O E Ozcan

Hacettepe University, Ankara, Ankara, Turkey

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Publications (96)119.07 Total impact

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    ABSTRACT: The aim of our study is to present the results of 11 children where auditory brainstem implantation (ABI) was successfully performed to restore hearing. Case presentation. This study was conducted at the departments of Otolaryngology and Neurosurgery at Hacettepe University Ankara, Turkey. Between July 2006 and April 2008, 11 prelingual (30-56 mo) deaf children with several cochlear malformations had ABI. All patients were programmed and were enrolled in auditory verbal therapy sessions and family counseling programs at Hacettepe Auditory Verbal Center. The evaluation was performed at preimplant and again 1, 3, 6, 9, and 12 months post-switch on. The main test components composing this test battery were Ling 6 Sound Detection-Identification Test, Word Identification Test in Turkish, Meaningful Auditory Integration Scale, and Meaningful Use of Speech Scale. Successful brainstem implantations were performed in all patients with retrosigmoid approach. Six children gained basic audiologic functions and were able to recognize and discriminate sounds, and many could identify environmental sounds such as a doorbell and telephone ring by the third month of ABI. Improvement in mean performance on Meaningful Auditory Integration Scale is apparent for all ABI children. Improvement in Meaningful Use of Speech Scale scores in 2 patients, demonstrating that the child using its own voice for speech performance, was observed between the baseline and 12th month. First, 5 children were able to identify Ling's 6 sound by the end of 2 to 6 months, and 2 of them also started to identify words due to their pattern differences and multisyllabic word identification by 6 to 9 months. Two children with Attention Deficit Hyperactivity Disorder have made slower progress than the other children with ABIs. Our preliminary results show that there is adequate contribution of brainstem implants in the development of auditory-verbal skills. Additional handicaps slow the progress of the prelingually deaf children.
    Otology & neurotology: official publication of the American Otological Society, American Neurotology Society [and] European Academy of Otology and Neurotology 10/2009; 30(6):708-15. · 1.44 Impact Factor
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    ABSTRACT: The aim of this experimental study was to investigate the early effects of interleukin-10 (IL-10) and interleukin-1beta antagonist (anti-IL-1beta) against cellular damage, inflammatory reactivity, lipid peroxidation (LPO), and myeloperoxidase (MPO) activity induced by spinal cord ischemia reperfusion injury (IRI). Thirty-two single strain female Albino rats were divided into four groups: control (sham-operated), IRI-alone, IL-10-treated (100 mug/kg), and anti-IL-1beta-treated (1 mg/kg) groups after IRI. IRI was induced by balloon occlusion of the aorta and simultaneous hypovolemia during occlusion. The animals were sacrificed at 24 h. Histopathological and ultrastructural analyses, biochemical studies for determination of LPO and MPO activity and Comet assays (single cell electrophoresis for detecting DNA single strand breaks) were performed in all study groups. Compared with the levels of control (sham-operated) animals, IRI produced a significant increase in the levels of LPO and MPO activity, and prominent tissue damage characterized by leukocyte infiltration, edema and neuronal and glial damage in the affected spinal cord in 24 h. The administration of IL-10 decreased LPO and MPO activity, and suppressed initial inflammatory response in the first 24 h. The effects of anti-IL-1beta were limited to decrease in LPO activity without considerable evidence of cellular preservation. These data suggest that systemic administration of IL-10 attenuates the early ischemic response, and may restrict the tissue damage in the first 24 h after spinal cord ischemia reperfusion injury. Anti-IL-1beta has no considerable effect in this time window. The results of this preliminary study promote further studies with longer time windows on the effects of anti-inflammatory cytokines in spinal cord IRI.
    Journal of Surgical Research 11/2008; 155(2):345-56. · 2.02 Impact Factor
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    ABSTRACT: Herein, we present a case of anaplastic oligodendroglioma with massive spinal metastasis in the first post-operative year without any residual tumor or recurrence in the primary tumor site. Along with the reported literature, our case highlights the importance of periodic radiological evaluation of the spinal canal including the pre- and post-treatment period, in patients with intracerebral oligodendroglioma.
    Turkish neurosurgery 02/2008; 18(3):276-80. · 0.58 Impact Factor
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    ABSTRACT: Almost all meningiomas presenting with intracranial hemorrhage in the literature were admitted with symptoms relating to the hemorrhage and there were no prehemorrhage scans which demonstrated the actual size and apperance of the meningioma. This is a very rare report of a case with a tentorial meningioma documented with pre- and posthemorrhage scans.
    Acta Neurochirurgica 01/2007; 148(12):1315-6. · 1.55 Impact Factor
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    ABSTRACT: A 30-year-old woman presented with a cervical syrinx manifesting as hemihypesthesia. Neuroimaging found no evidence of Chiari malformation or tight cisterna magna. Serial magnetic resonance imaging studies over a 6-year period demonstrated spontaneous and complete resolution of the syrinx accompanied by an asymptomatic clinical course. The natural history of syringomyelia is highly unpredictable. The outcome of surgical treatment for patients with syringomyelia is not always satisfactory, so the indications for surgery are controversial. Spontaneous resolution of syringomyelia unrelated with foramen magnum lesion has various causes. Close follow up of the patient is necessary to monitor for recurrence.
    Neurologia medico-chirurgica 11/2006; 46(10):512-7. · 0.49 Impact Factor
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    ABSTRACT: We present the long-term clinical and angiographic follow-up results of 100 consecutive intracranial aneurysms treated with Onyx liquid embolic system (MTI, Irvine, Calif.), either alone or combined with an adjunctive stent, in a single center. A total of 100 aneurysms in 94 patients were treated with endosaccular Onyx packing. Intracranial stenting was used adjunctively in 25 aneurysms including 19 during initial treatment and 6 during retreatment. All aneurysms except two were located in the internal carotid artery. Of the 100 aneurysms, 35 were giant or large/wide-necked, and 65 were small. Follow-up angiography was performed in all 91 surviving patients (96 aneurysms) at 3 and/or 6 months. Follow-up angiography was performed at 1, 2, 3, 4 and 5 years in 90, 41, 26, 6 and 2 patients, respectively. Overall, aneurysm recanalization was observed in 12 of 96 aneurysms with follow-up angiography (12.5%). All 12 were large or giant aneurysms, resulting in a 36% recanalization rate in the large and giant aneurysm group. One aneurysm out of 25 treated with the combination of a stent and Onyx showed recanalization. There was also no recanalization in the follow-up of small internal carotid artery aneurysms treated with balloon assistance only. At final follow-up, procedure- or device-related permanent neurological morbidity was present in eight patients (8.3%). There were two procedure-related and one disease-related (subarachnoid hemorrhage) deaths (mortality 3.2%). Delayed spontaneous asymptomatic occlusion of the parent vessel occurred in two patients, detected on routine follow-up. Onyx provides durable aneurysm occlusion with parent artery reconstruction resulting in perfectly stable 1-year to 5-year follow-up angiography both in small aneurysms treated with balloon assistance only (0% recanalization rate) and large or giant aneurysms treated with stent and Onyx combination (4% recanalization rate). Endosaccular Onyx packing with balloon assistance may not be adequate for stable long-term results in those with a large or giant aneurysm. However, the recanalization rate of 36% in these aneurysms is better than the reported results with other techniques, i.e., coils with or without adjunctive bare stents.
    Neuroradiology 03/2006; 48(2):113-26. · 2.70 Impact Factor
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    ABSTRACT: A 67-year-old female presented with isolated unilateral abducens nerve palsy progressing in 10 days. There were no signs of elevated intracranial pressure. Magnetic resonance imaging revealed a right parasagittal meningioma. The tumor was grossly totally removed and the patient's nerve palsy gradually improved within 3 weeks. The mechanism of the isolated abducens nerve palsy in this case is attributed to compression of the abducens nerve by entrapment of the cerebrospinal fluid just before entering Dorello's canal under the petrolingual ligament. Linear forces in the midsagittal plane due to the mass effect of the tumor may have temporarily increased the local cerebrospinal fluid pressure and caused 'pseudoentrapment' of the abducens nerve.
    Neurologia medico-chirurgica 03/2006; 46(2):98-100. · 0.49 Impact Factor
  • Neurologia Medico-chirurgica - NEUROL MED-CHIR. 01/2006; 46(10):512-517.
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    ABSTRACT: The nomenclature and borders of the segments of the internal carotid artery (ICA) remain confusing. A classification of segments of the ICA is proposed based on constant anatomical structures, such as the carotid foramen and canal, the petrous bone, the petrolingual ligament (PLL), and the proximal and distal dural rings. The bilateral ICAs were dissected in 15 cadaveric head specimens using different neurosurgical approaches. The bilateral lacerum foramina were studied in five dry skulls. The bilateral segments of the ICA were also examined on carotid angiograms of 10 normal patients and another with the ophthalmic artery originating from the intracavernous portion of the ICA. The present classification divides the ICA into five segments in the direction of the blood flow. The cervical segment is extradural and extracranial, the petrous segment is extradural and intraosseous, the cavernous segment is interdural and intracavernous, the clinoidal segment is interdural and paracavernous, and the cisternal segment is intradural and intracisternal. The ICA did not pass through the lacerum foramen in any specimen. In all specimens, 1/8 to 5/8 of the lacerum foramen was under the deep dural layer of the cavernous sinus. The term 'lacerum segment' as used previously and called the 'trigeminal segment' by us cannot be justified. The PLL is the posterolateral border of the cavernous sinus and the lacerum and trigeminal segments should be included in the cavernous and petrous segments. The ophthalmic artery may originate from the clinoidal ICA, from the cavernous ICA, or from the middle meningeal artery. Instead of using the term 'ophthalmic segment,' the term 'cisternal segment' should be used for the anatomically distinct ICA in the subarachnoid space. This classification should be minimally affected by anatomical variations.
    Neurologia medico-chirurgica 05/2005; 45(4):184-90; discussion 190-1. · 0.49 Impact Factor
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    ABSTRACT: 'Silk cocoon' appearance on spinal angiography is pathognomonic to differentiate paragangliomas from several vascular tumors and malformations of cauda-filar region.
    Acta Neurochirurgica 02/2005; 147(1):99-100; discussion 100. · 1.55 Impact Factor
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    ABSTRACT: Diagnosis of oligodendroglioma from other clear cell neoplasms of central nervous system (CNS) is still challenging despite advances in neuroradiology and molecular diagnostic tools. Herein, we present a 44-year-old male patient who had a diagnosis of right parietal oligodendroglioma grade II in 1994 which recurred in 2002. He presented with intratumoral hemorrhage and he underwent radical resection of tumor in 2003. Histopathological examination of the recurrent tumor showed anaplastic progression with confusing immunohistochemical (IHC) results; the tumor was positive for NeuN and synaptophysin staining. The question arisen was whether the recurrent tumor was an oligodendroglioma with neuronal differentiation or an extraventricular neurocytoma initially misdiagnosed as oligodendroglioma. Repeated IHC staining showed negative results for NeuN and synaptophysin. Chromosomal analysis revealed 1p/19q deletion, which led to the diagnosis ofanaplastic oligodendroglioma grade III. Accurate diagnosis of oligodendroglioma is crucial due to recent advances and promises in its treatment. Current diagnostic methods of oligodendroglial tumors are discussed in context of differentiating oligodendrogliomas from other clear cell neoplasms of CNS, especially from extraventricular neurocytomas.
    Clinical neuropathology 01/2005; 24(5):225-9. · 1.34 Impact Factor
  • Ibrahim M Ziyal, Osman E Ozcan
    Neurosurgery 05/2004; 54(4):1033; author reply 1033. · 2.53 Impact Factor
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    ABSTRACT: Arteriovenous malformation (AVM) may change the cerebral hemodynamics. The purpose of this study was to detect the effects of ionizing radiation (IR) on tissues surrounding AVM in a rat caroticojugular fistula model. Forty rats were divided into four groups. Eight weeks after caroticojugular fistulas and chronic hypoperfusion were created in groups 1 and 2, IR was administered to groups 1 and 3. Group 4 was the control. Brain tissue samples were taken 72 h after irradiation. Comet assay to detect DNA strand breaks (DSB), terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) assay for apoptosis, and free radical measurement were performed. Although the difference between fistula plus irradiation (group 1) and fistula (group 2) was statistically insignificant in terms of DSB and free radical measurement, apoptotic cell count was significantly higher in group 1. Nonetheless, apoptotic cell count corresponded well with both free radicals and DSB in the irradiated group (group 3). Ionizing radiation resulted in significant apoptosis in both groups with or without fistulas. Chronic hypoperfusion might not prevent cerebral damage after IR. Optimal care should be taken with brain tissue around AVM during radiotherapy, regardless of presence or absence of the "steal" phenomenon.
    Neurosurgical Review 05/2004; 27(2):121-7. · 1.97 Impact Factor
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    ABSTRACT: A 58-year-old male was admitted with headache to our neurosurgery clinic. His neurological examination revealed slight left hemiparesis. The radiological evaluation with contrast administred magnetic resonance imaging (MRI) scan demonstrated a right temporo-parietal ring enhancing mass lesion surrounded by edema which was resembling a typical glioma (Fig. 1). The patient was operated on via a temporo-parietal craniotomy and an arteriovenous malformation surrounded by abnormal glial tissue was observed during the exposure. A nidus supplied by several branches arising from the middle cerebral artery (MCA) was obvious. The venous drainage of the malformation was to the superficial venous system. The observed arterial feeders and the draining vein were coagulated and the nidus was macroscopically totally excised. The frozen examination from surrounding glial tissue revealed a high grade glioma. The tumor was also macroscopically totally excised. Postoperatively, the cerebral angiogram demonstrated a right temporal arteriovenous malformation with a centrally excised nidus. The remaining major feeders involved the angular gyrus and the posterior temporal arteries. The venous drainage was to the straight and sigmoid sinuses (Fig. 2). The final histopathological examination of the specimen revealed an arteriovenous malformation surrounded by a high grade glioma (Fig. 3). The patient refused a second operation for total removal of the AVM. Postoperatively, he is doing well with improvement of his left hemiparesis.
    Acta Neurochirurgica 02/2004; 146(1):83-6; discussion 86. · 1.55 Impact Factor
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    ABSTRACT: In this study, the mobilization of all cranial nerves with drilling of several bony structure,cutting of ligaments, folds and dural attachments were performed via different skull baseapproaches.Twenty cadaveric head specimens filled with microfil were dissected bilaterally. On 5 dryskulls, important bony structures were also studied.We observed that the mobilization of the nerves II, III, VI, VIII, and XII were not easycomparing to other cranial nerves. The subfrontal parenchymal tissue should be removedand the olfactory nerve should be dissected for mobilization of the first cranial nerve. Themobilization of the nerves IV, V, VII, IX, and XI were dramatically remarkable after drillingof superior orbital fissure, foramen ovale, foramen rotundum, Fallopian canal, and jugularforamen.
    Neuroanatomy. 01/2004;
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    ABSTRACT: We present our preliminary experience, including mid-term angiographic and clinical follow-up results, with an alternative technique for the endovascular treatment of intracranial aneurysms in a series of patients. This new method, previously described in anecdotal case reports, consists of endovascular deployment of an artificial vessel graft (stent graft or covered stent) in the parent vessel to exclude the intracranial aneurysm sac from circulation. Twenty-five internal carotid artery (ICA) aneurysms in 24 patients were successfully treated by using a Jostent coronary stent graft deployed in the parent artery across the aneurysm neck. All except four aneurysms were extradural, located in the petrous or cavernous portion of the ICA. The four intradural aneurysms were located in the carotico-ophthalmic region. Seventeen aneurysms in 16 patients occurred posttraumatically, secondary to motor vehicle accidents or surgical injury. Twenty-three aneurysms were immediately excluded from circulation after stent graft placement. In two aneurysms, a slow contrast material filling (endoleak) into the aneurysm cavity was observed immediately after treatment. One was thrombosed, as shown by late control angiography; in the other one, a second larger bare stent was used to appose the stent graft's distal end to the ICA wall, thus sealing the endoleak into the distal graft. No technical adverse event, including vessel dissection, vessel perforation, or thromboembolism, occurred with or without clinical consequence. No mortality or morbidity developed during or after the procedure, including the follow-up period. Two-year control angiography in one patient, 1.5-year control angiography in two patients, 1-year control angiography in six patients, and 6-month control angiography in 12 patients were performed, revealing reconstruction of the ICA with no aneurysm recanalization. All symptoms resolved after treatment in the patients who had initially presented with mass effect. Initial anatomic, clinical and mid-term follow-up results in this small series of patients are encouraging. This technique has been proved to have potential in the reconstructive treatment of intracranial aneurysms. Further research and development are needed to optimize the stent graft technology for the cerebrovascular system.
    American Journal of Neuroradiology 01/2004; 25(10):1742-9. · 3.17 Impact Factor
  • M Berker, S Gulsen, O E Ozcan
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    ABSTRACT: We report a case of 57 year-old man with documented posttraumatic acute subdural hematoma and a linear temporal bone fracture. He suffered from a blunt head injury and presented with sudden loss of consciousness. Within 2 hours he became alert and oriented. Follow-up CT scan of brain 2 hours after the initial one showed resolution and redistribution of the subdural hematoma. To our knowledge, this is the first case in the literature about spontaneous resolution of an acute subdural hematoma in a patient with a linear fracture and the fastest resolution period. In this article, the authors discuss the underlying pathophysiology of this uncommon phenomenon.
    Acta Neurochirurgica 09/2003; 145(8):715-7; discussion 717. · 1.55 Impact Factor
  • M Berker, O Cataltepe, O E Ozcan
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    ABSTRACT: A series of 16 children (nine males, seven females) with traumatic epidural haematoma of the posterior fossa (TEHPF) is presented. All patients had a history of mild to moderate trauma to the occiput. The causes were falls in 15 and traffic accident in one case. Four of the 16 cases had depressed fractures of the occipital bone. Surgical intervention was performed in all cases. In 14 patients the outcome was good, one patient had moderate disability and one died. Our study revealed that early diagnosis and urgent surgical intervention may give the patient a chance of total recovery and craniotomy with haematoma evacuation is an appropriate surgical technique as in the case of supratentorial extradural hematoma.
    British Journal of Neurosurgery 07/2003; 17(3):226-9. · 0.86 Impact Factor
  • Acta Neurochirurgica 03/2003; 145(2):159-61; discussion 161. · 1.55 Impact Factor
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    ABSTRACT: The goal of this study was to investigate whether stimulation of trigeminal afferents in the cornea could enhance cerebral blood flow (CBF) in rats after they have been subjected to experimental subarachnoid hemorrhage (SAH). Cerebral vasospasm following SAH may compromise CBF and increase the risks of morbidity and mortality. Currently, there is no effective treatment for SAH-induced vasospasm. Direct stimulation of the trigeminal nerve has been shown to dilate constricted cerebral arteries after SAH; however, a noninvasive method to activate this nerve would be preferable for human applications. The authors hypothesized that stimulation of free nerve endings of trigeminal sensory fibers in the face might be as effective as direct stimulation of the trigeminal nerve. Autologous blood obtained from the tail artery was injected into the cisterna magna of 10 rats. Forty-eight and 96 hours later (five rats each) trigeminal afferents were stimulated selectively by applying transcorneal biphasic pulses (1 msec, 3 mA, and 30 Hz), and CBF enhancements were detected using laser Doppler flowmetry in the territory of the middle cerebral artery. Stimulation-induced changes in cerebrovascular parameters were compared with similar parameters in sham-operated controls (six rats). Development of vasospasm was histologically verified in every rat with SAH. Corneal stimulation caused an increase in CBF and blood pressure and a net decrease in cerebrovascular resistance. There were no significant differences between groups for these changes. Data from the present study demonstrate that transcorneal stimulation of trigeminal nerve endings induces vasodilation and a robust increase in CBF. The vasodilatory response of cerebral vessels to trigeminal activation is retained after SAH-induced vasospasm.
    Journal of Neurosurgery 12/2002; 97(5):1179-83. · 3.15 Impact Factor

Publication Stats

832 Citations
119.07 Total Impact Points


  • 1989–2008
    • Hacettepe University
      • • Department of Neurosurgery
      • • Department of Medicine
      Ankara, Ankara, Turkey
    • Kahramanmaras State Hospital
      Marache, Kahramanmaraş, Turkey
  • 2001
    • Pamukkale University
      • Department of Neurosurgery
      Denisli, Denizli, Turkey
  • 1996–1998
    • Adnan Menderes University
      • Department of Neurosurgery
      Güsel Hissar, Aydın, Turkey