Acquired nystagmus as the initial presenting sign of chiasmal glioma in young children

Simplifying the Diagnosis of Pediatric Nystagmus with Fundus Photography

BACKGROUND/OBJECTIVES

To simplify diagnosing congenital and acquired nystagmus using fundus photographs.

METHODS

A retrospective study included patients with congenital or childhood-acquired nystagmus examined at a hospital-based ophthalmology clinic (September 2020-September 2023) with fundus photos taken. Exclusions were for incomplete data or low-quality images. Demographics, aetiology, orthoptic measurements, and ophthalmologic and neurological exams were reviewed. Two independent physicians graded fundus photos based on amplitude (distance between "ghost" images), the number of images visible, and the direction of nystagmus. Severity was rated on a 0-3 scale using qualitative and quantitative methods. Photographic findings were compared to clinical data, and statistical analysis used Mann-Whitney tests.

RESULTS

A total of 53 eyes from 29 patients (16 females, 13 males; mean age 12.5 years, range 3-65) were studied: 25 with binocular nystagmus and 3 with monocular nystagmus. Diagnoses included congenital (n = 15), latent-manifest (n = 3), neurologically associated (n = 2), and idiopathic (n = 9). Types observed were vertical (n = 5), horizontal (n = 23), rotatory (n = 10), and multidirectional (n = 15). Visual acuity ranged from 20/20 to no light perception. Fundus photos correlated with clinical diagnoses, aiding qualitative assessment of direction and amplitude and mitigating eye movement effects for clearer retinal detail visualization.

CONCLUSIONS

Fundus photography effectively captures nystagmus characteristics and retinal details, even in young children, despite continuous eye movements. Integrating fundus cameras into routine practice may enhance nystagmus diagnosis and management, improving patient outcomes.

Management of Optic Pathway Glioma: A Systematic Review and Meta-Analysis

Background: OPG accounts for 3−5% of childhood central nervous system (CNS) tumors and about 2% of pediatric glial lesions. Methods: Article selection was performed by searching PubMed, Web of Science, and Cochrane databases. Results: The pooled mortality rate was 0.12 (95%CI 0.09−0.14). Due to the unrepresentative data, improved and not changed outcomes were classified as favorable outcomes and worsened as unfavorable. Meta-analyses were performed to determine the rate of clinical and radiological favorable outcomes. In terms of visual assessment, the pooled rate of a favorable outcome in chemotherapy, radiotherapy, and surgery was 0.74, 0.81, and 0.65, respectively, and the overall pooled rate of the favorable outcome was 0.75 (95%CI 0.70−0.80). In terms of radiological assessment, the rate of a favorable outcome following chemotherapy, radiotherapy, and surgery was 0.71, 0.74, and 0.67, respectively, and the overall pooled rate of the favorable outcome is 0.71 (95%CI 0.65−0.77). The subgroup analysis revealed no significant difference in the rate of clinical and radiological favorable outcomes between the different treatment modalities (p > 0.05). Conclusion: Our analyses showed that each therapeutic modality represents viable treatment options to achieve remission for these patients.

Visual Function, Brain Imaging, and Physiological Factors in Children With Asymmetric Nystagmus due to Chiasmal Gliomas

PURPOSE

Asymmetric nystagmus can be an important presenting sign of optic pathway gliomas in young children. We investigated the causes of asymmetric nystagmus in children with chiasmal or suprasellar optic pathway gliomas compared with children with similar optic pathway gliomas and stable gaze.

METHODS

Longitudinal magnetic resonance imaging before and after treatment, age-corrected visual acuity, ocular examinations, video-oculography, visual evoked potentials, and retinal nerve fiber layer thickness were retrospectively reviewed.

RESULTS

Twenty-two children were included (eight with asymmetric nystagmus and 14 with stable gaze). Subjects with asymmetric nystagmus presented at a younger age than those with stable gaze (2.0 vs 5.6 years; P < 0.001). None had neurofibromatosis type 1. Visual acuity, visual evoked potentials, nerve fiber layer, severity of optic atrophy, hydrocephalus, tumor volume, and tumor locations did not differ between those with asymmetric nystagmus and stable gaze. Asymmetric nystagmus resolved shortly after treatment, even though the average visual acuity did not improve. Changes in visual acuity or tumor volume were not different between those with asymmetric nystagmus and stable gaze after treatment. Eye movement recording from two subjects with asymmetric nystagmus revealed an asymmetric pendular-oscillation with vertical components. One subject with stable gaze developed asymmetric nystagmus with tumor growth into the rostral midbrain and associated unilateral vision loss. Another subject with tumor growth into the rostral midbrain acquired vertical saccade dysmetria.

CONCLUSION

We hypothesize that asymmetric nystagmus associated with optic pathway gliomas is caused by subclinical abnormalities to retinal axons that connect to gaze holding centers in the rostral midbrain. Direct compression of the rostral midbrain was a possible factor to asymmetric nystagmus in some subjects. However, many subjects with stable gaze also show midbrain compression.

Comparison of multi-shot and single shot echo-planar diffusion tensor techniques for the optic pathway in patients with neurofibromatosis type 1

PURPOSE

Diffusion tensor imaging (DTI) may be helpful in assessing optic pathway integrity as a marker for treatment in neurofibromatosis type 1 (NF1) patients with optic gliomas (OG). However, susceptibility artifacts are common in typical single-shot echo planar imaging (ssDTI). A readout-segmented multi-shot EPI technique (rsDTI) was utilized to minimize susceptibility distortions of the skull base and improve quantitative metrics.

METHODS

Healthy controls, children with NF1 without OG, and NF1 with OG ± visual symptoms were included. All subjects were scanned with both rsDTI and ssDTI sequences sequentially. Diffusion metrics and deterministic fiber tracking were calculated. Tract count, volume, and length were also compared by a two-factor mixed ANOVA.

RESULTS

Five healthy controls, 7 NF1 children without OG, and 12 NF1 children with OG were imaged. Six OG patients had visual symptoms. Four subjects had no detectable optic pathway fibers on ssDTI due to susceptibility, for which rsDTI was able to delineate. Tract count (p < 0.001), tract volume (p < 0.001), and FA (P < 0.001) were significantly higher for rsDTI versus ssDTI for all subjects. MD (p < 0.001) and RD (p < 0.001) were significantly lower for rsDTI vs ssDTI. Finally, MD, AD, and RD had a significantly lower difference in NF1 children with visual symptoms compared to NF1 children without visual symptoms only on ssDTI scans.

CONCLUSION

DTI with readout-segmented multi-shot EPI technique can better visualize the optic pathway and allow more confident measurements of anisotropy in NF1 patients. This is shown by a significant increase in FA, tract count, and volume with rsDTI versus ssDTI.

Use of Optical Coherence Tomography to Detect Retinal Nerve Fiber Loss in Children With Optic Pathway Glioma

Optic pathway glioma (OPG) presents in childhood and can cause significant morbidity and visual loss. Magnetic resonance imaging (MRI) is the current imaging modality of choice for evaluation of OPG progression, but it is a relatively limited resource often requiring sedation in the pediatric age group. Additionally, OPG progression on MRI does not always correlate with clinical progression. As a result, several other modalities for evaluating OPG are being investigated, including optical coherence tomography (OCT), a readily available imaging technique in ophthalmic practice. The purpose of the present study was to examine the association between retinal nerve fiber layer (RNFL) thickness measured using OCT and optic nerve function in children with OPG with and without neurofibromatosis-1 (NF-1). A retrospective chart review was conducted to identify children diagnosed with OPG from 2001 to 2015 at a tertiary pediatric medical center. The correlation between OCT measurements and clinical visual parameters was statistically analyzed. Included were 23 children with imaging-confirmed OPG and spectral domain OCT: 10 with NF-1 (mean age at diagnosis 5.8 years) and 13 without (mean age at diagnosis 5.9 years). The glioma involved the chiasma-hypothalamus in 19 patients, optic nerve in 11, and optic tract in 7; more than one anatomic site was affected in 15. Symptoms were reported in 2 patients with NF-1 and most patients without NF-1. Visual field defects included monocular, bitemporal, nasal, and homonymous hemianopia. Initial mean RNFL was 85.4 μm in the NF-1 group and 65 μm in the non-NF-1 group. Visual acuity deteriorated in 1/10 patients and 5/13 patients, respectively. Repeated OCT showed continued RNFL thinning in 3 patients (5 eyes) in the NF-1 group and in 8 patients (11 eyes) in the non-NF-1 group, often associated with a decrease in optic nerve function. In conclusion, visual function in children with OPG is correlated with repeated OCT measurements and weakly with neuroimaging. Children without NF-1 are usually symptomatic and have a worse clinical outcome. These findings may have important implications when considering initiating, continuing or stopping chemotherapy for OPG. The application of OCT in the assessment of OPG and the correlation of the findings to clinical progression can have a significant impact on OPG patient management.

Pediatric Optic Pathway/Hypothalamic Glioma

Optic pathway/hypothalamic gliomas (OP/HGs) are rare astrocytic tumors that appear more commonly among young children and often are unresectable. They comprise approximately 2% of all central nervous system tumors and account for 3–5% of pediatric intracranial tumors. Initial manifestations are often visual disturbances, endocrinopathies and hypothalamic dysfunction such as the diencephalic syndrome, and sometimes hydrocephalus due to cerebrospinal fluid (CSF) outflow obstruction. In many cases, the tumors are diagnosed late in the clinical course because they silently enlarge. These tumors consist mostly of histologically benign, World Health Organization (WHO) grade I tumors represented by pilocytic astrocytomas (PA), the rest being pilomyxoid astrocytomas (PXA) – WHO grade II tumors. In young pediatric patients, however, can be seen PXA that show aggressive clinical course such as CSF dissemination. Our small series of 14 non-Neurofibromatosis type 1 (NF-1) OP/HGs PA patients underwent extended resection without any adjuvant treatments. The median age at initial treatment was 11.5 ± 6.90 years (range, 1–25 years) and median follow up 85.5 ± 25.0 months. Surgical resection for OP/HGs results in acceptable middle-term survival, tumor control and functional outcome equivalent to chemotherapy. There is, however, no longer doubt that chemotherapy with or without biopsy and as-needed debulking surgery remains the golden standard in management of OP/H. Clinical conditions and treatment plans for OP/HGs vary depending on their structure of origin.

Incidence and Types of Pediatric Nystagmus

PURPOSE

To report the incidence, prevalent subtypes, and clinical characteristics of pediatric nystagmus diagnosed over a 30-year period.

DESIGN

Retrospective, population-based study.

METHODS

Using the Rochester Epidemiology Project, we reviewed the medical records of all children (<19 years) diagnosed as residents in Olmsted County, Minnesota, with any form of nystagmus from January 1, 1976, through December 31, 2005.

RESULTS

Seventy-one children were diagnosed during the 30-year period, yielding an annual incidence of 6.72 per 100,000 younger than 19 years (95% confidence interval [CI], 5.15-8.28) Infantile nystagmus, onset by 6 months, comprised 62 (87.3%) of the study patients, corresponding to a birth prevalence of 1 in 821. The median age at diagnosis for the cohort was 12.7 months (range, 0 days to 18.6 years) and 42 subjects (59.2%) were male. The main types of nystagmus, in declining order, were nystagmus associated with retinal/optic nerve disease in 23 (32.4%), idiopathic or congenital motor nystagmus in 22 (31.0%), manifest latent nystagmus or latent nystagmus in 17 (24.0%), and 2 (2.8%) each associated with Chiari malformation, medication use, tumor of the central nervous system, and no diagnosis. Developmental delay was diagnosed in 31 (43.6%), strabismus in 25 (35.2%), and amblyopia in 10 (14.1%). Eighty percent had 20/40 (or equivalent) or better vision at presentation in at least 1 eye.

CONCLUSIONS

This study provides population-based data on incidence and clinical characteristics of childhood nystagmus in North America. Idiopathic and nystagmus associated with retinal/optic nerve disease were the most common presentations, with most patients having good vision. Developmental delay, strabismus, and amblyopia were common in this cohort.

Acquired pendular nystagmus

Acquired pendular nystagmus is comprised of quasi-sinusoidal oscillations of the eyes significantly affecting gaze holding and clarity of vision. The most common causes of acquired pendular nystagmus include demyelinating disorders such as multiple sclerosis and the syndrome of ocular palatal tremor. However, several other deficits, such as pharmacological intoxication, metabolic and genetic disorders, and granulomatous disorders can lead to syndromes mimicking acquired pendular nystagmus. Study of the kinematic features of acquired pendular nystagmus has suggested a putative pathophysiology of an otherwise mysterious neurological disorder. Here we review clinical features of neurological deficits that co-occur with acquired pendular nystagmus. Subsequent discussion of the pathophysiology of individual forms of pendular nystagmus speculates on mechanisms of the underlying disease while providing insights into pharmacotherapy of nystagmus.

Neurofibromatosis Type 1 Presenting with Ophthalmic Features: A Case Series

Neurofibromatosis type 1 (NF-1) is an autosomal dominant disorder involving multiple systems and affects approximately 1 out of 3000 persons. Ocular manifestations are lisch nodules, plexiform neurofibroma, optic pathway gliomas. The proper diagnosis of NF-1 is a crucial task for a clinician due to the various clinical manifestations including vision and life threatening malignancies in few patients, which may arise in the different phases of life. The authors report three cases of NF-1, presenting with ophthalmic symptoms in teenager boys. On further ophthalmic and paediatric evaluation the diagnosis of NF-1 was confirmed on the basis of clinical criteria. This series also describe the abnormal facial features like telecanthus and broad nose which has been reported rarely. Case 1 was kept under regular follow-up and Case 2 and Case 3 were planned for the debulking surgery for plexiform neurofibroma of upper eye lid. A multidisciplinary approach is required to diagnose and treat such patients keeping in mind the myriad of clinical manifestations and life-long follow-up is required.