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Öğe Assessment of Cases With Intracranial Hydatid Cyst: A 23-Year Experience(Journal Neurological Sciences, 2014) Turan, Yahya; Yilmaz, Tevfik; Gocmez, Cuneyt; Kamasak, Kagan; Kemaloglu, Serdar; Tekin, Recep; Hattapoglu, SalihObjective: Brain is involved in 1-2% of hydatid cyst infections. A cranial location is rare. In this study, we aimed to assess clinical findings, radiological investigations, and treatment modalities of cases with intracranial hydatid cyst. Materials and Method: The present study included 26 patients operated for cerebral hydatid cyst disease between January 1990 and October 2012. Results: Seventeen patients were male and 9 were female. The mean age of the study population was 20.3 years (range 7-50 years). Headache and nausea were the most common clinical symptoms. The lesions were demonstrated by computed tomography (CT) and magnetic resonance imaging (MRI) as large, smooth, thin walled, spherical-shaped, cystic homogenous lesions with the same density as cerebro spinal fluid, which showed no edema or contrast uptake. Two patients were complicated or infected cysts with perifocal edema and contrast uptake. In 20 patients, the cysts were removed completely with Dowlings technique, by rectifying cysts without rupturing. Eleven patients with ruptured cysts during operation, recurrent or systemic hydatid cyst were treated medically. Conclusion: Medical therapy appears effective in hydatid cyst disease. Cerebral hydatid cysts should be excised totally without rupturing them. Preoperative imaging techniques are central to surgical planning. Intracranial hydatid cyst should be remembered when CT or MRI shows a cystic lesion, especially in countries where hydatid cyst is endemic.Öğe Co-occurrence of lumbar spondylolysis and lumbar disc herniation with lumbosacral nerve root anomaly(Medknow Publications & Media Pvt Ltd, 2014) Yilmaz, Tevfik; Turan, Yahya; Gulsen, Ismail; Dalbayrak, SedatLumbosacral nerve root anomalies are the leading cause of lumbar surgery failures. Although co-occurrence of lumbar spondylolysis and disc herniation is common, it is very rare to observe that a nerve root anomaly accompanies these lesions. A 49-year-old male patient presented with sudden-onset right leg pain. Examinations revealed L5/S1 lumbar spondylolysis and disc herniation. At preoperative period, he was also diagnosed with lumbosacral root anomaly. Following discectomy and root decompression, stabilization was performed. The complaints of the patient diagnosed with lumbosacral root anomaly at intraoperative period were improved at postoperative period. It should be remembered that in patients with lumbar disc herniation and spondylolysis, lumbar root anomalies may coexist when clinical and neurological picture is severe. Preoperative and perioperative assessments should be made meticulously to prevent neurological injury.Öğe The Contribution of Cervical Dynamic Magnetic Resonance Imaging to the Surgical Treatment of Cervical Spondylotic Myelopathy(Turkish Neurosurgical Soc, 2015) Dalbayrak, Sedat; Yaman, Onur; Firidin, Mustafa Nevzat; Yilmaz, Tevfik; Yilmaz, MesutAIM: Cervical spine is the most kinetic segment of the whole vertebrae. The radiologic imaging methods concern with the morphologic changes but give no functional data. At flexion, spinal cord strains, anterior osteophytic compression increases. At extension, spinal canal gets narrower, cord shortens and gets thicker, compression of posterior ligament gets abberant and cord compression increases. MATERIAL and METHODS: 258 cervical spondylotic myelopathy (CSM) cases were scanned by conventional magnetic resonance imaging (MRI) and additionally dynamic MRI. Contributions of dynamic cervical MRI to the surgical plans and results were evaluated. RESULTS: We had sagittal and axial T2W MR scans at flexion and extension, in addition to the neutral cervical MR imaging. We found that the AP diameter of spinal canal is increased 14.9% in flexion and decreased 13.4% in extension relative to the neutral MR imaging. CONCLUSION: The changes of the cord compression and the transvers area of cord which is the most important prognostic indicator in spinal diseases and also the area of spinal cord and subarachnoid space can be detected via dynamic axial sections of MRI. Dynamic MR images may be helpfull in the decision making for the surgical treatment of CSM.Öğe Current and future surgery strategies for spinal cord injuries(Baishideng Publishing Group Inc, 2015) Dalbayrak, Sedat; Yaman, Onur; Yilmaz, TevfikSpinal cord trauma is a prominent cause of mortality and morbidity. In developed countries a spinal cord injury (SCI) occurs every 16 min. SCI occurs due to tissue destruction, primarily by mechanical and secondarily ischemic. Primary damage occurs at the time of the injury. It cannot be improved. Following the primary injury, secondary harm mechanisms gradually result in neuronal death. One of the prominent causes of secondary harm is energy deficit, emerging from ischemia, whose main cause in the early stage, is impaired perfusion. Due to the advanced techniques in spinal surgery, SCI is still challenging for surgeons. Spinal cord doesn't have a self-repair property. The main damage occurs at the time of the injury primarily by mechanical factors that cannot be improved. Secondarily mechanisms take part in the following sections. Spinal compression and neurological deficit are two major factors used to decide on surgery. According to advanced imaging techniques the classifications systems for spinal injury has been changed in time. Aim of the surgery is to decompress the spinal channel and to restore the spinal alinement and mobilize the patient as soon as possible. Use of neuroprotective agents as well as methods to achieve cell regeneration in addition to surgery would contribute to the solution.Öğe The Effect of Hydrocephalus on the Optic Nerve in the Presence of Intracranial Mass(Elsevier Science Inc, 2024) Arpa, Abdurrahman; Yigit, Abdullah; Basar, Ibrahim; Yilmaz, Tevfik- OBJECTIVE: The measurement of optic nerve sheath diameter is a noninvasive, practical, and economical method used to identify increased intracranial pressure. The purpose of this study is to detect the preoperative and postoperative changes in optic nerve sheath diameter in patients with intracranial mass, to correlate these changes with optic nerve diameter variations, and to evaluate the impact of hydrocephalus on these alterations. - MATERIAL AND METHOD: This study was conducted with patients who presented to our clinic with complaints of intracranial mass, were decided for surgery, and underwent surgical procedures.- FINDINGS: The optic nerve and optic nerve sheath diameter measurement values were different preoperatively and postoperatively, with a significant decrease in the optic nerve sheath diameter in all groups in postoperative measurements, while the optic nerve diameter significantly increased. - CONCLUSIONS: Although there was no significant difference between the effects of hydrocephalus and intracranial mass-related increase in intracranial pressure on the optic nerve and optic nerve sheath, it was observed that hydrocephalus increased intracranial pressure when considering the Evans ratio. It has been determined that as ventricular dilatation increases, so does intracranial pressure, which leads to an increase in the diameter of the optic nerve sheath, resulting in papilledema and thinning of the optic nerve. These findings indicate the importance of early cerebrospinal fluid diversion and monitoring optic nerve sheath diameter in the managementÖğe Effects of Bemiparin Sodium Versus Dabigatran Etexilate After Anastomosis in Rat Carotid Arteries on the Development of Neointima and Thrombolytic Efficacy(Elsevier Science Inc, 2019) Ozturk, Pinar Aydin; Yilmaz, Tevfik; Ozturk, UnalBACKGROUND: Revascularization before infarct development after cerebral ischemia may affect morbidity. The success of revascularization can be less than expected because of spontaneous thrombosis or restenosis with intimal hyperplasia. The aim of this study was to compare dabigatran etexilate, a direct thrombin inhibitor, with bemiparin sodium, a second-generation low-molecular-weight heparin, after carotid artery anastomosis. METHODS: This study used 24 randomly selected Sprague-Dawley rats. The rats were separated into 3 equal groups: group 1 (control group); group 2 (dabigatran group), in which dabigatran 10 mg/kg was orally administered for 7 days; and group 3 (bemiparin group), in which bemiparin 250 IU/kg was subcutaneously administered for 7 days. The right-side carotid artery of rats was used for anastomosis and the left-side carotid artery was used for the control. The carotid artery was explored and transected. Anastomosis was applied using 10/0 polypropylene sutures. After 7 days of treatment, the right and left carotid arteries were removed. Lumen diameter, lumen area, tunica media thickness, edema, vessel wall injury, intimal hyperplasia, thrombus, and inflammation were evaluated in tissue biopsy specimens. RESULTS: Bemiparin used after anastomosis caused less thickening of tunica media and reduced intimal hyperplasia but did not decrease lumen diameter and area. Dabigatran increased edema and inflammation but did not prevent intimal hyperplasia. CONCLUSIONS: Bemiparin reduced intimal hyperplasia and prevented thrombosis angiogenesis, but dabigatran did not prevent intimal hyperplasia, and its anticoagulation effect was more than the antithrombotic effect.Öğe Efficacy of dexamethasone on penicillin-induced epileptiform activity in rats: An electrophysiological study(Elsevier Science Bv, 2014) Yilmaz, Tevfik; Akca, Metehan; Turan, Yahya; Ocak, Hakan; Kamasak, Kagan; Yildirim, MehmetCorticosteroids are extensively used in treatment of many diseases. In neurosurgery practice, dexamethasone (DEX) is commonly used particularly in cerebral edema secondary to brain tumors, head trauma, and central nervous system infections. There are some uncertainties surrounding the secure use of DEX in patients with epilepsy or seizures induced by diseases of the central nervous system such as head trauma and brain tumors. Despite its extensive use, the effect of DEX on epileptiform activity is unclear. In this study the effect of DEX on epileptiform activity was investigated in rats. The effects of 1, 3, and 10 mg/kg DEX on epileptiform activity was compared with effects of antiepileptic drugs commonly employed in treatment of epilepsy, namely phenytoin (PHT) 50 mg/kg and levetiracetam (LEV) 50 mg/kg that were administered intraperitoneally for 1 week. All groups were administered intracortical penicillin (500 IU) to induce epileptiform activity. DEX at the doses of 3 mg/kg and 10 mg/kg significantly reduced spike frequencies compared to the initial values. In conclusion, we think that DEX can effectively decrease the epileptiform activity. (C) 2014 Elsevier B.V. All rights reserved.Öğe Local Tissue Electrical Resistances in Transpedicular Screw Application in the Thoracolumbar Region(Turkish Neurosurgical Soc, 2016) Turan, Yahya; Sayin, Murat; Yurt, Alaattin; Yilmaz, Tevfik; Demircivi Ozer, Fusun; Temiz, CuneytAIM: To determine local tissue electrical resistance differences generated during a screw pass from the pedicle to another tissue rather than determining all individual electrical tissue resistance values. MATERIAL and METHODS: We attempted to measure electrical resistance values of regional tissues in addition to fluoroscopic imaging during application of fixation via a transpedicular screw. We also attempted to detect local tissue electrical resistance alterations in case of malposition of the screw inside the pedicle. For this purpose, local tissue electrical resistances of 10 transpedicular tracks opened with standard track openers bilaterally in 5 vertebrae, and of spinal cord accessed by puncturing the medial walls of three vertebrae in a cadaver were measured. These resistance differences were not only measured in human cadaveric tissue but also in 36 pedicles belonging to a total of 18 vertebrae between Th 1-S1 vertebrae of a sheep cadaver. Both medial and lateral walls were drilled to measure local tissue resistance differences in a sheep cadaver. RESULTS: Our results indicated that local tissue electrical resistance changes were statistically significant in both human and sheep cadaver. CONCLUSION: It is possible to prevent screw malposition using a simple and cheap electrical resistance measurement. Local tissue electrical resistance measurement during transpedicular screw insertion is a safe, simple, cheap, and practical method.Öğe A Modified Technique for the Treatment of Isthmic Spondylolisthesis(Turkish Neurosurgical Soc, 2015) Yilmaz, Tevfik; Dalbayrak, Sedat; Yaman, Onur; Yilmaz, Mesut; Ayten, Murat; Turan, Yahya; Ozturk, KadirAIM: To describe a modified technique for the treatment of single level, isthnnic spondylolisthesis (IS) MATERIAL and METHODS: Forty-two patients who underwent posterior lumbar interbody fusion (PLIF) with spinolaminar autologous bone graft for the treatment of isthmic spondylolisthesis between May 2007 and November 2011, were retrospectively reviewed. All patients underwent total removal of the spinolaminar process, total discectomy and endplate decortication, and proper size spinolaminar autologous bone graft was sequentially inserted into the disc space with posterior instrumentation. Outcomes of the study included visual analogue scale (VAS), Oswestry disability index (ODI), and radiographic fusion. RESULTS: The average duration of follow-up was 3.5 years. Neither has implant failure been observed nor has revision been required so far.The mean Oswestry Disability Index improved from 53% to 9.5%, and visual analog scale for back pain from 8.5 to 3.8 at the first month and 1.3 at the sixth month postoperatively. Visual analog scale for leg pain from 8.3 to 1.4 at the first month and 0.8 at the sixth month postoperatively. All patients had clinical and radiographic evidence of solid fusion without any need for revision. CONCLUSION: The modified posterior lumbar interbody fusion and posterior instrumentation technique is a safe and effective treatment for isthmic spondylolisthesis.Öğe Outcome of Primary Bone Fragment Replacement in Pediatric Patients with Depressed Skull Fracture(Karger, 2019) Oktay, Kadir; Guzel, Ebru; Unal, Emre; Yilmaz, Tevfik; Okten, Ali Ihsan; Guzel, AslanObjective: To evaluate pediatric patients who were operated with the diagnosis of depressed skull fracture. Methods: The records of pediatric patients who presented with traumatic head injury to multicenter neurosurgery clinics between 2002 and 2018 and who were operated with a diagnosis of depressed skull fracture were retrospectively reviewed. All of the patients underwent primary bone fragment replacement operation, and the patients' own bone flaps were used to repair depressed skull fractures in all of them. Results: A total of 78 patients were included in the study. Of the study group, 20 patients presented with mild head injury, 37 had moderate head injury, and 21 had severe head injury. Dural injury was present in 67 patients (86%) and the dura was intact in 11 patients (14%). After surgery, 63 patients (81%) had good outcome, 8 patients (10%) had moderate disability, and 5 patients (6.5%) had severe disability. Two patients with multiple accompanying cranial pathologies died and the mortality rate was 2.5%. Infection was detected in only 2 of the 78 patients who were treated within the first 72 h after trauma. One of them had meningitis and the other skin infection. Both patients were treated with appropriate antibiotherapy. None of the patients in the study group had an infection involving the bone, such as osteomyelitis, or the tissues under the bone, such as subdural-epidural empyema or abscess. None of the patients required reoperation and removal of the bone. Conclusion: In the present study, as the pathologies accompanying the depressed skull fractures of the patients increased, Glasgow Coma Scale scores at arrival and Glasgow Outcome Scale scores at discharge decreased. Regardless of whether the depressed fracture is simple or compound, primary bone fragment replacement with appropriate decontamination of the fractured bone and operation area via single-session intervention gives good results. It is important to perform the surgery as soon as possible to reduce the risk of contamination. Primary bone fragment replacement seems to be an appropriate treatment option for depressed skull fractures. (c) 2019 S. Karger AG, BaselÖğe Pediatric Orbital Roof Intradiploic Meningioma Operated by Eyebrow Incision(Karger, 2020) Aydin Ozturk, Pinar; Yilmaz, Tevfik; Ozturk, Unal; Aydin, KamuranIntroduction: Primary intradiploic meningiomas account for <1% of all osseous calvarial lesions and are categorized as bone tumors. They are frequently observed in the frontotemporal region of the calvarium, anterior cranial fossa, and orbit. We present a case of intradiploic meningioma of the orbital roof, which is rarely observed in the pediatric age-group; it was surgically treated with a unique minimally invasive approach. Case Presentation: A 16-year-old male with chief complaints of headache on the right side for approximately 1 year was presented to our clinic. Cranial MRI revealed an intradiploic mass with homogeneous, hypointense contrast patterns on the T1W and T2W images of the right orbital roof. A skin incision was made through the right eyebrow, and the frontal sinus anterior wall was opened by craniotomy. Gross total resection was achieved by reaching the tumor present in the orbital roof. The mass was characterized as psammomatous meningioma by a pathological examination. Discussion/Conclusion: In cranial oncologic surgery, lesion localization and possible pathological diagnosis are essential for the determination of the correct surgical technique. In particular, in pediatric cases, selecting a method that will reduce the need for transfusion, shorten the surgical time, minimize the chances of facial deformity, and facilitate postoperative care will ensure compliance with the correct and appropriate treatment process.Öğe Recurrent Gliosarcoma in Pregnancy(Hindawi Ltd, 2014) Gulsen, Ismail; Ak, Hakan; Yilmaz, Tevfik; Bulut, Mehmet Deniz; Alkis, Ismet; Bayram, IrfanGliosarcoma is a rare tumor of the central nervous system and it constitutes about 1 to 8% of all malignant gliomas. In this report we are presenting a recurrent gliosarcoma case during a pregnancy in a 30-year-old woman. This is the first report presenting gliosarcoma in the pregnancy.Öğe Surgical management of sporadic hemangioblastomas located in the posterior fossa of brain(Pisa Univ Press, 2021) Basar, Ibrahim; Ozturk, Pinar Aydin; Tuncer, Mehmet Cudi; Turan, Yahya; Yilmaz, TevfikPurpose: Hemangioblastomas (HBs) are highly vascular tumors, constituting 2%-3% of central nervous system (CNS) tumors. Surgery is a treatment option for HBs. The purpose of this study was to evaluate the demographic, clinical, and radiological findings of patients with HBs who were operated on via microsurgical technique at our clinic and to determine the findings specific to HBs and evaluate their pathological findings and confirmation. Methods: We evaluated age, gender, initial complaints and duration of 100 patients (50 female and 50 male patients), presence of cranial nerve deficits, magnetic resonance imaging, data (localization, presence of hydrocephalus, tumor size, enhancement pattern, and cystic and solid component features), resection rates, pathological findings (grade, Ki-67 ratio, and staining results), recurrence, special conditions of patients, and the final status of patients in this study. Results: Mean age was 39.08 +/- 14.77 years and 66.7% of the patients presented with cerebellar findings. Five of the cases were located in the brainstem, five were located in the cerebellopontine angle, and two were in the cerebellar cortex. In all patients, gross total resection was performed using arteriovenous malformation repair. Conclusions: Surgical intervention of small and cystic tumors can be performed safely with en bloc resection along with preoperative detailed imaging, improved microsurgical techniques, and an extensive understanding of anatomical and vascular structures. On the contrary, patients with a brainstem invasion and solid structure present surgical difficulties due to arteriovenous malformation-like vascularizations; therefore, gross total resection is the optimal treatment in HBs.Öğe Surgical Therapy of a Vertebral Artery Aneurysm With Saccular and Fusiform Segments(Lippincott Williams & Wilkins, 2014) Yilmaz, Tevfik; Turan, Yahya; Ceviz, AdnanVertebral artery aneurysms form a group of aneurysms having high rates of rebleeding, morbidity, and mortality, poor treatment outcomes, as well as low rate of surgical treatment. Examinations for subarachnoid bleeding revealed a vertebral artery aneurysm with a diameter of 12 mm in a 67-year-old man who presented with headache. The vertebral artery aneurysm with saccular and fusiform segments was shrunk and clipped via lateral left suboccipital approach. No neurologic deficit was present at the postoperative period. Control digital subtraction angiography showed complete shrinkage of aneurysm with continued blood flow and no residue. Clinical findings, treatments, and surgical approaches of VA aneurysms are different from anterior and posterior circulation aneurysms. Microneurosurgical clipping is the most effective treatment of vertebral artery aneurysms in suitable cases. Although endovascular intervention is commonly applied as therapeutic modality for patients with vertebral artery aneurysm, researchers have also emphasized that saccular vertebral aneurysms with fusiform extension can also be surgically treated in suitable cases.Öğe Three-Dimensional Analysis of Foramen Magnum and its Adjacent Structures(Lippincott Williams & Wilkins, 2014) Gocmez, Cuneyt; Goya, Cemil; Hamidi, Cihad; Kamasak, Kagan; Yilmaz, Tevfik; Turan, Yahya; Uzar, ErtugrulThe goal of this effort is to evaluate the anatomy of the foramen magnum (FM) using 3-dimensional computed tomography (3D CT), and determine whether or not the anatomical features of vascular structures and condylar foramen (CF) affect the types of FM. The CT angiography records of 101 patients (44 men and 57 women) were retrospectively examined in this study. Details of the FM, CF, and the vertebral and basilar arteries were examined using maximum intensity projection and 3D rendering images. The average age of the 101 patients was 45.28 +/- 16.3 years. The 8 types of FM, in order of their frequency of occurrence, are as follows: round (19 cases; 18.8%), 2 semicircles (18; 17.8%), egg-shaped (15; 14.9%), hexagonal (14; 13.9%), tetragonal (11; 10.9%), oval (11; 10.9%), pentagonal (9; 8.9%), and irregular (4; 4%). There was no statistically significant relationship between the anatomical features of the vertebral and basilar arteries and the CF with the different types of FM (P >= 0.05). In our study, the diameter of the anteroposterior (AP) FMwas 34.7 +/- 3.6 mm, and the transverse (T) diameter was 29.5 +/- 2.5 mm. The AP and T diameters were significantly higher in men than in women (P = 0.006 and P <= 0.001, respectively). Our study revealed that 3D CT is a safe and easy method for visualizing the anatomical structure of the FM and neighboring structures. Furthermore, this study was the first to demonstrate that there is no correlation between the 8 types of FM and the vertebral artery, basilar artery, and CF.Öğe Treatment Principles for Coccygodynia(Turkish Neurosurgical Soc, 2014) Dalbayrak, Sedat; Yaman, Onur; Yilmaz, Tevfik; Yilmaz, MesutAIM: An evaluation of treatment methods and outcomes for coccygodynia cases that do not respond to conservative treatment. MATERIAL and METHODS: Local anesthetic and steroid injections were applied in 32 coccygodynia cases that did not respond to conservative treatment (average of 15 months). Coccyx excision was performed as surgical treatment in 25 cases that had pain relief after the injections but later re-presented with complaints. The patients' pain levels were assessed with VAS. Postacchini classification was used for patient classification based on plain radiography. RESULTS: 20 (62%) of the cases (the total including injection and surgery groups) had a trauma history. Majority of the cases treated with local steroid injection included patients with Type I, while the 25 cases that received surgical treatment predominantly included Type II patients. One case had post-operative skin infection, which was treated with antibiotics. It was observed by comparing pre-operative and post-operative pain scores that both methods provided significant pain relief in all patients. CONCLUSION: While local steroid injection is an effective method of treatment for Type I patients, the coccyx removal I is an effective method for controlling the pain in patients with trauma history and in Type II, III and IV patients.
