Is the frequency of abnormalities on magnetic resonance imaging in isolated optic neuritis related to the prevalence of multiple sclerosis? A global comparison.

The link between optic neuritis and multiple sclerosis is well established, as is the increased risk of conversion to multiple sclerosis, with lesions seen at presentation on the magnetic resonance imaging (MRI) scan of the brain. One or more asymptomatic lesions were present in 77% of the optic neuritis cohort from London, UK, a higher proportion than that reported in other large cohorts studied elsewhere, where generally lower prevalence rates for multiple sclerosis are also reported. These observations may support the hypothesis that optic neuritis is more likely to be associated with abnormalities on MRI and to be due to multiple sclerosis in geographical regions where multiple sclerosis is more common.

Quantification of optic nerve head topography in optic neuritis: a pilot study.

Aims: To investigate optic nerve head topography in patients with optic neuritis compared to controls using the Heidelberg retina tomograph-II (HRT-II) and to determine if detected changes are related to visual function and electrophysiology.

Methods: 25 patients with a previous single episode of unilateral optic neuritis and 15 controls were studied with HRT-II, visual evoked potentials, and pattern electroretinogram. Patients also had testing of visual acuity, visual field, and colour vision.

Causes and outcomes for patients presenting with diplopia to an eye casualty department.

Purpose: To evaluate the causes and outcomes for patients presenting with diplopia to an eye casualty department.

Methods: Patients presenting with diplopia as a principal symptom, who were referred to the Orthoptic Department from Moorfields Eye Casualty over a 12-month period, were retrospectively investigated.

Results: One hundred and seventy-one patients were identified with complete records in 165 cases.

AAV-mediated expression of CNTF promotes long-term survival and regeneration of adult rat retinal ganglion cells.

We compared the effects of intravitreal injection of bi-cistronic adeno-associated viral (AAV-2) vectors encoding enhanced green fluorescent protein (GFP) and either ciliary neurotrophic factor (CNTF), brain-derived neurotrophic factor (BDNF) or growth-associated protein-43 (GAP43) on adult retinal ganglion cell (RGC) survival and regeneration following (i) optic nerve (ON) crush or (ii) after ON cut and attachment of a peripheral nerve (PN). At 7 weeks after ON crush, quantification of betaIII-tubulin immunostaining revealed that, compared to AAV-GFP controls, RGC survival was not enhanced by AAV-GAP43-GFP but was increased in AAV-CNTF-GFP (mean RGCs/retina: 17 450+/-358 s.e.

Clinical disorders affecting mesopic vision.

Vision in the mesopic range is affected by a number of inherited and acquired clinical disorders. We review these conditions and summarize the historical background, describing the clinical characteristics alongside the genetic basis and molecular biological mechanisms giving rise to rod and cone dysfunction relevant to twilight vision. The current diagnostic gold standards for each disease are discussed and curative and symptomatic treatment strategies are summarized.

Olfactory ensheathing cells: characteristics, genetic engineering, and therapeutic potential.

Injured neurons in the mammalian central nervous system (CNS) do not normally regenerate their axons after injury. Neurotrauma to the CNS usually results in axonal damage and subsequent loss of communication between neuronal networks, causing long-term functional deficits. For CNS regeneration, repair strategies need to be developed that promote regrowth of lesioned axon projections and restoration of neuronal connectivity.

Genetic alterations of the BRI2 gene: familial British and Danish dementias.

Classic arguments sustaining the importance of amyloid in the pathogenesis of dementia are usually centered on amyloid beta (Abeta) and its role in neuronal loss characteristic of Alzheimer disease, the most common form of human cerebral amyloidosis. Two non-Abeta cerebral amyloidoses, familial British and Danish dementias, share many aspects of Alzheimer disease, including the presence of neurofibrillary tangles, parenchymal pre-amyloid and amyloid deposits, cerebral amyloid angiopathy, and a widespread inflammatory response. Both early-onset conditions are linked to specific mutations in the BRI2 gene, causing the generation of longer-than-normal protein products and the release of 2 de novo created peptides ABri and ADan, the main components of amyloid fibrils in these inherited dementias.

Form completion across a hemianopic boundary: behindsight?

Patients with homonymous hemianopia may report the completion of forms that overlap the vertical meridian of their field defects. While previous investigations of "hemianopic completion" have variously attributed to the disorder to inattention, residual vision or unstable fixation, we believe that our investigation has controlled for such potentially confounding factors. We report patient P.

Ventricular enlargement in MS: one-year change at various stages of disease.

Objectives: To investigate ventricular enlargement (VE) over 1 year at three different stages of multiple sclerosis (MS).

Methods: A semi-automated technique for measuring VE was applied to MRI scans in 26 patients with clinically isolated syndromes (CIS) suggestive of MS, 30 with early relapse-onset MS of 1 year duration, 41 with established relapsing remitting (RR) MS, and 23 with secondary progressive (SP) MS.

Results: VE at 1 year was seen in early MS (median increase 0.

Optic nerve atrophy and retinal nerve fibre layer thinning following optic neuritis: evidence that axonal loss is a substrate of MRI-detected atrophy.

Magnetic resonance imaging (MRI) measures of brain atrophy are often considered to be a marker of axonal loss in multiple sclerosis (MS) but evidence is limited. Optic neuritis is a common manifestation of MS and results in optic nerve atrophy. Retinal nerve fibre layer (RNFL) imaging is a non-invasive way of detecting axonal loss following optic neuritis.

Adult olfactory ensheathing glia promote the long-distance growth of adult retinal ganglion cell neurites in vitro.

In vivo, transplanted adult olfactory ensheathing glia (OEG) and adult Schwann cells (SC) can support the regrowth of at least some transected axons within adult CNS neuropil. In the present study, we developed an in vitro adult rat retinal explant model to explore the influence of primary adult SC and OEG on retinal ganglion cell (RGC) neurite regrowth in the presence of glial cells endogenous to the retina. Retinal quadrants were plated RGC-side down onto aclar hats coated with either pure collagen (type 1), collagen with OEG, collagen with SCs, or collagen coated with both OEG and SCs.

Optic nerve diffusion tensor imaging in optic neuritis.

Diffusion tensor magnetic resonance imaging (DT-MRI) provides in vivo information about the pathology of multiple sclerosis lesions. Increases in mean diffusivity (MD) and reductions in fractional anisotropy (FA) have been found and may represent axonal disruption. The optic nerve is an ideal structure for study by DT-MRI but previous clinical studies did not obtain the full diffusion tensor necessary to calculate MD and FA.

Optical coherence tomography (OCT) findings in congenital/long-standing homonymous hemianopia.

Purpose: To report abnormalities of retinal nerve fiber layer (RNFL) thickness using optical coherence tomography (OCT) in patients with trans-synaptic degeneration.

Design: Observational case reports.

Methods: Two patients with congenital/long standing occipital lobe lesions who had asymptomatic homonymous hemianopic field defects were examined using OCT.

Magnetization transfer histograms in clinically isolated syndromes suggestive of multiple sclerosis.

In established multiple sclerosis, magnetization transfer ratio (MTR) histograms reveal abnormalities of normal-appearing white matter (NAWM) and grey matter (NAGM). The aim of this study was to investigate for such abnormalities in a large cohort of patients presenting with clinically isolated syndromes suggestive of multiple sclerosis. Magnetization transfer imaging was performed on 100 patients (67 women, 33 men, median age 32 years) a mean of 19 weeks (SD 3.

ALK positive inflammatory myofibroblastic tumour of the pineal region.

Inflammatory myofibroblastic tumours (IMTs) are an uncommon spindle cell neoplasm with a dense inflammatory infiltrate, usually encountered in children. IMTs of the central nervous system are extremely rare. This report describes the case of an IMT in a 61 year old man, in the pineal region.

Familial Danish dementia: co-existence of Danish and Alzheimer amyloid subunits (ADan AND A{beta}) in the absence of compact plaques.

Familial Danish dementia is an early onset autosomal dominant neurodegenerative disorder linked to a genetic defect in the BRI2 gene and clinically characterized by dementia and ataxia. Cerebral amyloid and preamyloid deposits of two unrelated molecules (Danish amyloid (ADan) and beta-amyloid (Abeta)), the absence of compact plaques, and neurofibrillary degeneration indistinguishable from that observed in Alzheimer disease (AD) are the main neuropathological features of the disease. Biochemical analysis of extracted amyloid and preamyloid species indicates that as the solubility of the deposits decreases, the heterogeneity and complexity of the extracted peptides exponentially increase.

Central and paracentral visual field defects and driving abilities.

The effect of central and paracentral visual field defects on driving abilities has until now received little attention. To date studies and surveys have concentrated on visual acuity and peripheral field loss. Here we summarise for the first time those diseases causing central visual field defects likely to be associated with binocular visual acuity adequate for driving.

Retinal nerve fiber layer axonal loss and visual dysfunction in optic neuritis.

Axonal loss is thought to be a likely cause of persistent disability after a multiple sclerosis relapse; therefore, noninvasive in vivo markers specific for axonal loss are needed. We used optic neuritis as a model of multiple sclerosis relapse to quantify axonal loss of the retinal nerve fiber layer (RNFL) and secondary retinal ganglion cell loss in the macula with optical coherence tomography. We studied 25 patients who had a previous single episode of optic neuritis with a recruitment bias to those with incomplete recovery and 15 control subjects.

Modification of MRI criteria for multiple sclerosis in patients with clinically isolated syndromes.

Background: The McDonald criteria include MRI evidence for dissemination in space and dissemination in time for the diagnosis of multiple sclerosis in young adult patients who present with clinically isolated syndromes (CIS) typical of the disease. Although a major advance, the criteria have limited sensitivity for making an early diagnosis.

Objective: To compare the performance of McDonald criteria and modified McDonald criteria for dissemination in space and time for assessing the development of clinically definite multiple sclerosis.

Optic flow induced nystagmus.

A new form of nystagmus is described in this paper: optic flow induced nystagmus (OFN). Optic field flow, for example when driving or viewing films on a large screen, triggered non-fatiguable upbeat nystagmus. This type of nystagmus could not be induced by vestibular stimuli, positioning, or self motion.