Two children without neurofibromatosis type 1 presented with unilateral decreased vision and MRI revealing optic nerve tumors. In the first case, chemotherapy was initiated empirically for presumed optic pathway glioma, but the lesion increased in size with associated clinical worsening, raising concern for a possible alternate diagnosis. Biopsy of the involved optic nerve resulted in worsening of vision due to a branch retinal artery occlusion and showed a grade I pilocytic astrocytoma. In the second case, sudden symptom onset and rapid tumor growth prompted an optic nerve biopsy, resulting in vision loss due to a central retinal artery occlusion and revealing grade I pilocytic astrocytoma. In both cases, tissue diagnosis did not alter the course of management. Instead, biopsy was associated with additional vision loss, highlighting the risk of biopsy in children with isolated optic nerve tumors and imaging that is most consistent with an optic pathway glioma.

Background: The benefit of thymectomy in reducing requirement for corticosteroids, symptom severity, need for immunosuppression, and hospitalization rates in patients with seropositive generalized myasthenia has recently been established. It is unclear whether this benefit applies to patients with myasthenia and purely ocular manifestations (ocular myasthenia gravis [OMG]). Methods: We conducted a retrospective single-center cohort study of patients with OMG. Patients were included if their diagnosis was confirmed by acetylcholine receptor or muscle-specific kinase antibodies, abnormal electrophysiology, or a positive edrophonium test and at least 1 year of clinical follow-up. At each visit, the presence and severity of ocular and generalized symptoms was ascertained using a 4-point scale. Prednisone dose, steroid-sparing agent use, and need for intravenous immunoglobulin or plasmapheresis were recorded. The effect of thymectomy on time-weighted prednisone dose and symptom severity score was assessed using linear regression models. To adjust for nonrandomization of thymectomy, we used inverse probability weighting using a propensity score model derived from the prethymectomy observation period for thymectomy patients and a 6-month lead-in period for nonthymectomy patients that incorporated age, sex, acetylcholine receptor antibody seropositivity, disease severity (as defined by both symptom severity and treatment requirement), and treating physician preferences. Results: Eighty-two patients (30 with thymectomy and 52 nonthymectomy) were included. In unadjusted analyses, time-weighted daily prednisone dose was 2.9 mg higher with thymectomy compared with nonthymectomy (95% CI: 0.2–5.7), but after inverse probability weighting, this was no longer statistically significant (difference = 1.7 mg, 95% CI: −0.8 to 4.2). There was no statistically significant difference in symptom severity score (adjusted difference = 0.35, 95% CI: −0.02 to 0.72) or risk of generalization (P = 0.22). Conclusions: In this retrospective study that used statistical techniques to account for nonrandomization, no significant differences in prednisone dose or symptom severity after thymectomy in ocular myasthenia were demonstrated.

In 2016, a randomized controlled trial demonstrated the clinical efficacy of trans-sternal thymectomy for patients with non-thymomatous myasthenia gravis (MG). Whether large-scale changes occurred in clinical practice after this trial is unknown. We performed a retrospective longitudinal cross-sectional analysis using National Inpatient Sample (NIS) data from 2012 to 2019. Our study included hospitalized adults at least 18 years of age diagnosed with MG without an associated thymoma. We used joinpoint regression to analyze annual trends in thymectomy volume and surgical approach (minimally invasive vs trans-sternal) from 2012 to 2019. Using logistic regression models, we examined patient and hospital-level factors that may have influenced whether thymectomy was performed, such as age, sex, race, insurance payor, hospital size and teaching status, and Elixhauser Comorbidity Index. Sampling weights were applied to account for the complex survey design of NIS. The total number of thymectomy procedures increased by 69.8% per year (95% CI 40.1-105.8) between 2012 and 2019. Trans-sternal thymectomies increased by 62.8% per year (95% CI 35.8-95.2) and minimally invasive thymectomies by 83.7% per year (95% CI 38.1-144.3). Thymectomies were significantly more likely to occur in 2017-2019 compared with 2012-2016 (OR 1.93, 95% CI 1.62-2.31). In a multivariable regression model, several factors decreased the odds of patients with MG having a thymectomy: older age, Black race (OR 0.62, 95% CI 0.49-0.77), female (OR 0.73, 95% CI 0.63-0.86), and higher Elixhauser Comorbidity Index. Patients in medium (OR 1.82, 95% CI 1.30-2.55) or large (OR 2.81, 95% CI 2.07-3.82) size and urban teaching hospitals (OR 6.09, 95% CI 2.65-13.97) were more likely to undergo thymectomy. Thymectomy is being performed more frequently for non-thymomatous MG, especially after 2016 after publication of a positive phase III clinical trial. There are several disparities in thymectomy utilization that warrant further attention.

Recognition of radiologic lag, the presence of clinical symptoms despite absence of a visible corresponding lesion on MRI, is essential when evaluating a patient suspected to have a demyelinating disease. In this report, we present the case of a 16-year-old girl with bilateral internuclear ophthalmoplegias (INO), in whom initial high-resolution 3T MRI failed to reveal an abnormality within the brainstem. Repeat MRI performed 2 months later demonstrated a lesion in the paramedian midbrain tegmentum, corresponding to the anatomical localization of her clinical symptoms. This case aims to raise awareness that radiologic lag can occur in pediatric-onset multiple sclerosis, similarly to what has been described in other demyelinating conditions such as myelin oligodendrocyte glycoprotein antibody-associated disease. The absence of a visible lesion on imaging in the context of an acute INO does not exclude the possibility of underlying demyelination, and short-interval follow-up imaging should be considered in these patients to establish the correct diagnosis and guide additional investigations and treatment.

Background and ObjectivesObesity is a well-established risk factor for idiopathic intracranial hypertension (IIH), yet the metabolic mechanisms linking obesity to IIH remain poorly understood. Prev...