Levent Güngör
Ondokuz Mayıs University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Levent Güngör.
Neurology | 2010
Hakan Ay; Levent Güngör; Ethem Murat Arsava; Jonathan Rosand; Mark G. Vangel; Thomas Benner; Lee H. Schwamm; Karen L. Furie; W. J. Koroshetz; A. G. Sorensen
Background: There is currently no instrument to stratify patients presenting with ischemic stroke according to early risk of recurrent stroke. We sought to develop a comprehensive prognostic score to predict 90-day risk of recurrent stroke. Methods: We analyzed data on 1,458 consecutive ischemic stroke patients using a Cox regression model with time to recurrent stroke as the response and clinical and imaging features typically available to physician at admission as covariates. The 90-day risk of recurrent stroke was calculated by summing up the number of independent predictors weighted by their corresponding β-coefficients. The resultant score was called recurrence risk estimator at 90 days or RRE-90 score (available at: http://www.nmr.mgh.harvard.edu/RRE-90/). Results: Sixty recurrent strokes (54 had baseline imaging) occurred during the follow-up period. The risk adjusted for time to follow-up was 6.0%. Predictors of recurrence included admission etiologic stroke subtype, prior history of TIA/stroke, and topography, age, and distribution of brain infarcts. The RRE-90 score demonstrated adequate calibration and good discrimination (area under the ROC curve [AUC] = 0.70–0.80), which was maintained when applied to a separate cohort of 433 patients (AUC = 0.70–0.76). The models performance was also maintained for predicting early (14-day) risk of recurrence (AUC = 0.80). Conclusions: The RRE-90 is a Web-based, easy-to-use prognostic score that integrates clinical and imaging information available in the acute setting to quantify early risk of recurrent stroke. The RRE-90 demonstrates good predictive performance, suggesting that, if validated externally, it has promise for use in creating individualized patient management algorithms and improving clinical practice in acute stroke care.
Clinical Imaging | 2002
Haydar Ali Tasdemir; Lutfi Incesu; Alper K. Yazicioglu; Ümit Belet; Levent Güngör
We reported five cases of Dyke-Davidoff-Masson syndrome (DDMS) with different clinical and radiological findings. The evaluated parameters were the location of the lesions, midline structural shift effect, pathological and morphological changes on the ipsilateral calvarium, paranasal sinuses and mesencephalon, presence of compensatory contralateral hypertrophy. With the help of both magnetic resonance (MR) and computerized tomography (CT) images, changing degrees of all the evaluated parameters were observed in all five of our patients. In conclusion, no relationship was found between parenchymal and calvarial changes and between the time after onset of the disease and amount of the morphologic and pathological changes.
Annals of Neurology | 2008
Hakan Ay; Ethem Murat Arsava; Levent Güngör; David M. Greer; Aneesh B. Singhal; Karen L. Furie; Walter J. Koroshetz; A. Gregory Sorensen
The level of anticoagulation at the time of stroke onset may influence the size, composition, and dissolution rate of the occlusive clot. We explored the relation between admission international normalized ratio (INR) and acute infarct volume in patients with ischemic stroke.
Brain and Language | 2011
Levent Güngör; Murat Terzi; Musa Onar
Aphasia causes significant disability and handicap among stroke survivors. Language therapy is recommended for aphasic patients, but not always available. Piracetam, an old drug with novel properties, has been shown to have mild beneficial effects on post-stroke aphasia. In the current study, we investigated the effects of 6 months treatment with piracetam on aphasia following stroke. Thirty patients with first-ever ischemic strokes and related aphasia were enrolled in the study. The scores for the National Institutes of Health Stroke Scale (NIHSS), Barthel Index (BI), modified Rankin Scale (mRS), and Gülhane Aphasia Test were recorded. The patients were scheduled randomly to receive either 4.8 g piracetam daily or placebo treatment for 6 months. At the end of 24 weeks, clinical assessments and aphasia tests were repeated. The level of improvement in the clinical parameters and aphasia scores was compared between the two groups. All patients had large lesions and severe aphasia. No significant difference was observed between the piracetam and placebo groups regarding the improvements in the NIHSS, BI and mRS scores at the end of the treatment. The improvements observed in spontaneous speech, reading fluency, auditory comprehension, reading comprehension, repetition, and naming were not significantly different in the piracetam and placebo groups, the difference reached significance only for auditory comprehension in favor of piracetam at the end of the treatment. Piracetam is well-tolerated in patients with post-stroke aphasia. Piracetam taken orally in a daily dose of 4.8 g for 6 months has no clear beneficial effect on post-stroke language disorders.
JAMA Neurology | 2016
Ethem Murat Arsava; Kim Gm; Oliveira-Filho J; Levent Güngör; Noh Hj; Lordelo Mde J; Ross Avery; Maier Il; Hakan Ay
IMPORTANCE Approximately half of recurrent strokes occur within days and weeks of an ischemic stroke. It is imperative to identify patients at imminent risk of recurrent stroke because recurrent events lead to prolonged hospitalization, worsened functional outcome, and increased mortality. OBJECTIVE To test the validity of a prognostic score that was exclusively developed to predict early risk of stroke recurrence in a multicenter setting. DESIGN, SETTING, AND PARTICIPANTS This hospital-based cohort study examined patients with and without magnetic resonance imaging-confirmed recurrent stroke within 90 days after an ischemic stroke. The study was performed at 3 teaching hospitals in the United States, Brazil, and South Korea and comprised adult patients admitted within 72 hours of symptom onset with a magnetic resonance imaging-confirmed diagnosis of acute ischemic stroke. Recruitment to the US cohort was performed from June 1, 2009, through April 30, 2011. Recruitment to the Korean and Brazilian cohorts was performed from January 1, 2007, through December 31, 2011. Data analysis was performed from June 1, 2013, to December 31, 2014. MAIN OUTCOMES AND MEASURES The primary outcome was recurrent ischemic stroke as defined by a clinical incident that was clearly attributable to a new area of brain infarction occurring within the 90 days of index infarction. An investigator who was masked to the patients recurrence status calculated the Recurrence Risk Estimator (RRE) score for each patient based on information available after initial line of testing in the emergency department. We assessed the predictive performance of the RRE by computing the area under the receiver operating characteristic curve. RESULTS The study included 1468 consecutive patients with 59 recurrent ischemic stroke events. The median age of the patients was 69 (interquartile range, 58-79) years, and 633 (43.1%) were female. The cumulative 90-day recurrence rate was 4.2% (95% CI, 3.2%-5.2%). The mean RRE score was 2.2 (95% CI, 1.9-2.5) in patients with recurrence and 1.0 (95% CI, 1.0-1.1) in patients without. The risk of recurrence increased with a higher RRE score (log-rank test, P < .001). The area under the receiver operating characteristic curve for discrimination was 0.76 (95% CI, 0.70-0.82). The RRE identified 710 patients (48.4%) in the study population as high risk (>10%) or low risk (<1%). The sensitivity and specificity were 38% and 93% for identifying low-risk subsets and 41% and 90% for identifying high-risk subsets, respectively. CONCLUSIONS AND RELEVANCE This study confirms the validity of the RRE score in a multicenter cohort of patients with diverse characteristics. Our findings suggest that the RRE could be useful in identifying high- and low-risk patients for targeted stroke prevention.
Medical Principles and Practice | 2011
İnci Güngör; Levent Güngör; Yakup Özarslan; Nurşen Aritürk; Ümit Beden; Dilek Erkan; Musa Onar; İhsan Öge
Objective: To compare the incidence of glaucomatous optic disk appearance between patients with symptomatic atherosclerotic stroke and healthy individuals with normal intraocular pressures (IOP). Subjects and Methods: 46 patients with ischemic stroke with evident lacunar infarction or large vessel atherosclerosis, and 93 age- and sex-matched healthy individuals, all with normal IOP, were included. Patients and controls were examined for the presence of high cup-to-disk ratios (>0.5). Results: Seven patients (15.22%) in the ischemic cerebrovascular disease (CVD) group and 3 controls (3.23%) had glaucomatous optic disk appearance. All subjects with glaucomatous optic disk appearance in the control group and 3 patients in the study group had visual field defects in concordance with normal-tension glaucoma (NTG). The incidence of glaucomatous optic disk appearance was significantly higher in the group with symptomatic atherosclerotic CVD. Conclusion: Atherosclerotic CVD is a risk factor for having glaucomatous optic disk appearance. Symptomatic atherosclerosis involving the brain vasculature may also affect the eye and lead to NTG. Patients with ischemic strokes due to large artery atherosclerosis or small artery occlusion must be examined and followed for NTG.
Thyroid | 2008
Hande Türker; Oytun Bayrak; Levent Güngör; Ahmet Yılmaz; Murat Terzi; Cuneyt Turker; Musa Onar; Hakki Kahraman
Although hypothyroid myopathy is seen frequently and the relationship with autoimmune hypothyroidism and myasthenia gravis is well known, specific forms of hypothyroid myopathy such as Hoffmans syndrome (HS) are rarely described. Here we describe a 40-year-old patient with Hashimoto thyroiditis showing symptoms and signs of two discrete forms of hypothyroid myopathy (HS and myasthenic syndrome) together. To our knowledge this is the first reported case with features of both of these syndromes. We discuss the diagnosis, speculate whether this patient may represent a unique form of hypothyroid myopathy, and report the 6-month follow-up of the patient both clinically and electrophysiologically.
Journal of Clinical Neurology | 2011
Levent Güngör; İnci Güngör; Hilal Eser Öztürk; Musa Onar
Background and Purpose Guillain-Barré syndrome (GBS) is an acute demyelinating polyneuropathy with various clinical features. Optic neuritis occurs in rare cases. In this study we determined the incidence and patterns of visual evoked potential (VEP) abnormality in GBS in association with ophthalmologic findings. Methods Thirty-two patients with a diagnosis of GBS were included in the study. The correlation between pathologic VEPs and categories of neurologic deficit and electrophysiological findings were examined statistically. Results The patients ranged in age from 19 to 77 years. Five cases (16%) had abnormal VEPs. All five of these patients exhibited increased P100 latency differences between the two eyes. Other abnormalities were prolonged p100 latency, increased interocular amplitude difference, and distorted p100 configuration. Pathologic signs on ophthalmologic examination were observed in 80% of patients with abnormal VEPs. VEP abnormality was never present in pure axonal forms. There was no significant correlation between pathologic VEP and cerebrospinal fluid protein level or categories of neurologic deficits. Conclusions Involvement of the optic pathways is not a frequent finding in GBS. When present it is always asymmetric and generally accompanied with pathologic findings on ophthalmologic examination. VEPs may be abnormal in different clinical variants of GBS, and especially in demyelinating forms.
Cerebrovascular Diseases | 2007
Levent Güngör; Musa Onar
312 References 1 Saver JL, Easton JD: Dissection and trauma of cervicocerebral arteries; in Barnett HJM, Mohr JP, Stein BM, Yatsu FM (eds): Stroke: Pathophysiology, Diagnosis and Management. New York, Churchill Livingstone, 1988, pp 769–786. 2 Toyoda K, Imamura T, Saku Y, et al: Medial medullary infarction: analysis of eleven patients. Neurology 1996; 47: 1141–1147. 3 Bassetti C, Bogousslavsky J, Mattle H, Bernasconi A: Medial medullary stroke. Report of seven patients and review of the literature. Neurology 1997; 48: 882–890. 4 Leppert D, Radue E-W: Medial medullary syndrome due to vertebral artery dissection. J Neurol Neurosurg Psychiatr 2001; 70: 130–131. 5 Ropper AH, Fisher CM, Kleinman GM: Pyramidal infarction in the medulla: a cause of pure motor hemiplegia sparing the face. Neurology 1979; 29: 91–95. 6 Kleinert G, Fazekas F, Kleinert R, et al: Bilateral medullary infarction: magnetic resonance imaging and correlative histopathologic findings. Eur Neurol 1993; 33: 74–76. 7 Maeda M, Shimono T, Tsukahara H, Maier SE, Takeda K: Acute bilateral medial medullary infarction: a unique ‘heart appearance’ sign by diffusion-weighted imaging. Eur Neurol 2004; 51: 236–237. 8 Moon S-Y, Kim H-Y, Chung C-S: A sequential bilateral medial medullary infarction separated by 4 months. Neurology 2002; 59: 1814–1815. 9 Mahmood A, Dujveony M, Torche M, Dragovic L, Ausman JL: Microvascular anatomy of foramen caecum medullae oblongata. J Neurosurg 1991; 75: 299–304. 10 Rodriguez-Baeza A, Muset-Lara A, Rodriguez-Pazos M, DomenechMateu JM: Anterior spinal arteries. Origin and distribution in man. Acta Anat 1989; 136: 217–221.
Vascular | 2017
Aysegul Idil Soylu; Sümeyra Arıkan Cortçu; Fatih Uzunkaya; Yunus Oktay Atalay; Tumay Bekci; Levent Güngör; Ümit Belet
Objectives Platelet-to-lymphocyte ratio is a novel biomarker, recently shown to be correlated with atherosclerotic inflammation. This study investigated the role of platelet-to-lymphocyte ratio in patients with carotid artery stenosis and stroke. Methods Patients, who underwent carotid angiography with Multiple Detector Computed Tomography Angiography at our hospital, were retrospectively screened. Patients enrolled were divided into three groups based on the platelet-to-lymphocyte ratio. Patients with a platelet-to-lymphocyte ratio value between 55.0 and 106.71 were assigned to Group I, patients with a platelet-to-lymphocyte ratio value between 106.79 and 160.61 were assigned to Group II and patients with a platelet-to-lymphocyte ratio value between 162.96 and 619.61 were assigned to Group III. The carotid arterial stenosis calculated was classified as per the criteria of North American Symptomatic Carotid Endarterectomy Trial. Results One hundred fifty patients were included in our trial (mean age 61.9 ± 13.1 with 104 males). The rate of carotid arterial stenosis was detected to be higher in patients with a high platelet-to-lymphocyte ratio value (p = 0.010). Additionally, the platelet-to-lymphocyte ratio was positively correlated with the carotid arterial stenosis percentage (r = 0.250, p = 0.002). In the multi-variate regression analysis, platelet-to-lymphocyte ratio was detected to be an independent variable with respect to stroke (odd’s ratio = 1.012, confidence interval = 1.001–1.024, p = 0.031). Conclusions Increased platelet-to-lymphocyte ratio could be a simple and practical marker of the clinical course in patients with carotid arterial stenosis.