Incidence and Etiology of Presumed Fourth Cranial Nerve Palsy: A Population-based Study

[Differential diagnosis of vertical strabismus in the elderly]

Due to the demographic changes, the number of older patients in ophthalmological practices and clinics, including those with diplopia, is increasing. Some of the patients report not only horizontally shifted double images but also or only vertically shifted double images. Vertical double vision often causes significant diagnostic problems for ophthalmologists. The underlying condition could urgently require further neurological, neuroradiological and/or internal medical diagnostics (e.g., skew deviation, 4th nerve palsy, myasthenia, Graves' orbitopathy, orbital floor fracture, orbital mass, 3rd nerve palsy) but the cause of diplopia could also be a condition in which overdiagnosis should be avoided (e.g., sagging eye syndrome, the prevalence of which significantly increases with increasing age; decompensated strabismus due to inferior oblique muscle overaction, myopia-associated vertical tropia). For some diseases early diagnosis is important for a better prognosis, e.g., tumor diagnosis, Graves' disease and stroke. This article presents an overview of the most common and most important differential diagnoses of vertical tropia in patients over 50 years of age.

Clinical characteristics and surgical outcomes in patients with superior oblique muscle palsy: a retrospective study on 1057 patients

BACKGROUND

To evaluate the clinical findings of patients with SOP who underwent surgery.

METHODS

This historical cohort study was performed on 1057 SOP patients managed with surgery in Farabi Hospital, Iran, from 2011 to 2022.

RESULTS

There were 990 (93.7%) patients with unilateral SOP with the mean age of 21.8 ± 14.8 years. Of these, 715 patients (72.2%) were diagnosed with congenital SOP, and 275 patients (27.8%) had acquired SOP (P < 0.001). In contrast, 67 (6.3%) patients were diagnosed with bilateral SOP, with the mean age of 19.4 ± 15.6 years. Among these, 18 cases exhibited the masked type. The mean angle of vertical deviation in primary position at far in unilateral and bilateral cases was 15.6 ± 8.3 and 13.3 ± 9.1 △, respectively (P < 0.001). In unilateral cases, abnormal head posture (AHP) was detected in 847 (85.5%) patients and 12 (1.2%) had paradoxical AHP. Amblyopia was found in 89 (9.9%) unilateral and 7 (10.3%) bilateral cases. Solitary inferior oblique myectomy, was the most common surgery in both unilateral (n = 756, 77.1%) and bilateral (n = 35, 52.2%) patients. The second surgery was performed for 84 (8.6%) unilateral and 33 (49.3%) bilateral cases (P < 0.001). The prevalence of amblyopia and the mean angle of horizontal deviation were significantly higher in patients who needed more than one surgery (all P < 0.05).

CONCLUSION

Congenital SOP was more than twice as frequent as acquired SOP and about 90% of unilateral and 50% of bilateral cases were managed with one surgery. Amblyopia and significant horizontal deviation were the most important factors for reoperation.

TRIAL REGISTRATION

The Institutional Review Board approval was obtained from the Tehran University of Medical Sciences (IR.TUMS.FNM.REC.1400.012) and this study adhered to the tenets of the Declaration of Helsinki and HIPAA.

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.

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.

First Intraoperative Trochlea Reconstruction

Traumatic detachment of the superior oblique muscle from the trochlea is very rare. The authors present a case of cyclovertical diplopia in downgaze due to traumatic trochlear damage where they performed surgery more than 40 years later. For the first time ever, they describe the reconstruction of the trochlea using a silicone tube, thereby regaining superior oblique muscle function.

Post-Traumatic Craniocervical Disorders From a Postural Control Perspective: A Narrative Review

Mild traumatic brain injury (mTBI) and whiplash injury (WI) may lead to long-term disabling consequences known as post-concussive syndrome (PCS) and whiplash-associated disorders (WADs). PCS and WAD patients commonly complain of conditions encompassing dizziness, vertigo, headache, neck pain, visual complaints, anxiety, and neurocognitive dysfunctions. A proper medical work-up is a priority in order to rule out any acute treatable consequences. However investigations may remain poorly conclusive. Gathered in the head and neck structures, the ocular sensorimotor, the vestibular, and the cervical proprioceptive systems, all involved in postural control, may be damaged by mTBI or WI. Their dysfunctions are associated with a wide range of functional disorders including symptoms reported by PCS and WAD patients. In addition, the stomatognathic system needs to be specifically assessed particularly when associated to WI. Evidence for considering the post-traumatic impairment of these systems in PCS and WAD-related symptoms is still lacking but seems promising. Furthermore, few studies have considered the assessment and/or treatment of these widely interconnected systems from a comprehensive perspective. We argue that further research focusing on consequences of mTBI and WI on the systems involved in the postural control are necessary in order to bring new perspective of treatment.

[Management of binocular diplopia in the department of ophthalmic emergencies at the Regional University Hospital of Tours]

OBJECTIVES

To describe the etiologies of binocular diplopia for patients presenting to the ophthalmologic emergency department of the Regional University Center Hospital (CHRU) of Tours.

METHODS

This is a retrospective study of the medical records of patients who presented with binocular diplopia in the ophthalmic emergency department of the CHRU of Tours between January 1st and December 31st, 2019. Binocular diplopia was classified as paralytic or non-paralytic according to the ocular motility examination.

RESULTS

One hundred twelve patients were included. The median age was 61 years. Internal referral from other hospital services represented 44.6% of the patients. On ophthalmological examination, 73.2% had paralytic diplopia, 13.4% non-paralytic diplopia and 13.4% normal examination. Neuroimaging was performed in 88.3% of cases, with 75.7% of patients receiving it on the same day. Oculomotor nerve palsy was the most frequent cause of diplopia in 58.9%, the majority represented by abducens nerve palsy (60.6%). The most frequent etiology of binocular diplopia was ischemic, with microvascular damage in 26.8% of cases and stroke in 10.7% of cases.

CONCLUSION

Among patients assessed in an ophthalmological emergency department setting, one in ten patients had stroke. It is essential to inform patients of the urgent nature of ophthalmological evaluation in the case of acute binocular diplopia. Urgent neurovascular management is also mandatory and should be based on the clinical description provided by the ophthalmologist. Neuroimaging should be performed as soon as possible, based on the ophthalmologic and neurological findings.

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.

Case report: isolated trochlear nerve palsy associated with posterior cerebral artery aneurysm

We describe a case of isolated trochlear nerve palsy caused by an unruptured posterior cerebral artery (PCA) aneurysm in an 82-year-old male who consulted an ophthalmologist after developing diplopia. Magnetic resonance angiography showed a left PCA aneurysm in the ambient cistern, and T2WI showed an aneurysm compressing the left trochlear nerve to the cerebellar tentorium. Digital subtraction angiography revealed that the lesion was located between the left P2a segment. We attributed this isolated trochlear palsy to left PCA unruptured aneurysm pressure. Thus, we performed stent-assisted coil embolization. The aneurysm was obliterated, and trochlear nerve palsy improved completely.

Masquerading Superior Oblique Palsy

PURPOSE

We evaluated patients with hypertropia compatible with a diagnosis of superior oblique (SO) palsy to ascertain whether the 3-step test (3ST) can distinguish SO atrophy characteristic of trochlear nerve pathology from masquerading conditions.

DESIGN

Prospective cross-sectional study.

METHODS

In an academic practice, we performed quasi-coronal plane, surface coil magnetic resonance imaging in 83 patients clinically diagnosed with SO palsy. We evaluated alignment, SO cross-sectional area, SO contractility, and rectus muscle pulley positions.

RESULTS

A total of 57 patients with mean age 39 years (SD = 21 years) had unilateral SO palsy manifested by SO atrophy (22 congenital and 35 acquired). There was normal SO size in 26 patients with an average age of 39 years (SD =16 years) considered masquerades (8 congenital and 18 acquired). Maximum palsied SO cross-section averaged 9.5 ± 3.8 mm2, less than 18.4 ± 3.9 mm2 contralaterally (P < 10-24). In masquerades, maximum hypertropic SO cross-section was 20.7 ± 3.1 mm2, which was not different from the hypotropic SO or the contralesional muscle in SO palsy. Head tilt testing in masquerades was indistinguishable from SO palsy. In SO palsy, central hypertropia averaged 13.2 ± 9.4Δ, increasing to 21.1 ± 14.0Δ in ipsilateral tilt, and decreasing to 4.3 ± 5.3Δ in contralateral tilt. In masquerades, central hypertropia averaged 13.1 ± 8.7Δ, and was 17.7 ± 11.1Δ in ipsilateral and decreasing to 4.9 ± 5.1Δ in contralateral tilt. Upright hypertropia was larger at 17.7 ± 9.9Δ in congenital than 12.0 ± 8.4Δ in acquired SO palsy (P = 0025) but was indistinguishable from congenital masquerades. Contractile change in SO cross-section was bilaterally similar in masquerades. Relevant coordinates of rectus pulleys were similar bilaterally in masquerades.

CONCLUSIONS

The 3ST pattern characteristic of unilateral SO palsy may be mimicked in all respects by masquerades.

Etiologic Distribution of Isolated Trochlear Palsy: Analysis of 1,020 Patients and Literature Review

BACKGROUND AND PURPOSE

Trochlear palsy is the most common cause of vertical diplopia. The etiologies of trochlear palsy have shown a large discrepancy among the studies. This study aimed to establish the clinical features and underlying etiologies of isolated trochlear palsy by recruiting the patients from all departments in a referral-based university hospital.

METHODS

We reviewed the medical records of 1,258 patients who had a confirmed diagnosis of isolated trochlear palsy at all departments of Seoul National University Bundang Hospital, Seongnam, South Korea, from 2003 to 2020. We also compared the proportion of etiology with that of the patients pooled from the previous studies.

RESULTS

The most common etiology was congenital (n = 330, 32.4%), followed by idiopathic (n = 256, 25.1%), microvascular (n = 212, 20.8%), and traumatic (n = 145, 14.2%). These four etiologies explained 92.5% of isolated trochlear palsy. Patients were mostly managed by ophthalmologists (n = 841, 82.5%), followed by neurologists (n = 380, 37.3%), emergency physicians (n = 197, 19.3%), neurosurgeons (n = 75, 7.4%), and others (n = 18, 1.8%). The etiologic distribution of isolated trochlear palsy in the current study did not differ from that of 2,664 patients pooled from the previous studies.

CONCLUSIONS

The proportion of etiologies of isolated trochlear palsy differs according to the age ranges of the patients and specialties involved in the management. The etiologic distribution of isolated trochlear palsy in the current study was comparable to the pooled result of previous reports.

Can Binocular Alignment Distinguish Hypertropia in Sagging Eye Syndrome From Superior Oblique Palsy?

Purpose

Although the three-step test (3ST) is typically used to diagnose superior oblique palsy (SOP), sagging eye syndrome (SES) has clinical similarities. We sought to determine if alignment measurements can distinguish unilateral SOP from hypertropia in SES.

Methods

We studied hypertropic subjects who underwent surface-coil magnetic resonance imaging (MRI) demonstrating either SO cross-section reduction indicative of congenital or acquired palsy (SOP group) or lateral rectus muscle sag (SES group). Alignment was measured by Hess screen and prism-cover testing. Multiple supervised machine learning methods were employed to evaluate diagnostic accuracy. Rectus pulley coordinates were determined in SES cases fulfilling the 3ST.

Results

Twenty-three subjects had unilateral SOP manifested by SO atrophy. Eighteen others had normal SO size but MRI findings of SES. Maximum cross-section of the palsied SO was much smaller than contralaterally and in SES (P < 2 × 10-5). Inferior oblique cross-sections were similar in SOP and SES. In both SOP and SES, hypertropia increased in contralateral and decreased in ipsilateral gaze and was greater in ipsilateral than contralateral head tilt. In SES, nine subjects (50%) fulfilled the 3ST and had greater infraplacement of the lateral than medial rectus pulleys in the hypotropic orbit. Supervised machine learning of alignment data distinguished the diagnoses with areas under the receiver operating curves up to 0.93, representing excellent yet imperfect differential diagnosis.

Conclusions

Because the 3ST is often positive in SES, clinical alignment patterns may confound SES with unilateral SOP, particularly acquired SOP. Machine learning substantially but imperfectly improves classification accuracy.

Types of Surgery Performed and Reoperation Rate for Congenital Superior Oblique Palsy: a Claims Database Study

PURPOSE

To investigate types of surgeries performed to treat a presumed congenital superior oblique palsy (SOP) and the reoperation rate.

METHODS

This was a population-based retrospective cohort study using claims data from the United States. Patients who underwent strabismus surgery for a presumed congenital SOP with ≥ 3 months of continuous enrolment after the initial surgery were included. We investigated age, surgical methods and the time interval between the initial surgery and reoperation. The hazard ratios for reoperation were estimated according to the surgical methods using Cox regression analysis.

RESULTS

A total of 3,998 patients underwent surgery for presumed congenital SOP; 2,981 (74.6%) on only one vertical muscle (excluding superior oblique). Reoperation was performed on 427 patients (10.7%). Compared to patients who underwent unilateral surgery on one vertical muscle (excluding superior oblique muscle), patients who underwent surgery that included the superior oblique muscle (unilateral 2.08; 95% CI, 1.61-2.67, p < 0.001; bilateral 2.44; 95% CI, 1.40-4.28, p = 0.002) and two or more vertical muscles (excluding the superior oblique muscle) (unilateral 2.99; 95% CI, 2.00-4.49, p < 0.001; bilateral 1.68; 95% CI, 1.23-2.28, p = 0.001) had increased hazard ratios for reoperation. The median period between the initial surgery and reoperation was 168.0 [Q1-Q3 84.0-407.8] days and negatively correlated with patient age at initial surgery (r = -0.199, p < 0.001).

CONCLUSION

The reoperation rate for presumed congenital SOP was 10.7%. Patients who underwent surgery on two or more vertical muscles or the superior oblique muscle had an increased risk of reoperation.

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.

Torticollis in childhood-a practical guide for initial assessment

Torticollis is encountered often in the paediatric setting and should be considered a presenting symptom, rather than a diagnosis. Aetiologies of torticollis are numerous, and the nomenclature describing underlying diagnosis can be confusing. Furthermore, children with torticollis typically present in the first instance to primary or secondary care rather than to the subspecialist. These factors can contribute to erroneous treatment of this patient-group which could be time critical in some instances. In this review, we discuss the common causes for torticollis and propose a simple clinical assessment tool and early management scheme that will assist in the differential-diagnosis and treatment pathway of this challenging condition.Conclusion: Torticollis can be the initial presentation of various conditions. The diagnosis and management tools provided in this article can aid in guiding paediatricians as to the correct initial management, imaging, and specialist referral. What is Known: • Torticollis in childhood is a very common presenting symptom with numerous aetiologies. • Management is complex, requires multiple clinical and imaging examinations, and is usually performed by non-specialized professionals. What is New: • A new, simple clinical-assessment tool under the acronym PINCH designed to aid paediatric general practitioners in diagnosing correctly the aetiology of torticollis. • A practical management scheme to aid in the treatment pathway of children with torticollis.

Vertical Comitance of Hypertropia in Congenital and Acquired Superior Oblique Palsy

BACKGROUND

Ivanir and Trobe have claimed that hypertropia (HT) that is greater in upgaze than downgaze, or equal to it, is characteristic of decompensated congenital superior oblique (SO) palsy and never present in ischemic, traumatic, or tumorous SO palsy. The reliability of this claim was tested in patients with SO palsy confirmed by MRI demonstration of subnormal ipsilesional SO size.

METHODS

Quasi-coronal, surface coil MRI was performed in target-controlled central gaze to identify patients with a unilateral reduction in SO cross section indicative of palsy. Nine patients gave an unequivocal history or had markedly increased vertical fusional amplitudes indicative of congenital onset (mean age 38 ± 16 years, SD). Seven patients had unequivocal acquired onset (age 47 ± 14 years and symptom duration 5.4 ± 4.8 years), including 2 with demonstrated trochlear Schwannoma and 5 with onset after severe head trauma. Fifteen patients had gradually progressive onset unequivocally not congenital yet not associated with any identifiable precipitating event (age 52 ± 20 years and symptom duration 13 ± 14 years).

RESULTS

Maximum SO cross section averaged 8.6 ± 3.9 mm2 in congenital palsy, not significantly different from 11.3 ± 3.5 mm2 in acquired palsy (P = 0.08) either unequivocally or progressively acquired, but significantly less than about 19 mm2 contralesionally in SO palsy (P < 10-4). Although mean central gaze HT was greater at 20.6 ± 8.0Δ in 9 cases of congenital than that in 22 acquired cases at 11.4 ± 6.8Δ (P = 0.002), HT was 8.4 ± 16.3Δ less in upgaze than downgaze in congenital SO palsy and 3.7 ± 11.2Δ less in acquired SO palsy. In congenital palsy, 33% of patients had HT greater in upgaze than downgaze while in 67% HT was greater in downgaze (by up to 42Δ). In acquired SO palsy, HT was greater in upgaze than downgaze or equal to it in 8 cases (36%, P = 0.87, X2). In acquired SO palsy, HT was greater in upgaze than downgaze in 37% and greater in downgaze than upgaze in 59% of cases. The HT was equal in upgaze and centralgaze in no congenital and 3 acquired cases of SO palsy. Trends were similar in unequivocal acquired and progressive acquired (noncongenital) SO palsy (P > 0.4).

CONCLUSIONS

Hypertropia is not characteristically greater in upgaze than downgaze in congenital SO palsy proven by SO atrophy on MRI. In fact, average HT is greater in downgaze than upgaze in both acquired and congenital palsy, sometimes strikingly so in the latter. The finding of HT greater in upgaze than downgaze, or equal to it, does not reliably indicate that SO palsy is congenital, nor does maximum SO cross section.

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.

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.

Approach to Common Visual Complaints Presenting to the Outpatient Neurologist

Visual complaints are commonly encountered by the practicing neurologist. We review assessment of vision loss, diplopia, and positive visual phenomena, all of which require a thoughtful evaluation to localize disease and refine management. While many causative entities are unlikely to cause poor visual outcomes, including dry eyes, migraine, and congenital strabismus, others may threaten vision, life, or both, such as posterior communicating artery aneurysms, pituitary apoplexy, or temporal arteritis. A systematic approach to vision loss and diplopia is reviewed along with focused differential diagnoses.

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.

Case 292: Lyme Neuroborreliosis

History A 24-year-old right-handed woman presented to a neuro-ophthalmology clinic in Massachusetts in the summer with acute binocular diplopia when looking down and to the left, which started about 1 month earlier. Her medical history was notable for Raynaud syndrome, recurrent streptococcal pharyngitis, and an allergy to amoxicillin. Three days prior to developing diplopia, she presented to an outside emergency department due to fever, chills, and back pain. She received ciprofloxacin for presumed urinary tract infection based on urinalysis, which demonstrated few bacteria and was negative for leukocyte esterase, nitrites, and white blood cells. She then presented again to an outside emergency department for diplopia evaluation. Initial MRI and MR angiography of the brain at that time did not demonstrate any relevant findings, and the patient was referred to our department for neuro-ophthalmic evaluation, where she was seen 4 weeks later. Neuro-ophthalmic examination revealed 20/20 visual acuity in both eyes, and a right hypertropia in left gaze, downgaze and right head tilt, with right eye excyclotorsion. There were no ocular signs of myasthenia gravis or thyroid eye disease, nor did the patient report ocular or systemic symptoms. She denied recent travel. High-spatial-resolution MRI of the brain and orbit were performed.

Disorders of the Fourth Cranial Nerve

ABSTRACT

This review of disorders of the fourth cranial nerve includes discussion on anatomy, examination techniques, congenital and acquired etiologies, differential diagnosis, and management options. The findings of the superior oblique muscle on orbital MRI in patients with fourth nerve palsy have had a major impact on our understanding of this cranial neuropathy. In addition, briefly reviewed are rare disorders of the fourth nerve: superior oblique myokymia, Brown syndrome, and ocular neuromyotonia. It behooves the clinician to have a clear understanding of the role that the fourth cranial nerve plays in a variety of neuro-ophthalmic conditions.

The etiologies of isolated fourth cranial nerve palsy: a 10-year review of 158 cases

PURPOSE

To identify the etiologies of isolated fourth cranial nerve palsy in Ramathibodi hospital, Thailand.

METHODS

Patients diagnosed with isolated fourth nerve palsy from January 1, 2009, through July 31, 2020 in Ramathibodi Hospital, were included in this retrospective, observational case series. The demographic data of patients, age at presentation, the etiologies of isolated fourth nerve palsy and neuroimaging results (if indicated) were recorded.

RESULTS

We identified 154 unilateral and 4 bilateral cases of isolated fourth nerve palsy. Mean age at presentation was 38.89 ± 25.71 years old. Most of the unilateral cases were congenital (57.79%), with microvasculopathy (27.92%), intracranial neoplasm (8.44%) and other etiologies. Trauma with closed head injury was the most common etiology of bilateral cases (75%), followed by ruptured arteriovenous malformation (25%). Twenty-one of the 43 (48.84%) patients with microvasculopathy fourth nerve palsy underwent neuroimaging, with normal findings, and all patients' symptoms resolved within 6 months of symptom onset.

CONCLUSIONS

In our series, most of the isolated fourth nerve palsy cases were congenital, followed in frequency by microvasculopathy and intracranial tumor, as in many studies. In cases of microvasculopathy, the clinical signs and symptoms resolved within 6 months in all cases: observation was sufficient, with no necessity for neuroimaging. However, neuroimaging should be considered in cases with atypical presentations, such as headache, periorbital pain, or if there is rapid progression or no recovery.

Isolated trochlear palsy as the only presentation of midbrain infarction: a case report

Trochlear palsy often results from traumatic, congenital and microvascular disorders. An intra-axial lesion as a cause of trochlear palsy is uncommon. Moreover, it usually accompanies other neurological deficits. Isolated trochlear palsy as the only presentation of brainstem stroke is unexpected. This current case report describes a 74-year-old male that presented with trochlear palsy without other neurological signs. Brain magnetic resonance imaging (MRI) revealed an acute midbrain infarction. The case report also reviews recent literature and provides a stepwise algorithm for clinicians to approach patients with trochlear palsy. Despite its rarity, clinicians are advised to consider ischaemic stroke as a cause of trochlear palsy even without other neurological deficits. Early MRI should be performed for prompt and proper management.

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.

Chameleons, red herrings, and false localizing signs in neurocritical care

False localizing signs (FLS) and other misleading neurological signs have long been an intractable aspect of neurocritical care. Because they suggest an incorrect location or etiology of the pathological lesion, they have often led to misdiagnosis and mismanagement of the patient. Here, we reviewed the existing literature to provide an updated, comprehensive descriptive review of these difficult to diagnose signs in neurocritical care. For each sign presented, we discuss the non-false localizing presentation of symptoms, the common FLS or misleading presentation, etiology/pathogenesis of the sign, and diagnosis, as well as any other clinically relevant considerations. Within cranial neuropathies, we cover cranial nerves III, IV, V, VI, VII, VIII, as well as multiple cranial nerve involvement of IX, X, and XII. FLS ophthalmologic symptoms indicate diagnostically challenging neurological deficits, and here we discuss downbeat nystagmus, ping-pong-gaze, one-and-a-half syndrome, and wall-eyed bilateral nuclear ophthalmoplegia (WEBINO). Cranial herniation syndromes are integral to any discussion of FLS and here we cover Kernohan's notch phenomenon, pseudo-Dandy Walker malformation, and uncal herniation. FLS in the spinal cord have also been relatively well documented, but in addition to compressive lesions, we also discuss newer findings in radiculopathy and disc herniation. Finally, pulmonary syndromes may sometimes be overlooked in discussions of neurological signs but are critically important to recognize and manage in neurocritical care, and here we discuss Cheyne-Stokes respiration, cluster breathing, central neurogenic hyperventilation, ataxic breathing, Ondine's curse, and hypercapnia. Though some of these signs may be rare, the framework for diagnosing and treating them must continue to evolve with our growing understanding of their etiology and varied presentations.

Traumatic bilateral fourth nerve palsy: Double vision induced by downward gaze after head injury

Clinicians should be alert to traumatic fourth nerve palsy in patients with double vision after head injury. In most cases with traumatic fourth nerve palsy, the imaging tests fail to show abnormal findings. In the cases of bilateral superior oblique paresis, the sensitivity of Bielschowsky head-tilt test is 40%.

Clinical outcomes and aetiology of fourth cranial nerve palsy with acute vertical diplopia in adults

Background

We investigated the clinical outcomes of fourth cranial nerve (CN4) palsy with acute vertical diplopia in adults.

Methods

A total of 80 patients with acute CN4 palsy who underwent at least 3 months of follow-up were included in this study. We retrospectively investigated the aetiology, rate of recovery, and factors associated with recovery between March 2016 and January 2019.

Results

The average age of patients with CN4 palsy was about 60 years, and the duration of recovery was 1.5 months: 48 (60.0%) patients had a vascular aetiology and 17 (21.3%) patients had a trauma history. Brain lesions were found in four (5.0%) patients and decompensated cause accounted for four (5.0%) cases. Among the total of 80 patients, 13 (16.3%) failed to completely recover. Non-isolated CN4 palsy with other cranial nerve palsies were recorded in seven cases. The comparison between recovery and non-recovery groups showed that initial deviation angle, aetiology, fundus extorsion, and head tilt status were significantly different factors.

Conclusion

The recovery rate of acute CN4 palsy was about 80% and duration of recovery was 1.5 months. However, the varying rates and duration of recovery was presented according to aetiology thus we should consider the prognosis by aetiology.

Imaging of Nontraumatic Orbital and Neuro-ophthalmological Emergencies

Emergency department (ED) visits for eye and vision-related concerns are common. In most cases, accurate diagnosis is made using clinical history and physical exam findings without the need for emergent imaging. When orbital imaging is performed in the ED, it is often in patients with orbital trauma where CT is used to assess for orbital fractures and associated injuries. However, CT or MR imaging can also be critical to appropriately diagnose and manage certain ED patients with nontraumatic eye and vision-related conditions. The purpose of this article is to review the imaging findings and differential diagnoses for nontraumatic orbital and neuro-ophthalmological emergencies from a practical, clinical perspective, based on a patient's typical presenting symptoms. The more commonly imaged clinical indications will be discussed including periorbital swelling, proptosis, eye pain, diplopia, and visual disturbances. In addition, rare but easily overlooked and clinically important diagnoses for the emergency radiologist to recognize will be highlighted.

A standardized recession of the inferior oblique extraocular muscle - a safe and self-grading surgical procedure for trochlear nerve palsy: a 10-year material

PURPOSE

To evaluate the results of surgical treatment in a large group of patients with trochlear nerve palsy, with emphasis on the self-grading effect of a standardized recession of the ipsilateral inferior oblique muscle.

METHODS

All patients who underwent first-time surgery for trochlear nerve palsy in the period 2005-2014 in our department (n = 114) were retrospectively evaluated regarding pre- and postoperative data, surgical procedure, and the need for reoperations. Mean follow-up time was 8.5 ± 13.8 months.

RESULTS

Among the 114 patients, 73 (64.0%) had a congenital palsy, 31 (27.2%) an acquired palsy, while in 10 cases (8.8%) the type of palsy was uncertain. A standardized recession of the ipsilateral inferior oblique muscle with reattachment at the lateral border of the inferior rectus muscle was carried out in 97.3% of the congenital palsies and in 80.5% of the acquired/uncertain group. In the total patient material, further surgery was needed in 15.8%. Among the patients who underwent a single standardized recession of the inferior oblique muscle, a significant correlation between preoperative vertical angle of deviation and the postoperative change in deviation was demonstrated (correlation coefficient -0.70, p < 0.001), confirming the self-grading nature of this procedure. Subjectively, 97.1% in the congenital and 91.4% in the acquired/uncertain group reported complete/near complete resolution or significant improvement of their symptoms at the final control examination.

CONCLUSION

In the majority of patients with trochlear nerve palsy, a favourable outcome may be achieved after a single, standardized recession of the ipsilateral inferior oblique muscle.

Isolated Trochlear Nerve Palsy in a Patient with Superior Cerebellar Rete Mirabile

BACKGROUND

Rete mirabile is a very rare vascular malformation and superior cerebellar artery (SCA) rete mirabile is not reported previously. We report a new case of rete mirabile of SCA initially detected by magnetic resonance imaging and transfemoral cerebral angiography.

CASE DESCRIPTION

This report illustrates the case of a 58-year-old man who presented with vertical diplopia. Brain magnetic resonance angiography and transfemoral cerebral angiography revealed a rete mirabile of SCA and 3-dimensional volume isotropic turbo spin echo acquisition, brain magnetic resonance imaging sequence, demonstrated that the cisternal segment of the ipsilateral trochlear nerve was compressed by this vascular malformation. We assumed that his cranial nerve palsy was caused by the rete mirabile of the right SCA. During the 8 weeks presence of diplopia, the patient was observed and the symptom was relieved spontaneously.

CONCLUSIONS

We provide a first report in the literature of rete mirabile involving the SCA and suggest a descriptive knowledge of rete mirabile for clinicians during decision-making of treatment.

Onodi cell mucocele causing isolated trochlear nerve palsy: A case report

RATIONALE

Acquired vertical diplopia is commonly observed in trochlear nerve palsy, often resulting from blunt head trauma or vascular problems. It is rarely caused by tumorous conditions or space occupying lesion. We report the first case of Onodi cell mucocele causing isolated trochlear nerve palsy.

PATIENT CONCERNS

A 62-year-old male noticed a double vision which worsened when looking down. On ophthalmologic examinations, the patient showed no abnormalities in visual acuity, intraocular pressure, and no swelling in optic disc. In ocular motility test, he was notable for 10° left hypertropia in primary position, 6° in right head tilt position, 14° in left head tilt position and this was aggravated in right and down gaze. Ostiomeatal complex CT depicted an expansile soft tissue density completely filling the left Onodi cell.

DIAGNOSES

He was diagnosed with a trochlear nerve palsy caused by an isolated mucocele in the left Onodi cell.

INTERVENTIONS

Three days after presentation, he underwent endoscopic sinus surgery for marsupialization of the mucocele in the left Onodi cell.

OUTCOMES

The mucocele was completely removed through the endoscopic endonasal approach. Within 4 months after surgery, his 4th nerve palsy had gradually and completely improved.

LESSONS

Onodi cell mucoceles that cause trochlear nerve palsy are extremely rare. Timely surgical decompression is essential to achieve optimal recovery of the neural function. Combined trochlear nerve palsy should be evaluated when Onodi cell mucocele involves the orbital apex from above.

The efficacy of superior rectus recession with simultaneous inferior oblique disinsertion on superior oblique palsy with superior rectus contracture

PURPOSE

The information about superior rectus (SR) recession in cases with SR contracture coexisting with superior oblique palsy (SOP) is very limited in previous literature. The aim of this study is to evaluate the effect of SR recession, as a combined procedure with inferior oblique (IO) disinsertion, in long-standing SOP with secondary SR contracture.

METHODS

The medical records of the 145 patients operated for SOP were retrospectively reviewed and 15 patients who underwent SR recession met the inclusion criteria. The mean follow-up was 50.4 months.

RESULTS

The preoperative angle of deviation was within the range of 16-35 prism dioptres (PD) with a mean of 23.0 ± 5.03 PD. In all of the cases, SR recession was performed in combination with IO disinsertion. Adult patients (12) underwent adjustable SR recession. Postoperative overcorrection developed in 3 cases (20%), and in 12 patients, the postoperative vertical deviation was within the range of 0-5 PD with a mean of 1.41 ± 1.88 PD. The overcorrected three patients underwent botulinum toxin A (BTXA) injection into the ipsilateral inferior rectus muscle. The deviation is well controlled by BTXA injection in two patients, whereas the other one was considered as masked bilateral SOP and underwent IO disinsertion in the other eye.

CONCLUSION

Our results suggested that SR recession in combination with IO disinsertion is an effective procedure to control large vertical deviations in SOP with SR contracture in the majority of cases. However, the risk of overcorrection should be considered despite adjustable SR weakening and BTXA injection seems efficient to rescue overcorrections in long term.

Ocular motor cranial nerve palsy and increased risk of stroke in the general population

Purpose

To determine whether ocular motor cranial nerve (CN) palsy raises the risk of subsequent stroke in the general population.

Methods

We investigated the association between ocular motor CN palsy and occurrence of stroke using the National Health Insurance Service-National Sample Cohort database from 2002 to 2013. We included individuals aged ≥ 20 years on January 1^st, 2004, and excluded those having any paralytic strabismus, disorders in binocular movement, diplopia and any cerebrovascular diseases before entering the cohort. Incident ocular motor CN palsy was identified by diagnostic codes for third, fourth, and sixth nerve palsies. To determine the effect of incident ocular motor CN palsy on the occurrence of subsequent stroke, we used time-varying covariate Cox regression models. Model 1 included only incident third, fourth, and sixth nerve palsies as a time-varying covariate. Model 2 included Model 1 and defined demographic information. Model 3 included Model 2, comorbidity, co-medication, and the Charlson index score.

Results

Among 727,689 individuals in the cohort, 1,633 patients developed ocular motor CN palsy and 17,657 patients suffered stroke. Cox regression models showed that development of ocular motor CN palsy was associated with an increased risk of subsequent stroke (hazard ratio [HR] = 4.65; 95% confidence intervals [CIs], 3.74–5.80 in Model 1), and the results were consistent even after adjusting for demographic factors and confounders in Model 2 and 3. Men, older age, and individuals not living in Seoul/Incheon area were associated with an increased risk of stroke, while individuals with higher income were associated with decreased risk of stroke in both Model 2 and 3. Sensitivity analyses using propensity score-based matching produced similar results in all three Models (HR = 1.95; 95% CI, 1.55–2.46 in Model 1, HR = 1.91; 95% CI, 1.52–2.41 in Model 2, and HR = 1.63; 95% CI, 1.29–2.06 in Model 3).

Conclusions

The occurrence of ocular motor CN palsy is a significant risk factor of subsequent stroke even after adjusting for demographic factors and confounders in the general population. Physicians may need to educate patients with ocular motor CN palsy regarding the higher risk of future stroke.

Isolated Ocular Motor Nerve Palsies

Isolated cranial nerve (CN) palsies are frequently encountered by strabismologists. Management decisions for patients with isolated ocular motor nerve palsies must take into account multiple factors, including patient age, historical features, the specific CN affected, examination findings, and coexistent medical diagnoses. In general, isolated ocular motor nerve palsies in children are assessed and managed differently than adults. Furthermore, older adults with vascular risk factors may be managed differently than younger adults and children. The need for urgent neuroimaging in older adults with microvascular risk factors is under debate and requires the physician to weigh the risks and benefits of close observation with immediate testing. The presence of multiple cranial neuropathies should also raise the level of concern and indicate the need for a more urgent work-up. The following manuscript aims to provide information on common etiologies of isolated ocular motor nerve palsies and to suggest algorithms for the management of these CN palsies in children and adult.

Fourth down and five

Binocular diplopia and right hemifacial numbness developed in a 52-year-old woman after resection of a right temporal lobe glioblastoma. Based on the Parks-Bielschowsky 3-step test, she was diagnosed with a right cranial nerve (CN) IV palsy in addition to right CN V dysfunction. Iatrogenic diplopia may result from temporal lobe surgery due to the intimate relationship of CN IV and CN III to the mesial temporal lobe. In addition, injury to CN V within Meckel cave is believed to be the cause of facial numbness in some patients after temporal lobe surgery. The anatomy of the intracranial portion of CN IV is reviewed, and the etiologies of CN IV palsy are discussed.