1. Articles in category: Neurology

    1-24 of 367 1 2 3 4 ... 14 15 16 »
    1. A systematic review and meta-analysis of retinal nerve fiber layer change in dementia, using optical coherence tomography

      A systematic review and meta-analysis of retinal nerve fiber layer change in dementia, using optical coherence tomography

      Introduction Retinal nerve fiber layer (RNFL) thinning, assessed by optical coherence tomography (OCT), has recently been reported in various dementias. Methods We conducted a systematic review and meta-analysis to investigate the diagnostic utility of RNFL thickness measurement using OCT in dementia (including Alzheimer's disease [AD] and mild cognitive impairment [MCI]) compared with healthy controls (HC). Results Seventeen studies comparing AD with HC (702 AD eyes and 790 HC eyes) were included, demonstrating a significant reduction in mean RNFL thickness in AD (weighted mean difference [WMD] 12.44, 95% confidence interval or CI [−16.64, −8.25], P <.0001). Five ...

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    2. Localization of cortical tissue optical changes during seizure activity in vivo with optical coherence tomography

      Localization of cortical tissue optical changes during seizure activity in vivo with optical coherence tomography

      Optical coherence tomography (OCT) is a high resolution, minimally invasive imaging technique, which can produce depth-resolved cross-sectional images. In this study, OCT was used to detect changes in the optical properties of cortical tissue in vivo in mice during the induction of global (pentylenetetrazol) and focal (4-aminopyridine) seizures. Through the use of a confidence interval statistical method on depth-resolved volumes of attenuation coefficient, we demonstrated localization of regions exhibiting both significant positive and negative changes in attenuation coefficient, as well as differentiating between global and focal seizure propagation.

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    3. Boston University Receives NIH Grant for Visualizing Cortical Microstructures by Optical Coherence Tomography

      Boston University Receives NIH Grant for Visualizing Cortical Microstructures by Optical Coherence Tomography

      Boston University Receives a 2015 NIH Grant for $259,490 for Visualizing Cortical Microstructures by Optical Coherence Tomography. The principal investigator is Katehleen Rockland. The program began in 2015 and ends in 2017. Below is a summary of the propose work.

      Area-specific differences in microstructure and cell-type distribution are well-established across cortical regions in the human brain; and specific morphological changes have been identified in different disease conditions, such as cortical thinning or, at a finer level of resolution, changes in specific pyramidal or non-pyramidal cell populations. These data, however, are based on relatively small sample sizes and can be ...

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    4. Retinal nerve fiber layer and macular thinning in systemic lupus erythematosus: an optical coherence tomography study comparing SLE and neuropsychiatric SLE

      Retinal nerve fiber layer and macular thinning in systemic lupus erythematosus: an optical coherence tomography study comparing SLE and neuropsychiatric SLE

      Objective Due to the lack of reliable biomarkers in diagnosing and monitoring neuropsychiatric systemic lupus erythematosus (NPSLE), the aim of this study was to examine the utility of measurements obtained through spectral domain optical coherence tomography (SD-OCT) as a biomarker for NP involvement in SLE. Methods Retinal nerve fiber layer (RNFL) and macula scans were performed using SD-OCT on 15 NPSLE patients, 16 SLE patients without NP symptoms (non-NP SLE), and 16 healthy controls. Macular volume and thickness of the central macula and peripapillary RNFL were compared between the groups and to scores on two validated cognitive tests. Results NPSLE ...

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    5. University of Texas, Austin Receives NIH Grant for Optical Imaging of Baseline Blood Flow and Oxygenation During Stroke

      University of Texas, Austin Receives NIH Grant for Optical Imaging of Baseline Blood Flow and Oxygenation During Stroke

      University of Texas, Austin Receives a 2015 NIH Grant for $465,127 for Optcial Imaging of Baseline Blood Flow and Oxygenation During Stroke. The principal investigator is Andrew Dunn. The program began in 2010 and ends in 2019. Below is a summary of the proposed work. Quantitative imaging of cerebral blood flow is essential in preclinical stroke studies for monitoring the efficacy of potential treatments and for understanding the role of vascular reorganization in functional recovery. Similarly, real-time imaging of blood flow is crucial during neurovascular surgery in humans, where intraoperative visualization of vascular patency and tissue perfusion are needed ...

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    6. OCT: New perspectives in neuro-ophthalmology

      OCT: New perspectives in neuro-ophthalmology

      Optical coherence tomography (OCT) has become essential to evaluate axonal/neuronal integrity, to assess disease progression in the afferent visual pathway and to predict visual recovery after surgery in compressive optic neuropathies. Besides that OCT testing is considered a powerful biomarker of neurodegeneration and a promising outcome measure for neuroprotective trials in multiple sclerosis (MS). Currently, spectral-domain OCT (SD-OCT) technology allows quantification of retinal individual layers. The Ganglion Cell layer (GCL) investigation has become one of the most useful tools from a neuro-ophthalmic perspective. It has a high correlation with perimetry, is predictive of future progression and is a highly ...

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    7. In vivo optical microscopy of peripheral nerve myelination with polarization sensitive-optical coherence tomography

      In vivo optical microscopy of peripheral nerve myelination with polarization sensitive-optical coherence tomography

      Assessing nerve integrity and myelination after injury is necessary to provide insight for treatment strategies aimed at restoring neuromuscular function. Currently, this is largely done with electrical analysis, which lacks direct quantitative information. In vivo optical imaging with sufficient imaging depth and resolution could be used to assess the nerve microarchitecture. In this study, we examine the use of polarization sensitive-optical coherence tomography (PS-OCT) to quantitatively assess the sciatic nerve microenvironment through measurements of birefringence after applying a nerve crush injury in a rat model. Initial loss of function and subsequent recovery were demonstrated by calculating the sciatic function index ...

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    8. Cadaveric in-situ testing of optical coherence tomography system-based skull base surgery guidance

      Cadaveric in-situ testing of optical coherence tomography system-based skull base surgery guidance

      Optical Coherence Tomography (OCT) has extensive potential for producing clinical impact in the field of neurological diseases. A neurosurgical OCT hand-held forward viewing probe in Bayonet shape has been developed. In this study, we test the feasibility of integrating this imaging probe with modern navigation technology for guidance and monitoring of skull base surgery. Cadaver heads were used to simulate relevant surgical approaches for treatment of sellar, parasellar and skull base pathology. A high-resolution 3D CT scan was performed on the cadaver head to provide baseline data for navigation. The cadaver head was mounted on existing 3- or 4-point fixation ...

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    9. A comparative optical coherence tomography study in neuromyelitis optica spectrum disorder and multiple sclerosis

      A comparative optical coherence tomography study in neuromyelitis optica spectrum disorder and multiple sclerosis

      Objectives: The aim of this study was to find, using spectral domain-optical coherence tomography (SD-OCT), retinal imaging biomarkers differentiating neuromyelitis optica spectrum disorder (NMOSD), multiple sclerosis (MS) and healthy controls (HCs). Materials and methods: The population was composed of patients with NMOSD ( n =23) or MS ( n =110) and of HCs ( n =75). Evaluation criteria were retinal thickness/volume, visual acuity, low contrast vision acuity and Expanded Disability Status Scale score. Results: Considering all eyes and after statistical adjustments including the number of optic neuritis (ON) episodes, we found that NMOSD patients did not have significantly more retinal atrophy than ...

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    10. Optical Coherence Tomography Opens a New Era in the Afferent Visual System Evaluation

      Optical Coherence Tomography Opens a New Era in the Afferent Visual System Evaluation

      For decades, thinning of the retinal nerve fiber layer in optic neuropathy could only be observed ophthalmoscopically or using red-free fundus photography. These days are over. Subsequently, different techniques to image the optic nerve and the retina have been developed. Optical coherence tomography (OCT) has gained the most attention and has opened a new area of revolutionary diagnostic possibilities. OCT is a noncontact diagnostic imaging technique that provides detailed, cross-sectional images of the retina and the optic disc in vivo. It was first used in 1991 to visualize the eye.[ 1 ] Image capture is noninvasive, painless, and fast. The technology ...

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    11. Applications of Optical Coherence Tomography in Pediatric Clinical Neuroscience

      Applications of Optical Coherence Tomography in Pediatric Clinical Neuroscience

      For nearly two centuries, the ophthalmoscope has permitted examination of the retina and optic nerve—the only axons directly visualized by the physician. The retinal ganglion cells project their axons, which travel along the innermost retina to form the optic nerve, marking the beginning of the anterior visual pathway. Both the structure and function of the visual pathway are essential components of the neurologic examination as it can be involved in numerous acquired, congenital and genetic central nervous system conditions. The development of optical coherence tomography now permits the pediatric neuroscientist to visualize and quantify the optic nerve and retinal ...

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    12. Measuring the optical characteristics of medulloblastoma with optical coherence tomography

      Measuring the optical characteristics of medulloblastoma with optical coherence tomography

      Medulloblastoma is the most common malignant pediatric brain tumor. Standard treatment consists of surgical resection, followed by radiation and high-dose chemotherapy. Despite these efforts, recurrence is common, leading to reduced patient survival. Even with successful treatment, there are often severe long-term neurologic impacts on the developing nervous system. We present two quantitative techniques that use a high-resolution optical imaging modality: optical coherence tomography (OCT) to measure refractive index, and the optical attenuation coefficient. To the best of our knowledge, this study is the first to demonstrate OCT analysis of medulloblastoma. Refractive index and optical attenuation coefficient were able to differentiate ...

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    13. Assessment of ultra-high resolution optical coherence tomography for monitoring tissue effects caused by laser photocoagulation of ex-vivo porcine retina

      Assessment of ultra-high resolution optical coherence tomography for monitoring tissue effects caused by laser photocoagulation of ex-vivo porcine retina

      Retinal laser photocoagulation is an established and successful treatment for a variety of retinal diseases. While being a valuable treatment modality, laser photocoagulation shows the drawback of employing high energy lasers which are capable of physically destroying the neural retina. For reliable therapy, it is therefore crucial to closely monitor the therapy effects caused in the retinal tissue. A depth resolved representation of optical tissue properties as provided by optical coherence tomography may provide valuable information about the treatment effects in the retinal layers if recorded simultaneously to laser coagulation. Therefore, in this work, the use of ultra-high resolution optical ...

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    14. Investigating the correlation between white matter and microvasculature changes in aging using large scale optical coherence tomography and confocal fluorescence imaging combined with tissue sectioning

      Investigating the correlation between white matter and microvasculature changes in aging using large scale optical coherence tomography and confocal fluorescence imaging combined with tissue sectioning

      Here, we present a serial OCT/confocal scanner for histological study of the mouse brain. Three axis linear stages combined with a sectioning vibratome allows to cut thru the entire biological tissue and to image every section at a microscopic resolution. After acquisition, each OCT volume and confocal image is re-stitched with adjacent acquisitions to obtain a reconstructed, digital volume of the imaged tissue. This imaging platform was used to investigate correlations between white matter and microvasculature changes in aging mice. Three age groups were used in this study (4, 12, 24 months). At sacrifice, mice were transcardially perfused with ...

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    15. Retinal Atrophy in Eyes With Resolved Papilledema Detected by Optical Coherence Tomography

      Retinal Atrophy in Eyes With Resolved Papilledema Detected by Optical Coherence Tomography

      Background: To apply automated spectral domain optical coherence tomography (SD-OCT) segmentation to eyes with resolving papilledema. Methods: Ninety-four patients with idiopathic intracranial hypertension seen at the Duke Eye Center neuro-ophthalmology clinic between November 2010 and October 2011 were reviewed. Excluded were eyes with papilledema with Frisen grade >2, other optic neuropathies or retinopathies, and those that did not have SD-OCT imaging. The remaining 43 patients were split into 2 groups: non-atrophic papilledema and atrophic papilledema. Automated SD-OCT segmentation was performed on patients with non-atrophic papilledema and age-matched controls for each of the 9 regions of the Early Treatment Diabetic Retinopathy ...

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    16. Retinal Ganglion Cell Layer Analysis by Optical Coherence Tomography in Toxic and Nutritional Optic Neuropathy

      Retinal Ganglion Cell Layer Analysis by Optical Coherence Tomography in Toxic and Nutritional Optic Neuropathy

      Objective: To analyze the retinal ganglion cell layer (RGL) by optical coherence tomography (OCT) in toxic and nutritional optic neuropathy and to correlate its thickness and volume with functional damage. Methods: We conducted an observational cross-sectional study in healthy subjects and in patients with toxic optic neuropathy observed in the Neuro-Ophthalmology Department of Central Lisbon Hospital Center. Complete ophthalmologic examination, OCT (Heidelberg Spectralis), and automated static perimetry were performed. Thickness and macular volume of RGL layer and inner plexiform layer were measured after manual segmentation. Results: The study included 16 eyes of 12 healthy subjects and 16 eyes of 8 ...

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    17. Optical Coherence Tomography versus Visual Evoked Potentials in detecting subclinical visual impairment in multiple sclerosis

      Optical Coherence Tomography versus Visual Evoked Potentials in detecting subclinical visual impairment in multiple sclerosis

      Rationale . Visual impairment is one of the most common clinical manifestations of multiple sclerosis (MS). Some multiple sclerosis patients complain of poor vision although the Snellen visual acuity is 20/20. This study reveals that sensitive measurements like visual evoked potential (VEP) and optical coherence tomography (OCT) can evidence subclinical disturbances of visual pathway. These methods examine the relation between the visual function (VEP) and retinal nerve fiber layer (RNFL) thickness, as a structural biomarker for axonal loss in patients with multiple sclerosis (MS). The findings in this study indicate the utility of combining structural and functional testing in clinical ...

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    18. In Vivo Characterization of Carotid Neointimal Hyperplasia by use of Optical Coherence Tomography: Before and After Cutting Balloon Angioplasty

      In Vivo Characterization of Carotid Neointimal Hyperplasia by use of Optical Coherence Tomography: Before and After Cutting Balloon Angioplasty

      Optical coherence tomography (OCT) is a modern intravascular imaging modality that has the capability to provide detailed, in vivo characterization of the arterial wall and atherosclerotic plaque. The current understanding of the appearance of atherosclerotic plaque via OCT is largely based on coronary arterial studies where OCT information has been employed to guide therapeutic management and permits the immediate evaluation of percutaneous intervention. The clinical success of OCT in the coronary arteries has laid the foundation for investigation of the carotid artery and thus, stroke risk assessment. We report the novel use of OCT for tissue characterization of severe stenosis ...

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    19. Optical coherence tomography predicts visual outcome for pituitary tumors

      Optical coherence tomography predicts visual outcome for pituitary tumors

      We evaluate if the relationship between optical coherence tomography (OCT) of the retinal nerve fibre layer (RNFL) continued over long-term visual recovery in 107 patients undergoing pituitary decompression. Recently, it has been recognized that OCT of RNFL has prognostic value in predicting visual outcomes after surgery for chiasmal compression caused by pituitary tumours. Patients were followed up at three time points: pre-operative (visit 1), 6 –10 weeks post-operative (visit 2) and 9–15 months follow-up (visit 3). We found that patients with thin pre-operative RNFL had more severe visual field defects (mean deviation [MD] -9.22 versus -3.96 decibels ...

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    20. Optical coherence tomography visualizes neurons in human entorhinal cortex

      Optical coherence tomography visualizes neurons in human entorhinal cortex

      The cytoarchitecture of the human brain is of great interest in diverse fields: neuroanatomy, neurology, neuroscience, and neuropathology. Traditional histology is a method that has been historically used to assess cell and fiber content in the ex vivo human brain. However, this technique suffers from significant distortions. We used a previously demonstrated optical coherence microscopy technique to image individual neurons in several square millimeters of en-face tissue blocks from layer II of the human entorhinal cortex, over 50     μ m in depth. The same slices were then sectioned and stained for Nissl substance. We registered the optical coherence tomography (OCT) images ...

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    21. Neuromyelitis optica and multiple sclerosis: Seeing differences through optical coherence tomography

      Neuromyelitis optica and multiple sclerosis: Seeing differences through optical coherence tomography

      Neuromyelitis optica (NMO) is an inflammatory autoimmune disease of the central nervous system that preferentially targets the optic nerves and spinal cord. The clinical presentation may suggest multiple sclerosis (MS), but a highly specific serum autoantibody against the astrocytic water channel aquaporin-4 present in up to 80% of NMO patients enables distinction from MS. Optic neuritis may occur in either condition resulting in neuro-anatomical retinal changes. Optical coherence tomography (OCT) has become a useful tool for analyzing retinal damage both in MS and NMO. Numerous studies showed that optic neuritis in NMO typically results in more severe retinal nerve fiber ...

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    22. OCT measurements of optic nerve head changes in idiopathic intracranial hypertension

      OCT measurements of optic nerve head changes in idiopathic intracranial hypertension

      Objective Severity of papilledema and vision loss constitute a basis for therapeutic intervention in idiopathic intracranial hypertension (IIH), but both are often subjective and insensitive in guiding clinical management. The aim of this study was to identify reliable and sensitive measurements of optic nerve head (ONH) and macula, to provide objective guidance for prognostic evaluation and treatment in IIH. We analyzed potential of spectral domain optical coherence tomography (SD-OCT), to measure neuro-retinal rim thickness and area, optic cup-to-disc ratio (C/D) and cup volume of ONH which have not previously been reported in IIH. In parallel, thickness of peripapillary retinal ...

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    23. Correlation between SD-OCT, immunocytochemistry and functional findings in an animal model of retinal degeneration

      Correlation between SD-OCT, immunocytochemistry and functional findings in an animal model of retinal degeneration

      Purpose: The P23H rhodopsin mutation is an autosomal dominant cause of retinitis pigmentosa (RP). The degeneration can be tracked using different anatomical and functional methods. In our case, we evaluated the anatomical changes using Spectral-Domain Optical Coherence Tomography (SD-OCT) and correlated the findings with retinal thickness values determined by immunocytochemistry.Methods: Pigmented rats heterozygous for the P23H mutation, with ages between P18 and P180 were studied. Function was assessed by means of optomotor testing and ERGs. Retinal thicknesses measurements, autofluorescence and fluorescein angiography were performed using Spectralis OCT. Retinas were studied by means of immunohistochemistry. Results: Between P30 and P180 ...

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    1-24 of 367 1 2 3 4 ... 14 15 16 »
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