Fakülteler / Faculties
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Item Predicting 10-day Mortality in Patients with Strokes Using Neural Networks and Multivariate Statistical Methods(2014) Celik, Guner; Baykan, Omer K.; Kara, Yakup; Tireli, Hulya; 24674954Background: The aim of the present study was to evaluate the performance of 2 different multivariate statistical methods and artificial neural networks (ANNs) in predicting the mortality of hemorrhagic and ischemic patients within the first 10 days after stroke. Methods: The multilayer perceptron (MLP) ANN model and multivariate statistical methods (multivariate discriminant analysis [MDA] and logistic regression analysis [LRA]) have been used to predict acute stroke mortality. The data of total 570 patients (230 hemorrhagic and 340 ischemic stroke), who were admitted to the hospital within the first 24 hours after stroke onset, have been used to develop prediction models. The factors affecting the prognosis were used as inputs for prediction models. Survival or death status of the patients was taken as output of the models. Results: For the MLP method, the accuracies were 99.9% in a training data set and 80.9% in a testing data set for the hemorrhagic group, whereas 97.8% and 75.9% for the ischemic group, respectively. For the MDA method, the training and testing performances were 89.8%, 87.8% and 80.6%, 79.7% for hemorrhagic and ischemic groups, respectively. For the LRA method, the training and testing performances for the hemorrhagic group were 89.7% and 86.1%, and for the ischemic group were 81.7% and 80.9%, respectively. Conclusions: Training and test performances yielded different results for ischemic and hemorrhagic groups. MLP method was most successful for the training phase, whereas LRA and MDA methods were successful for the test phase. In the hemorrhagic group, higher prediction performances were achieved for both training and testing phases. (C) 2014 by National Stroke AssociationItem Evaluation of Choroidal Thickness Using Spectral-Domain Optical Coherence Tomography in Patients with Migraine: A Comparative Study(2015) Karalezli, Aylin; Celik, Guner; Koktekir, Bengu Ekinci; Kucukerdonmez, Cem; 25633615; GOE-6067-2022; HTO-3612-2023Purpose: To assess choroidal thickness in patients with migraine and compare them with healthy controls, using spectral-domain optical coherence tomography (OCT). Methods: In this prospective case-control study, choroidal thicknesses of 20 newly diagnosed migraine patients and 20 age-and sex-matched healthy subjects were measured using a high-speed, high-resolution frequency domain (FD) OCT device (lambda = 840 nm, 26.000 A-scans/s, 5 mu m axial resolution). All patients underwent a complete ophthalmic examination before the measurements. OCT measurements were taken at the same time of day (9: 00 AM), in order to minimize the effects of diurnal variation. Results: There was a statistically significant difference in median choroidal thickness between the migraine patients (277.00 [interquartile range (IQR) 85.75] mu m) and controls (301.00 [IQR 90.50] mu m) (p = 0.012). There were significant differences at all measurement points (p<0.05 for all). Conclusions: The decreased choroidal thickness of patients with migraine might be related to the vascular pathology of the disease. Further studies are needed to evaluate the etiopathologic relationship between choroidal thickness and migraine.Item Effects of Two Different Treatment Techniques on the Recovery Parameters of Moderate Carpal Tunnel Syndrome: A Six-Month Follow-up Study(2016) Celik, Guner; Ilik, Mustafa Kemal; 26657237Purpose: The optimal therapy for moderately severe carpal tunnel syndrome (CTS) remains unclear. In this study, the authors aimed at comparing the clinical and electrophysiologic recovery of CTS after local steroid injection and operation. Methods: This is a clinical prospective study consisting of 100 patients with moderate CTS. The patients were diagnosed electrophysiologically with isolated median nerve neuropathy and had CTS symptoms for at least 3 months. While the patients undergoing local steroid injection were defined as injection group (42 women, 8 men and n = 50), other participants undergoing surgery were defined as operation group (47 women, 3 men and n = 50). The severity of the symptoms and electrophysiologic findings were evaluated before and at the first, third, and sixth months after the treatment. Results: The authors found that all parameters were improved at the end of the first month in both groups. However, the recovery of all parameters increased at the third month and was statistically higher in operation group, compared with injection group. Furthermore, the recovery rate of distal sensory latencies and the visual analog scale scores was decreased in injection group at the third month. The authors observed that the recovery continued in both groups in the sixth month, and the rates of recovery were markedly lower in injection group than in operation group, compared with those obtained at the first month. Conclusions: The clinical recovery was more pronounced than the electrophysiologic recovery. And surgery is more effective technique than steroid injection for the treatment of the moderate CTS in the long term.Item Topiramate-Induced Changes in Anterior Chamber Angle and Choroidal Thickness(2016) Karalezli, Aylin; Koktekir, Bengu Ekinci; Celik, Guner; 26020486; GOE-6067-2022Purpose: To investigate the acute effects of topiramate on the anterior chamber angle (ACA) and choroidal thickness in patients with migraine. Methods: This prospective study included 15 eyes of 15 patients with migraine who have been scheduled to start topiramate therapy. All patients underwent complete ophthalmic examination including measurement of the ACA and choroidal thickness using a spectral domain optical coherence tomography device (Optovue Inc.) and refractive status evaluation with an autorefractokeratometer (KR-8100; Topcon) at the baseline and 1 week after starting therapy. The patients were asked to report any pain or discomfort in their eyes during therapy at the follow-up visit. Results: None of the patients experienced pain or discomfort in their eyes. The mean ACA significantly decreased at the first week of the therapy compared with the baseline levels (40.34 +/- 7.06 degrees and 36.89 +/- 6.87 degrees, respectively) (P=0.001). However, the mean choroidal thickness increased from 277.33 +/- 95.60 mu m at the baseline to 323.40 +/- 84.50 mu m at the first week (P=0.01). There was a nonsignificant increase in the mean refractive error (from -0.25 +/- 0.54 diopter [D] at the baseline to -0.38 +/- 0.49 D after 1 week) (P=0.06). Conclusions: Topiramate can acutely decrease the ACA and increase the choroidal thickness. Because these effects may be asymptomatic, patients with migraine who start this therapy should be warned to be closely followed up by an ophthalmologist.