Sixth nerve palsies in children

Do infants with isolated congenital sixth nerve palsy require comprehensive work-up? A retrospective cohort and review of the literature

PURPOSE

The purpose of this study is to describe a case series of infants with isolated congenital sixth nerve palsy (ICSNP) and suggest a management algorithm based on our experience and a review of the literature.

METHODS

A retrospective cohort design was used. The clinical database of a single tertiary medical center was reviewed to identify all patients diagnosed with ICSNP from January 2020 to November 2022. Data were collected as follows: demographic parameters, age at initial presentation, presenting symptoms and signs, findings on ophthalmic and neurologic examinations, findings on follow-up, and outcome.

RESULTS

Six patients were included. All were born at term. The average gestational weight was 3675.7 ± 262.7 g. Three mothers had gestational diabetes. Five deliveries necessitated labor induction either by oxytocin (n = 4) or by membrane stripping followed by oxytocin (n = 1). One had also gone a forceps assisted delivery. Symptoms were noticed in all newborns by their parents within the first week of life. Ophthalmological and neurological examinations were otherwise unremarkable apart of one patient with a head turn to the side of the involved eye. Four patients underwent brain imaging that were unremarkable. All abduction deficits resolved by 1 to 3 months of age. Follow up examinations were unremarkable (mean follow up 14.3 ± 5.0 months, range 4-23).

CONCLUSIONS

This case series, together with previous reports, support ICSNP's benign nature. We suggest an initial basic work-up that solely includes ophthalmological and neurological examinations which will be elaborated in case of any additional pathologic findings or if ICSNP does not fully resolve by 3 months.

New Surgical Double Interlacing Technique for Correction of Sixth Cranial Nerve Palsy

This interventional case series presents a novel surgical procedure involving double interlacing for the correction of esotropia in individuals with sixth cranial nerve palsy. The technique involves first splitting the tendons of the superior rectus, inferior rectus, and lateral rectus muscles. Subsequently, the superior half of the lateral rectus muscle is passed through the undisinserted superior rectus muscle, and the inferior half of the lateral rectus muscle is passed through the undisinserted inferior rectus muscle. Finally, the two halves of the lateral rectus muscle are sutured together and reattached at the original insertion point. The surgical outcomes demonstrate a significant improvement in alignment, abduction, and binocular vision. [J Pediatr Ophthalmol Strabismus. 2023;60(5):e58-e64.].

Surgical outcomes following strabismus surgery for abducens nerve palsy

PURPOSE

To assess ocular alignment outcomes and their stability for patients who underwent strabismus surgery for abducens nerve palsy and to identify preoperative patient variables that predict surgical success or repeated surgeries.

METHODS

We retrospectively reviewed the medical records of patients diagnosed with abducens nerve palsy and who subsequently underwent strabismus surgery.

RESULTS

A total of 209 patients (386 procedures) were included. The mean number of surgeries for patients was 1.9 ± 1.4. Success was achieved after a single surgery for 112 patients (53.6%), and success was achieved for an additional 42 patients, for a total of 154 patients (73.7%), following all surgeries. Preoperative abduction deficit severity was the only variable predictive of surgical success, with mild deficits having the highest odds of both initial success (OR = 5.555; CI, 2.722-11.336) and final success (OR = 5.294; 95% CI, 1.931-14.512). When analyzing survival time until additional surgery, the median survival was 406 days; abduction deficit severity, older age, other coincidental motility abnormalities, greater magnitude esotropia, and surgical technique were predictive of repeat surgical incidence.

CONCLUSIONS

In our patient cohort, preoperative abduction deficit was an important predictor of both surgical success and repeat surgical incidence for abducens nerve palsy. Older patient age, additional motility abnormalities, and greater amounts of baseline strabismus were also associated with greater likelihood of multiple surgeries.

An overview of third, fourth and sixth cranial nerve palsies in the setting of COVID-19: A case report and systematic review

BACKGROUND

Covid-19 has serious sequelae that may be poorly understood, underreported, and, as a result, not diagnosed promptly, such as variations in clinical manifestations of hyperinflammation among people infected with SARS-CoV-2. ophthalmoplegia can be one of these manifestations.

METHODS

We are reporting a 55-year-old male patient with unilateral diplopia considering it as a case of multisystem inflammatory syndrome in adults. We also reviewed the literature systematically for the previously reported studies/cases with third, fourth and sixth cranial nerve palsies due to or after Covid-19.

RESULTS

The literature search yielded 17 studies reporting 29 patients. 71.4% of the patients were males with a mean age of 42.23 years. Ophthalmological symptoms took 9.7 days to appear after the respiratory involvement. All patients had diplopia as part of their visual symptoms. 41.4% of the patients had unilateral sixth nerve palsy, 24% had bilateral sixth nerve involvement, 17% had fourth nerve involvement, and 27.6% had third nerve involvement.

CONCLUSION

Ophthalmoplegia is considered presenting symptom of Covid-19. Further research is needed to detect all neuro-ophthalmological manifestations of Covid-19.

Aetiologies of acquired pediatric sixth nerve palsies in a U.K. based population

Due to the low incidence of sixth cranial nerve palsies in children, there has been limited evidence published on this subject, especially from a population based within the UK. The incidence of etiologies has been found to vary significantly within the literature, especially with regard to neoplasms. The main aim of this study is to present the etiologies of newly diagnosed pediatric sixth nerve palsies in a UK-based population. We also take into consideration if the palsies were isolated or associated with other neurological signs or symptoms. Retrospective data collection was carried out on the medical records of 50 pediatric patients with a new-onset sixth nerve palsy. They all presented to a large tertiary referral hospital in the South of the UK between 1 January 2007 and 31 December 2017. Data collected for each patient included age, gender, ethnicity, unilateral versus bilateral, other signs and symptoms, etiology, where the patient first presented, and whether the palsy was the first presenting feature. Thirty-three (66%) patients had a new-onset sixth nerve palsy in conjunction with other neurological signs or symptoms and were considered non-isolated. Seventeen cases (34%) were found to be isolated. Etiologies included high intracranial pressure (18%), neoplasm (14%), surgery for neoplasm (14%), viral (14%), infection (12%), trauma (8%), idiopathic (6%), benign space-occupying lesion (4%), congenital (2%), inflammation (2%), Alexander's disease (2%), Kawasaki syndrome (2%), and diabetes (2%). Our study found non-isolated sixth nerve palsies to be the most common presentation. These patients had a high number of potentially sinister etiologies, the most common being high intracranial pressure followed by post-surgery for neoplasm and neoplasm. Isolated sixth nerve palsies were more commonly due to viral or idiopathic etiology; however, two cases of benign space-occupying lesion and one of neoplasm were identified.

Apparent Defective Abduction Without Diplopia

Sixth nerve palsies present with horizontal diplopia and typically have a neurological or neurovascular aetiology. They can be confirmed by clinically evaluating the velocity of the abducting saccade, which is slowed. Three cases are presented in which the patients had apparent defective abduction of one eye, resulting from not only neurological causes but also orbital causes. Clinicians should have a high index of suspicion in patients with defective abduction without diplopia and should include apparent defective abduction without diplopia (ADAD) in the list of potential differential diagnoses, considering not only neurological involvement but also orbital involvement.

Ophthalmological Evaluation in Children Presenting With a Primary Brain Tumor

BACKGROUND

Children with a brain tumor are prone to develop visual impairment, which to date is often underestimated and unrecognized. Our aim was to assess the prevalence of ophthalmological evaluation and abnormal ophthalmological findings, and investigate whether demographic and tumor-related characteristics are associated with abnormal ophthalmological findings in children presenting with a primary brain tumor.

METHODS

Medical records of all 90 children diagnosed with a primary brain tumor between June 2018 and May 2019 and treated at the Princess Máxima Center for Pediatric Oncology, a tertiary referral center in the Netherlands, were retrospectively reviewed. Univariate regression analysis was used to investigate associations between demographic, tumor-related and clinical characteristics, and abnormal ophthalmological findings.

RESULTS

Sixty children (34 male [56.7%]; median [range] age, 9.3 [0-16.9] years) underwent ophthalmological evaluation within 6 weeks before or after diagnosis, 11 children (5 male [45.5%]; median [range] age, 5.7 [0.1-17.2] years) were seen more than 6 weeks before or after diagnosis, and 19 children (7 male [36.8%]; median [range] age, 7.2 [1.9-16.6] years) did not receive ophthalmological evaluation within at least 6 months from diagnosis. A total of 19 children (21.1%) presented with visual symptoms as first sign leading to the diagnosis of a brain tumor. Children who presented with visual symptoms (odds ratio [OR], 22.52; 95% confidence interval [CI], 4.90-103.60) and/or hydrocephalus (OR, 3.60; 95% CI, 1.38-9.36) at diagnosis were more often seen for ophthalmological evaluation. The most common abnormal ophthalmological findings were eye movement disorders (66.0%), papilledema (44.1%), and visual field defects (58.1%). Eye movement disorders occurred more frequently in patients with an infratentorial tumor (OR, 4.71; 95% CI, 1.03-21.65). The risk of papilledema was associated with older age (OR, 1.19; 95% CI, 1.05-1.34), hydrocephalus (OR, 9.63; 95% CI, 2.68-34.61), and infratentorial (OR, 9.11; 95% CI, 1.77-46.78) and supratentorial (OR, 13.13; 95% CI, 1.92-89.52) tumors.

CONCLUSIONS

In this study, most children with a primary brain tumor underwent ophthalmological evaluation around diagnosis, 21% of the children were not evaluated. The high prevalence of abnormal ophthalmological findings stresses the importance of early standardized ophthalmological evaluation to detect visual impairment and provide timely treatment to potentially prevent permanent visual loss.

Sixth Nerve Palsy in Children Etiology, Long-Term Course, and a Diagnostic Algorithm

BACKGROUND

Acute onset strabismus is worrisome for parents and physicians. This condition is sometimes attributed to sixth cranial nerve palsy, which may be secondary to various etiologies. Debate still exists about the appropriate diagnostic approach.

OBJECTIVE

The objective of this study was to describe the common etiologies of sixth nerve palsy in our pediatric population and to suggest a clear, implementable diagnostic algorithm.

METHODS

The authors conducted an electronic medical review of files of patients admitted to the pediatric department at Emek Medical Center between January 2014 and April 2020. They reviewed the medical records from the study period of patients with the following diagnoses according to the International Classification of Diseases 9: sixth nerve palsy, acute infective polyneuritis, Guillain-Barré syndrome, benign intracranial hypertension, malignant neoplasm of the brain, strabismus, myasthenia gravis, and multiple sclerosis. The authors extracted information regarding clinical presentation, previous history, and diagnostic work-up, including serological testing, cerebrospinal fluid testing, and neuroimaging. Final diagnosis and clinical follow-up were assessed.

RESULTS

Seventeen patients with sixth nerve palsy were identified. The most common etiologies were increased intracranial hypertension and anti-GQ1B syndrome (3 patients each).

CONCLUSIONS

This is a retrospective study of patients diagnosed in one medical center. The suggested algorithm was not validated on a prospective study. The etiologies of sixth nerve palsy in children are variable. The authors suggest performing neuroimaging in all patients and considering serum and cerebrospinal fluid testing in selected patients. Initial neuroimaging combined with laboratory testing is useful and provides rational tools for proper diagnosis.

Etiology and Outcomes of Acquired Pediatric Sixth Nerve Palsies

BACKGROUND

Acquired sixth nerve (CN6) palsies in children may be benign or associated with an underlying neurologic condition. In children who presented with isolated (no associated neurologic or ophthalmic symptoms or signs) CN6 palsies, the rate of newly diagnosed neurologic disorders (such as tumors) is unclear. Moreover, the factors associated with spontaneous resolution and amblyopia in children with acquired CN6 palsies are unknown.

METHODS

We retrospectively reviewed the charts of all children younger than 18 years diagnosed with CN6 palsy at our institution from 2010 to 2020. We recorded ophthalmologic and neurologic history and examination findings, neuroimaging results, etiology of CN6 palsy, and outcomes including spontaneous resolution and amblyopia. We assessed etiologies of isolated and nonisolated CN6 palsies as well as frequency and factors associated with spontaneous resolution and amblyopia (in children ≤7 years).

RESULTS

One hundred seventy-two children met inclusion criteria. Twenty CN6 palsies (12%) were isolated at presentation. Most isolated cases were presumed postviral or postvaccination (50%) or idiopathic (30%), but 2 cases (10%) were associated with newly diagnosed tumors. Spontaneous resolution occurred in 59% of CN6 palsies at a median of 12.3 weeks and was associated with older age (P = 0.03) and nontumor etiology (P = 0.006). Amblyopia developed in 18% of children at risk, exclusively in those with anisometropia, pre-existing strabismus, or younger than 12 months.

CONCLUSIONS

Our findings and chart reviews suggest that approximately 10% of isolated acquired pediatric CN6 palsies are associated with a newly diagnosed brain tumor. This risk must be discussed with parents when considering immediate vs delayed neuroimaging. In addition, infants and children ≤7 years with secondary amblyogenic risk factors (anisometropia or pre-existing strabismus) require close follow-up to monitor and treat amblyopia.

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.

Acute abducens nerve palsy following COVID-19 vaccination

We report the case of a healthy 59-year-old woman who presented with an acute abducens nerve palsy 2 days after receiving the Pfizer-BioNTech COVID-19 vaccine. In adults, such palsies are typically caused by microvascular disease or compressive tumors, although they have also been described after routine vaccinations. Given the temporal relationship between vaccination and the onset of symptoms, the lack of preexisting medical conditions, and unremarkable magnetic resonance imaging, the patient's abducens nerve palsy was felt to be related to her vaccination. This case highlights the importance of recognizing the potential of a COVID-19 vaccine to have neurologic sequelae similar to those that as have been reported with the virus itself as well as with other vaccines.

Paralytic Strabismus in Turkish Children Examined at Three Tertiary Care Services: A Retrospective Cohort Study

PURPOSE

To assess the etiology and distribution of pediatric ocular motor nerve palsy manifesting as paralytic strabismus.

METHODS

The authors retrospectively examined the medical files of patients younger than 18 years who were suspected to have strabismus between January 1999 and June 2012 in three Turkish clinics and followed up for at least 6 months. Patients with paralytic strabismus were stratified according to age, sex, affected cranial nerve, and etiology (congenital, traumatic, neoplastic, post-viral, vascular, undetermined, or other), and compared the proportions between groups.

RESULTS

Paralytic strabismus was observed in 33 of 1,263 patients (2.6%), with a mean age of 5.9 ± 4.4 years (range: 6 months to 16 years). Seventeen patients (51.5%) were boys and 16 (48.5%) were girls. Twelve patients (36.4%) had congenital paralytic strabismus, and 21 patients (63.6%) had acquired strabismus. The most prevalent cause of acquired paralytic strabismus was trauma in 11 patients (52.4%), undetermined in 6 patients (28.6%), post-viral cranial nerve paralysis in 3 patients (14.3%), and a history of hydrocephalus in 1 patient (9.1%). The fourth cranial nerve was the most frequently affected (45.5% [15 of 33]), followed by the sixth (39.4% [13 of 33]) and the third (15.2% [5 of 33]).

CONCLUSIONS

Evaluating the incidence and etiology of paralytic strabismus in children in a clinical setting may improve disease management and reduce unnecessary invasive examinations. This study will assist clinicians in understanding the clinic-based distribution of pediatric paralytic strabismus. [J Pediatr Ophthalmol Strabismus. 2021;58(5):282-286.].

Ten-year review of neuroimaging in acute paediatric strabismus

BACKGROUND

Acute childhood strabismus is often a clinical conundrum faced by ophthalmologists. Currently, there are no clear clinical guidelines on how to investigate a child presenting with acute strabismus. Furthermore, there is no consensus as to whether to initially perform neuroimaging of a child to rule out the small but serious risk of intracranial pathology, or to pursue a careful observational approach. This paper aims to outline a standardised approach to investigating acute strabismus in paediatric patients.

METHODS

A retrospective chart review of all paediatric patients that presented over a 10-year period to the ophthalmology departments at two tertiary level hospitals in New Zealand was conducted. Patients under 18 years of age with an acute presentation of strabismus, who underwent neuroimaging, were included.

RESULTS

A total of 500 patient records were reviewed. Seventy patients met the study inclusion criteria. Of these patients, 17 (24.3%) had non-isolated strabismus while 53 patients (75.7%) had isolated strabismus. Twelve patients (70.6%) who presented with a non-isolated strabismus had abnormal neuroimaging. Of those who presented with an isolated strabismus, 4 (7.5%) had abnormal neuroimaging.

CONCLUSIONS

Acute onset non-isolated strabismus is a significant predictor of underlying neurological abnormality in children and requires urgent neuroimaging. However, a cautious approach in which there is close observation, along with general paediatric and/or paediatric neurology input, may be appropriate for children presenting acutely with an isolated strabismus.

Pediatric ocular motor cranial nerve palsy: Demographics and etiological profile

Purpose:

The aim of this study was to describe epidemiological and clinical characteristics of pediatric ocular motor cranial nerve palsy.

Methods:

This was a retrospective record-based study, carried out at a tertiary eye care hospital in India, between January 2011 and January 2015 and included patients up to 16 years of age at the time of presentation, diagnosed with third, fourth, sixth nerve palsy or a combination of these with other cranial nerve palsy. Data analyzed included demographic details, etiologies, presence or absence of amblyopia, relevant investigations, and management.

Results:

A total of 90 cases were included in the study. Eighty patients (88.88%) presented with isolated nerve palsy. Forty-three patients (47.77%) had congenital nerve palsy. The most common nerve involved was third (n = 35, 38.88%) followed by sixth (n = 23, 25.55%) and fourth nerve (n = 22, 24.44%). Most common cause of third and fourth cranial nerve palsy was congenital (n = 18, 51.42% and n = 17, 77.30%, respectively), while it was trauma for the sixth nerve (n = 7, 30.40%). Amblyopia was most frequently associated with third cranial nerve palsy (n = 27, 77.14%). The radio-imaging yield was maximum (n = 7, 70%) for combined cranial nerve palsy. Overall 44 (48.88%) patients were managed conservatively, while 46 (51.11%) patients needed squint with or without ptosis surgery.

Conclusion:

The most common ocular motor cranial nerve involved in the pediatric population was the third cranial nerve, and it was found to be the most amblyogenic in this age group. The neuroimaging yield was maximum for combined cranial nerve palsy. The most common conservatively managed nerve palsy in this study group was the fourth nerve palsy.

Neuroimaging in Children with Ophthalmological Complaints: A Review

Pediatric patients are commonly referred to imaging following abnormal ophthalmological examinations. Common indications include papilledema, altered vision, strabismus, nystagmus, anisocoria, proptosis, coloboma, and leukocoria. Magnetic resonance imaging (MRI) of the brain and orbits (with or without contrast material administration) is typically the imaging modality of choice. However, a cranial CT scan is sometimes initially performed, particularly when MRI is not readily available. Familiarity with the various ophthalmological conditions may assist the radiologist in formulating differential diagnoses and proper MRI protocols afterward. Although MRI of the brain and orbits usually suffices, further refinements are sometimes warranted to enable suitable assessment and accurate diagnosis. For example, the assessment of children with sudden onset anisocoria associated with Horner syndrome will require imaging of the entire oculosympathetic pathway, including the brain, orbits, neck, and chest. Dedicated orbital scans should cover the area between the hard palate and approximately 1 cm above the orbits in the axial plane and extend from the lens to the midpons in the coronal plane. Fat-suppressed T2-weighted fast spin echo sequences should enable proper assessment of the globes, optic nerves, and perioptic subarachnoid spaces. Contrast material should be given judiciously, ideally according to clinical circumstances and precontrast scans. In this review, we discuss the major indications for imaging following abnormal ophthalmological examinations.

Two cases of benign abducens nerve palsy in children and their long-term follow-up

Our aim was to explore the clinical characteristics and diagnostic methods of benign abducens nerve palsy in children. The clinical and laboratory characteristics, treatment approach, and prognosis of two children with benign abducens nerve palsy were retrospectively evaluated. The main clinical symptoms of the two children were limited binocular movement accompanied by double vision, and the positive physical signs were limited binocular abduction accompanied by diplopia. No abnormalities were found in laboratory examinations or in imaging of the head, chest, and abdomen. Both children were treated with B vitamins, methylprednisolone, and gamma globulin, and the clinical symptoms disappeared within 3 months of starting treatment. The cause of benign abducens nerve palsy in children is unknown, but may be related to immune factors. In the two cases presented here, the patients recovered after treatment with immunomodulators.

What did he eat?

A 13-year-old boy reported acute horizontal binocular diplopia and headache. Ten days before these symptoms he suffered from a gastrointestinal infection. Ophthalmological examination revealed bilateral ophthalmoparesis and diffuse hyporeflexia. Magnetic resonance imaging of the brain was normal. Lumbar puncture revealed albumin-cytological dissociation. There were no anti-GQ1b antibodies, but serum anti-GM1 antibodies were detected. He received intravenous immunoglobulins and had fully recovered two weeks later. Miller Fisher syndrome and its atypical variants are uncommon in childhood; nevertheless, they should be considered in the differential diagnosis of bilateral acute ophthalmoparesis.

Approach to patient with diplopia

This article presents an overview of the most important points a neurologist must remember when dealing with a patient complaining of diplopia. Patients with monocular diplopia and those with full ocular motility and comitant misalignment should be referred to an ophthalmologist and do not require further testing. Patients with recent onset of binocular diplopia who have associated "brainstem" symptoms should have an urgent brain MRI. All patients with 3rd cranial nerve palsy require urgent brain CTA to rule out compressive aneurysmal lesion. Management of patients over 50 years of age with microvascular risk factors with new onset of 6th nerve palsy is controversial: some image these patients at presentation while others choose a short period of observation as most of these patients would have a microvascular etiology for the 6th nerve palsy which should improve spontaneous in 2-3 months. All others with 6th nerve palsy require brain MRI with contrast. Patients with 4th palsy with hyperdeviation that worsens in downgaze should have an MRI with contrast and all others referred to an ophthalmologist. If there is more than one cranial nerve palsy, urgent neuroimaging should be performed with attention to cavernous sinus and superior orbital fissure. Ocular myasthenia should be suspected in patients with eye misalignment that does not fit a pattern for any cranial nerve palsy. Orbital pathology (most commonly thyroid eye disease) can result in restriction of ocular motility and has specific clinical signs associated with it.

Acute abducens nerve palsy in a patient with the novel coronavirus disease (COVID-19)

We present a case of an abducens nerve palsy in a previously healthy young man in the setting of SARS-CoV-2 infection. Magnetic resonance imaging obtained 5 weeks after the onset of diplopia demonstrated an atrophic left lateral rectus muscle, which was hyperintense on T2 weighting, consistent with denervation. Although the mechanism of the nerve palsy remains unclear, it is suspected to be related to his viral illness, because the patient had no preexisting vascular risk factors or evidence of other neurologic disease on neuroimaging. Cranial nerve palsies may represent part of the neurologic spectrum of COVID-19.

Unilateral Abducens Nerve Palsy Following Perinatal Stroke of the Middle Cerebral Artery

The authors describe a case of unilateral abducens nerve palsy following perinatal stroke of the middle cerebral artery. A 1-year-old boy presented with left eye esotropia but no other ocular abnormalities. The patient's history, examination, and diagnostic tests were consistent with abducens nerve palsy. He underwent left medial rectus recession of 5.5 mm and left lateral rectus resection of 7 mm followed by patching. At 15 months after surgery, primary gaze by prism alternate cover testing revealed a 4 prism diopter (PD) esophoria (small angle in left gaze with essentially no action of lateral rectus) and 2 PD right hyperphoria. Ophthalmologic management of abducens nerve palsy entails addressing neurological sequelae in a timely manner, treating the esotropia and strabismic amblyopia to optimize visual system development. [J Pediatr Ophthalmol Strabismus. 2020;57:e30-e33.].

Acquired Ocular Motor Palsy: Current Demographic and Etiological Profile

PURPOSE

To describe the clinical, demographic, and etiological profile of patients of acquired ocular motor palsy presenting in a tertiary eye care center.

DESIGN

A retrospective hospital record-based study was conducted in patients of paralytic strabismus presenting from April 2016 to December 2017.

METHODS

Data included demographic and clinical details, diagnosis, underlying etiology, imaging, laboratory reports, and the outcome.

RESULTS

Mean age of presentation of 345 patients included in the study was 38.2 ± 19.5 years (range = 365 years). Pediatric patients (age: ≤16 years) constituted 9.5% of the entire cohort. Mean duration of complaints was 5.87 ± 2 months. Of the 372 eyes of 345 cases, 42.7% were sixth nerve palsy, 34.7% were third nerve palsy, 17.7% were fourth nerve palsy, and 4.8% had multiple ocular motor nerve involvement. Third and sixth nerve palsies were mostly due to ischemic event (58.1% and 69.8% cases, respectively), whereas fourth nerve palsies were commonly caused by trauma (63.6%). Amongst traumatic cases, road traffic accident was the most common mode of trauma. Systemic risk factors were preexistent in 18.2% cases (n = 63); in the remaining (40.8%; n = 141), they were diagnosed after presentation. Complete or partial recovery was noted in 69.7% cases in third nerve palsy, 67.9% cases in sixth nerve palsy, and 45% cases in fourth nerve palsy.

CONCLUSIONS

Acquired cranial nerve palsy has younger onset in Indian scenario. Ischemia is the most common etiology raising concerns about the health issues of young Indians. Sixth nerve is most commonly involved in all age groups. Low recovery rate in fourth nerve palsy can be attributed to traumatic etiology.

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

We aimed to investigate the incidence, prevalence, and etiology of sixth cranial nerve (CN6) palsy in the general Korean population. The nationally representative dataset of the Korea National Health Insurance Service–National Sample Cohort from 2006 through 2015 was analyzed. The incidence and prevalence of CN6 palsy were estimated in the cohort population, confirming that incident cases of CN6 palsy involved a preceding disease-free period of ≥4 years. The etiologies of CN6 palsy were presumed using comorbidity conditions. Among the 1,108,256 cohort subjects, CN6 palsy developed in 486 patients during the 10-year follow-up. The overall incidence of CN6 palsy was estimated to be 4.66 per 100,000 person-years (95% confidence interval [CI], 4.26–5.08) in the general population. This incidence increased with age, accelerating after 60 years of age and peaking at 70–74 years of age. The mean male-to-female incidence ratio was estimated as 1.41 in the whole population, and the incidence and prevalence of CN6 palsy showed an increasing trend over time in the study period. Surgical incidence for CN6 palsy was only 0.19 per 100,000 person-years (95% CI, 0.12–0.29). The etiologies were presumed to be vascular (56.6%), idiopathic (27.2%), neoplastic (5.6%), and traumatic (4.9%). In conclusion, the incidence of CN6 palsy increases with age, peaking at around 70 years, and shows a mild male predominance in Koreans.

Utility of Magnetic Resonance Imaging (MRI) in Children With Strabismus

PURPOSE

Magnetic resonance imaging (MRI) of the brain can provide valuable information about structural abnormalities in strabismus. The aim of this study was to evaluate the utility of MRI in this regard and to identify risk factors for abnormal MRI results in children with strabismus.

METHODS

A retrospective analysis of children <18 years of age presenting with strabismus, who underwent brain MRI at Pusan National University Hospital (Busan, Korea) between January 2012 and March 2017, was performed. Clinical characteristics, MRI results, and ophthalmologic findings were reviewed. Findings were classified as normal or abnormal according to MRI results. Additionally, patients were divided according to age to compare characteristics of infantile and childhood strabismus.

RESULTS

A total of 90 patients (47 [52.2%] male, 43 [47.8%] female; mean age, 2.19 ± 0.53 years) were enrolled. Of those, 64 (71.1%) presented with normal and 26 (28.9%) with abnormal MRI results. The age at presentation was lower and abnormal findings on fundus examination were more common in the abnormal MRI group (P = .002 and P = .008, respectively). Among the patients, 46 (51.1%) had infantile strabismus and 44 (48.9%) had childhood strabismus. Global developmental delays, speech delays, and MRI abnormalities were more common in patients with infantile than in those with childhood strabismus. Ptosis and headaches were more common in patients with childhood strabismus (P = .025, P = .025, respectively).

CONCLUSION

Brain MRI was helpful for accurate diagnosis and treatment of strabismus in younger children, those with abnormal findings on fundus examination, and infants with developmental, especially speech, delays.

Don't Miss This! Red Flags in the Pediatric Eye Examination: Ophthalmoplegia in Childhood

Paralytic strabismus in children is rare, occurring in about 0.1% of children. This rate is far less common than the 3% rate usually noted for comitant strabismus. The relative rates of ocular motor pareses were fourth nerve palsies in 36%, sixth in 33%, third in 22%, with multiple ocular motor nerve palsies in 9%. In a single population series from Minnesota, few cases were associated with neoplasm. However, institutional case series reports a high rate of neoplasm for acquired third nerve and sixth nerve palsies after excluding trauma and congenital causes. Tumor is rare in children with fourth cranial nerve palsies, usually associated with other neurologic disease. Rare causes of external ophthalmoplegia, to be considered when the motility pattern is variable or not fitting an ocular motor nerve pattern, include myasthenia gravis and congenital fibrosis of the extraocular muscles. Myasthenia most often presents as ptosis with exotropia. Rarer still is involvement of the extraocular muscles in childhood thyroid disease.

Acquired onset of third, fourth, and sixth cranial nerve palsies in children and adolescents

PURPOSE

To describe the causes of third, fourth, and sixth cranial nerve palsies in children and adolescents.

METHODS

In this retrospective case series, a total of 66 patients aged 0-19 years with third, fourth, and sixth cranial nerve palsies seen in strabismus and neuro-ophthalmic practice from 2010 to 2017 were included. Causes of palsies were determined based on clinical assessment, high-resolution magnetic resonance imaging (MRI), and laboratory work-up.

RESULTS

Thirty-five patients had sixth cranial nerve palsy, 14 patients had third cranial nerve palsy (7 partial, 7 complete), 13 patients had fourth cranial nerve palsy, and 4 patients had combined cranial nerve palsies in this study. Neoplasia involving central nervous system was one of the most common causes of third, fourth, and sixth cranial nerve palsies both in children (age: 0-14 years) and adolescents (age: 15-19 years) (20% and 31%, respectively). Overall, neoplasia (23%) was the most common cause of acute third, fourth, and sixth cranial nerve palsies, followed by idiopathic cause (14%), inflammation (11%), and non-aneurysmal vascular contact (11%). Neoplasia was also the most common cause of sixth and third cranial nerve palsies (25% and 29%, respectively). The most common cause of fourth cranial nerve palsy was late decompensation in congenital fourth cranial nerve palsy (46%).

CONCLUSIONS

A substantial proportion of pediatric and juvenile patients had serious pathologies for third, fourth, and sixth cranial nerve palsies. If nerve palsies are indicated, prompt diagnosis of etiologies using high-resolution MRI with contrast and laboratory work-up are important for this disease population.

Primary Sphenoidal Sinus Lymphoma with Initial Presentation as Unilateral Abducens Nerve Palsy Symptom

A 48-year-old man presented with 3 days of mild horizontal diplopia in the left direction, followed by the onset of headache 17 days later. A physical examination revealed isolated left abducens nerve palsy. Head computed tomography (CT) and magnetic resonance imaging (MRI) scans revealed soft-tissue density neoplasms that occupied the sphenoidal sinus and further invaded to destroy the clivus. Immunohistochemical staining of neoplasms was performed from biopsies samples. The pathological diagnosis was extranodal natural killer (NK)/T-cell lymphoma (ENKL), nasal type, associated with Epstein-Barr virus (EBV). The patient subsequently exhibited secondary symptoms (fever, night sweats), enlarged lymph nodes, renal metastases, and hemophagocytic syndrome, with clinical diagnosis stage IV of ENKL. The patient has a poor prognosis. This report is unique in two aspects: the unilateral abducens nerve palsy as the initial and isolated symptom of ENKL, and the primary sphenoidal sinus ENKL.

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.

A Review of Visual and Oculomotor Outcomes in Children With Posterior Fossa Tumors

Tumors of the posterior fossa represent the most common solid malignancy of childhood and can affect the visual system in several ways. This article outlines the relevant visual anatomy affected by these tumors and reviews the visual and oculomotor outcomes associated with the following 3 most common tumor types-medulloblastoma, juvenile pilocytic astrocytoma, and ependymoma. The available data suggest that the rate of permanent vision loss is low (5.9%-8.3%), with patients having juvenile pilocytic astrocytoma demonstrating the best outcomes. The rate of long-term strabismus (25%-29.1%) and nystagmus (12.5%-18%) is higher and associated with significant morbidity.

Paroxysmal vertigo with nystagmus in children

INTRODUCTION

A pathological nystagmus is an objective sign that a patient feels vertigo. However, there have been few opportunities to observe and record pathological nystagmus during a paroxysmal vertigo attack. Furthermore, it can be difficult to obtain cooperation in pediatric patients. We present two cases of paroxysmal vertigo in children in whom we successfully recorded and analyzed their pathological nystagmus during a vertigo attack.

METHODS

Of a total sample of 4349 patients seen at our hospital for dizziness in the last decade, a retrospective analysis revealed that 68 were children (<15 years old; 1.6%). Of these 68 children, we successfully identified pathological nystagmus during paroxysmal vertigo in only two (2.9%).

RESULTS

Case 1 was a 4-year-old girl. She felt vertigo the strongest when her left ear was down in the supine position. We observed and recorded her nystagmus during a vertigo attack with her mother's permission. Her positional nystagmus in the supine position was horizontal persistent apogeotropic nystagmus. Rightward nystagmus in the left-ear-down supine position was stronger than leftward nystagmus in the right-ear-down supine position. Therefore, the diagnosis was right lateral canal type of benign paroxysmal positional vertigo, of which the pathophysiology was cupulolithiasis. The other patient was an 11-year-old boy. He had a family history of migraines. His vertigo attacks occurred after onset of a severe migraine and lasted between 2 and 48 h. During an attack that we observed, he showed nystagmus, which was direction-fixed right torsional and rightward in darkness. His mother had noticed that his eyes moved abnormally and that his left eye did not shift to the left side when he looked leftward. He was old enough to clearly express his own symptoms. Other neurological examinations were normal. The diagnosis was vestibular migraine.

CONCLUSIONS

We analyzed a pathological nystagmus during paroxysmal vertigo in two children. We conclude that children can be diagnosed with a combination of careful history taking and accurate examinations of a pathological nystagmus.

Acute Abducens Nerve Paralysis in the Pediatric Emergency Department: Analysis of 14 Patients

OBJECTIVES

Sixth cranial nerve (SCN) palsy is an uncommon but important neurological problem in patients admitted to pediatric emergency department. The underlying etiology of SCN palsy has a wide range from viral infections to intracranial tumors; therefore, a careful and systematic approach is necessary while examining these patients.

METHODS

Fourteen patients who presented with acute SCN paralysis to pediatric emergency department during the last 10 years were examined.

RESULTS

The age at the time of admission ranged between 14 months and 16 years (median, 9.5 years). Of the 14 patients, 5 were girls and 9 were boys. A total of 3 of the 14 patients had bilateral cranial nerve VI paralysis, and 9 patients had additional abnormal findings on neurological examination. Neuroimaging studies included cranial tomography (n = 3) and brain magnetic resonance imaging in all patients. The underlying etiology was malignancy (n = 3); glioma, medulloblastoma, acute lymphoblastic leukemia, and dural sinus thrombosis (n = 2); as well as Guillain-Barre syndrome (n = 2), multiple sclerosis (n = 1), pseudotumor cerebri (n = 1), and meningitis (n = 1). The remaining 4 patients had miscellaneous benign etiologies.

CONCLUSIONS

Other lesions of primary brain tumors causing increased intracranial pressure constitute 50% of the underlying etiology, followed by Guillain-Barre syndrome (14.2%). However, these patients had neurological symptoms signs, in addition to diplopia or SCN paralysis. Patients admitted to pediatric emergency department with acute SCN paralysis should be examined in detail to disclose the underlying etiology especially if they present with additional clinical signs or symptoms.

Anti-GQ1b antibody syndrome presenting as acute isolated bilateral ophthalmoplegia: Report on two patients and review of the literature

BACKGROUND

Miller Fisher syndrome (MFS) is an acute polyradiculoneuritis regarded as an uncommon clinical variant of Guillain-Barré syndrome (GBS). MFS is characterized by the acute onset of the clinical triad of ophthalmoplegia, cereballar ataxia and areflexia. Atypical forms of MFS presenting as isolated ophthalmoplegia without ataxia have been rarely described, mostly in adults.

PATIENTS

We present two cases of acute isolated bilateral ophthalmoplegia in childhood, both occurring shortly after Campylobacter jejuni enteritis. Serum analysis of anti-ganglioside antibodies revealed elevated levels of anti-GQ1b IgG and IgM. We observed in both children complete spontaneous resolution several weeks after onset.

CONCLUSION

The cases of the two patients confirm the rare but possible occurrence of atypical MFS in young children a few weeks after gastrointestinal infection. Identification of high levels of anti-GQ1b antibodies in the serum may help confirm the diagnosis of MFS even when its clinical presentation is incomplete.

Isolated abducens nerve palsy after closed head injury in a child

The authors present the rare case of a 5-year-old child with an isolated right abducens nerve palsy following a minor closed head injury. Occlusion of the left eye for 4 h daily was prescribed, and the child remained under close ophthalmological follow-up. Significant improvement was noticed in the following 6 months.

Benign Recurrent Sixth (Abducens) Nerve Palsy following Measles-Mumps-Rubella Vaccination

Benign, isolated, recurrent sixth nerve palsy is rare in children. It may be associated with febrile viral illness and vaccination in exceptional circumstances although this is a diagnosis of exclusion. Here, we present the case of a 2-year-old Caucasian girl who developed recurrent 6th nerve palsy following vaccination with the measles-mumps-rubella (MMR) vaccine. No underlying pathology was identified following extensive investigations and followup. There is limited data available on the pathophysiology of vaccination-related nerve palsies. As with all previous reports of cranial nerve palsies following vaccination, there was complete resolution in this case. Long term followup with repeated physical examination and investigations is warranted to avoid missing severe pathology and operating unnecessarily.

Cranial nerve palsies in childhood

We review ocular motor cranial nerve palsies in childhood and highlight many of the features that differentiate these from their occurrence in adulthood. The clinical characteristics of cranial nerve palsies in childhood are affected by the child's impressive ability to repair and regenerate after injury. Thus, aberrant regeneration is very common after congenital III palsy; Duane syndrome, the result of early repair after congenital VI palsy, is invariably associated with retraction of the globe in adduction related to the innervation of the lateral rectus by the III nerve causing co-contraction in adduction. Clinical features that may be of concern in adulthood may not be relevant in childhood; whereas the presence of mydriasis in III palsy suggests a compressive aetiology in adults, this is not the case in children. However, the frequency of associated CNS abnormalities in III palsy and the risk of tumour in VI palsy can be indications for early neuroimaging depending on presenting features elicited through a careful history and clinical examination. The latter should include the neighbouring cranial nerves. We discuss the impact of our evolving knowledge of congenital cranial dysinnervation syndromes on this field.

Hypertropia in unilateral isolated abducens palsy

PURPOSE

To evaluate the incidence and features of hypertropia in abducens nerve palsy.

METHODS

The records of consecutive patients with unilateral, isolated, previously unoperated abducens nerve palsy were reviewed for binocular alignment on cover testing, Krimsky measurement, or Hess screen testing. Patients with associated cranial nerve palsy (including bilateral abducens palsies), orbital disease, myasthenia gravis, Horner syndrome, hemiplegia, cerebellar signs, arteritis, or previous strabismus surgery were excluded. Control subjects underwent complete examination to confirm normality.

RESULTS

A total of 79 patients were included (40 males; mean age 49.2 years). Hypertropia in lateral or central gazes was present in 15 of 79 cases (19%) on alternate cover or Krimsky testing, in 32 of 56 cases (57%) on Hess screen testing, and absent in all 30 normal controls. Of cases with hypertropia, the mean of the greatest hypertropia in lateral or central gaze on was 5.0(Δ) ± 2.3(Δ) (standard deviation; range, 1(Δ)-8(Δ)) routine clinical examination, and 5.8(Δ) ± 4.2(Δ) (range, 2(Δ)-24(Δ)) on Hess screen testing. Of 39 cases with partial abducens palsy evaluated by Hess screen testing, the ipsilesional eye was hypertropic in 24 (61%) and hypotropic in 15 cases (39%).

CONCLUSIONS

Small-angle hypertropia is common in isolated, unilateral abducens and does not imply existence of multiple cranial neuropathies or skew deviation.

Isolated abducens nerve palsy following neonatal hepatitis B vaccination

We report a case of sudden-onset abducens nerve palsy in an otherwise healthy 8-day-old boy following neonatal hepatitis B vaccination. A complete workup, including magnetic resonance imaging of the brain and orbits revealed no abnormalities. The patient recovered fully, with no recurrence of the abducens nerve palsy despite receiving the full course of the hepatitis B vaccine as well as other recommended immunizations through 18 months of age. We review the literature regarding vaccination-induced abducens nerve palsy and discuss the possible mechanisms of injury.

Recurrent and self-remitting sixth cranial nerve palsy: pathophysiological insight from skull base chondrosarcoma

Palsy of the abducens nerve is a neurological sign that has a wide range of causes due to the nerve's extreme vulnerability. Need of immediate neuroimaging is a matter of debate in the literature, despite the risks of delaying the diagnosis of a skull base tumor. The authors present 2 cases of skull base tumors in which the patients presented with recurrent and self-remitting episodes of sixth cranial nerve palsy (SCNP). In both cases the clinical history exceeded 1 year. In a 17-year-old boy the diagnosis was made because of the onset of headache when the tumor reached a very large size. In a 12-year-old boy the tumor was incidentally diagnosed when it was still small. In both patients surgery was performed and the postoperative course was uneventful. Pathological diagnosis of the tumor was consistent with that of a chondrosarcoma in both cases. Recurrent self-remitting episodes of SCNP, resembling transitory ischemic attacks, may be the presenting sign of a skull base tumor due to the anatomical relationships of these lesions with the petroclival segment of the sixth cranial nerve. Physicians should promptly recommend neuroimaging studies if SCNP presents with this peculiar course.

The role of neuroimaging in the evaluation process of children with isolated sixth nerve palsy

PURPOSE

The purpose of this study was to assess the role of neuroimaging in identifying the etiology of pediatric isolated sixth nerve palsy (SNP).

METHODS

A retrospective cohort study was conducted of all patients younger than 18 years of age with an isolated SNP seen at our medical center between 2003 and 2011.

RESULTS

Sixteen children (nine girls; mean age, 4.5 years) with isolated SNP were identified during an 8-year period. Only cases with normal optic disk appearance and otherwise normal neurological examination were included into this study. Thus, 12 other children with SNP were excluded: ten children with papilledema, one child who developed a SNP following a resection of a brain tumor, and one with hydrocephalus and a shunt malfunction. All cases of isolated SNP were unilateral (ten left eyes). The most common cause for the SNP in these children was a tumor that was found in five patients. Other etiologies encountered in decreasing frequencies were: benign recurrent SNP (in four children), postviral or vaccination (in three children), and one case each of post trauma, Chiari malformation, congenital, and undetermined. Children who were found to have a tumor (9.9 ± 5.5 years) were significantly older (P = 0.019) than children who did not have a tumor (2.1 ± 1.8 years).

CONCLUSIONS

Isolated SNP can be the presentation of a brain tumor in children, and therefore, early neuroimaging of the brain is recommended, especially in older children.

The neuro-ophthalmology of multiple sclerosis

Multiple sclerosis (MS) is a disease marked by focal demyelinating inflammatory plaques throughout the CNS. Neuro-ophthalmologic sequelae are common in MS and may arise from the disease itself or from treatment of the disease. Both afferent and efferent functions may be affected. Despite much progress, our understanding of the pathophysiology of MS, and the efficacy of our available treatments, remain inadequate. Here, we review the chief neuro-ophthalmologic abnormalities associated with MS and discuss the emerging diagnostic and therapeutic advances that are likely to further our understanding of MS and its treatment.

Herpes zoster ophthalmicus and lateral rectus palsy in an elderly patient

Acquired palsy of the lateral rectus presents with horizontal diplopia and has a broad differential. Herpes zoster ophthalmicus- (HZO) related cranial nerve palsy is a transient and self-limiting condition. Systemic antiviral treatment is administered in order to prevent sight-threatening complications. In suspected cases, zosteriform rash should be questioned. One should keep in mind that acquired esotropia in the elderly may sometimes present following HZO.

Acquired infantile abducens palsy associated with anti-GM2 antibodies

Anti-ganglioside antibodies have been associated with acquired neuropathies, including Guillain-Barré syndrome. We describe a case of acute abducens nerve palsy acquired 2 weeks after symptoms of upper respiratory tract infection and rash in a 6-month-old. Elevated anti-GM2 ganglioside immunoglobulin M antibodies were detected in the serum. The palsy slowly improved over time, although eventually surgical intervention was required. Elevated anti-GM2 immunoglobulin M antibodies have previously been reported in Guillain-Barré syndrome variants involving sensory and cranial neuropathies, but never in isolated unilateral cranial nerve VI mononeuropathy. Anti-ganglioside antibodies may play a role in the pathogenesis of postinfectious isolated abducens palsy in young children.

Etiology and treatment of pediatric sixth nerve palsy

PURPOSE

To describe the causes and treatment of sixth (abducens) nerve palsy in a series of pediatric patients.

METHODS

This was a 14-year retrospective study of sixth nerve palsy in children under 14 years of age. Outcomes studied included horizontal deviation, degree of limitation of abduction, and head turn. Patients were treated with botulinum toxin injection at the time of diagnosis; surgery was indicated if treatment with botulinum toxin was unsuccessful. Success was defined as final deviation of orthotropia with no head turn or diplopia.

RESULTS

Sixth nerve palsy was diagnosed in 15 patients (10 boys; mean age, 4.1 years) between 1995 and 2008. Involvement was bilateral in 2 cases and unilateral in 13 (7 right eyes). Causes included neoplasm (4 cases), trauma (2), idiopathic (3), congenital (2), viral (2), and inflammatory (1). Neoplastic causes were associated with other neurologic signs. Recovery was spontaneous in 5 cases (2 idiopathic, 1 traumatic, 1 congenital, and 1 inflammatory). Botulinum toxin was successful in 7 of 10 patients treated, with follow-up surgery required in the remaining 3 cases. The final result was good in all cases. In all 15 patients, mean time from diagnosis to resolution was 39 months (range, 5 to 170 months).

CONCLUSIONS

Neoplasms were the most frequent cause of sixth nerve palsy in our patient population. Recovery was spontaneous in one third of the patients. Most required treatment with botulinum toxin, which was successful in most cases. Surgery was successful after a single procedure.