1. Articles in category: Neurology

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    1. Optical Coherence Tomography for Brain Imaging (Book Chapter)

      Optical Coherence Tomography for Brain Imaging (Book Chapter)

      Optical coherence tomography (OCT) is an imaging technique based on the detection of light back-reflected or backscattered by tissue. Based on the principles of low-coherence interferometry, OCT provides rapid volumetric imaging with micrometer-scale resolution. OCT has been massively successful in ophthalmology where it became a routine tool for retinal diagnostics. In recent years, however, OCT has also been applied to other fields including—amongst others—cardiovascular imaging, endoscopy of the gastrointestinal tract, and neuroimaging. In the brain and other neural tissues, OCT provides contrast for tissue microstructures and enables noninvasive in vivo and in vitro imaging with high resolution. Novel ...

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      Mentions: Bernhard Baumann
    2. Polarization-sensitive optical coherence tomography reveals gray matter and white matter atrophy in SCA1 mouse models

      Polarization-sensitive optical coherence tomography reveals gray matter and white matter atrophy in SCA1 mouse models

      Spinocerebellar ataxia type 1 (SCA1) is a fatal inherited neurodegenerative disease. In this study, we demonstrate the label-free optical imaging methodology that can detect, with a high degree of sensitivity, discrete areas of degeneration in the cerebellum of the SCA1 mouse models. We used ATXN1[82Q] and ATXN1[30Q]-D776 mice in which the transgene is directed only to Purkinje cells. Molecular layer, granular layer, and white matter regions are analyzed using the intrinsic contrasts provided by polarization-sensitive optical coherence tomography. Cerebellar atrophy in SCA1 mice occurred both in gray matter and white matter. While gray matter atrophy is obvious ...

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    3. Optic Disc Drusen in Children: The Copenhagen Child Cohort 2000 Eye Study

      Optic Disc Drusen in Children: The Copenhagen Child Cohort 2000 Eye Study

      Background: Optic disc drusen (ODD) are seen in up to 2.4% of the general population, but the etiology and pathophysiology of the condition is still unknown. The purpose of this study was to determine the prevalence of ODD in a population-based child cohort and to determine if scleral canal diameter and fetal birth and pubertal parameters are associated with the presence of ODD. Methods: This observational, longitudinal population-based birth cohort study, with a nested case–control, included 1,406 children. Eye examinations were performed when the children were between 11 and 12 years of age. Assessment was performed of ...

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    4. Evolution of Visual Outcomes in Clinical Trials for Multiple Sclerosis Disease-Modifying Therapies

      Evolution of Visual Outcomes in Clinical Trials for Multiple Sclerosis Disease-Modifying Therapies

      rom the Section Editor: In March 2018, the Journal of Neuro-Ophthalmology (JNO) launched its inaugural “Disease of the Year” section, featuring multiple sclerosis (MS). Beginning from a “Bench” perspective, Meltzner and colleagues presented an elegant overview of the pathogenic mechanisms believed to underpin central nervous system (CNS) injury in MS. To complement these efforts, Backner and Levin highlighted how the afferent visual pathway, as a putative model of CNS inflammation, can be interrogated with measures of structure and function to capture clinical and sub-clinical evidence disease activity in MS patients. Building on these concepts in this issue of the JNO ...

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    5. Extracting morphometric information from rat sciatic nerve using optical coherence tomography

      Extracting morphometric information from rat sciatic nerve using optical coherence tomography

      We apply three optical coherence tomography (OCT) image analysis techniques to extract morphometric information from OCT images obtained on peripheral nerves of rat. The accuracy of each technique is evaluated against histological measurements accurate to +/-1 µm. The three OCT techniques are: 1) average depth resolved profile (ADRP); 2) autoregressive spectral estimation (AR-SE); and, 3) correlation of the derivative spectral estimation (CoD-SE). We introduce a scanning window to the ADRP technique which provides transverse resolution, and improves epineurium thickness estimates - with the number of analysed images showing agreement with histology increasing from 2/10 to 5/10 (Kruskal-Wallis test, α = 0 ...

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    6. Dr. Steven Galetta Recognized For Lifetime Achievement in Neurologic Education

      Dr. Steven Galetta Recognized For Lifetime Achievement in Neurologic Education

      Steven L. Galetta , MD , the Philip K. Moskowitz, MD Professor and Chair of Neurology at NYU Langone Health, has been awarded the 2018 A.B. Baker Award for Lifetime Achievement in Neurological Education by the American Academy of Neurology for his career contributions to the field. Dr. Galetta received this prestigious honor on Monday, April 23 , during the 2018 American Academy of Neurology Annual Meeting in Los Angeles, California .

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    7. Imaging of cortical structures and microvasculature using extended-focus optical coherence tomography at 1.3  μm

      Imaging of cortical structures and microvasculature using extended-focus optical coherence tomography at 1.3  μm

      Extended-focus optical coherence tomography (xf-OCT) is a variant of optical coherence tomography (OCT) wherein the illumination and/or detection modes are engineered to provide a constant diffractionless lateral resolution over an extended depth of field (typically 3 to 10 × 10× the Rayleigh range). xf-OCT systems operating at 800 nm have been devised and used in the past to image brain structures at high-resolution in vivo , but are limited to ∼ 500    μm ∼500  μm in penetration depth due to their short illumination wavelength. Here we present an xf-OCT system optimized to an image deeper within the cortex by using a longer ...

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    8. Can Optical Coherence Tomography Be Used to Guide Treatment Decisions in Adult or Pediatric Multiple Sclerosis?

      Can Optical Coherence Tomography Be Used to Guide Treatment Decisions in Adult or Pediatric Multiple Sclerosis?

      Purpose of review With the recognition that neurodegeneration represents the principal substrate of disability in multiple sclerosis (MS), there has been increased strives towards identifying biomarkers for accurately quantifying and tracking neurodegeneration during the disease course. The retina provides an opportune “window” into the central nervous system (CNS) in MS, with retinal changes in MS reflecting not only local, but also global aspects of neurodegeneration and inflammation operative in the disease. Optical coherence tomography (OCT) is a rapid, inexpensive, reproducible, high-resolution imaging technique allowing accurate quantification of discrete retinal layers. OCT determined thinning of inner retinal layers such as the ...

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    9. Visualization of neuritic plaques in Alzheimer’s disease by polarization-sensitive optical coherence microscopy

      Visualization of neuritic plaques in Alzheimer’s disease by polarization-sensitive optical coherence microscopy

      One major hallmark of Alzheimer’s disease (AD) and cerebral amyloid angiopathy (CAA) is the deposition of extracellular senile plaques and vessel wall deposits composed of amyloid-beta (A β ). In AD, degeneration of neurons is preceded by the formation of A β plaques, which show different morphological forms. Most of them are birefringent owing to the parallel arrangement of amyloid fibrils. Here, we present polarization sensitive optical coherence microscopy (PS-OCM) for imaging mature neuritic A β plaques based on their birefringent properties. Formalin-fixed, post-mortem brain samples of advanced stage AD patients were investigated. In several cortical brain regions, neuritic A β plaques were successfully ...

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    10. In vivo high-resolution cortical imaging with extended-focus optical coherence microscopy in the visible-NIR wavelength range

      In vivo high-resolution cortical imaging with extended-focus optical coherence microscopy in the visible-NIR wavelength range

      Visible light optical coherence tomography has shown great interest in recent years for spectroscopic and high-resolution retinal and cerebral imaging. Here, we present an extended-focus optical coherence microscopy system operating from the visible to the near-infrared wavelength range for high axial and lateral resolution imaging of cortical structures in vivo . The system exploits an ultrabroad illumination spectrum centered in the visible wavelength range (λ c   =  650  nm, Δλ  ∼  250  nm) offering a submicron axial resolution (∼0.85  μm in water) and an extended-focus configuration providing a high lateral resolution of ∼1.4  μm maintained over ∼150  μm in depth in water. The ...

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    11. Optic Nerve Head Parameters Measured with Spectral-Domain Optical Coherence Tomography in Healthy Turkish Children: Normal Values, Repeatability, and Interocular Symmetry

      Optic Nerve Head Parameters Measured with Spectral-Domain Optical Coherence Tomography in Healthy Turkish Children: Normal Values, Repeatability, and Interocular Symmetry

      To determine normal values, repeatability, and interocular symmetry of optic nerve head measurements, three spectral-domain optical coherence tomography (SD-OCT) scans were obtained from 128 healthy Turkish children aged 5–17 years consecutively and prospectively. The mean disc area, rim area, cup volume, cup to disc area ratio, and vertical and horizontal cup to disc ratios were 2.30 ± 0.42 mm 2 , 1.84 ± 0.45 mm 2 , 0.09 ± 0.10 mm 3 , 0.20 ± 0.13, 0.37 ± 0.17, and 0.45 ± 0.20, respectively. The intraclass correlation coefficients were >0.9 for repeatability and >0.75 ...

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    12. White matter atrophy in spinocerebellar ataxia type 1 mouse models revealed by serial optical coherence scanner

      White matter atrophy in spinocerebellar ataxia type 1 mouse models revealed by serial optical coherence scanner

      Spinocerebellar ataxia type 1 (SCA1) is a fatal inherited neurodegenerative disease. Post-mortem studies showed neurodegeneration involving white matter components in the cerebral lobes, the cerebellar peduncles and the more distal cranial nerves in human patients. However, the progression of SCA1 in the brain remains unclear. We present the study of white matter atrophy of SCA1 mouse models using serial optical coherence scanner (SOCS). SOCS consists of a polarization sensitive optical coherence tomography and a tissue slicer (vibratome) with associated controls for serial imaging. The optical system has 5.5 µm axial resolution and utilizes a scan lens or a water-immersion ...

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    13. Multicenter reliability of semiautomatic retinal layer segmentation using OCT

      Multicenter reliability of semiautomatic retinal layer segmentation using OCT

      Objective To evaluate the inter-rater reliability of semiautomated segmentation of spectral domain optical coherence tomography (OCT) macular volume scans. Methods Macular OCT volume scans of left eyes from 17 subjects (8 patients with MS and 9 healthy controls) were automatically segmented by Heidelberg Eye Explorer (v1.9.3.0) beta-software (Spectralis Viewing Module v6.0.0.7), followed by manual correction by 5 experienced operators from 5 different academic centers. The mean thicknesses within a 6-mm area around the fovea were computed for the retinal nerve fiber layer, ganglion cell layer (GCL), inner plexiform layer (IPL), inner nuclear layer, outer ...

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    14. Optical coherence tomography in autosomal recessive spastic ataxia of Charlevoix-Saguenay

      Optical coherence tomography in autosomal recessive spastic ataxia of Charlevoix-Saguenay

      Autosomal recessive spastic ataxia of Charlevoix-Saguenay is a rare neurodegenerative disorder caused by mutations in the SACS gene. Thickened retinal nerve fibres visible on fundoscopy have previously been described in these patients; however, thickening of the retinal nerve fibre layer as demonstrated by optical coherence tomography appears to be a more sensitive and specific feature. To test this observation, we assessed 292 individuals (191 patients with ataxia and 101 control subjects) by peripapillary time-domain optical coherence tomography. The patients included 146 with a genetic diagnosis of ataxia (17 autosomal spastic ataxia of Charlevoix-Saguenay, 59 Friedreich’s ataxia, 53 spinocerebellar ataxias ...

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    15. Optical Coherence Tomography versus Visual Evoked Potentials for Detecting Visual Pathway Abnormalities in Patients with Neuromyelitis Optica Spectrum Disorder

      Optical Coherence Tomography versus Visual Evoked Potentials for Detecting Visual Pathway Abnormalities in Patients with Neuromyelitis Optica Spectrum Disorder

      Background and Purpose Optical coherence tomography (OCT) and visual evoked potentials (VEPs) can be used to detect optic neuritis (ON). However, the comparative sensitivities of OCT and VEPs for detecting ON in neuromyelitis optica spectrum disorder (NMOSD) are unclear, and so we assessed these sensitivities. Methods This cross-sectional study included 73 patients with aquaporin-4 antibody-seropositive NMOSD, and 101 eyes with ON. The clinical characteristics, visual acuity (VA), Expanded Disability Status Scale (EDSS) scores, OCT peripapillary retinal nerve fiber layer (RNFL) thickness, and VEPs of the patients were evaluated. Results OCT and VEPs were abnormal in 68% and 73% of eyes ...

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    16. A pilot study assessing retinal pathology in psychosis using optical coherence tomography: choroidal and macular thickness

      A pilot study assessing retinal pathology in psychosis using optical coherence tomography: choroidal and macular thickness

      Mounting evidence supports a genetic-vascular-inflammatory etiology of schizophrenia. The retina provides an indirect assessment of inflammation and degeneration in the brain. In particular, the use of spectral domain optical coherence tomography (SD-OCT) has emerged as a powerful tool for examining single retinal nerve cell layers and the choroid, the vascular layer supplying the outer retina. In this study, choroidal and macular thicknesses were measured in six patients with psychosis with either schizophrenia or bipolar disorder, and in 18 age- and sex-matched healthy controls. Mean choroidal thickness was reduced in psychosis, though not significantly so. There was a statistically significant decrease ...

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    17. Brain tissue analysis using texture features based on optical coherence tomography images

      Brain tissue analysis using texture features based on optical coherence tomography images

      Brain tissue differentiation is highly demanded in neurosurgeries, i.e. tumor resection. Exact navigation during the surgery is essential in order to guarantee best life quality afterwards. So far, no suitable method has been found that perfectly covers this demands. With optical coherence tomography (OCT), fast three dimensional images can be obtained in vivo and contactless with a resolution of 1-15 μm. With these specifications OCT is a promising tool to support neurosurgeries. Here, we investigate ex vivo samples of meningioma, healthy white and healthy gray matter in a preliminary study towards in vivo brain tumor removal assistance. Raw OCT ...

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    18. In Vivo Fascicle Bifurcation Imaging of Rat Sciatic Nerve Using Swept-Source Optical Coherence Tomography

      In Vivo Fascicle Bifurcation Imaging of Rat Sciatic Nerve Using Swept-Source Optical Coherence Tomography

      The sciatic nerve is the longest and widest single nerve in the human body and is responsible for the signal transduction of the entire hind limb region. Its wide nerve dynamic range and size makes it sensitive to injury. The branching and location of the sciatic nerve are important, and unlike histology, optical coherence tomography (OCT) can provide rapid non-destructive cross-sectional images. The sciatic nerves of ten rats were analyzed using swept-source (SS)-OCT. The sufficient depth penetration of the SS-OCT system allowed clear identification of the internal bifurcation point of the external branching and the internal route for the ...

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    19. Automated differentiation between meningioma and healthy brain tissue based on optical coherence tomography ex vivo images using texture features

      Automated differentiation between meningioma and healthy brain tissue based on optical coherence tomography ex vivo images using texture features

      Brain tissue analysis is highly desired in neurosurgery, such as tumor resection. To guarantee best life quality afterward, exact navigation within the brain during the surgery is essential. So far, no method has been established that perfectly fulfills this need. Optical coherence tomography (OCT) is a promising three-dimensional imaging tool to support neurosurgical resections. We perform a preliminary study toward in vivo brain tumor removal assistance by investigating meningioma, healthy white, and healthy gray matter. For that purpose, we utilized a commercially available OCT device (Thorlabs Callisto) and measured eight samples of meningioma, three samples of healthy white, and two ...

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    20. Retinal signs and 20-year cognitive decline in the Atherosclerosis Risk in Communities Study

      Retinal signs and 20-year cognitive decline in the Atherosclerosis Risk in Communities Study

      Objective To test the hypothesis that retinal vascular signs are associated with greater cognitive decline over 20 years in 12,317 men and women 50 to 73 years of age at baseline. Methods A composite cognitive score was created with 3 neuropsychological tests measured at 3 time points (1990–1992 to 2011–2013). Retinal signs were measured with fundus photography (1993–1995). Differences in cognitive change by retinal signs status were estimated with linear mixed models. Cognitive scores were imputed for living participants with incomplete cognitive testing. Results In multivariable-adjusted analyses that controlled for attrition, loss of vascular integrity (retinopathy ...

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    21. Optic Nerve Head and Macular Optical Coherence Tomography Measurements in Papilledema Compared With Pseudopapilledema

      Optic Nerve Head and Macular Optical Coherence Tomography Measurements in Papilledema Compared With Pseudopapilledema

      Background: To compare macular and optic nerve head optical coherence tomography (OCT) measurements in mild to moderate papilledema and pseudopapilledema. Methods: One hundred nineteen eyes of 61 patients with mild to moderate papilledema, 84 eyes of 48 patients with pseudopapilledema, and 60 eyes of 60 healthy normal individuals were enrolled in this cross-sectional study. Using Spectralis SD-OCT, macular scans with macular ganglion cell–inner plexiform layer (GCIPL) and macular retinal nerve fiber layer (RNFL) segmentation were performed and divided into 2 regions (inner and outer, with a diameter of 3 and 6 mm, respectively); in addition, Bruch membrane opening (BMO ...

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