Myelin-associated glycoprotein gene mutation causes Pelizaeus-Merzbacher disease-like disorder

Pelizaeus-Merzbacher disease is an X-linked hypomyelinating leukodystrophy. Lossos et al. describe a family with an early-onset Pelizaeus-Merzbacher disease-like phenotype that slowly evolves into complicated hereditary spastic paraplegia, affecting both the CNS and PNS. Exome sequencing reveals a causative homozygous missense mutation in MAG, which encodes myelin associated glycoprotei

Granular Cell Tumor of the Pituitary Stalk Presenting as Optic Neuropathy

Symptomatic granular cell tumors of the pituitary stalk are rare tumors. They comprise less than 0.1% of primary brain tumors. The presenting symptoms include insidious but progressive development of headache, bitemporal visual field defects, reduced visual acuity and pituitary insufficiency

Ocular Toxicity Induced by High-Dose Tamoxifen

To assess ocular toxicity of high-dose tamoxifen, a synthetic nonsteroidal antiestrogen drug currently used in high doses for glioblastoma

Seven Recurrent Palsies of a Sixth Nerve

We describe a patient in whom seven recurrent, self-limited, episodes of isolated ipsilateral abducens nerve palsy were related to tortuous ectasia (dolichoectasia) of the internal carotid artery. A previously healthy 59-year-old man presented with a history of seven episodes of painless horizontal diplopia in the last four years

Eye Problems and Dysproteinemia in Two Patients

Red eyes; DiplopiaCase 1: A 49-year old male red eyes. Case 2: A 59-year old female with double vision and left upper lid ptosis.N/ACTCase 1. Skin biopsy, face. The dermis 1s diffusely Infiltrated by sheets of histiocytic cells which occupy the majority of the dermis. Case 2. Biopsy, right temporal fossa. The connective tissue 1s largely replaced by an Infiltrate of mononuclear histiocytic cells, foreign body and Touton giant oells.N/A1. Kossard S, Wlnkelmann RK: Necrobiotic xanthogranulcma with paraproteinemia. J Am Acad Dermatol 1980;3:257-270. 2. Oodere F, Lee RD and Anderson RL: Necrobiotic xanthogranulcma of the eyelid. Arch Ophthalmol 1983; 101:60-63. 3. Robertson DM, Wlnkelmann RK: Ophthalmic features of necnobiotic xanthogranulcma with paraprotelnonia. An J Ophthalmol 1984;97:173-183. 4. Finan MC, Wlnkelmann RK: Necrobiotic xanthogranulcma with paraproteinemia - A review of 22 cases. Msdicine 1986; 65 676-388

Top-Down Engagement Modulates the Neural Expressions of Visual Expertise

Perceptual expertise is traditionally associated with enhanced brain activity in response to objects of expertise in category-selective visual cortex, primarily face-selective regions. We reevaluated this view by investigating whether the brain activity associated with expertise in object recognition is limited to category-selective cortex and specifically whether the extent of expertise-related activity manifests automatically or whether it can be top-down modulated. We conducted 2 functional magnetic resonance imaging studies comparing changes in hemodynamic activity associated with car expertise in a conventional 1-back task (Experiment 1) and when the task relevance of cars was explicitly manipulated (Experiment 2). Whole-brain analysis unveiled extensive expertise-related activity throughout the visual cortex, starting as early as V1 and extending into nonvisual areas. However, when the cars were task irrelevant, the expertise-related activity drastically diminished, indeed, becoming similar to the activity elicited by cars in novices. We suggest that expertise entails voluntary top-down engagement of multiple neural networks in addition to stimulus-driven activation associated with perceptual mechanisms

Optic Neuritis After Refractive Surgery

"Although the number of laser-assisted in situ keratomileusis (LASIK) and photorefractive keratectomy (PRK) procedures performed is growing steadily, there are no reports in the literature on associated optic neuritis.

Isolated foveal hypoplasia.

Fifteen patients presented with foveal hypoplasia as an isolated ocular finding. The characteristic findings associated with this entity are a visual acuity of 6/21 or worse, nystagmus, and a typical ophthalmoscopic appearance of the macular area, including absent or abnormal maculofoveal reflexes, unclear definition of the maculofoveal area, and capillaries running abnormally close to the presumed macular area, some of them even crossing the horizontal meridian. Fluorescein angiography revealed a variable and incomplete filtering effect of the choroidal fluorescence in the macular area, suggesting abnormalities in the amount and distribution of macular pigments. The fundal findings of isolated foveal hypoplasia, although typical, are very subtle and often difficult to detect, especially because of the accompanying nystagmus. For this reason we suspect that foveal hypoplasia may be more common than is generally believed