Myelin Oligodendrocyte Glycoprotein Antibody Disease Optic Neuritis: A Structure-Function Paradox?

BACKGROUND: Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) is a demyelinating disorder that most commonly presents with optic neuritis (ON) and affects children more often than adults. We report 8 pediatric patients with MOG-associated ON and characterize focal optical coherence tomography (OCT) abnormalities over time that help distinguish this condition from the trajectories of other demyelinating disorders. These OCT findings are examined in the context of longitudinal visual function testing. METHODS: This is a retrospective case series of 8 pediatric patients with MOG-associated ON who were referred for neuro-ophthalmic evaluation. Longitudinal data for demographics, clinical history, physical examination, and OCT obtained in the course of clinical evaluations were collected through retrospective medical record review. RESULTS: Patients demonstrated acute peripapillary retinal nerve fiber layer (RNFL) thickening in one or both eyes, consistent with optic disc swelling. This was followed by steady patterns of average RNFL thinning, with 9 of 16 eyes reaching significantly low RNFL thickness using OCT platform reference databases (P < 0.01), accompanied by paradoxical recovery of high-contrast visual acuity (HCVA) in every patient. There was no correlation between HCVA and any OCT measures, although contrast sensitivity (CS) was associated with global thickness, PMB thickness, and nasal/temporal (N/T) ratio, and color vision was associated with PMB thickness. There was a lower global and papillomacular bundle (PMB) thickness (P < 0.01) in clinically affected eyes compared with unaffected eyes. There was also a significantly higher N:T ratio in clinically affected eyes compared with unaffected eyes in the acute MOG-ON setting (P = 0.03), but not in the long-term setting. CONCLUSIONS: MOG shows a pattern of prominent retinal atrophy, as demonstrated by global RNFL thinning, with remarkable preservation of HCVA but remaining deficits in CS and color vision. These tests may be better clinical markers of vision changes secondary to MOG-ON. Of the OCT parameters measured, PMB thickness demonstrated the most consistent correlation between structural and functional measures. Thus, it may be a more sensitive marker of clinically significant retinal atrophy in MOG-ON. The N:T ratio in acute clinically affected MOG-ON eyes in our study was higher than the N:T ratio of neuromyelitis optica (NMO)-ON eyes and similar to the N:T ratio in multiple sclerosis (MS)-ON eyes as presented in the prior literature. Therefore, MOG may share a more similar pathophysiology to MS compared with NMO.

Editors' Note: Challenges to Brain Death in Revising the Uniform Determination of Death Act: The UDDA Revision Series.

Despite decades of striving to simplify the diagnosis of human death according to irreversible cessation of function of a single organ system-the brain-we are relentlessly plagued by disagreement between experts spanning disciplines from medicine to philosophy. Dr. Bernat summarizes the current state of this controversy in their narrative summary, recently published in Neurology. In this review, the first of a planned series on the Uniform Determination of Death Act (UDDA) and brain death determination in Neurology, Dr. Bernat appraises the current criteria for determining brain death and highlights the need for careful revision to the UDDA. Is death determined by irreversible loss of function of the brain-as-a-whole or loss of function of the whole brain? And how does one define irreversible brain dysfunction? With the upcoming revisions to this statute by the US Uniform Law Commission (ULC), we hope to find more answers than new questions, although both are likely to be a consequence of this update. In response to the article, Dr. Machado proposes death be defined by irreversible failure of the 2 elements of consciousness-arousal and awareness. Furthermore, Dr. Machado challenges the notion of biological death and emphasizes the value of specific testing depending on the region of brain injury, with ancillary (neurophysiologic) testing in patients with posterior fossa lesions. Dr. Bernat comments that the objective of the ULC is not to disentangle the controversy of defining death, which may be subjective-e.g., influenced by personal beliefs, religious background, and interpretation of diagnostic testing-but instead to provide objective criteria for determining death. The revised UDDA may provide clarity in medical decision-making; however, it may not reconcile our division over ontology.

Assignment Completed: The Optic Nerve Should Graduate to Be the Fifth Lesion Site for the Diagnosis of Multiple Sclerosis

Optic neuritis has long been considered a characteristic finding of multiple sclerosis and the initial manifestation of the disorder in about 25% of patients. Approximately 70% of patients will experience optic nerve dysfunction during their disease course.1.

Relapsing White Matter Disease and Subclinical Optic Neuropathy: From the National Multiple Sclerosis Society Case Conference Proceedings

A 16-year-old adolescent boy presented with recurrent episodes of weakness and numbness. Brain MRI demonstrated subcortical, juxtacortical, and periventricular white matter T2 hyperintensities with gadolinium enhancement. CSF was positive for oligoclonal bands that were not present in serum. Despite treatment with steroids, IV immunoglobulins, plasmapheresis, and rituximab, he continued to have episodes of weakness and numbness and new areas of T2 hyperintensity on imaging. Neuro-ophthalmologic examination revealed a subclinical optic neuropathy with predominant involvement of the papillomacular bundle. Genetic evaluation and brain biopsy led to an unexpected diagnosis.

Precision Concussion Management: Approaches to Quantifying Head Injury Severity and Recovery.

Mitigating the substantial public health impact of concussion is a particularly difficult challenge. This is partly because concussion is a highly prevalent condition, and diagnosis is predominantly symptom-based. Much of contemporary concussion management relies on symptom interpretation and accurate reporting by patients. These types of reports may be influenced by a variety of factors for each individual, such as preexisting mental health conditions, headache disorders, and sleep conditions, among other factors. This can all be contributory to non-specific and potentially misleading clinical manifestations in the aftermath of a concussion. This review aimed to conduct an examination of the existing literature on emerging approaches for objectively evaluating potential concussion, as well as to highlight current gaps in understanding where further research is necessary. Objective assessments of visual and ocular motor concussion symptoms, specialized imaging techniques, and tissue-based concentrations of specific biomarkers have all shown promise for specifically characterizing diffuse brain injuries, and will be important to the future of concussion diagnosis and management. The consolidation of these approaches into a comprehensive examination progression will be the next horizon for increased precision in concussion diagnosis and treatment.