The incidence and etiology of sixth cranial nerve palsy in Koreans: A 10-year nationwide cohort study

Surgical management of unilateral restrictive strabismus in an 8-month-old dog

CASE HISTORY

An 8-month-old male, entire, mixed-breed dog was presented with a 1-month history of left exophthalmos and green mucopurulent ocular discharge. Subsequently, exophthalmos resolved but esotropia (medial strabismus) developed in the left eye, prompting referral to an ophthalmologist.

CLINICAL FINDINGS

At the initial referral consultation, enophthalmos and esotropia of the left eye were identified. The patient showed mild improvement after a 3-week tapering course of oral prednisolone and doxycycline. MRI was performed and showed left medial rectus muscle atrophy with increased contrast enhancement which was consistent with chronic extraocular muscle myositis (EOM). A forced duction test was performed to confirm the diagnosis of fibrosing esotropia, which is likely a sequela of chronic EOM.

DIAGNOSIS

Fibrosing esotropia presumably caused by untreated EOM.

TREATMENT AND OUTCOME

One month later, esotropia progressed to a marked ventro-medial strabismus resulting in visual deprivation. Surgical release of the ventral oblique, medial and ventral recti muscles was performed, resulting in immediate resolution of the enophthalmos. Despite a tapering post-operative course of oral prednisolone, mild esotropia was present 4 weeks later. In an effort to stabilise the globe position, the low dose of prednisolone was increased to a higher anti-inflammatory dose before slowly tapering over 2 months. The vision in the left eye was improved after surgery and has been maintained since without further treatment.

CLINICAL RELEVANCE

This is the first documented case of fibrosing esotropia in a young dog with prior signs of acute exophthalmos. Fibrosing esotropia has been documented in certain breeds or as a sequela to chronic EOM. In this patient, it was presumably caused by EOM, which was strongly supported by the case history, progression and MRI findings. Most historical reports of EOM described it as a bilateral condition that resolves with systemic corticosteroids at an anti-inflammatory dose. EOM has been shown to also present unilaterally and it can progress to strabismus if not promptly recognised and treated with systemic steroids. Surgical management can restore vision when severe strabismus results in visual deprivation.

Cranial Nerve Palsy and Risk of Kidney Cancer: A Nationwide Population-Based Study

Background and Objective: Understanding whether cranial nerve palsy (CNP) acts as an independent risk factor for kidney cancer could have important implications for patient care, early detection, and potentially the development of preventive strategies for this type of cancer in individuals with CNP. This study aimed to examine the risk of kidney cancer following the onset of ocular motor CNP and assess whether CNP could be considered an independent risk factor for kidney cancer. Materials and Methods: A population-based cohort study was conducted using data from the National Sample Cohort (NSC) database of Korea's National Health Insurance Service which was collected from 2010 to 2017. Follow-up was until kidney cancer development, death, or 31 December 2018. Cox proportional hazard regression analysis was performed to determine hazard ratios (HRs) for kidney cancer according to CNP status. Participants aged 20 years or more diagnosed with CNP from 2010 to 2017 were included. Exclusions comprised individuals with specific pre-existing conditions, inability to match a control group, and missing data, among others. CNP patients were age-sex matched in a 1:5 ratio with control cases. The primary outcome was incidence of kidney cancer during the follow-up period. Results: This study comprised 118,686 participants: 19,781 in the CNP group, and 98,905 in the control group. Compared to the control group, participants with CNP had a higher risk of kidney cancer (adjusted HR in model 4, 1.599 [95% CI, 1.116-2.29]). After a 3-year lag period, the CNP group had a significantly higher risk (adjusted HR in model 4, 1.987 [95% CI, 1.252-3.154]). Conclusions: Ocular motor CNP may be an independent risk factor for kidney cancer, as indicated by a higher incidence of kidney cancer in CNP patients. Further research is needed to elucidate the underlying mechanisms and explore potential preventive measures for kidney cancer in patients with ocular motor CNP.

Botulinum Toxin Injection for the Treatment of Third, Fourth, and Sixth Nerve Palsy: A Meta-Analysis

The efficacy of botulinum toxin injection for the treatment of third, fourth, and sixth nerve palsy was evaluated. PubMed, Scopus, EMBASE, Web of Science, and Google Scholar databases were searched. Data about the duration of palsy (acute vs chronic), cause of the palsy, type of toxin used, mean dose, and other background characteristics were collected. Outcome variables were success rate (defined by alleviation of diplopia or reduction in eye deviation) and standardized mean difference of prism diopter and abduction deficit before and after injection. The Joanna Briggs Institute checklist was implemented for the risk of bias assessment. The analysis included 38 articles, comprising 643 patients. The overall treatment success rate in acute and chronic nerve palsy was 79% and 33%, respectively. The success rate was not significantly different between different subgroups of age, type of botulinum toxin, pre-injection prism diopter, etiology of the palsy, duration of follow-up, and mean dose of botulinum toxin injection. However, in both acute and chronic palsy, diabetes etiology was accompanied by the highest success rate. Overall symptomatic response to botulinum injection was 84% (95% CI: 67% to 96%), whereas functional response was observed in 64% (95% CI: 47% to 79%) of the patients. The odds ratio for the success rate of treatment of palsies with botulinum toxin versus expectant management was 2.67 (95% CI: 1.12 to 6.36) for acute palsy and 0.87 (95% CI: 0.17 to 4.42) for chronic palsy. Botulinum toxin can be used for the treatment of acute third, fourth, and sixth nerve palsy, especially in patients with acute palsy and more severe tropia. [J Pediatr Ophthalmol Strabismus. 2024;61(3):160-171.].

Abducens Nerve Palsy in a Patient with COVID-19: A Case Report

Numerous neurological manifestations associated with COVID-19 have been reported. However, abducens nerve palsy (ANP) associated with COVID-19 is very rare and mostly related to accompanying respiratory symptoms. Here we present a 29-year-old woman with unilateral ANP manifesting with diplopia and positive SARS-CoV-2 S antibodies, which were checked later. On admission, she had signs of viral pneumonia in thorax CT without any respiratory symptoms. Her cranial neuroimaging revealed no abnormality. Following treatment with favipiravir 2x1600 mg loading dose and then 2x600mg daily maintenance, dexamethasone 8 mg/day and enoxaparin 6000 IU/day, her CT findings recovered completely whereas her ANP only partially resolved. One week after the end of COVID-19 treatment, she also developed Herpes simplex keratitis which was successfully treated with valacyclovir. It should be kept in mind that isolated abducens nerve palsy may be the only finding of COVID-19 cases without any respiratory symptoms.

Early-Onset Ocular Motor Cranial Neuropathy Is a Strong Predictor of Dementia: A Nationwide, Population-Based Cohort Study

PURPOSE

To assess the risk of dementia in individuals with newly diagnosed ocular motor cranial neuropathy (OMCN).

DESIGN

A nationwide, population-based cohort study using authenticated data from the Korean National Health Insurance Service (KNHIS).

PARTICIPANTS

This study included 60 781 patients with OMCN who received a diagnosis between 2010 and 2017 and were followed up through 2018, with an average follow-up of 3.37 ± 2.21 years with a 1-year lag. After excluding patients with disease related to oculomotor dysfunction preceding the OMCN diagnosis, a total of 52 076 patients with OMCN were established. Of these, 23 642 patients who had participated in the National Health Screening Program (NHSP) within 2 years before the OMCN diagnosis were included. After applying the exclusion criteria, the final cohort comprised 19 243 patients and 96 215 age and sex-matched control participants without OMCN.

METHODS

We identified patients with newly diagnosed OMCN in the KNHIS database and collected participant characteristics from the health checkup records of the NHSP. The study end point was determined by the first claim with a dementia diagnostic code and antidementia medications. The association of OMCN with dementia risk was examined using Cox proportional hazards regression analysis, adjusting for potential confounding factors.

MAIN OUTCOME MEASURES

The main outcome measures were hazard ratios (HRs) and 95% confidence intervals (CIs) for all-cause dementia (ACD), Alzheimer's disease (AD), and vascular dementia (VaD) development in patients with OMCN relative to those without OMCN.

RESULTS

Patients with newly diagnosed OMCN demonstrated higher metabolic comorbidities than those without OMCN. New OMCN was associated with an elevated risk of ACD (HR, 1.203; 95% CI, 1.113-1.300), AD (HR, 1.137; 95% CI, 1.041-1.243), and VaD (HR, 1.583; 95% CI, 1.286-1.948), independent of potential confounding factors. The younger age groups exhibited a stronger association between OMCN and ACD (HR, 8.690 [< 50 years] vs. 1.192 [≥ 50 years]; P = 0.0004; HR, 2.517 [< 65 years] vs. 1.099 [≥ 65 years]; P < 0.0001).

CONCLUSIONS

This nationwide population-based study assessed the association between OMCN and dementia risk. Our results demonstrated a robust relationship between OMCN and the risk of dementia, particularly in the younger population.

FINANCIAL DISCLOSURE(S)

The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Retrospective Analysis of Factors Related to the Long-Term Recovery of Third, Fourth, and Sixth Cranial Nerve Palsy with Etiologies and Clinical Course in a Tertiary Hospital

Purpose

Although various studies have explored the causes and clinical aspects of cranial nerve palsies, there remains a significant gap in understanding the prognostic factors that influence outcomes. In this study, we sought to address this gap by investigating the incidence, etiologies, clinical courses, and factors associated with long-term recovery, with the aim of enhancing the knowledge base in this field and providing valuable insights for improved patient care.

Patients and Methods

This retrospective study evaluated the data gathered from subjects who had third, fourth, and sixth cranial nerve palsy at the ophthalmology outpatient clinic of Phramongkutklao Hospital between April 1, 2012, and April 30, 2022.

Results

Among the three nerves, abducens nerve palsy was the most prevalent finding by most commonly involved. Our study revealed that ischemic and compressive lesions were the most common etiology of oculomotor nerve palsy, comprising 24.6% each. In addition, the most common etiology of trochlear and abducens nerve palsy was trauma, at 31.6% and 27.1%, respectively. Compared with the other nerves, oculomotor nerve palsy was associated with a shorter duration onset of symptoms and recovery period. The best recovery outcomes among the various etiologies were inflammation, ischemic events, and trauma in oculomotor, trochlear, and abducens nerve palsy, respectively. Logistic regression revealed that an onset of <7 days and isolated nerve involvement were significantly associated with good long-term outcomes, with an adjusted odds ratio of 1.73 (95% confidence interval, 1.03-2.89) and 2.56 (95% confidence interval, 1.21-5.39) adjusted for the type of cranial nerve palsy, aged at 50 years, sex, diabetes mellitus, hypertension, dyslipidemia, onset at 7 days, and number of cranial nerves involved, respectively.

Conclusion

The onset of symptoms in less than 1 week and isolated nerve involvement were associated with better prognosis in subjects with third, fourth, and sixth cranial nerve palsy.

Dynamic Changes in Metabolic Status Are Associated With Risk of Ocular Motor Cranial Nerve Palsies

BACKGROUND

To investigate whether recovery from or development of metabolic syndrome (MetS) in a population is associated with an altered risk for ocular motor cranial nerve palsy (CNP).

METHODS

This cohort study included 4,233,273 adults without a history of ocular motor cranial nerve palsy (ocular motor CNP) who underwent 2 consecutive biennial health screenings provided by the Korean National Health Insurance System between 2009 and 2011. They were followed up until December 31, 2018. Participants were categorized into a MetS-free, MetS-developed, MetS-recovered, or MetS-chronic group. A multivariable Cox proportional hazard regression model was used. Model 3 was adjusted for age, sex, smoking status, alcohol consumption, and physical activity.

RESULTS

Compared with the MetS-free group, the MetS-chronic group had the highest risk of ocular motor CNP (hazard ratio [HR]: 1.424; 95% confidential interval [CI]: 1.294-1.567, Model 3), followed by the MetS-developed group (HR: 1.198, 95% CI: 1.069-1.343), and the MetS-recovered group (HR: 1.168, 95% CI: 1.026-1.311) after adjusting for potential confounders. The hazard ratio of ocular motor CNP in men with chronic MetS was 1.566 (95% CI, 1.394-1.761) while that of women with chronic MetS was 1.191 (95% CI, 1.005-1.411). Among age groups, those in their 30s and 40s showed the highest association between dynamic MetS status and ocular motor CNP.

CONCLUSIONS

In our study, recovering from MetS was associated with a reduced risk of ocular motor CNP compared with chronic MetS, suggesting that ocular motor CNP risk could be managed by changing MetS status.

Ocular motility disorders following coronavirus disease-19 vaccination

PURPOSE

To describe clinical manifestations and short-term prognosis of ocular motility disorders following coronavirus disease-2019 (COVID-19) vaccination.

METHODS

Ocular motility disorders were diagnosed by clinical assessment, high-resolution magnetic resonance imaging, and laboratory testing. Clinical manifestations, short-term prognosis, and rate of complete recovery were analyzed.

RESULTS

Sixty-three patients (37 males, 26 females) with a mean age of 61.6 ± 13.3 years (range, 22-81 years) were included in this study. Among 61 applicable patients with sufficient information regarding medical histories, 38 (62.3%) had one or more significant underlying past medical histories including vasculopathic risk factors. The interval between initial symptoms and vaccination was 8.6 ± 8.2 (range, 0-28) days. Forty-two (66.7%), 14 (22.2%), and 7 (11.1%) patients developed symptoms after the first, second, and third vaccinations, respectively. One case of internuclear ophthalmoplegia, 52 cases of cranial nerve palsy, two cases of myasthenia gravis, six cases of orbital diseases (such as myositis, thyroid eye disease, and IgG-related orbital myopathy), and two cases of comitant vertical strabismus with acute onset diplopia were found. Among 42 patients with follow-up data (duration: 62.1 ± 40.3 days), complete improvement, partial improvement, no improvement, and exacerbation were shown in 20, 15, 3, and 4 patients, respectively.

CONCLUSION

This study provided various clinical features of ocular motility disorders following COVID-19 vaccination. The majority of cases had a mild clinical course while some cases showed a progressive nature. Close follow-up and further studies are needed to elucidate the underlying mechanisms and long-term prognosis.

Trends in Etiologies, Demographics, and Neuroimaging in New-Onset Adult Strabismus at an Ophthalmic Emergency Department

PURPOSE

To evaluate new-onset strabismus in adults presenting to an ophthalmic emergency department, and to identify which patients require neuroimaging.

METHODS

This was a retrospective review of electronic medical records of patients 18 years and older who presented to an ophthalmic emergency department between January 1, 2019 and December 31, 2020 with new-onset strabismus. Data regarding demographics, causes, neuroimaging, and resolution were recorded and analyzed.

RESULTS

Of the 557 patients in the current study, 54.8% were men and the mean age was 57.3 ± 16.7 years (range: 18 to 92 years). Most patients (72.4%) presented with diplopia. Esotropia was the most common ocular misalignment (43.6%) and was more common in women than men (51.6% vs 37.0%, respectively) (P = .001). The most common diagnoses were cranial nerve palsies (66.8%) for both sexes and all age groups, with the most common etiology being microvascular (48.1%) for patients 50 years and older and idiopathic (20.1%) for patients between 18 and 49 years old. The incidence of cranial nerve palsies was significantly higher in older patients (P < .001). Neuroimaging was performed in 58% of patients (n = 323), of whom 37.2% (n = 120) had abnormal findings. The most common abnormal neuroimaging finding was mass for all age groups and sexes (19.2%). Patients with cranial nerve palsy and microvascular etiology had a significantly lower proportion of abnormal neuroimaging findings (P < .001).

CONCLUSIONS

Most cases of new-onset strabismus in adults presenting to the emergency department were due to cranial nerve palsy, particularly in older patients. Despite high rates of neuroimaging, patients with cranial nerve palsy had mostly normal findings. The current study supports the belief that neuroimaging may be deferred in patients older than 50 years with micro-vascular risk factors. [J Pediatr Ophthalmol Strabismus. 2022;59(4):269-273.].

Association between migraine and risk of ocular motor cranial nerve palsy

To assess association between migraines and development of ocular motor cranial nerve palsy (CNP) and finding risk factors using the National Sample Cohort database from the Korea National Health Insurance Service. Data was analyzed from 4,234,341 medical screening examinees aged 20–90 years in 2009. Cox proportional hazard regression analysis was used to the adjusted hazard ratios (HR) for ocular motor CNP according to presence of migraine. Subgroup analysis was performed to evaluate effect of other factors on association of migraine with ocular motor CNP. A total of 5806 participants (0.14% of subjects) developed ocular motor CNP and were assigned to CNP group, 4,048,018 were assigned to control group, with an average of 8.22 ± 0.93 years of follow-up. Incidence of ocular motor CNP increased in migraine group compared to control. After adjusting potential confounding variables, HR for ocular motor CNP was 1.166 (confidence interval [CI] 1.013–1.343) in migraine group. Subgroups of relatively younger age less than 65 years (HR = 1.267, 95% CI 1.067–1.504), male gender (HR = 1.228, 95% CI 1.000–1.122), smokers (HR 1.426, 95% CI 1.127–1.803), and diabetes mellitus patients (HR = 1.378, 95% CI 1.045–1.378) showed a stronger association between migraines and development of ocular motor CNP. Our population-based cohort study demonstrated a significant association between presence of migraines and incidence of ocular motor CNP. Especially, relatively younger age, males, smokers, and diabetes patients with migraines could have a higher risk of developing ocular motor CNP.

Clinical outcomes and etiology of acquired sixth cranial nerve palsy

ABSTRACT

The objective of this study was to investigate the difference in clinical features according to age and factors affecting recovery of acquired sixth cranial nerve (CN6) palsy.A total of 156 patients with acute CN6 palsy between March 2016 and August 2021 who were followed up for at least 3 months were included in this study. Etiology, rate of recovery, and factors associated with recovery were retrospectively investigated.The average age of patients with CN6 palsy was about 60years and the mean duration of recovery was about 2.5 months. Of 156 patients, 72 (46.15%) had a microvascular etiology and 25 (16.03%) patients had a brain vascular lesions. Brain neoplasm, trauma, and "others" were found in 10 (6.41%), 11 (7.05%), and 15 (9.62%) patients, respectively. Among the total of 156 patients, 28 (17.95%) failed to completely recover. Non-isolated CN6 palsy with other cranial nerve palsies were recorded in 29 (18.59%) cases. Comparison of age (<50years vs ≥50years), between recovery and non-recovery groups showed that etiology was significantly different.The recovery rate of acquired CN6 palsy was about 82% and about 27% of patients had brain lesions. Also, varying rates and duration of recovery were found according to etiology, so we should be pay attention to diagnosis of causative disease in CN6 palsy patients.

Association of Obesity and Incidence of Third, Fourth, and Sixth Cranial Nerve Palsies

STUDY DESIGN

Retrospective cohort study.

OBJECTIVE

To assess the association between obesity and the development of third, fourth, and sixth cranial nerve palsy (CNP).

METHODS

We analyzed a cohort of 4,067,842 adults aged between 20 and 90 years who underwent health checkups within the National Health Insurance Service between January 1 and December 31, 2009. The participants were followed until December 31, 2017. Cox proportional hazards regression analysis was used to determine the adjusted hazard ratios (HRs) for CNP. Model 3 (the main analysis model) was adjusted for age, sex, smoking status, alcohol consumption, and physical activity. Model 4 was additionally adjusted for hypertension, dyslipidemia, and diabetes mellitus in the setting of model 3.

RESULTS

A total of 5,835 individuals were diagnosed with CNP during the follow-up period (7.3 years). General obesity (body mass index [BMI] ≥25 kg/m²) was associated with an increased risk of CNP compared to individuals without general obesity (model 3, HR 1.248, 95% CI 1.184-1.315; model 4, HR 1.162, 95% CI 1.102-1.227). Abdominal obesity (waist circumference [WC] ≥90 cm in men and ≥85 cm in women) also showed an increased HR compared to individuals without abdominal obesity (model 3, 1.239, 95% CI 1.170-1.313; model 4, HR 1.127, 95% CI 1.062-1.196). Compared to the group without either type of obesity, the group with only abdominal obesity (model 3, HR 1.167, 95% CI 1.035-1.317), the group with only general obesity (HR 1.19, 95% CI 1.14-1.24), and the group with both obesity types (HR 1.317, 95% CI 1.236-1.404) showed increased HRs for CNP.

CONCLUSION

Based on our population-based cohort study, both general and abdominal obesity increased the risk of CNP. Also, the combination of general and abdominal obesity may further increase the risk of CNP.

Clinical profile and management of sixth nerve palsy in pediatric patients (0-15 years) in Southern India - A hospital-based study

PURPOSE

This study was done to evaluate the clinical profile in pediatric patients (0-16 years) presenting with acute onset esotropia due to sixth nerve palsy and its management options in a tertiary care set up of Southern India.

METHODS

A total of 12 patients presenting to our OPD with acute onset esotropia due to sixth nerve palsies were included in this retrospective study. All patients were observed for 6 months and managed with prism and/or patching while waiting for spontaneous resolution and later managed surgically. Neuroimaging was done in all cases.

RESULTS

The mean deviation of esotropia at presentation was 30.17 ± 5.7 Prism Diopter (range 12-50 Prism Diopter 95% CI, SD 10.11). Mean age of the patients during presentation was 8.6 ± 2.4 years (range: 1-15 years, SD 4.27). Among the common causes of sixth nerve palsy in our study population were trauma and idiopathic intracranial hypertension followed by tumor and miscellaneous causes. Only three patients underwent surgical correction of residual deviation after a waiting period of 6 months for self-resolution. Spontaneous resolution was observed in 41.6% patients, and surgical correction (unilateral resection-recession) was done in 25% of the patients with good surgical outcome.

CONCLUSION

At 1-year follow up, the motor outcome was satisfactory except for one patient who had diffuse pontine glioma and had worsening neurological symptoms on follow-up.

Stroke risk after ocular cranial nerve palsy - A systematic review and meta-analysis

BACKGROUND

Isolated ischemic ocular cranial nerve palsies (OCNP) involving the 3rd, 4th and 6th cranial nerves (CN) are prevalent conditions in ophthalmic practice. However, it is not clearly established whether such patients are at increased risk of stroke after onset of OCNPs.

METHODS

Medline, PubMed, Embase and Cochrane Central registers were systematically searched for eligible studies comparing isolated ischemic OCNPs against matched controls on the subsequent development of stroke with at least two years of follow up. Case reports and series were excluded. Appropriate studies were entered for meta-analysis to determine hazard ratios. Search and data extraction was completed on 22 Feb 2021. Random effect models were used to generate pooled hazard ratios (HRs) and 95% confidence intervals (CIs).

RESULTS

Three studies were suitable for meta-analysis (total n = 2,756 OCNP cases and 21,239 matched controls). The meta-analysis demonstrated a hazard ratio of 5.96 (4.20-8.46 95% CI) of subsequent stroke after isolated OCNP within the first year. The hazard ratio reduced to 3.27 (2.61-4.10 95% CI) after five years although remains raised at 2.49 (1.53-4.06 95% CI) up to 12 years. The highest risk was demonstrated with 3rd cranial nerve palsies. Two additional studies assessed the risk of stroke with newly diagnosed diabetics and compared OCNPs against lacunar stroke. These studies did not demonstrate a significant increased risk of stroke, although they may be statistically underpowered.

CONCLUSION

Ischemic OCNPs represent a significant risk factor for development of subsequent stroke in a similar magnitude to transient ischemic attack within the first year.

Isolated Bilateral Abducens Palsy as a Presenting Feature of Multi-Infarct State: A Case Report

Isolated abducens palsy is a rare clinical entity. The usual causes of bilateral sixth nerve palsy are head trauma, tumor (skull base), aneurysm, and ischemic stroke. Bilateral abducens palsy without any other neurological deficit secondary to ischemic stroke is a rare clinical presentation. We present a case of a 78-year-old male without any comorbidities with a history of diplopia for the last two months. Physical examination was unremarkable except for bilateral sixth nerve palsy. MRI brain showed the chronic ischemic area in the pons, bilateral basal ganglia, deep white matter, and periventricular region of bilateral frontal, temporal, parietal, and occipital lobe. This report highlights an unusual presentation of ischemic stroke as isolated bilateral abducens palsy without any other focal neurological deficit.

The Immediate Onset of Isolated and Unilateral Abducens Nerve Palsy Associated with COVID-19 Infection: A Case Report and Literature Review

Cranial nerve palsy associated with coronavirus disease 2019 (COVID-19) is rare. We herein report the first Asian case of the immediate onset of isolated and unilateral abducens nerve palsy (ANP) accompanied with COVID-19 infection. A 25-year-old man developed diplopia one day after the COVID-19 symptom onset. Neurological examination revealed limitation of left eye abduction without ataxia and hyporeflexia. Negative anti-ganglioside antibody results and mild albuminocytological dissociation were noted. The patient was diagnosed with left ANP accompanied by COVID-19 infection. The ANP spontaneously recovered without treatment. ANP can develop during the early phase of COVID-19 infection and adversely affect patients' quality of life.

Metastatic Lesions of the Clivus: A Systematic Review

BACKGROUND

Metastatic lesions of the clivus are extremely rare, having previously been estimated as representing 0.02% of all intracranial tumors. Owing to its close intracranial relationship with the clivus before entering the cavernous sinus, clinical palsies of the sixth cranial nerve have been classically associated with destructive lesions of this structure.

METHODS

A comprehensive search of PubMed was conducted for studies of patients with metastasis to the clivus from primary cancer at any site. Studies reported in English in the past 20 years from our last search on April 12, 2021 were included. The data collected included patient age, sex, symptoms at presentation, histopathology and treatment timeline of the primary tumor, treatment, follow-up, and mortality.

RESULTS

After the literature review, 46 studies reporting on 58 patients with clivus metastasis were included in the final analysis. The mean age of the patients was 57.5 years, and 39 were male (67.2%). The most common sites of the primary tumor were the prostate (22%), gastrointestinal tract (15%), lung (13%), and kidney (11%). In 43% of patients, symptoms of clivus metastasis had presented before the diagnosis of primary cancer was known, and 71% of the patients had presented with sixth nerve palsy. Of the 58 patients, 53% had undergone surgery, and 37% had received adjuvant radiotherapy. Of the 58 patients, 25% had received radiotherapy alone. The endoscopic transsphenoidal approach to the clivus was almost uniquely used for surgical management. Survival data were available for 31 patients. Death had occurred at a mean of 9.4 months after the presentation of clivus metastasis. A strong correlation was found between the interval from primary cancer to the presentation of clivus metastasis and mortality.

CONCLUSIONS

Although an extremely rare occurrence, clivus metastasis should be considered in patients with a history of malignancy, in particular, prostate malignancy, presenting with new-onset isolated sixth nerve palsy.

Unilateral Abducens Palsy and Headache in Postpartum Patient Presenting to Ophthalmology

Postpartum patients rarely present to eye casualty. Here we report a case of a seven-day postpartum patient with sudden onset horizontal diplopia and an occipital headache from the perspective of the ophthalmology eye casualty in a tertiary hospital. Intracranial imaging ruled out any acute pathology. The patient required epidural anaesthesia during labour, and a diagnosis of a post-dural puncture headache (PDPH) with an abducens nerve palsy was reached. A blood patch was not provided in this case. The headache settled and the diplopia self-resolved three weeks postpartum. PDPH with extra-ocular muscle paresis is rare, and, as the diplopia onset usually follows the characteristic orthostatic headaches of PDPH, it is likely that these patients are followed up by obstetricians or anaesthetists. These patients rarely present to ophthalmology services to receive this diagnosis, therefore ophthalmologists might not be familiar with this pathology. To our knowledge, this is the first case report of PDPH with cranial nerve palsy that has been documented to present to an ophthalmology department.

Liver enzymes and risk of ocular motor cranial nerve palsy: a nationwide population-based study

This study aimed to assess the associations between liver enzymes including γ-glutamyl transferase (GGT) and the development of ocular motor cranial nerve palsy (CNP) using the National Sample Cohort database from Korea's National Health Insurance Service. We analyzed data from 4,233,273 medical screening examinees aged 20 years or more in 2009. Study participants were followed up until December 31, 2018. A Cox proportional hazard regression analysis was performed for quartiles of liver enzymes to determine the linkage between each value and ocular motor CNP using quartile 1 as a reference after adjusting for potential confounders. A total of 5,807 (0.14%) patients developed ocular motor CNP during the follow-up period of 8.22 ± 0.94 years. The incidence of ocular motor CNP gradually increased as the GGT levels increased. The highest quartile of the GGT group had hazard ratio (HR) of 1.245 (95% confidence interval [CI], 1.136-1.365). Regarding alanine aminotransferase (ALT), the highest quartile of the ALT group had HR of 1.141 (95% CI, 1.049-1.241). However, the incidence of ocular motor CNP did not gradually increase as the ALT levels increased. The coexistence of the increased level of GGT, metabolic syndrome, and obesity showed a stronger association with ocular motor CNP development (HR, 1.331; 95% CI, 1.173, 1.511) compared to having a single factor or two factors. In conclusion, our population-based cohort study demonstrated a significant association between serum GGT level and the incidence of ocular motor CNP, suggesting that GGT could be a new clinical marker for predicting the occurrence of ocular motor CNP.

Clinical Factors Affecting Recovery Periods of Vascular and Idiopathic Acquired Paralytic Strabismus

Purpose: Clinical factors affecting the recovery period in patients with vascular or idiopathic paralytic strabismus were evaluated.Methods: This study involved a retrospective review of medical records of patients diagnosed with vascular and idiopathic acquired paralytic strabismus. Vascular paralysis was defined in cases of hypertension, diabetes mellitus, or cardiovascular disease. The angle of deviation and limitation of extraocular movement were evaluated at each visit. Recovery was defined as the absence of diplopia and complete resolution of limitation of extraocular movement. Factors affecting recovery success and recovery period were analyzed.Results: We retrospectively reviewed data of 145 patients consisting of 87 with vascular paralytic strabismus (cranial nerve [CN] III: 21, CN IV: 28, CN VI: 38) and 58 with idiopathic paralytic strabismus (CN IV: 20, CN VI: 24, CN III: 14). The recovery rate did not significantly differ between vascular (60.9%) and idiopathic (63.8%) groups (p = 0.15). The recovery period was longer in the vascular group (130.1 ± 145.1 days) than in the idiopathic group (92.6 ± 76.6) (p = 0.02). Age at onset was significantly associated with the recovery period in both vascular and idiopathic groups. In the vascular group, the recovery periods were 107.4 ± 74.8 days in CN III palsy, 97.2 ± 51.9 days in CN IV palsy, and 159.3 ± 194.1 days in CN VI palsy. The recovery period was significantly longer in patients with CN VI palsy (p = 0.03). Hypertension was significantly influencing the recovery period in patients with vascular CN VI palsy (odds ratio = 2.54, p = 0.01).Conclusions: The recovery period was longer in patients with vascular paralytic strabismus than in patients with idiopathic paralytic strabismus. Recovery rates were not significantly different between groups. In patients with vascular CN VI palsy, a history of hypertension was significantly associated with the recovery period.

The incidence and presumed aetiologies of fourth cranial nerve palsy in Korea: a 10-year nationwide cohort study

AIMS

To investigate the incidence and presumed aetiologies of fourth cranial nerve (CN4) palsy in Korea METHODS: Using the nationally representative dataset of the Korea National Health Insurance Service-National Sample Cohort from 2006 to 2015, newly developed CN4 palsy cases confirmed by a preceding disease-free period of ≥4 years were identified. The presumed aetiology of CN4 palsy was evaluated based on comorbidities around the CN4 palsy diagnosis.

RESULTS

Among the 1,108,292 cohort subjects, CN4 palsy newly developed in 390 patients during 10-year follow-up, and the overall incidence of CN4 palsy was 3.74 per 100,000 person-years (95% confidence interval, 3.38-4.12). The incidence of CN4 palsy showed a male preponderance in nearly all age groups, and the overall male-to-female ratio was 2.30. A bimodality by age-group was observed, with two peaks at 0-4 years and at 75-79 years. The most common presumed aetiologies were vascular (51.3%), congenital (20.0%), and idiopathic (18.5%). The incidence rate of a first peak for 0-4 years of age was 6.17 per 100,000 person-years, and cases in this group were congenital. The second peak incidence rate for 75-79 years of age was 11.81 per 100,000 person-years, and the main cause was vascular disease. Strabismus surgery was performed in 48 (12.3%) patients, most of whom (72.9%) were younger than 20 years.

CONCLUSION

The incidence of CN4 palsy has a male predominance in Koreans and shows bimodal peaks by age. The aetiology of CN4 palsy varies according to age-groups.

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.