Primary CNS Melanoma

A 49-year-old female was referred to Neuro-Ophthalmology for evaluation of bilateral disc edema associated with headache. On initial presentation she was found to have a constricted visual field in her left eye and evidence an atrophic optic disc in the right eye and optic disc edema in the left eye. Evaluation with MRI showed no evidence of a mass lesion and lumbar puncture showed an elevated opening pressure leading to a presumed diagnosis of pseudotumor cerebral eye. The patient was started on treatment with an oral carbonic anhydrase inhibitor and encouraged to attempt weight loss. She was subsequently followed for 4 months with varying doses of oral carbonic anhydrase inhibitor and 62 having 15 lb of weight loss since her initial presentation, however she had no subsequent improvement of her optic disc edema. Two months later she developed new symptoms of nausea, vomiting, and difficulty with her gait which prompted a repeat MRI showing a leptomeningeal pattern of enhancement and nodularity throughout the basal cistern, cerebellum and bilateral temporal lobes with areas of abnormal enhancement in the basilar cisterns do demonstrate some increased signal on T1-weighted images without contrast. Repeat lumbar puncture again showed elevated opening pressure. These findings were concerning for a CNS melanoma and a MRI cervical/thorax/lumbar was performed showing an intrinsically T1 hyperintense, intramedullary mass centered at T2-T3 with larger intradural, extra-medullary component extending into the ventral CSF space of the upper thoracic spine suggestive of primary melanotic spinal cord melanoma. A laminectomy from C7 to T3 was performed and pathology revealed metastatic melanoma. A full dermatologic exam was performed revealing vision all sites consistent with melanoma, suggesting the diagnosis of a primary CNS melanoma. The patient was started on systemic chemotherapy per medical oncology and received 1 of fusion, unfortunately she had rapid decline in subsequently died 5 weeks after diagnosis. Primary CNS melanoma is uncommon and constitute approximately 1% of all melanoma cases and 0.07% of all brain tumors, median survival is generally only 10 weeks after there is leptomeningeal spread.https://scholarlycommons.henryford.com/merf2020caserpt/1075/thumbnail.jp

Optic nerve hypoplasia: Risk factors and epidemiology.

OBJECTIVES: To study the epidemiology of optic nerve hypoplasia. DESIGN AND METHODS: Children with optic nerve hypoplasia and visual impairment were identified through the Swedish Register of Visually Impaired Children. Pre- and perinatal characteristics were obtained from the Medical Birth Registry and by scrutinizing pregnancy and delivery records. Clinical characteristics of children with optic nerve hypoplasia are described. The following risk factors were studied: maternal age, parity, maternal smoking, gestational duration, birth weight, delivery method, Apgar score, maternal disease during pregnancy, drugs used in early pregnancy. RESULTS: Young maternal age, first parity, maternal smoking, preterm birth and factors associated with preterm birth were risk factors for optic nerve hypoplasia. There was an indicated association with the use of fertility drugs and antidepressant drugs. CONCLUSIONS: Optic nerve hypoplasia is apparently associated not only with other anomolies, notably of the central nervous system, but also with signs of general disturbance in fetal development

Afferents to the midbrain auditory center in the bullfrog, Rana catesbeiana

Horseradish peroxidase (HRP) histochemistry was used to visualize cells afferent to the bullfrog torus semicircularis. These afferent cells are located in several sensory and nonsensory nuclei. The sensory structures which project to the torus are mainly auditory nuclei, with the major input coming from the ipsilateral superior olive. A very small contralateral projection is also present. In addition, afferents arise from the contralateral, and to a lesser extent ipsilateral, dorsal acoustic nucleus and nucleus caudalis, both primary eighth nerve nuclei. A vestibular input is also apparent in that HRP-positive cells were seen in the magnocellular vestibular nucleus and among elongated bipolar cells at the ventral border of the eighth nerve nuclei. In addition, the torus receives somatosensory input from the contralateral perisolitary band. Afferents from spinal cord cells proved difficult to visualize. Nonsensory areas throughout the brain innervate the torus as well. In the medulla, HRP-positive cells were present bilaterally in both medial and lateral reticular areas. The tegmentum contributes a major input from the superficial isthmal reticular nucleus and a minor input from the tegmental fields. Commissural toral projections are also present. Descending forebrain input arises from the pretectal gray bilaterally, the ventral half of the ipsilateral lateral pretectal nucleus, and, possibly, from the ipsilateral posterior thalamic nucleus. HRP-positive cells were also occasionally seen in the posterior tuberculum, ventral hypothalamus, and caudal suprachiasmatic preoptic area. Finally, a telencephalic projection from the ipsilateral anterior entopeduncular nucleus is present.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50015/1/901980304_ftp.pd

Optic Neuropathy in Progressive Systemic Sclerosis (Scleroderma)

A 46 yr old white male complained of decreasing vision in his left eye of 6 days duration when he presented for neuro-ophthalmologic evaluation. The patient stated that he developed "a small gray cloud just below the horizontal" in the visual field of left eye and claimed that the deficit had been expanding for 6 days. He denied having any pain in either eye at rest or with eye movement. He also did not have headache, nausea, vertigodizziness, diplopia, weakness or numbness, loss of sphincter control or prior history oftransient visual loss. He was not photophobic

Osäkerhetsskattning för stråldospredicerande U-Nets

The ability to quantify uncertainties associated with neural network predictions is crucial when they are relied upon in decision-making processes, especially in safety-critical applications like radiation therapy. In this paper, a single-model estimator of both epistemic and aleatoric uncertainties in a regression 3D U-net used for radiation dose prediction is presented. To capture epistemic uncertainty, Monte Carlo Dropout is employed, leveraging dropout during test-time inference to obtain a distribution of predictions. The variability among these predictions is used to estimate the model’s epistemic uncertainty. For quantifying aleatoric uncertainty quantile regression, which models conditional quantiles of the output distribution, is used. The method enables the estimation of prediction intervals of a user-specified significance level, where the difference between the upper and lower bound of the interval quantifies the aleatoric uncertainty. The proposed approach is evaluated on two datasets of prostate and breast cancer patient geometries and corresponding radiation doses. Results demonstrate that the quantile regression method provides well-calibrated prediction intervals, allowing for reliable aleatoric uncertainty estimation. Furthermore, the epistemic uncertainty obtained through Monte Carlo Dropout proves effective in identifying out-of-distribution examples, highlighting its usefulness for detecting anomalous cases where the model makes uncertain predictions.Förmågan att kvantifiera osäkerheter i samband med neurala nätverksprediktioner är avgörande när de åberopas i beslutsprocesser, särskilt i säkerhetskritiska tillämpningar såsom strålterapi. I denna rapport presenteras en en-modellsimplementation för att uppskatta både epistemiska och aleatoriska osäkerheter i ett 3D regressions-U-net som används för att prediktera stråldos. För att fånga epistemisk osäkerhet används Monte Carlo Dropout, som utnyttjar dropout under testtidsinferens för att få en fördelning av prediktioner. Variabiliteten mellan dessa prediktioner används för att uppskatta modellens epistemiska osäkerhet. För att kvantifiera den aleatoriska osäkerheten används kvantilregression, eller quantile regression, som modellerar de betingade kvantilerna i outputfördelningen. Metoden möjliggör uppskattning av prediktionsintervall med en användardefinierad signifikansnivå, där skillnaden mellan intervallets övre och undre gräns kvantifierar den aleatoriska osäkerheten. Den föreslagna metoden utvärderas på två dataset innehållandes geometrier för prostata- och bröstcancerpatienter och korresponderande stråldoser. Resultaten visar på att kvantilregression ger välkalibrerade prediktionsintervall, vilket tillåter en tillförlitlig uppskattning av den aleatoriska osäkerheten. Dessutom visar sig den epistemiska osäkerhet som erhålls genom Monte Carlo Dropout vara användbar för att identifiera datapunkter som inte tillhör samma fördelning som träningsdatan, vilket belyser dess lämplighet för att upptäcka avvikande datapunkter där modellen gör osäkra prediktioner

Walsh & Hoyt: Eyelid Retraction

Inappropriate and excessive elevation of the eye lids-eyelid retraction-makes a patient appear to be staring and also produces an illusion of exophthalmos

Walsh & Hoyt: Anatomy of the Muscles of Eyelid Opening and Positioning

The principal muscle involved in opening the upper eyelid and in maintaining normal lid posture is the levator palpebrae superioris. Two accessory muscles of lid opening, Mullers muscle and the frontalis muscle, play only minor roles

Neuro-Ophthalmology Interview With Barry Skarf

Interview with Dr. Barry Skarf about his career in neuro-ophthalmology

Visual Outcome in Anterior Ischemic Optic Neuropathy

To evaluate the natural history of anterior ischemic optic neuropathy (AION) so as to determine the extent and rate of recovery of visual acuity. A retrospective review of the spontaneous changes in visual acuity as a function of time in a series of patients with non-arteritic AION