1. Articles in category: Neurology

    1-24 of 819 1 2 3 4 ... 33 34 35 »
    1. INS-fOCT: a label-free, all-optical method for simultaneously manipulating and mapping brain function

      INS-fOCT: a label-free, all-optical method for simultaneously manipulating and mapping brain function

      Significance: Current approaches to stimulating and recording from the brain have combined electrical or optogenetic stimulation with recording approaches, such as two-photon, electrophysiology (EP), and optical intrinsic signal imaging (OISI). However, we lack a label-free, all-optical approach with high spatial and temporal resolution. Aim: To develop a label-free, all-optical method that simultaneously manipulates and images brain function using pulsed near-infrared light (INS) and functional optical coherence tomography (fOCT), respectively. Approach: We built a coregistered INS, fOCT, and OISI system. OISI and EP recordings were employed to validate the fOCT signals. Results: The fOCT signal was reliable and regional, and the ...

      Read Full Article
    2. Insight into the fundamental trade-offs of diffusion MRI from polarization-sensitive optical coherence tomography in ex vivo human brain

      Insight into the fundamental trade-offs of diffusion MRI from polarization-sensitive optical coherence tomography in ex vivo human brain

      In the first study comparing high angular resolution diffusion MRI (dMRI) in the human brain to axonal orientation measurements from polarization-sensitive optical coherence tomography (PSOCT), we compare the accuracy of orientation estimates from various dMRI sampling schemes and reconstruction methods. We find that, if the reconstruction approach is chosen carefully, single-shell dMRI data can yield the same accuracy as multi-shell data, and only moderately lower accuracy than a full Cartesian-grid sampling scheme. Our results suggest that current dMRI reconstruction approaches do not benefit substantially from ultra-high b-values or from very large numbers of diffusion-encoding directions. We also show that accuracy ...

      Read Full Article
    3. Long-term in vivo Monitoring of Gliotic Sheathing of Ultrathin Entropic Coated Brain Microprobes with Fiber-based Optical Coherence Tomography

      Long-term in vivo Monitoring of Gliotic Sheathing of Ultrathin Entropic Coated Brain Microprobes with Fiber-based Optical Coherence Tomography

      Microfabricated neuroprosthetic devices have made possible important observations on neuron activity; however, long-term high-fidelity recording performance of these devices has yet to be realized. Tissue-device interactions appear to be a primary source of lost recording performance. The current state of the art for visualizing the tissue response surrounding brain implants in animals is Immunohistochemistry + Confocal Microscopy, which is mainly performed after sacrificing the animal. Monitoring the tissue response as it develops could reveal important features of the response which may inform improvements in electrode design. Optical Coherence Tomography (OCT), an imaging technique commonly used in ophthalmology, has already been adapted ...

      Read Full Article
    4. Optical coherence tomography evaluation of vertebrobasilar artery stenosis: case series and literature review

      Optical coherence tomography evaluation of vertebrobasilar artery stenosis: case series and literature review

      Background Intracranial vertebrobasilar artery stenosis is an important cause of ischemic stroke. With its high resolution, intravascular optical coherence tomography (OCT) provides detailed assessment of vessel wall features. It is widely applied to identify high-risk plaque in the cardiovascular system, but its use in the intracranial artery has been limited. Objective To explore, in this pilot study, the usefulness of OCT in imaging of the intracranial artery wall. Methods Between November 2017 and July 2018, four patients with severe intracranial vertebrobasilar artery stenosis were enrolled for preintervention OCT evaluation of the lesion artery. Stenosis was present in the basilar artery ...

      Read Full Article
    5. Optical coherence tomography imaging after endovascular thrombectomy: a novel method for evaluating vascular injury in a swine model

      Optical coherence tomography imaging after endovascular thrombectomy: a novel method for evaluating vascular injury in a swine model

      Although studies have shown that some degree of iatrogenic endothelial injury occurs during endovascular thrombectomy (EVT), the clinical significance of such injury is uncertain. Furthermore, it is likely that iatrogenic effects such as endothelial denudation, intimal dissection, and tunica media edema will have varying clinical implications. The purpose of this study was to assess the feasibility of endovascular optical coherence tomography (OCT) in quantifying vessel injury in real time after EVT, correlate vessel injury with histological findings, and perform imaging at varying time intervals after EVT to assess the impact of prolonged direct exposure of the vessel to the thrombus ...

      Read Full Article
    6. Evaluation of macular thickness and volume tested by optical coherence tomography as biomarkers for Alzheimer’s disease in a memory clinic

      Evaluation of macular thickness and volume tested by optical coherence tomography as biomarkers for Alzheimer’s disease in a memory clinic

      Building on previous studies that report thinning of the macula in Alzheimer’s disease (AD) and mild cognitive impairment (MCI) patients, the use of optical coherence tomography (OCT) has been proposed as a potential biomarker for AD. However, other studies contradict these results. A total of 930 participants (414 cognitively healthy people, 192 with probable amnestic MCI, and 324 probable AD patients) from a memory clinic were consecutively included in this study and underwent a spectral domain OCT scan (Maestro, Topcon) to assess total macular volume and thickness. Macular width measurements were also taken in several subregions (central, inner, and ...

      Read Full Article
    7. Georgia Institute of Technology Receives NIH Grant for Stimulated Raman Scattering Spectroscopic Optical Coherence Tomography (SRS-SOCT) for Label-Free Molecular Imaging of Brain Tumor Pathology

      Georgia Institute of Technology Receives NIH Grant for Stimulated Raman Scattering Spectroscopic Optical Coherence Tomography (SRS-SOCT) for Label-Free Molecular Imaging of Brain Tumor Pathology

      Georgia Institute of Technology Receives a 2020 NIH Grant for $233,796 for Stimulated Raman Scattering Spectroscopic Optical Coherence Tomography (SRS-SOCT) for Label-Free Molecular Imaging of Brain Tumor Pathology. The principal investigator is Francisco Robles. Below is a summary of the proposed work. The extent of resection of brain tumors is one of the most important factors associated with prolonged survival for patients with brain cancer. Unfortunately, achieving complete resection of the preoperatively-defined tumor region remains a significant clinical challenge. This is due, in part, to the lack of intraoperative tools available to help surgeons differentiate between healthy tissue that ...

      Read Full Article
    8. In vivo brain imaging with multimodal optical coherence microscopy in a mouse model of thromboembolic photochemical stroke

      In vivo brain imaging with multimodal optical coherence microscopy in a mouse model of thromboembolic photochemical stroke

      We used a new multimodal imaging system that combines optical coherence microscopy and brightfield microscopy. Using this in vivo brain monitoring approach and cranial window implantation, we three-dimensionally visualized the vascular network during thrombosis, with high temporal (18 s) and spatial (axial, 2.5  μm; lateral, 2.2  μm) resolution. We used a modified mouse model of photochemical thromboembolic stroke in order to more accurately parallel human stroke. Specifically, we applied green laser illumination to focally occlude a branch of the middle cerebral artery. Despite the recanalization of the superficial arteries at 24 h after stroke, no blood flow was ...

      Read Full Article
    9. Correlation Between Optic Disc Peripapillary Capillary Network and Papilledema Grading in Patients With Idiopathic Intracranial Hypertension A Study of Optical Coherence Tomography Angiography

      Correlation Between Optic Disc Peripapillary Capillary Network and Papilledema Grading in Patients With Idiopathic Intracranial Hypertension A Study of Optical Coherence Tomography Angiography

      Background: The continued increase in idiopathic intracranial hypertension (IIH) prevalence has many implications for societal health care. Its potential vision-threatening consequences make ophthalmologists key players in its diagnosis and management. Newer technology such as optical coherence tomography angiography (OCT-A) enables evaluation of the branching complexity of the peripapillary capillary plexus, a region where accurate imaging via fluorescein angiography was previously limited. Methods: A cross-sectional, observational study of 23 (46 eyes) consecutive patients with IIH. Peripapillary total vasculature was recorded using commercial OCT-A en face vessel density mapping. In addition, OCT-A blood flow slab was compared with papilledema grading. OCT-A images ...

      Read Full Article
    10. Use of optical coherence tomography deemed feasible after first-in-human analysis

      Use of optical coherence tomography deemed feasible after first-in-human analysis

      Results of the first-in-human analysis of acute interactions and healing process after flow diverter implantation using optical coherence tomography (OCT) imaging was presented by Boris Pab ón and Juan Mejia as members of Angioteam, Angiodinamia, Clinica Del Norte, Medellín, Colombia, at the 15 th Congress of the World Federation of Interventional and Therapeutic Neuroradiology (WFITN; 21–24 October 2019, Naples, Italy). Having evaluated three patients at the time of presentation, Pabón said: “The ultimate objective was to evaluate the feasibility and success of OCT technology after deploying dual layer flow diverter stents intracranially and extracranially, and to describe ...

      Read Full Article
      Mentions: Gentuity
    11. Vascular changes with optical coherence tomography angiography during aura of migraine: A case report

      Vascular changes with optical coherence tomography angiography during aura of migraine: A case report

      Purpose: To demonstrate macular and optic disk vessel changes by optical coherence tomography angiography during and after a migraine attack with aura Methods: Case report Results: A 34-year-old healthy female patient was evaluated by optical coherence tomography angiography imaging during visual aura with phosphenes in the left visual field. Optical coherence tomography angiography imaging showed diffuse narrowing of the retinal vessels, decreased radial peripapillary capillary density, and decreased superficial and deep foveal vessel density in the right eye. These changes improved 3 hours after visual aura. The patient suffered from right eye pain and right-sided headache, which are typical for ...

      Read Full Article
    12. Optical coherence tomography of the retina in schizophrenia: Inter-device agreement and relations with perceptual function

      Optical coherence tomography of the retina in schizophrenia: Inter-device agreement and relations with perceptual function

      Background Optical coherence tomography (OCT) studies have demonstrated differences between people with schizophrenia and controls. Many questions remain including the agreement between scanners. The current study seeks to determine inter-device agreement of OCT data in schizophrenia compared to controls and to explore the relations between OCT and visual function measures. Methods Participants in this pilot study were 12 individuals with schizophrenia spectrum disorders and 12 age- and sex-matched controls. Spectralis and Cirrus OCT machines were used to obtain retinal nerve fiber layer (RNFL) thickness and macular volume. Cirrus was used to obtain ganglion cell layer + inner plexiform layer (GCL + IPL ...

      Read Full Article
    13. Retinal Nerve Fiber Layer Thickness and Total Macular Volume in Multiple Sclerosis Subtypes and Their Relationship with Severity of Disease, a Cross-Sectional Study

      Retinal Nerve Fiber Layer Thickness and Total Macular Volume in Multiple Sclerosis Subtypes and Their Relationship with Severity of Disease, a Cross-Sectional Study

      Background: Optic neuritis (ON) is an inflammatory demyelinating lesion in the optic nerve, which is strongly associated with multiple sclerosis (MS). Optical coherence tomography (OCT) is a noninvasive technique for the evaluation of the retinal layers. Our aim was to examine OCT metrics including retinal nerve fiber layer thickness (RNFLT), and total macular volume (TMV), in MS subtypes and their relationship with duration, first manifestation, and severity of disease. Material and Methods: In this cross-sectional study, patients with a definite diagnosis of MS underwent complete ophthalmic and neurologic examination. OCT parameters including TMV and RNFLT were compared between MS subtypes ...

      Read Full Article
    14. New Methods for Spatial Analysis of Thickness in Optical Coherence Tomography

      New Methods for Spatial Analysis of Thickness in Optical Coherence Tomography

      The retina is the most accessible alive neuronal tissue and is relevant not only for ophthalmology but also for neuroscience, because of the increasing evidence that it shows degeneration processes similar to those found in the brain of patients with Alzheimer’s disease and Amyotrophic Lateral Sclerosis. Optical Coherence Tomography (OCT) provides retinal scanning noninvasively, in few seconds, at low cost, and with a spatial resolution thousand times finer than what today is feasible in the living brain. But OCT data have some features derived from its 3D structure that render unsuited classical data analysis methods. Current proposal is to ...

      Read Full Article
    15. Associations Between Retina and Brain Function

      Associations Between Retina and Brain Function

      Case-control studies and meta-analysis have reported that several fundus features, especially the thickness of the peripapillary retinal nerve fiber layer, are related to the brain degeneration and cognitive impairment. In our study, we aim to quantitatively assess retina features using OCT and define its associations with brain development and intelligence in children.

      Read Full Article
    16. Measurement and visualization of stimulus-evoked tissue dynamics in mouse barrel cortex using phase-sensitive optical coherence tomography

      Measurement and visualization of stimulus-evoked tissue dynamics in mouse barrel cortex using phase-sensitive optical coherence tomography

      We describe a method to measure tissue dynamics in mouse barrel cortex during functional activation via phase-sensitive optical coherence tomography (PhS-OCT). The method measures the phase changes in OCT signals, which are induced by the tissue volume change, upon which to localize the activated tissue region. Phase unwrapping, compensation and normalization are applied to increase the dynamic range of the OCT phase detection. To guide the OCT scanning, intrinsic optical signal imaging (IOSI) system equipped with a green light laser source (532 nm) is integrated with the PhS-OCT system to provide a full field time-lapsed images of the reflectance that ...

      Read Full Article
    17. University of Houston Receives NIH Grant for Artificial Intelligence for Optical Coherence Tomography To Study Effects of Poly-Drug Exposure on Fetal Brain Development

      University of Houston Receives NIH Grant for Artificial Intelligence for Optical Coherence Tomography To Study Effects of Poly-Drug Exposure on Fetal Brain Development

      University of Houston Receives a 2020 NIH Grant for $311,241 for Artificial Intelligence for Optical Coherence Tomography To Study Effects of Poly-Drug Exposure on Fetal Brain Development. The principal investigator is Kirill Larin. Below is a summary of the proposed work. The overall objective of this study is to develop an optical coherence tomography (OCT) based high- resolution mouse embryonic brain imaging and analysis approach, and to use this method in correlation with molecular analysis to understand the interplay between ethanol (EtOH) and nicotine (NIC) effects on embryonic brain development. Maternal exposures to these substances are linked to fetal ...

      Read Full Article
    18. OCT and Imaging in Central Nervous System Diseases: The Eye as a Window to the Brain (Textbook)

      OCT and Imaging in Central Nervous System Diseases: The Eye as a Window to the Brain (Textbook)

      The second edition of OCT and Imaging in Central Nervous System Diseases offers updated state-of-the-art advances using optical coherence tomography (OCT) regrading neuronal loss within the retina. Detailed information on the OCT imaging and interpretation is provided for the evaluation of disease progression in numerous neurodegenerative disorders and as a biological marker of neuroaxonal injury. Covering disorders like multiple sclerosis, Parkinson’s disease, Alzheimer’s disease, intracranial hypertension, Friedreich’s ataxia, schizophrenia, hereditary optic neuropathies, glaucoma, and amblyopia, readers will given insights into effects on the retina and the and optic nerve. Individual chapters are also devoted to OCT technique ...

      Read Full Article
    19. Feasibility evaluation of micro-optical coherence tomography (μOCT) for rapid brain tumor type and grade discriminations: μOCT images versus pathology

      Feasibility evaluation of micro-optical coherence tomography (μOCT) for rapid brain tumor type and grade discriminations: μOCT images versus pathology

      Background Precise identification, discrimination and assessment of central nervous system (CNS) tumors is of critical importance to brain neoplasm treatment. Due to the complexity and limited resolutions of the existing diagnostic tools, however, it is difficult to identify the tumors and their boundaries precisely in clinical practice, and thus, the conventional way of brain neoplasm treatment relies mainly on the experiences of neurosurgeons to make resection decisions in the surgery process. The purpose of this study is to explore the potential of Micro-optical coherence tomography (μOCT) as an intraoperative diagnostic imaging tool for identifying and discriminating glioma and meningioma with ...

      Read Full Article
    20. Reader response: Optical coherence tomography for diagnosing optic neuritis: Are we there yet?

      Reader response: Optical coherence tomography for diagnosing optic neuritis: Are we there yet?

      I read with interest the editorial by Drs. Saidha and Naismith. 1 The corresponding study by Xu et al. 2 that reported the sensitivity of detecting previous optic neuritis (ON) is elegant. However, many questions remain. One of the reasons why neurologists in the United States do not use optical coherence tomography (OCT) routinely is because of the high cost of hardware and the continually changing algorithms that are used to perform retinal segmentation. In addition, why not use pattern shift visual evoked response data that shows delayed P100 latencies in most patients, even with visual recovery in detecting previous ...

      Read Full Article
    21. Author response: Optical coherence tomography for diagnosing optic neuritis: Are we there yet?

      Author response: Optical coherence tomography for diagnosing optic neuritis: Are we there yet?

      We thank Dr. Avasarala for his comments on our editorial regarding the corresponding study by Xu et al., 1,2 in which the sensitivity of optical coherence tomography (OCT) measures for detecting previous optic neuritis (ON) was examined. Although Naismith et al. reported that OCT was less sensitive than visual evoked potentials (VEP) in detecting previous ON, 3 this study used older third-generation time domain OCT. Undoubtedly, the greatest advance in OCT in the past decade has been the development of fourth-generation spectral domain OCT. Current commercially available spectral domain OCT has extremely high resolution (3–5 μm). Moreover, peripapillary ...

      Read Full Article
    22. Retinal Imaging in Alzheimer’s Disease: In Search of the Holy Grail

      Retinal Imaging in Alzheimer’s Disease: In Search of the Holy Grail

      Alzheimer’s disease (AD) is the most common cause of dementia, accounting for 60% to 80% of cases worldwide. 1 The pathologic hallmark of the disease is the accumulation of extracellular beta amyloid plaques and intracellular tau filaments, ultimately leading to neuronal death. The current approved treatments slow down the progression of the disease, but do not stop the neurodegeneration caused by it. The past 2 decades have witnessed repeated failures of clinical trials using disease-modifying therapies targeting amyloid. 2 These failures have prompted a major rethinking of the approach, with the general consensus being that potential treatments would work ...

      Read Full Article
    1-24 of 819 1 2 3 4 ... 33 34 35 »
  1. Categories

    1. Applications:

      Art, Cardiology, Dentistry, Dermatology, Developmental Biology, Gastroenterology, Gynecology, Microscopy, NDE/NDT, Neurology, Oncology, Ophthalmology, Other Non-Medical, Otolaryngology, Pulmonology, Urology
    2. Business News:

      Acquisition, Clinical Trials, Funding, Other Business News, Partnership, Patents
    3. Technology:

      Broadband Sources, Probes, Tunable Sources
    4. Miscellaneous:

      Jobs & Studentships, Student Theses, Textbooks
  2. Popular Articles

  3. Organizations in the News

    1. (1 articles) Boston University
    2. (1 articles) Harvard University
    3. (1 articles) Massachusetts General Hospital
    4. (1 articles) Oregon Health & Science University
    5. (1 articles) Zhejiang University
  4. People in the News

    1. (1 articles) David A. Boas
    2. (1 articles) Hui Wang
    3. (1 articles) Peng Li