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Survey of Ophthalmology 2017Optic disk hemorrhage occurs in all age groups from neonates to the elderly. Optic disk hemorrhage is best known for its association with visual field loss and... (Review)
Review
Optic disk hemorrhage occurs in all age groups from neonates to the elderly. Optic disk hemorrhage is best known for its association with visual field loss and progression in patients with glaucoma; however, it may occur in conjunction with other ocular or systemic conditions as well as in healthy individuals. It may also be the first sign of a sight-threatening condition. Variations in the shape, location, and size of the optic disk hemorrhage, as well as associated ocular and systemic signs or symptoms, may help determine the underlying pathology. We address the epidemiology, demographics, pathophysiology, clinical presentations and implications, differential diagnoses, and management of eyes with optic disk hemorrhage in diseased and healthy subjects.
Topics: Diagnosis, Differential; Diagnostic Techniques, Ophthalmological; Glaucoma; Humans; Incidence; Ocular Hypertension; Optic Disk; Optic Nerve Diseases; Prevalence; Retinal Hemorrhage; Risk Factors
PubMed: 28400276
DOI: 10.1016/j.survophthal.2017.04.001 -
Advanced Materials (Deerfield Beach,... Sep 2023Using ions in aqueous milieu for signal processing, like in biological circuits, may potentially lead to a bioinspired information processing platform. Studies, however,...
Using ions in aqueous milieu for signal processing, like in biological circuits, may potentially lead to a bioinspired information processing platform. Studies, however, have focused on individual ionic diodes and transistors rather than circuits comprising many such devices. Here a 16 × 16 array of new ionic transistors is developed in an aqueous quinone solution. Each transistor features a concentric ring electrode pair with a disk electrode at the center. The electrochemistry of these electrodes in the solution provides the basis for the transistor operation. The ring pair electrochemically tunes the local electrolytic concentration to modulate the disk's Faradaic reaction rate. Thus, the disk current as a Faradaic reaction to the disk voltage is gated by the ring pair. The 16 × 16 array of these transistors performs analog multiply-accumulate (MAC) operations, a computing modality hotly pursued for low-power artificial neural networks. This exploits the transistor's operating regime where the disk current is a multiplication of the disk voltage and a weight parameter tuned by the ring pair gating. Such disk currents from multiple transistors are summated in a global reference electrode to complete a MAC task. This ionic circuit demonstrating analog computing is a step toward sophisticated aqueous ionics.
PubMed: 35998945
DOI: 10.1002/adma.202205096 -
Radiographics : a Review Publication of... 2016Beyond the familiar disk herniations with typical clinical features, intervertebral disk pathologic conditions can have a wide spectrum of imaging and clinical... (Review)
Review
Beyond the familiar disk herniations with typical clinical features, intervertebral disk pathologic conditions can have a wide spectrum of imaging and clinical manifestations. The goal of this review is to illustrate and discuss unusual manifestations of intervertebral disk pathologic conditions that radiologists may encounter, including disk herniations in unusual locations, those with atypical imaging features, and those with uncommon pathophysiologic findings. Examples of atypical disk herniations presented include dorsal epidural, intradural, symptomatic thoracic (including giant calcified), extreme lateral (retroperitoneal), fluorine 18 fluorodeoxyglucose-avid, acute intravertebral (Schmorl node), and massive lumbar disk herniations. Examples of atypical pathophysiologic conditions covered are discal cysts, fibrocartilaginous emboli to the spinal cord, tiny calcified disks or disk-level spiculated osteophytes causing spinal cerebrospinal fluid (CSF) leak and intracranial hypotension, and pediatric acute calcific discitis. This broad gamut of disease includes a variety of sizes of disk pathologic conditions, from the tiny (eg, the minuscule calcified disks causing high-flow CSF leaks) to the extremely large (eg, giant calcified thoracic intradural disk herniations causing myelopathy). A spectrum of clinical acuity is represented, from hyperacute fibrocartilaginous emboli causing spinal cord infarct, to acute Schmorl nodes, to chronic intradural herniations. The entities included are characterized by a range of clinical courses, from the typically devastating cord infarct caused by fibrocartilaginous emboli, to the usually spontaneously resolving pediatric acute calcific discitis. Several conditions have important differential diagnostic considerations, and others have relatively diagnostic imaging findings. The pathophysiologic findings are well understood for some of these entities and poorly defined for others. Radiologists' knowledge of this broad scope of unusual disk disease is critical for accurate radiologic diagnoses. Online supplemental material is available for this article. (©)RSNA, 2016.
Topics: Diagnostic Imaging; Humans; Intervertebral Disc Degeneration; Intervertebral Disc Displacement
PubMed: 27082664
DOI: 10.1148/rg.2016150223 -
World Neurosurgery Jan 2018Low back pain is the principal cause of long-term disability worldwide. We intend to address one of its main causes, degenerative disk disease, a spinal condition... (Review)
Review
Low back pain is the principal cause of long-term disability worldwide. We intend to address one of its main causes, degenerative disk disease, a spinal condition involving degradation of an intervertebral disk. Following unsuccessful conservative treatment, patients may be recommended for surgery. The two main surgical treatments for lumbar degenerative disk disease are lumbar fusion: traditional standard surgical treatment and lumbar disk arthroplasty, also known as lumbar total disk replacement. Lumbar fusion aims to relieve pain by fusing vertebrae together to eliminate movement at the joint, but it has been criticized for problems involving insignificant pain relief, a reduced range of motion, and an increased risk of adjacent segment degeneration. This leads to development of the lumbar total disk replacement technique, which aims to relieve pain replacing a degenerated intervertebral disk with a moveable prosthesis, thus mimicking the functional anatomy and biomechanics of a native intervertebral disk. Over the years a large range of prosthetic disks has been developed. The efficacy and current evidence for these prostheses are discussed in this review. The results of this study are intended to guide clinical practice and future lumbar total disk replacement device choice and design.
Topics: Humans; Intervertebral Disc; Intervertebral Disc Degeneration; Low Back Pain; Lumbar Vertebrae; Total Disc Replacement
PubMed: 28987839
DOI: 10.1016/j.wneu.2017.09.153 -
Journal of Chiropractic Medicine Jun 2018The purpose of this paper was to review the literature regarding the mechanisms leading to degeneration in intervertebral disks and to discuss contributing mechanical... (Review)
Review
OBJECTIVE
The purpose of this paper was to review the literature regarding the mechanisms leading to degeneration in intervertebral disks and to discuss contributing mechanical and biological factors.
METHODS
The inclusion criteria for the literature review were research studies conducted in the last 3 decades with free full-text available in English. Review articles and articles pertaining to temporomandibular joints and joints of the body other than the intervertebral disk were excluded. The following databases were searched: PubMed, EBSCOhost, and Google Scholar through September 9, 2016.
RESULTS
A total of 57 articles were used in this review. Intervertebral disk cells require glucose for sustainability and oxygen to synthesize matrix components. Nutrients enter the disk via 2 vascular supply routes: capillary beds of end plates and the peripheral annulus fibrosus. Solute size, shape and charge, compression, and metabolic demand all influence the efficiency of nutrient transport, and alterations of any of these factors may have effects on nutrient transport and, potentially, disk degeneration.
CONCLUSIONS
Progressive nutrient transport disruptions may actively contribute in advancing the phases of degenerative disk disease. Such disruptions include dysfunctional loading and spinal position, lack of motion, high frequency loading, disk injury, aging, smoking, an acidic environment, and a lack of nutrient bioavailability.
PubMed: 30166966
DOI: 10.1016/j.jcm.2017.11.006 -
Spine Surgery and Related Research 2022Intervertebral disk degeneration is a universal and natural process. However, no reports have summarized anatomical age-related intervertebral disk height and disk...
INTRODUCTION
Intervertebral disk degeneration is a universal and natural process. However, no reports have summarized anatomical age-related intervertebral disk height and disk degenerative changes in the thoracolumbar spine or examined sex-specific differences. This study aimed to establish age-related changes and gender-specific differences of intervertebral disk height and disk degeneration of the thoracolumbar spine in a large cohort of relatively healthy subjects and also to evaluate the relationship between the degree of thoracolumbar disk height and disk degeneration.
METHODS
Six hundred and twenty-seven relatively healthy subjects (307 males and 320 females; average age, 49.6±16.5 years) were enrolled. We included at least 50 males and 50 females in each decade of life between the 20s and the 70s. We measured intervertebral disk height from T10/T11 to L5/S1, vertebral body height from T10 to S1 on lateral neutral radiographs. Lumbar disk degeneration was defined according to the Pfirrmann classification in sagittal plane magnetic resonance imaging.
RESULTS
Age-related decreases in intervertebral disk height were most prominent at L4/L5 in middle-aged and elderly individuals of both sexes. The grade of disk degeneration significantly increased with age in both genders at every level. Mild disk degeneration was observed even in the 20s. The disk degeneration occurred around the L4/L5 level. Although grade V disk degeneration was not identified for males in the 20s and the 30s, it appeared after the 40s and then increased further with age. The intervertebral disk height at the lower lumbar disks decreased with a progression in the disk degeneration grade in both genders.
CONCLUSIONS
This large-scale cross-sectional analysis of the thoracolumbar spine in relatively healthy subjects demonstrated that lumbar disk height narrowing progresses with age and is correlated with the progression of disk degeneration.
PubMed: 36051683
DOI: 10.22603/ssrr.2021-0187 -
European Journal of Gastroenterology &... Dec 2021The aim of this study was to validate the IBD-Disk in a Portuguese cohort according to the COnsensus-based Standards for the selection of the health Measurement...
OBJECTIVE
The aim of this study was to validate the IBD-Disk in a Portuguese cohort according to the COnsensus-based Standards for the selection of the health Measurement INstruments (COSMIN) recommendations.
METHODS
After translation of the original IBD-Disk to Portuguese, a group of IBD patients was invited to complete the IBD-Disk at baseline (T0), after 1-4 weeks (T1) and after more than 3 months (T2), from July 2020 to February 2021. At T0 and T2, the patients also completed the IBD Disability Index. We evaluated reliability (internal consistency, test-retest, interrater reliability and measurement error), construct validity, responsiveness, interpretability of IBD-Disk, sociodemographic and clinical factors associated with IBD-Disk.
RESULTS
At T0, 154 patients (107 - Crohn's disease; 46 - ulcerative colitis) completed the IBD-Disk; 1 - IBD-unclassified). At T1 and T2, 64 and 114 patients repeated the questionnaire, respectively. Factor analysis confirmed the unidimensionality of the scale and reduced the final version to 10 items. Internal consistency was excellent with a Cronbach's α of 0.916. The intraclass correlation coefficient was 0.95 for test-retest (T0 and T1). To evaluate construct validity, the IBD-Disk was compared with the IBD Disability Index and Manitoba IBD Index with a significative positive correlation (r = 0.850 and r = 0.459, respectively; P < 0.001 for both). IBD-Disk scores ranged from 0 to 93 with a mean of 38.18 ± 25.39. Female sex, professional inactivity, longer IBD duration and clinical activity were associated with significantly higher IBD-Disk scores.
CONCLUSION
The Portuguese version of IBD-Disk is a reliable and valid tool to assess disability in Portuguese IBD patients.
Topics: Colitis, Ulcerative; Female; Humans; Portugal; Reproducibility of Results; Severity of Illness Index; Translations
PubMed: 34907981
DOI: 10.1097/MEG.0000000000002330 -
The Journal of the American Academy of... Jul 2017Lumbar disk herniation, degenerative disk disease, and spondylolysis are the most prevalent lumbar conditions that result in missed playing time. Lumbar disk herniation... (Review)
Review
Lumbar disk herniation, degenerative disk disease, and spondylolysis are the most prevalent lumbar conditions that result in missed playing time. Lumbar disk herniation has a good prognosis. After recovery from injury, professional athletes return to play 82% of the time. Surgical management of lumbar disk herniation has been shown to be a viable option in athletes in whom nonsurgical measures have failed. Degenerative disk disease is predominately genetic but may be accelerated in athletes secondary to increased physiologic loading. Nonsurgical management is the standard of care for lumbar degenerative disk disease in the elite athlete. Spondylolysis is more common in adolescent athletes with back pain than in adult athletes. Nonsurgical management of spondylolysis is typically successful. However, if surgery is required, fusion or direct pars repair can allow the patient to return to sports.
Topics: Athletes; Humans; Intervertebral Disc Degeneration; Intervertebral Disc Displacement; Lumbar Vertebrae; Lumbosacral Region; Spondylolysis
PubMed: 28574940
DOI: 10.5435/JAAOS-D-16-00135 -
Klinische Monatsblatter Fur... Oct 2016
Topics: Documentation; Germany; Glaucoma; Humans; Image Interpretation, Computer-Assisted; Ophthalmology; Optic Disk; Practice Guidelines as Topic; Retinoscopy; Tomography, Optical Coherence
PubMed: 27764848
DOI: 10.1055/s-0042-117228 -
International Ophthalmology Clinics 2018
Review
Topics: Atrophy; Brain Diseases; Child; Humans; Optic Disk; Optic Nerve Diseases; Pallor; Retinal Ganglion Cells; Retinal Vessels
PubMed: 30239368
DOI: 10.1097/IIO.0000000000000244