that the mechanisms underlying meningioma involve ectopic arachnoid cap cells within the nerve sheath. Thus, the tumor should be removed completely; also, nerve reconstruction is suggested.

Posterior communicating artery infundibulum with oculomotor nerve palsy treated with microvascular decompression: a case report and 2-dimensional technical operative video.

Oculomotor nerve palsies are typically associated with posterior communicating artery (PcommA) aneurysms. We report a rare case of an oculomotor nerve palsy caused by a PcommA infundibular dilatation. Although there are cases of infundibular dilatations causing cranial nerve palsies, only reports of three involving the PcommA exists. We review these reported cases in the literature and discuss their treatments as well as other non-aneurysmal compressive etiologies that may cause oculomotor nerve palsies. We present the case of a 53-year-old female with transient oculomotor nerve palsy that was initially diagnosed with a PcommA aneurysm. She underwent a craniotomy with plans of microsurgical clipping; however, the dilatation was identified correctly as an infundibulum intraoperatively. The operation was completed as a microvascular decompression and her oculomotor nerve palsy has not returned at the 1-year follow-up. We provide a detailed microsurgical report and video detailing the operative technique and relevant anatomy for this operation. Although rare and not as life-threatening as aneurysms, infundibular dilatations as a cause of oculomotor nerve palsy should remain as a differential diagnosis. Given the difference in natural history and treatment of these two entities, it is important to diagnose and treat them appropriately. Multimodal imaging such as thin-sliced computed tomography angiogram (CTA) and 3-dimensional (3D) rotational angiography can aid in diagnosis.

Glioblastoma multiforme with oculomotor nerve involvement: case report and literature review.

Gliomas involving the cranial nerves III-XIII are rare. Even rarer are glioblastomas multiforme (GBMs) with only 10 cases previously reported. Oculomotor nerve involvement was described in only 2 patients. The mechanisms proposed so far include an origin from the nerve itself or an extension within the nerve of a midbrain tumor. We report the case of a 69-year-old man who presented with an isolated left oculomotor nerve palsy. He was found to have a left temporal GBM extended to the frontal lobe. Diagnostics and intraoperative and pathological findings clearly demonstrated a massive infiltration of the cisternal portion of the left oculomotor nerve. We suppose this could be the first case of direct oculomotor nerve invasion by exophytic spread of a supratentorial GBM or by subarachnoid seeding from a temporal tumor. Less probably, it could be the first case of an oculomotor nerve GBM with a temporal lobe invasion.

Complete and Uneventful Recovery in a Case of Lymphocytic Hypophysitis Causing a Third Nerve Palsy.

Lymphocytic hypophysitis (LH) is a neuroendocrine disorder characterised by autoimmune inflammation of the pituitary gland with resultant pituitary dysfunction. Rarely, the presenting symptom can be diplopia due to irritation of the third, fourth, or sixth cranial nerves secondary to cavernous sinus involvement of the mass or increased intracranial pressure. We describe the case of a healthy, 20-year-old female with a pupillary sparing third nerve palsy, who was subsequently diagnosed with LH after an endoscopic transsphenoidal biopsy of the mass. She was treated with hormone replacement therapy and corticosteroids, resulting in full resolution of symptoms with no recurrence to date. To our knowledge, this is the first report of a third nerve palsy due to definitive biopsy proven LH. Despite its rarity, the unique presentation and favourable evolution of this case should aid clinicians in its timely recognition, appropriate workup, and treatment.

Oculomotor nerve palsy, an unusual onset of polyarteritis nodosa.

Introduction: Cranial nerve involvement in polyarteritis nodosa(PAN) is underrecognized and rarely reported. The aim of this article is to review the available literature and present an example of oculomotor nerve palsy in the course of PAN. Material and methods: Evaluation of texts describing the analyzed problem using the terms "polyarteritis nodosa", "nerve", "oculomotor", "cranial nerve" and "cranial neuropathy" for searching the PubMed database was done. Only full-text articles in English language with titles and abstracts were included in the analysis. As a guideline for the analysis of articles, the methodology described in the Principles of Individual Patient Data systematic reviews (PRISMA-IPD) was used. Results: After screening articles only 16 reported cases of PAN with cranial neuropathy were included in the analysis. In 10 the cranial neuropathy was reported as the initial manifestation of PAN with optic nerve involvement as the most frequent (62.5%); among these cases the oculomotor nerve was involved in 3 cases. Treatment with glucocorticosteroids and cyclophosphamide was the most common. Conclusions: Although cranial neuropathy, especially oculomotor nerve palsy is a rare first neurological manifestation of PAN, this clinical problem should be considered in the differential diagnosis.Especially patients with peripheral neuropathy, general symptoms, skin lesions and hepatitis B virus infection should be evaluated for cranial nerve involvement in the course of vasculitis.In the case of unclear involvement of the cranial nerves, PAN should also be considered in the differential diagnosis as the cause of symptoms and the first manifestation of the disease.

Oculomotor nerve guidance and terminal branching requires interactions with differentiating extraocular muscles.

Muscle function is dependent on innervation by the correct motor nerves. Motor nerves are composed of motor axons which extend through peripheral tissues as a compact bundle, then diverge to create terminal nerve branches to specific muscle targets. As motor nerves approach their targets, they undergo a transition where the fasciculated nerve halts further growth then after a pause, the nerve later initiates branching to muscles. This transition point is potentially an intermediate target or guidepost to present specific cellular and molecular signals for navigation. Here we describe the navigation of the oculomotor nerve and its association with developing muscles in mouse embryos. We found that the oculomotor nerve initially grew to the eye three days prior to the appearance of any extraocular muscles. The oculomotor axons spread to form a plexus within a mass of cells, which included precursors of extraocular muscles and other orbital tissues and expressed the transcription factor Pitx2. The nerve growth paused in the plexus for more than two days, persisting during primary extraocular myogenesis, with a subsequent phase in which the nerve branched out to specific muscles. To test the functional significance of the nerve contact with Pitx2+ cells in the plexus, we used two strategies to genetically ablate Pitx2+ cells or muscle precursors early in nerve development. The first strategy used Myf5-Cre-mediated expression of diphtheria toxin A to ablate muscle precursors, leading to loss of extraocular muscles. The oculomotor axons navigated to the eye to form the main nerve, but subsequently largely failed to initiate terminal branches. The second strategy studied Pitx2 homozygous mutants, which have early apoptosis of Pitx2-expressing precursor cells, including precursors for extraocular muscles and other orbital tissues. Oculomotor nerve fibers also grew to the eye, but failed to stop to form the plexus, instead grew long ectopic projections. These results show that neither Pitx2 function nor Myf5-expressing cells are required for oculomotor nerve navigation to the eye. However, Pitx2 function is required for oculomotor axons to pause growth in the plexus, while Myf5-expressing cells are required for terminal branch initiation.

Automatic oculomotor nerve identification based on data-driven fiber clustering.

The oculomotor nerve (OCN) is the main motor nerve innervating eye muscles and can be involved in multiple flammatory, compressive, or pathologies. The diffusion magnetic resonance imaging (dMRI) tractography is now widely used to describe the trajectory of the OCN. However, the complex cranial structure leads to difficulties in fiber orientation distribution (FOD) modeling, fiber tracking, and region of interest (ROI) selection. Currently, the identification of OCN relies on expert manual operation, resulting in challenges, such as the carries high clinical, time-consuming, and labor costs. Thus, we propose a method that can automatically identify OCN from dMRI tractography. First, we choose the multi-shell multi-tissue constraint spherical deconvolution (MSMT-CSD) FOD estimation model and deterministic tractography to describe the 3D trajectory of the OCN. Then, we rely on the well-established computational pipeline and anatomical expertise to create a data-driven OCN tractography atlas from 40 HCP data. We identify six clusters belonging to the OCN from the atlas, including the structures of three kinds of positional relationships (pass between, pass through, and go around) with the red nuclei and two kinds of positional relationships with medial longitudinal fasciculus. Finally, we apply the proposed OCN atlas to identify the OCN automatically from 40 new HCP subjects and two patients with brainstem cavernous malformation. In terms of spatial overlap and visualization, experiment results show that the automatically and manually identified OCN fibers are consistent. Our proposed OCN atlas provides an effective tool for identifying OCN by avoiding the traditional selection strategy of ROIs.

Effects of endovascular treatment and prognostic factors for recovery of oculomotor nerve palsy caused by posterior communicating artery aneurysms: a multi-center retrospective analysis.

BACKGROUND: Oculomotor nerve palsy (ONP) may result from posterior communicating artery (PcomA) aneurysms. We aimed to evaluate the resolution of ONP after endovascular treatment with the intention of clarifying predictors of nerve recovery in a relatively large series. METHODS: A total of 211 patients with ONP caused by PcomA aneurysms underwent endovascular coiling between May 2010 and December 2020 in four tertiary hospitals. We evaluated the demographics, clinical characteristics, aneurysm morphology parameters and ONP resolution to analyze the predictors of ONP recovery using univariate and multivariate analyses. RESULTS: At the last available clinical follow-up, ONP resolution was complete in 126 (59.7%) patients, partial in 73 (34.6%) patients, and no recovery in 12 (5.7%) patients. The median resolution time after endovascular treatment was 55 days (interquartile range: 40-90 days). In multivariate analysis, degree of ONP (incomplete palsy) on admission (OR 5.396; 95% CI 2.836-10.266; P < 0.001), duration of ONP (≤ 14 days) before treatment (OR 5.940; 95% CI 2.724-12.954; P < 0.001) were statistically significant predictors of complete recovery of ONP. In the subgroup analysis of patients with unruptured aneurysms, aspirin showed a higher complete recovery rate in univariate analysis (OR 2.652; 95% CI 1.057-6.656; P = 0.038). CONCLUSION: Initial incomplete ONP and early management might predict better recovery of ONP after endovascular treatment.

Bevacizumab-induced isolated oculomotor nerve palsy in glioblastoma multiforme.

INTRODUCTION: Bevacizumab, a monoclonal antibody against the vascular endothelial growth factor receptor, is the standard treatment of recurrent glioblastoma multiforme. In addition to common systemic side effects of bevacizumab, there are rare cases of cranial nerve palsy. CASE REPORT: We report a case of transient oculomotor nerve palsy after systemic administration of bevacizumab. Twenty-four hours after the systemic infusion of bevacizumab, transient oculomotor nerve palsy developed in a 49-year-old male patient. In the cranial MRI, there was no malignancy-related progression. MANAGEMENT AND OUTCOME: Bevacizumab treatment was discontinued. Methylprednisolone was started considering that bevacizumab increased the inflammatory response. Oculomotor nerve palsy resolved in 14 days. DISCUSSION: There are many side effects of bevacizumab whose mechanisms of action have not been fully explained. Cranial nerve involvement is rarely reported. Our case is the first reported case of bevacizumab-induced oculomotor nerve palsy.

Malignant nerve sheath tumor of oculomotor nerve in a pediatric patient.

Malignant nerve sheath tumors are extremely rare pathologies. They tend to occur within peripheral nerves and have close association of neurofibromatosis disease. Here, we present the second case of MNST of oculomotor nerve in literature. The patient was a 2-year-old girl with left sided oculomotor nerve palsy. After resection, the patient immediately had chemotherapy and radiotherapy. One year after surgery disease progressed with extensive intracranial seedings, and she passed away.

Hakuba's triangle: a cadaveric study detailing its anatomy and neurovascular contents with vascular and skull base implications.

Hakuba's triangle is a superior cavernous sinus triangle that allows for wide and relatively safe exposure of vascular and neoplastic lesions. This study provides cadaveric measurements of the borders of Hakuba's triangle and describes its neurovascular contents in order to enrich the available literature. The anatomical borders of the Hakuba's triangle (lateral, medial, and posterior borders) were defined based on Hakuba's description and identified. Then the triangle was dissected to reveal its morphology and relationship with adjacent neurovascular structures in Embalmed Caucasian cadaveric specimens. The oculomotor nerve occupied roughly one-third of the area of the triangle and the nerve was more or less parallel to its medial border. The mean lengths of the lateral border, posterior border, and medial border were 17 mm ± 0.5 mm, 12.2 mm ± 0.4 mm, and 10.6 mm ± 0.4 mm, respectively. The mean area of Hakuba's triangle was 63.9 mm2 ± 4.4 mm2. In this study, we provided cadaveric measurements of the borders of Hakuba's triangle along with descriptions of its neurovascular contents.