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Dive into the research topics where Greg Christoforidis is active.

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Featured researches published by Greg Christoforidis.


Stroke | 2005

Intra-Arterial Thrombolytic Therapy in Peri-Coronary Angiography Ischemic Stroke

Osama O. Zaidat; Andy P. Slivka; Yousef Mohammad; Carmelo Graffagnino; Tony P. Smith; David S. Enterline; Greg Christoforidis; Michael J. Alexander; Dennis M. D. Landis; Jose I. Suarez

Background— Intra-arterial thrombolysis (IAT) for peri-coronary angiography (CA) stroke may be safe and efficacious. However, IAT may increase the risk of intracranial hemorrhage (ICH). Methods— A retrospective study was performed involving 3 university hospitals. All peri-CA IAT-treated cases were identified. Patient demographics, stroke severity, angiographic findings, thrombolytic use, modified Rankin Scale (mRS), ICH, and mortality were determined. Results— A total of 21 patients with post–left CA stroke were treated with IAT (mean age 71.8±12.3 years). Arterial occlusion was found in 14 (66.7%) and 7 (33.3%) of the anterior and posterior circulation, respectively. Mean time-to-therapy was 36±12 minutes from the time the neurological deficit was noted. mRS ≤2 occurred in 10 of 21 (48%) patients. Patients with younger age and shorter time-to-IAT had more complete arterial recanalization and clinical recovery. Symptomatic ICH occurred in 3 (14%) cases, and 4 (19%) patients died. Conclusions— Peri-CA IAT appears to be feasible and safe without increased risk of symptomatic ICH and death when compared with the previously reported IAT literature.


Journal of Neuroimaging | 2004

Qureshi grading scheme for angiographic occlusions strongly correlates with the initial severity and in-hospital outcome of acute ischemic stroke.

Yousef Mohammad; Andrew Xavier; Greg Christoforidis; Eric C. Bourekas; Andrew Slivka

Background. The thrombolysis in myocardial infarction (TIMI) grading scheme and other classification systems have limitations in evaluating patients with ischemic stroke because they do not account for occlusion location or collateral circulation. The Qureshi grading scheme has been recently proposed to evaluate the severity of arterial occlusion in acute ischemic stroke because of limitations in existing grading systems. Methods. The Qureshi grading scheme assigns a score from 0 to 5 on the basis of occlusion site and collateral supply. The authors determined the relationship between initial severity of stroke and outcome at discharge measured by the National Institutes of Health Stroke Scale (NIHSS) and the Qureshi grading scale assessed from initial angiography (by a neuroradiologist blinded to the clinical examination) in 57 patients who underwent intra arterial therapy for acute ischemic stroke within 6 hours of symptom onset. Results. A strong association was observed between the initial severity of neurological deficits and Qureshi scheme on angiography (F ratio = 2.6, P = .03). The initial NIHSS for grade 1 was 11 ± 4 and progressively increased to 23 ± 6 for grade 5. In the multivariate analysis, initial NIHSS was significantly associated with Qureshi scheme on angiography (R2 = 358, P = .03). The mean discharge NIHSS was 12 ± 10 (range, 0–40). There was also a direct relationship between the Qureshi scheme and discharge NIHSS (F ratio = 2.8, P = .02).Conclusion. The Qureshi grading scheme can be effectively used to determine the severity of ischemic stroke (brain at risk) from the initial angiography.


Proceedings of the National Academy of Sciences of the United States of America | 2008

Minimally invasive neuroradiologic model of preclinical transient middle cerebral artery occlusion in canines.

Cameron Rink; Greg Christoforidis; Amir M. Abduljalil; Marinos S. Kontzialis; Valerie Bergdall; Sashwati Roy; Savita Khanna; Andrew Slivka; Michael V. Knopp; Chandan K. Sen

Stroke is currently the third leading cause of death in the United States, with approximately 780,000 Americans affected by a new or recurring stroke each year. Although a variety of therapeutic approaches have shown promise in small-animal models of stroke, the vast majority of clinical trials to test the efficacy of such modalities have failed. To bridge the translational gap between laboratory and clinical research, we developed a preclinical model of acute ischemic stroke in dogs. Using a minimally invasive endovascular approach, a platinum coil was intravascularly guided through the vertebrobasilar system under C-arm fluoroscopy to occlude the M1 segment of the middle cerebral artery (MCA) for 1 h. The approach included femoral artery catheterization to access the MCA and therefore eliminated the occurrence of head trauma associated with other preclinical stroke models relying on transorbital or craniectomy approaches. After 1 h of focal MCA ischemia, the coil was retrieved to cause reperfusion, which was verified by arteriograms. At 24 h, T2-weighted coronal magnetic resonance (MR) images were acquired and processed for three-dimensional reconstruction of the brain and its vasculature. Infarction, limited to the area at risk, was noted. Two independent observers calculated the mean percentage hemispherical lesion volumes as follows: observer 1, 30.9 ± 2.1%; observer 2, 31.2 ± 4.3%. Infarct-affected changes in histology were determined by hematoxylin and eosin as well as by Fluoro-Jade staining. This work reports the successful development of a powerful preclinical model of stroke that lends itself to the study of biologic mechanisms as well as to testing experimental therapeutics.


Journal of Neuroimaging | 2008

Qureshi Grading Scheme Predicts Subsequent Volume of Brain Infarction Following Intra-Arterial Thrombolysis in Patients with Acute Anterior Circulation Ischemic Stroke

Yousef Mohammad; Greg Christoforidis; Eric C. Bourekas; Andrew Slivka

The importance of the site of occlusion and the presence or absence of collaterals on initial angiography in patients with acute ischemic stroke has been recognized. Qureshi recently proposed a scheme that categorizes patients with ischemic stroke based on findings observed on initial angiography.


Journal of Cerebral Blood Flow and Metabolism | 2011

Tocotrienol vitamin E protects against preclinical canine ischemic stroke by inducing arteriogenesis

Cameron Rink; Greg Christoforidis; Savita Khanna; Laura Peterson; Yojan Patel; Suchin Khanna; Amir M. Abduljalil; Okan M. Irfanoglu; Raghu Machiraju; Valerie Bergdall; Chandan K. Sen

Vitamin E consists of tocopherols and tocotrienols, in which α-tocotrienol is the most potent neuroprotective form that is also effective in protecting against stroke in rodents. As neuroprotective agents alone are insufficient to protect against stroke, we sought to test the effects of tocotrienol on the cerebrovascular circulation during ischemic stroke using a preclinical model that enables fluoroscopy-guided angiography. Mongrel canines (mean weight=26.3±3.2 kg) were supplemented with tocotrienol-enriched (TE) supplement (200 mg b.i.d, n=11) or vehicle placebo (n=9) for 10 weeks before inducing transient middle cerebral artery (MCA) occlusion. Magnetic resonance imaging was performed 1 hour and 24 hours post reperfusion to assess stroke-induced lesion volume. Tocotrienol-enriched supplementation significantly attenuated ischemic stroke-induced lesion volume (P<0.005). Furthermore, TE prevented loss of white matter fiber tract connectivity after stroke as evident by probabilistic tractography. Post hoc analysis of cerebral angiograms during MCA occlusion revealed that TE-supplemented canines had improved cerebrovascular collateral circulation to the ischemic MCA territory (P<0.05). Tocotrienol-enriched supplementation induced arteriogenic tissue inhibitor of metalloprotease 1 and subsequently attenuated the activity of matrix metalloproteinase-2. Outcomes of the current preclinical trial set the stage for a clinical trial testing the effects of TE in patients who have suffered from transient ischemic attack and are therefore at a high risk for stroke.


European Spine Journal | 2007

C2/C3 pathologic fractures from polyostotic fibrous dysplasia of the cervical spine treated with percutaneous vertebroplasty

David Dang; Mirza N. Baig; Greg Christoforidis; E. Antonio Chiocca; Joshue Gabriel

We will discuss a potential role of percutaneous vertebroplasty (PVP) in the management of patients with severe fibrous dysplasia of the spine with multiple cervical lesions and C2–C3 pathologic fractures that may not be a good surgical candidate. Polyostotic fibrous dysplasia involvement of the cervical spine is rare. Review of literature indicates only few reported cases of surgical management with one case of mortality indicating increased risks associated with surgical intervention. While PVP is commonly used for the treatment of osteoporotic thoracolumbar vertebral compression fractures, its role in vertebral stabilization for fibrous dysplasia has not been reported. A 35-year-old man with McCune–Albright syndrome and severe polyostotic fibrous dysplasia of C2 and C3 vertebrae presented with severe neck pain, radiculopathy, quadriparesis and myelopathy. The lesion had pathologic fractures, and there was an os odontoideum with cervical cord atrophy at the C1 level. After discussing need for aggressive surgical management and potential complications, we offered PVP due to surgical risks involved. PVP was performed with a posterolateral transpedicular approach without complication. The patient had remarkable improvement in clinical relief of neck pain and improvement of myelopathic symptoms at 1-year follow-up. We present a case that illustrates a potential use of PVP in the management of a patient with symptomatic spinal fibrous dysplasia with associated pathologic fractures who was poor surgical candidate.


Topics in Magnetic Resonance Imaging | 2006

Clinical magnetic resonance imaging of brain tumors at ultrahigh field: a state-of-the-art review.

William T.C. Yuh; Greg Christoforidis; R.M. Koch; Steffen Sammet; Petra Schmalbrock; Ming Yang; Michael V. Knopp

With the advancement of the magnetic resonance (MR) technology, the whole-body ultrahigh field MR system operated from 7 to 9.4 T becomes feasible for the routine patient imaging in clinical settings. The associated potentials and challenges from the perspectives of technology, physics, and biology as well as clinical application of the ultrahigh field MR systems are different from those systems operated at 3 T, 1.5 T, or lower field strength. In this article, we will present our initial experiences of brain tumor imaging using the 7 and 8 T whole-body MR systems at the Ohio State University Medical Center and provide a brief overview pertinent to the ultrahigh field clinical MR systems.


Journal of Neurosurgery | 2007

Use of intraoperative sodium tetradecyl sulfate for the treatment of a spinal epidural hemangioma. Technical note.

Mirza N. Baig; Syed Saquib; Greg Christoforidis; Louis P. Caragine

Spinal hemangiomas can be categorized into three different groups based on location. Vertebral body (VB) hemangiomas are frequent incidental findings on magnetic resonance (MR) imaging. There is a subdivision of these with spinal epidural extension that have been reported in the literature. Spinal hemangiomas can also be epidural without VB involvement; these are extremely rare with few reported cases in the thoracic epidural spinal column. The diagnosis and imaging characteristics as well as the surgical tools used in gross-total resection of spinal epidural hemangioma are not well understood. The authors present a detailed characterization of a spinal epidural hemangioma in a 30-year-old woman who presented with complaints of gradual onset of low-back pain that worsened over 1 year. The MR imaging findings indicated a large L2-S1 epidural spinal mass causing thecal sac compression. The patient underwent an L2-S1 laminectomy, and a vascular extradural mass was noted on the posterior aspect of the dura mater. Preoperative spinal angiography as well as intraoperative angiography was performed. Total resection of the tumor was achieved using intraoperative embolization with sodium tetradecyl sulfate and microscopic dissection. The postoperative MR imaging findings and clinical outcome were excellent. The findings and use of sodium tetradecyl sulfate in gross-total resection are discussed. The authors also review treatment modalities and demonstrate the utility and effectiveness of intraoperative sodium tetradecyl sulfate in grosstotal resection of large difficult spinal epidural hemangiomas.


American Journal of Neuroradiology | 2018

MR Thermography–Guided Head and Neck Lesion Laser Ablation

Daniel Thomas Ginat; Steffen Sammet; Greg Christoforidis

SUMMARY: Interstitial laser ablation has been successfully used as a minimally invasive treatment option for tumors in many parts of the body, including the head and neck. In this article, we describe the use of MR imaging guidance and mapping sequences for accurate localization of the target lesion, percutaneous interstitial laser ablation methods, and the use of MR thermography for temperature monitoring during laser ablation, with a focus on applications in the head and neck region.


Graefes Archive for Clinical and Experimental Ophthalmology | 2013

Retrobulbar vasculature using 7-T magnetic resonance imaging with dedicated eye surface coil

John B. Christoforidis; Peter A. Wassenaar; Greg Christoforidis; Vincent Y. Ho; Michael V. Knopp; Petra Schmalbrock

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Michael V. Knopp

The Ohio State University Wexner Medical Center

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Ming Yang

Ohio State University

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R.M. Koch

Ohio State University

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