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

Electroacupuncture for oculomotor nerve palsy after chemotherapy: A case report

INTRODUCTION

Oculomotor nerve palsy (ONP) is often discovered in the ophthalmology department, manifested as ptosis with the same side, eyeball in the fixed external booth, or accompanied by limited inward, upward, and downward movements. The present case report described the effect of electroacupuncture (EA) on a breast cancer patient with ONP after chemotherapy.

PATIENT CONCERNS

A 56-year-old breast cancer patient presented with severe ptosis and fixed right eye exotropia. Besides, it is challenging to perform the movement inward, upward, and downward, and with obvious diplopia.

DIAGNOSES

The breast cancer patient was diagnosed with ONP, chemotherapy history.

INTERVENTIONS

The patient was introduced to acupuncture department to receiving EA treatment.

OUTCOMES

After 12 times of EA treatments, the symptom of ptosis was significantly improved, and the right upper eyelid can lift autonomously as same as the left eye. Besides, the patient's right lateral eye could move freely, and the symptoms of double vision disappeared.

CONCLUSION

The case suggests that EA may be an effective alternative treatment for ONP.

The profiles and clinical significance of extraocular muscle-expressed lncRNAs and mRNAs in oculomotor nerve palsy

Introduction

Oculomotor nerve palsy (ONP) arises from primary abnormalities in the central neural pathways that control the extraocular muscles (EOMs). Long non-coding RNAs (lncRNAs) have been found to be involved in the pathogenesis of various neuroparalytic diseases. However, little is known about the role of lncRNAs in ONP.

Methods

We collected medial rectus muscle tissue from ONP and constant exotropia (CXT) patients during strabismus surgeries for RNA sequencing analysis. Differentially expressed mRNAs and lncRNAs were revealed and included in the functional enrichment analysis. Co-expression analysis was conducted between these differentially expressed mRNAs and lncRNAs, followed by target gene prediction of differentially expressed lncRNAs. In addition, lncRNA-microRNA and lncRNA-transcription factor-mRNA interaction networks were constructed to further elaborate the pathological changes in medial rectus muscle of ONP. Furthermore, RT-qPCR was applied to further validate the expression levels of important lncRNAs and mRNAs, whose clinical significance was examined by receiver operating characteristic (ROC) curve analysis.

Results

A total of 618 differentially expressed lncRNAs and 322 differentially expressed mRNAs were identified. The up-regulated mRNAs were significantly related to cholinergic synaptic transmission (such as CHRM3 and CHRND) and the components and metabolism of extracellular matrix (such as CHI3L1 and COL19A1), while the down-regulated mRNAs were significantly correlated with the composition (such as MYH7 and MYL3) and contraction force (such as MYH7 and TNNT1) of muscle fibers. Co-expression analysis and target gene prediction revealed the strong correlation between MYH7 and NR_126491.1 as well as MYOD1 and ENST00000524479. Moreover, the differential expressions of lncRNAs (XR_001739409.1, NR_024160.1 and XR_001738373.1) and mRNAs (CDKN1A, MYOG, MYOD1, MYBPH, TMEM64, STATH, and MYL3) were validated by RT-qPCR. ROC curve analysis showed that lncRNAs (XR_001739409.1, NR_024160.1, and NR_002766.2) and mRNAs (CDKN1A, MYOG, MYOD1, MYBPH, TMEM64, and STATH) might be promising biomarkers of ONP.

Conclusions

These results may shed light on the molecular biology of EOMs of ONP, as well as the possible correlation of lncRNAs and mRNAs with clinical practice.

Immediate effects of electroacupuncture in oculomotor nerve palsy following brainstem infarction: A case report

INTRODUCTION

Research has demonstrated that electroacupuncture (EA) stimulation of paralyzed muscles significantly improves nerve regeneration and functional recovery.

DESCRIPTION

An 81-year-old man with no history of diabetes mellitus or hypertension presented with a history of brainstem infarction. Initially, the patient had medial rectus palsy in the left eye and diplopia to the right in both eyes, which almost returned to normal after six sessions of EA.

METHODS

The CARE guidelines informed the case study report. The patient was diagnosed with oculomotor nerve palsy (ONP) and photographed to document ONP recovery after treatment. The selected acupuncture points and surgical methods are listed in the table.

DISCUSSION

Pharmacological treatment of oculomotor palsy is not ideal, and its long-term use has side effects. Although acupuncture is a promising treatment for ONP, existing treatments involve many acupuncture points and long cycles, resulting in poor patient compliance. We chose an innovative modality, electrical stimulation of paralyzed muscles, which may be an effective and safe complementary alternative therapy for ONP.

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.

Ocular motor nerve palsy in patients with diabetes: High-resolution MR imaging of nerve enhancement

OBJECTIVE

To evaluate the extent of signal abnormality in impaired ocular motor nerves using high signal and spatial resolution MRI sequences and to discuss the involvement of inflammatory or microvascular impairment in patients with diabetic ophthalmoplegia.

METHODS

We conducted a retrospective study of 10 patients referred for acute ocular motor nerve palsy in the context of diabetes mellitus from September 15th, 2021 to April 24th, 2022. 3T MRI evaluation included diffusion, 3D TOF, FLAIR, coronal STIR and post-injection 3D T1 SPACE DANTE sequences.

RESULTS

Ten patients were included: 9 males and 1 female aged from 46 to 79 years. Five patients presented with cranial nerve (CN) III palsy, and 5 presented with CN VI palsy. Third nerve palsy was pupil-sparing in 4 patients and pupil-involved in 1 patient. Pain was associated in all patients with CN III deficiencies and in 2 patients CN VI deficiencies. In all patients, MRI sequences ruled out mass effect and vascular pathology, such as acute stroke or aneurysm. Eight patients presented with STIR hypersignals, some with enlargement of the involved nerve. The diagnosis was confirmed through a post-injection 3D T1 SPACE DANTE sequence, which showed extended enhancement along the abnormal portion of the nerve.

CONCLUSION

High-resolution MRI evaluation of diplopia in diabetic patients is used to rule out a diagnosis of acute stroke and contributes to the positive diagnosis of ocular motor nerve impairment, possibly combining the influences of inflammatory and microvascular phenomena. Dedicated MR imaging should be included in the initial diagnosis and longitudinal follow-up of patients with diabetic ophthalmoplegia.

Acupuncture treated oculomotor nerve palsy with diabetes mellitus: A case reported

The incidence of diabetes mellitus is increasing rapidly, and this condition often results in severe complications. One such complication, diabetic oculomotor nerve palsy (ONP), that can lead to significant impairment of visual function is increasingly recognized. However, there are few reports in the literature on the treatment of diabetic ONP. In the present case, the use of needling a selection of local and distal acupoints showed promising results for the treatment of diabetic ONP. We also present a brief literature review related to this case.

The Superior Cerebellar Artery: Variability and Clinical Significance

The superior cerebellar artery (SCA) arises from the distal part of the basilar artery and passes by the oculomotor, trochlear, and trigeminal nerves. SCA is known to play a crucial role in the development of trigeminal neuralgia. However, due to its anatomical variability, it may also trigger other neurovascular compression (NVC), including hemifacial spasm, oculomotor nerve palsy, and ocular neuromyotonia. Additionally, it may be associated with ischemic syndromes and aneurysm development, highlighting its clinical significance. The most common anatomical variations of the SCA include duplication, a single vessel origin from the posterior cerebral artery (PCA), and a common trunk with PCA. Rarely observed variants include bifurcation and origin from the internal carotid artery. Certain anatomical variants such as early bifurcation and caudal course of duplicated SCA trunk may increase the risk of NVC. In this narrative review, we aimed to examine the impact of the anatomical variations of SCA on the NVCs based on papers published in Pubmed, Scopus, and Web of Science databases with a snowballing approach. Our review emphasizes the importance of a thorough understanding of the anatomical variability of SCA to optimize the management of patients with NVCs associated with this artery.

Single internal carotid cavernous sinus aneurysm presented as bilateral painful ophthalmoplegia: a case report

BACKGROUND

Intracranial aneurysms are the most common vascular cause of painful ophthalmoplegia. Symptoms include retro-orbital pain, diplopia, ophthalmoplegia, trigeminal neuropathy, or a combination of these. Most single aneurysms cause ipsilateral, painful ophthalmoplegia. Here, we report the first, to our knowledge, case of bilateral painful ophthalmoplegia possibly caused by an aneurysm of the cavernous segment of the left internal carotid artery.

CASE PRESENTATION

A 62-year-old male patient presented with headache and bilateral ptosis. Laboratory tests revealed hypopituitary function. Computerized tomography angiography showed a large aneurysm in the cavernous sinus segment of the left internal carotid artery. Aneurysm embolization was performed in the Nerve Interventional Department. Four months after surgery, the patient's symptoms returned to normal.

CONCLUSIONS

This case suggests that patients with bilateral painful ophthalmoplegia should be screened for aneurysms using computed tomography angiography or magnetic resonance angiography immediately.

Research hotspots and trends of oculomotor nerve palsy from 2001 to 2021 based on web of science: A bibliometric analysis

Background

Oculomotor nerve palsy (ONP) is a clinically occurring neurological disorder. Due to the complex anatomy and long travel distances of the oculomotor nerve, the causes of ONP vary and manifest in various ways. With continued interest in this area, it has become necessary to conduct a bibliometric study in ONP. This work aims to synthesize and visually identify current research themes and future trends in ONP through a literature-based analysis.

Method

Articles and reviews on ONP published from 2002 to 2021 were derived from the Web of Science Core Collection (WoSCC) database. We generated visual images and performed quantitative and qualitative analysis through an online bibliometric tool, Citespace and VOSviewer software.

Results

A total of 1,205 published articles were included in this analysis. The annual number of this area's publications is showing an overall upward trend, with the number of citations increasing every year, reaching 2,698 by 2021. The United States (367) and Japan (116) dominated the list with the most numerous articles published. The University of California Los Angeles in the USA is the institution that published the highest number of articles (47). Engle EC (23) and the JOURNAL OF NEUROSURGERY (46) are the most influential authors and journals in this field. The co-occurrence network analysis divided the keywords into five main research themes, which mainly include clinical manifestations of ONP, aneurysms, cerebral neurological symptoms, diseases with ONP as a complication, and other neurological disorders.

Conclusion

This study is the first comprehensive and systematic bibliometric analysis of the current state of global ONP research over the past 20 years. We organized current hotspots and expected trends and provided key information for exploring potential research frontiers in ONP.

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.

Isolated oculomotor nerve palsy secondary to non-aneurysmal subarachnoid hemorrhage

We present a case series of two patients who developed unilateral cranial nerve III (CNIII) palsy following non-aneurysmal SAH (NASAH). Subarachnoid hemorrhage (SAH) can present with various signs and symptoms. Early diagnosis is paramount to determine treatment course. Thus, clinicians must be aware of the variable clinical presentations of this condition. Two patients were admitted to a single institution for SAH. Patient 1, 52-year-old male, presented with headache, left eye ptosis, and painless diplopia. A non-contrast head computed tomography (CT) demonstrated a SAH within the left sylvian fissure and blood surrounding the mesencephalon and falx. Patient 2, 70-year-old male, presented with mild headache, acute onset of blurry vision, and right eye ptosis. A non-contrast head CT demonstrated a diffuse SAH predominantly in the Sylvian and suprasellar cisterns. Patients were admitted to the neuro intensive care unit and underwent diagnostic angiograms to identify possible aneurysms. Magnetic resonance imaging and angiograms for both patients were negative. Patients were managed with best medical therapy and followed up in the outpatient setting. Unilateral CNIII palsy in the setting of NASAH was identified in both patients. Diagnostic angiograms were negative for aneurysms; therefore, SAH were determined to be spontaneous. We propose that unilateral CNIII palsy is a possible sign of NASAH.

Etiology and Clinical Features of Diplopia in South China: Analysis of 303 Cases

Purpose

To provide a new classification system for diplopia and evaluate the etiology and clinical features of diplopia subtypes in south China.

Methods

In this retrospective study, all patients presenting with diplopia over the period from 2012 to 2014 in south China were reviewed. Patients were categorized into 3 groups according to their extraocular muscle (EOM) dysfunction: single EOM (sEOM), multiple EOMs (mEOMs), and a comitant strabismus group. Clinical data evaluated included age, sex, medical history, etiology and duration of diplopia, ocular alignment, and ocular motility.

Results

A total of 303 patients were enrolled. The most common type of EOM dysfunction was sEOM (158 cases, 52.1%), followed by mEOMs (n = 119, 39.3%), and finally the comitant strabismus group (n = 26, 8.6%). Overall, the most common cause of diplopia involved orbital diseases. Within the sEOM group, microangiopathy (n = 42, 26.6%) and trauma (n = 41, 25.9%) were the major etiologies, with the lateral rectus (LR) (n = 86, 54.4%) being the most frequently involved. There were 12 (4.0%) patients who were considered as nasopharyngeal carcinoma (NPC)-associated diplopia (10 caused by radiation neuropathy following radiation therapy). Thyroid associated ophthalmopathy (TAO, 56 cases, 47.1%) was the predominant etiology found in the mEOMs group. Acute acquired comitant esotropia (AACE, 14 cases, 53.9%) was the most common etiology in the comitant strabismus group.

Conclusions

This new classification system for assessing diplopia as based on EOM dysfunction represents an easy-to-follow approach that can be readily adapted for the clinical use. While microangiopathy and trauma represent common etiologies of diplopia, both orbital diseases and NPC-associated diplopia also warrant special attention when assessing diplopia within patients in south China.

Frontalis Sling Using a Silicone Rod for Ptosis in Third Nerve Palsy: Cosmesis Versus Safety

Purpose

To evaluate the results of the frontalis sling operation using a silicone rod for the correction of ptosis in patients with third nerve palsy with a focus on corneal safety.

Methods

Patients with third nerve palsy who underwent the frontalis sling operation using a silicone rod between 2008 and 2019 were included in this study. The medical records of all patients were reviewed, and their clinical characteristics and postoperative outcomes were analyzed. In this retrospective, interventional case series, the main outcome measures were eyelid contour, eyelid height by margin reflex distance, and corneal status.

Results

Twenty-four eyes of 18 patients (12 male and six female patients) were included. The mean age at the time of surgery was 35.1 years (range, 5–64 years). Twelve patients underwent a unilateral ptosis operation, and six patients received a bilateral ptosis operation. The mean follow-up period was 32.1 months (range, 2–87 months). Most patients (21 of 24 eyes, 88%) showed poor Bell’s phenomenon on preoperative examination. Satisfactory eyelid height and eyelid contour were achieved in almost all patients (mean postoperative margin reflex distance, +1.2 mm) postoperatively. Although corneal erosions were detected for several months in eight of 24 eyes after surgery, these findings were well controlled medically with artificial tear eye drops and ointments.

Conclusions

Frontalis sling surgery using a silicone rod can safely and effectively correct ptosis without severe corneal complications in patients with third nerve palsy. Our study outlines a new method to define the postoperative safety outcome by specifically focusing on categorized corneal status.

Advances in the genetics of congenital ptosis

Congenital ptosis, a birth defects presents at birth or by 1 year of age, is characterized by the drooping of the upper eyelid. either in isolation (non-syndromic) or with many different systemic disorders (syndromic). The estimated prevalence of ptosis (congenital & acquired) ranges from 0.79 to 1.99 per 10,000 people in different populations, and it is more prevalent in males. The underlying pathogenesis of congenital ptosis are myogenic and neurogenic, related to the development of muscles and nerves. Although most cases are sporadic, there are familial transmission characteristics, including autosomal dominant, recessive mode and X-linkage inheritance patterns. Moreover, some forms are due to chromosomal aberrations and mutations and deletions in mitochondrial DNA. Genes involved in simple congenital ptosis are ZFHX4 and COL25A1. The clinical aspects of various syndromes involving congenital ptosis are partly caused by single gene mutations. However, the pathogenesis of congenital ptosis is not fully understood. We review the reported epidemiology, genetics and clinical features of congenital ptosis and associated syndromes here.

A Clinical Retrospective Study of Recurrent Painful Ophthalmoplegic Neuropathy in Adults

Introduction

Recurrent painful ophthalmoplegic neuropathy (RPON) is quite rare and usually occurs in children. In this report, we describe the clinical features, diagnosis, and treatment of RPON in adults.

Methods

A retrospective review was conducted of all RPON cases seen and treated at the Zhongshan Ophthalmic Center of Sun Yat-sen University and the Department of Neurology of the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, China, over the period from January 2016 to May 2020.

Results

A total of 8 patients (3 males and 5 females) with a mean age of 42.9 years (range: 23–64 years) met the diagnostic criteria of RPON. Headaches were present prior to the onset of ophthalmoplegic neuropathy in 50% of these patients, while in the remaining 50%, headaches occurred simultaneously with eye symptoms. The degree of these headaches was described as being mild or moderate. Abnormalities involving cranial nerve III were the most frequently reported pathologies (6 cases, 75%), followed by nerve VI (4 cases, 50%) and then nerve IV (1 case, 12.5%) (more than one nerve was affected in some cases). Following either with glucocorticoid treatment or with observation only, symptoms and signs within all 8 patients completely dissipated within 3–28 days.

Conclusions

All adult cases of RPON along with their clinical features as reported here were similar to those of children.

Acute Complete Oculomotor Nerve Palsy in a Young Male Due to a Skull Base Myofibroma

ABSTRACT

A 25-year-old male patient visited the ophthalmology clinic because of upper eye lid ptosis in the right eye, binocular double vision, and light sensitivity. He was diagnosed with a complete third nerve palsy caused by a skull base myofibroma, a rare clinical entity that has not been described before in oculomotor nerve palsy.

Unilateral Pupil Sparing: Viral Oculomotor Neuritis With Concomitant Vestibular Neuritis

Unilateral oculomotor nerve palsy is a common clinical condition with various etiologies, including aneurysm, diabetes mellitus, central nervous system (CNS) infections, pituitary tumors, and ischemic changes. Due to the plethora of possible causes, early and thorough investigation is essential for treatment. We report the case of a 45-year-old male who presented with left ptosis, vertigo, and blurry vision and was diagnosed with oculomotor neuritis. Past medical history (PMH) was significant for hyperlipidemia, diabetes, and chronic kidney disease. Patient imaging revealed chronic left cerebellar infarction but no acute changes. Significantly, he was experiencing intractable nausea, dizziness, and vomiting attributed to concomitant vestibular neuritis. Infectious etiologies of oculomotor neuritis are rarely reported. However, idiopathic vestibular and facial palsies are commonly attributed to viral infection. The patient was treated with a steroid taper for viral vestibular neuritis, with noticeable clinical improvement to his oculomotor neuritis manifestations. This postulates a common viral etiology uniquely causing both oculomotor and vestibular neuritis.

Case Report: Isolated, unilateral oculomotor palsy with anti-GQ1b antibody following COVID-19 vaccination

Neurological complications following vaccinations are extremely rare, but cannot be eliminated. Here, we report the first case of unilateral oculomotor nerve palsy (ONP) with anti-GQ1b antibody after receiving the Pfizer-BioNTech COVID-19 (BNT162b2) mRNA vaccine. A 65-year-old man developed diplopia and ptosis in the right eye 17 days after vaccination, without preceding infection. Neurological examination revealed mild blepharoptosis, limitation of adduction, and vertical gaze on the right side. Increased levels of anti-GQ1b ganglioside antibody in the serum and albuminocytologic dissociation in the cerebrospinal fluid were detected. Cranial magnetic resonance imaging showed swelling and enhancement of the right oculomotor nerve. The patient was diagnosed with right ONP accompanied with anti-GQ1b antibody, and intravenous immunoglobulin (IVIG) therapy for 5 days was administered. The limitation of adduction and vertical gaze improved, and ptosis markedly resolved after IVIG treatment. Given the temporal sequence of disease progression, laboratory findings, and a favorable response to IVIG, a causal relationship cannot be ruled out between the occurrence of ONP and COVID-19 immunization. Since immunomodulatory treatments significantly hasten the recovery and minimize the residual symptoms in anti-GQ1b antibody syndrome, clinicians should be aware of this clinical condition following COVID-19 vaccination.

Case Report: Isolated, unilateral oculomotor palsy with anti-GQ1b antibody following COVID-19 vaccination

Neurological complications following vaccinations are extremely rare, but cannot be eliminated. Here, we report the first case of unilateral oculomotor nerve palsy (ONP) with anti-GQ1b antibody after receiving the Pfizer-BioNTech COVID-19 (BNT162b2) mRNA vaccine. A 65-year-old man developed diplopia and ptosis in the right eye 17 days after vaccination, without preceding infection. Neurological examination revealed mild blepharoptosis, limitation of adduction, and vertical gaze on the right side. Increased levels of anti-GQ1b ganglioside antibody in the serum and albuminocytologic dissociation in the cerebrospinal fluid were detected. Cranial magnetic resonance imaging showed swelling and enhancement of the right oculomotor nerve. The patient was diagnosed with right ONP accompanied with anti-GQ1b antibody, and intravenous immunoglobulin (IVIG) therapy for 5 days was administered. The limitation of adduction and vertical gaze improved, and ptosis markedly resolved after IVIG treatment. Given the temporal sequence of disease progression, laboratory findings, and a favorable response to IVIG, a causal relationship cannot be ruled out between the occurrence of ONP and COVID-19 immunization. Since immunomodulatory treatments significantly hasten the recovery and minimize the residual symptoms in anti-GQ1b antibody syndrome, clinicians should be aware of this clinical condition following COVID-19 vaccination.

Diabetic Oculomotor Nerve Palsy Displaying Enhancement of the Oculomotor Nerve in the Orbit and Cavernous Sinus on MRI

INTRODUCTION

Imaging data were scarce on diabetic oculomotor nerve palsy (ONP). Our study explored the MRI features and their clinical implications for diabetic ONP.

METHODS

Fifty-nine patients with a clinical diagnosis of diabetic ONP were recruited from our department between January 2015 and December 2019. Orbital MRI was retrospectively analyzed, and follow-up scans were obtained for 5 patients. Based on the ocular motor nerve palsy scale, the difference in the scores on the first and last hospital days was defined as the improvement score and was used to assess the treatment effects in all.

RESULTS

Thirty-eight (64.41%) patients presented thickening and enhancement of the cavernous segment and inferior division of the intraorbital segment of the ipsilateral oculomotor nerve, with the cisternal segment spared in all. After complete resolution of symptoms, follow-up MRI in 5 patients revealed that the enhancement was less obvious compared with the previous images. 6 patients in the enhancement group and 4 patients in the nonenhancement group were treated with 80 mg of methylprednisolone. Significant differences were not detected in the median improvement scores between patients with and those without corticosteroid use (p = 0.240).

CONCLUSION

Thickening and enhancement of the unilateral oculomotor nerve were common imaging findings in diabetic ONP, and they persisted after complete resolution of symptoms in some patients. The cavernous segment and the inferior division of the intraorbital segment were simultaneously involved, and the cisternal segment was often spared. Refraining from corticosteroids was recommended even with nerve enhancement.

High-resolution magnetic resonance imaging in isolated, traumatic oculomotor nerve palsy: A case report

Traumatic, isolated oculomotor nerve palsy is a rare clinical finding and only few reports demonstrate associated magnetic resonance imaging (MRI) findings. Here, we present the case of a 70-year-old woman with left-sided oculomotor nerve palsy following a mild head trauma due to an e-bike accident. Post-traumatic cerebral computed tomography revealed punctiform hemorrhage in the left interpeduncular cistern and the following MRI confirmed an intraneural hemorrhage of the left oculomotor nerve. Nine weeks later, the follow-up MRI showed progressive atrophy and contrast-enhancement of the left oculomotor nerve. To support functional recovery, a treatment with intravenous corticosteroids was started. Six months later, the patient presented with improved oculomotor nerve function and partial recovery of ptosis and diplopia. In accordance, MRI demonstrated recurrent contrast-enhancement of the atrophic nerve. In conclusion, high-resolution MRI allows the reliable delineation of the oculomotor nerve and can support diagnosis in trauma patients with isolated oculomotor nerve palsy.

The Incidence and Etiologies of Third Cranial Nerve Palsy in Koreans: A 10-year Nationwide Cohort Study

PURPOSE

This study aimed to determine the incidence, prevalence, and etiologies of third cranial nerve (CN3) palsy in Koreans.

METHODS

Data were collected from the National Health Insurance Service-National Sample Cohort (NHIS-NSC) database of South Korea and analyzed. Incident CN3 palsy subjects in the cohort population were defined as cases occurring after the initial 4-year or longer washout period. The incidence and prevalence were analyzed by sex, age group, and year. The etiologies of CN3 palsy were evaluated using comorbidities.

RESULTS

Of 1,108,253 subjects, 387 patients were newly diagnosed with CN3 palsy between 2006 and 2015. The incidence of CN3 palsy was 3.71 per 100,000 person-years (95% confidence interval, 3.35-4.09). The incidence of CN3 palsy increased with age and accelerated after the age of 60 years. The mean male-to-female incidence ratio was 1.16. The main cause was presumed to be vascular disease (52.7%), followed by idiopathic causes (25.8%), intracranial neoplasm (7.8%), unruptured cerebral aneurysm (5.4%), and trauma (5.2%).

CONCLUSIONS

The incidence of CN3 palsy in Koreans increased with age and peaked between 75 and 79 years. The main cause of CN3 palsy was vascular disease.

Intermittent oculomotor nerve paresis and hollow appearance on MRI manifested by pituitary adenoma

A 71-year-old man had sustained intermittent ptosis and double vision for 2 weeks. Neurological examination found unilateral oculomotor nerve (CN III) paresis manifesting as limitations of gaze, ptosis, and mydriasis. Neither headache nor any other cranial neuropathy was noted. Cerebral magnetic resonance imaging revealed a well-circumscribed mass in the pituitary fossa extending laterally into the left cavernous sinus. The segment of the left CN III lying in the oculomotor cistern was considerably compressed by the tumor. The cisternal segments of the left CN III showed an undescribed, “hollow” appearance. The left orbit and brainstem were intact. The patient underwent tumor resection via an endoscopic transsphenoidal approach. The tumor tissue was soft in consistency, involving xanthochromic fluid. The pathological diagnosis was pituitary adenoma accompanied with considerable hemorrhagic changes. The patent's ptosis and limitations of gaze showed remarkable improvements on postoperative day 1, with resolution of the hollow appearance of the affected CN III that was confirmed on day 3. We assumed that the intralesional bleeds and lateral tumor extension into the oculomotor cistern were associated with the intermittent paresis of the CN III as the sole presentation. A hollow appearance identified in the CN III might indicate a reversible dysfunction of the nerve that can anticipate an improvement by prompt surgical intervention.