Donald C Hood

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..Standards for performance of the basic clinical mfERG test with a stimulus array of 61 or 103 hexagons, as well as for reporting the results, are specified...

..To better understand the influence of cones on the appearance of this band, the intensity of its signal in patients with diminished cone function was examined...

..To the best of the authors' knowledge, this is the first reported case of discal cyst resulting in bilateral radiculopathy...

..Repeated anterior surgery, operations lasting more than 10 hours, involving four or more levels (including C-2), obesity, asthma, and blood transfusions of more than 4 U (1000-1200 ml) are all considered major risk factors...

..To investigate the repeat reliability of the multifocal visual evoked potential (mfVEP)...

..Complications observed in the first 2 years of a study involving 116 single-level dynamic-plated ACF were largely eliminated by introducing more prolonged bracing and improved surgical techniques for the study's last 4 years...

..Second, previous work by others was shown to be consistent with this model...

..However, this technique is developing rapidly; advances in commercial hardware and software are expected in the near future...

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..To evaluate a linear model that relates the glaucomatous loss in retinal nerve fiber (RNFL) thickness, measured with optical coherence tomography (OCT), to the loss in sensitivity, measured with standard automated perimetry (SAP)...

..To test a linear model relating the regional loss in retinal nerve fiber (RNFL) thickness to the corresponding regional loss in sensitivity with data from patients with previous anterior ischemic optic neuropathy (AION)...

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..These 2007 guidelines, from the International Society for Clinical Electrophysiology of Vision (ISCEV: http://www.iscev.org ), replace the ISCEV guidelines for the mfERG published in 2003...

..A wide variety of bone volume expanders are being used in performing posterolateral lumbar noninstrumented and instrumented lumbar fusions. This article presents a review of their efficacy based on fusion rates, complications, and outcomes...

..High fusion rates and adequate outcomes were observed after multilevel laminectomies and 1 and 2-level instrumented posterolateral fusions performed using lamina autograft and demineralized bone matrix: Osteofil/ICM...

..To gain better understanding of the relationship between abnormalities detected by the multifocal VEP (mfVEP) compared with those detected by static achromatic, automated perimetry in patients with glaucoma...

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..To describe a methodology for measuring abnormal timing of monocular multifocal visual evoked potentials (mfVEP)...

..To describe methods for measuring interocular latency differences of multifocal visual evoked potentials (mfVEP) and for determining regions with abnormal interocular latencies in patients...

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..Following gross total resection of lumbar tumors in adults, reserving radiation therapy for secondary recurrences provides optimal management...

..To better understand the relationship between the amplitude of the pattern electroretinogram (PERG) and visual loss, measured with static automated perimetry...

..This deviation suggests that one or more of the model's assumptions may be violated. Second, the latency of the mfVEP changed far less than expected based upon single-cell data...

..Although Vitoss/B-TCP and laminar autograft resulted in pseudarthrosis for 1 of 27 single level and 2 of 13 two level posterolateral instrumented lumbar fusions, only 1 of the latter patients required a secondary fusion...

..Outcome measures spanning 1- to 2-year postoperative intervals frequently included surgeon-based rather than the current patient-based analysis, the lat-ter including the Medical Outcomes Trust Short Form-36...

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..Given the software and techniques needed to record and interpret the results, mfVEP testing should be performed in centers experienced with this technique...

..Finally, more information is needed about these tests from longitudinal or prospective studies...

..0 in the fovea. Instead, it appears that there is a change in gain before the mfVEP is generated in area 17...

..The results were comparable. More importantly, we learned that the key factor determining whether results from different machines will be comparable is the algorithm used to segment RNFL thickness, not the type of OCT...

..Retinal nerve fiber (RNFL) thickness and visual field loss data from patients with glaucoma were analyzed in the context of a model, to better understand individual variation in structure versus function...

..Beta tricalcium phosphate (B-TCP) is increasingly used to supplement lamina autograft to perform posterolateral lumbar-instrumented arthrodesis...

..To determine if adjusting for blood vessel (BV) location can decrease the intersubject variability of retinal nerve fiber layer (RNFL) thickness measured with optical coherence tomography (OCT)...

..The complex management of dural lacerations occurring after the resection of multilevel ossification of the posterior longitudinal ligament (OPLL) requires further clarification...

..Utilizing Verdict Search (East Islip, New York), a medicolegal research service for civil and criminal court cases, 78 cervical spine surgical malpractice suits were identified (10-year period)...

..To describe the structural changes in the transition zone from relatively healthy retinal regions to severely affected regions in patients with retinitis pigmentosa (RP) using frequency domain optical coherence tomography (fdOCT)...

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..To assess the within- and between-operator agreement of a computer-aided manual segmentation procedure for frequency-domain optical coherence tomography scans...

..Deliberate or traumatic dural fistulas are typically augmented by a "sealant" or "fibrin glue" to enhance the strength of dural closure...

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..Three and 6 months following single-level anterior corpectomy with fusion, two-dimensional CT scans more accurately confirmed fusion compared with radiographs alone...

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..Pneumatic compression stocking (CS) could provide an alternative means of mechanical prophylaxis alone against DVT and PE and would possibly avoid its hemorrhagic complications...

..To understand better the influence of retinal blood vessels (BVs) on the interindividual variation in the retinal nerve fiber layer (RNFL) thickness measured with optical coherence tomography (OCT)...

..However, this is an evolving technology and the future will undoubtedly see major improvements in the mfVEP technique...

..However, the negative results of this procedure are typically underreported in the literature because few spine surgeons submit and even fewer journals publish negative results...

..Multiplanar CT studies obtained 6 months postoperatively documented 100% donor site fusion for the 23 reconstructed patients. Although iliac crest reconstruction failed to reduce Bodily Pain, it did result in 100% fusion...

..To understand and improve the detection of glaucomatous damage with multifocal visual evoked potentials (mfVEP) obtained from single eyes...

..To determine the relationship between spatially localized multifocal visual evoked potentials (mfVEPs) and Humphrey visual fields (HVFs) in patients with unilateral field defects...

..A study of cervical spine malpractice cases was conducted. Identifying tort reform models may help to resolve a crisis in medical malpractice...

..The artificial bone-volume expander, beta tricalcium phosphate (B-TCP, Vitoss, OrthoVita, Malvern, PA), is increasingly used to supplement autograft in posterolateral lumbar fusions...

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..This study prospectively analyzed posterolateral fusion rates and Short-Form 36 (SF-36) outcomes after multilevel lumbar laminectomies and noninstrumented fusions...

..The immunogenicity of Gelfoam (Pharmacia and Upjohn, Kalamazoo, MI) or microfibrillar collagen, applied during laminectomy, may promote postoperative swelling and significant neural compression...

..Additional electrodes and multiple channels of recording substantially improve the quality of the mfVEP records and the SNR measure provides a useful metric for assessing these benefits...

..The X-Stop (Kyphon, Sunnyvale, CA), a device implanted between adjacent lumbar spinous processes at one or two levels particularly in the geriatric population, theoretically decompresses the spinal canal by reversing the lordosis...

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..To compare loss in sensitivity measured using standard automated perimetry (SAP) with local retinal ganglion cell layer (RGC) thickness measured using frequency-domain optical coherence tomography in the macula of patients with glaucoma...

..To better understand hypodense regions (holes) that appear in the retinal nerve fiber layer (RNFL) of frequency-domain optical coherence tomography (fdOCT) scans of patients with glaucoma and glaucoma suspects...

..In general, this does not present a problem when using the mfVEP in the clinic. However, a retinal problem can be confused with ON/MS or, in fact, dismissed as functional, especially if the fundus appears normal...

..In general, the results of the functional and structural measures showed agreement; however, there were clear examples of disagreements that merit further study...

..5% vs 5.0%, P <.001, chi square).In glaucomatous eyes with achromatic visual fields defects limited to one hemifield, the mfVEP technique can detect evidence of glaucomatous damage in the unaffected hemifield...

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..J. Heeger, A. C. Huk, W. S. Geisler, and D. G. Albrecht (2000) does not fit the results...

..Recurrent pain signaled delayed autograft strut fractures in four of 56 patients undergoing plated single-level anterior corpectomy with fusion...

..Alternatively, for 35 patients undergoing focal laminectomy with posterior fusions using spinous process-based wiring techniques, no screw-related neurovascular injuries occurred, whereas 100% of patients fused...

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..Further, in patients with marked mfVEP delays, a retinal problem could be confused with optic neuritis, especially in a patient with a normal appearing fundus...

..Perhaps PWF with halo stabilization for morbidly obese individuals undergoing one-level ACF would avoid future plate-related problems...

..CONCLUSIONS: Following circumferential cervical procedures, posterior fusions failed in 3 morbidly obese patients where iliac crest autograft was omitted in an attempt to avoid donor site morbidity...

..The differences in the pattern of results in the long duration mfERG data are consistent with a selective loss of the onset responses in our patient population...

..These responses were associated with areas of decreased visual field sensitivity. As RP, CD and DR affect the outer retina, the results are consistent with damage to the outer plexiform layer rather than damage to the inner retina...

..4 degrees ). For the first ring, mfERG amplitudes were more impaired than were the mfVEPs or the visual field thresholds. For most of the patients, there was local response correspondence among our measures of visual function...

..CONCLUSIONS: The mfVEP technique can detect visual field deficits in a minority of eyes with glaucomatous optic disks and normal SAP results...

..To assess the normal variations in retinal nerve fiber layer (RNFL) thickness measured with optical coherence tomography (OCT)...

..To determine the osteogenicity of posterior longitudinal ligament ossification, the posterior longitudinal ligament obtained during anterior cervical surgery from patients with the disorder was analyzed with in vitro cultures...

..Static and dynamic X-ray studies routinely determine whether or not fusion of a fibula strut allograft has occurred after multilevel anterior corpectomy with fusion (ACF) combined with posterior wiring and fusion (PWF)...

..To develop a quantitative measure of local damage to the ganglion cells/optic nerve based on an interocular comparison of multifocal visual evoked potentials (mVEP)...

..A combination of these two factors, a sensitivity change at the receptor and a delay in the response of the inner retina, produces the delayed response of the cone flicker ERG in patients with RP...

..A clinical protocol was developed based on a single white flash energy. It is possible to determine whether a disease is producing a change in S and/or Rm with this single flash energy without the use of any equations...

..The waveform of this component resembles the ONHC reported for the human mERG...

..Basic behavioral and physiological descriptions of light adaptation are reviewed, and recent attempts to model lower-level processing are discussed...

..It is speculated that a markedly diminished second-order kernel is diagnostic of outer plexiform layer damage, not inner plexiform layer damage as is commonly assumed...

..These components were found to be missing or diminished in the records from some patients with glaucoma and diabetes, diseases which affect the inner retina...

..To assess the effects of focal photocoagulation on retinal function in the macular and perimacular areas in patients with diabetes who have clinically significant macular edema...

..To explore the multifocal visual evoked potential (mVEP) as a technique for tracking local optic nerve damage after unilateral optic neuritis (ON)...

..An analysis of the derived inner nuclear layer (INL) response suggests that the sites of disease action are beyond the outer segment and involve a delay in the activation of INL activity...

..CONCLUSIONS: Good agreement exists between macular thickness and functional defects in patients with glaucoma. Study of the macular region may provide a quantitative measure for disease staging and monitoring...

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..Finally areas with extreme sensitivity loss show multi-focal responses with a wide range of amplitudes and implicit times across patients, suggesting different mechanisms of disease action in different patients...

..To detect glaucomatous damage to the inner retina using the multifocal electroretinogram (mERG)...

..To evaluate the nature and extent of retinal dysfunction in the macular and surrounding areas that occurs in patients with diabetes with clinically significant macular edema (CSME)...

..The monkey mfERGs were recorded before and after injections of pharmacologic agents known to selectively block activity of particular cells and circuits in the retina...

..To determine the effect of optic disc drusen on the latency of the pattern-reversal checkerboard visual evoked potentials (VEPs) and multifocal (mf)VEPs and to better understand the pathophysiology of the condition...

..These same techniques can enable the ophthalmologist to monitor the health of these cells and, thus the effectiveness of alternative treatments. ..

..monkeys in which INL activity is pharmacologically dissected, b. normal human subjects, c. patients with disease of the INL, and d. mathematical work. ..

..This could be especially valuable in assessing retinal function of patients with heterogeneous damage as in retinitis pigmentosa, diabetic retinopathy, and glaucoma. ..

..Finally, patients with acute optic neuritis will be followed with behavioral and mVEP techniques. An attempt will be made to understand the recovery o vision following optic neuritis (ON). ..

..The experiments under Aim 4 are designed to improve on the currently available methods of recording and analyzing the multifocal VEP. The aim is to improve the efficacy of the multifocal VEP technique in the clinic. ..

..The experiments under Aim 4 are designed to improve on the currently available methods of recording and analyzing the multifocal VEP. The aim is to improve the efficacy of the multifocal VEP technique in the clinic. ..

..We propose as part of aim 3 to improve our understanding of these relationships as well as to improve our analysis of visual field data. ..

..Thus, we propose to develop a model of the human ERG that encompasses the activity of the inner nuclear layer as well as the receptors...

..The data will be analyzed within the context of recent models of cone systems, models based on recent physiology...

..Finally, we intend to obtain a better understanding of the relative involvement of the rod and different cone mechanisms in retinitis pigmentosa and in progressive cone dystrophy...