O E Ozcan

Hacettepe University, Ankara, Ankara, Turkey

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Publications (82)109.22 Total impact

  • [Show abstract] [Hide abstract]
    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. · 1.79 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. · 1.79 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. · 1.31 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. · 1.79 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;
  • 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. · 1.79 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. · 0.95 Impact Factor
  • Acta Neurochirurgica 03/2003; 145(2):159-61; discussion 161. · 1.79 Impact Factor
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    ABSTRACT: Basilar artery fenestrations are most commonly located in the proximal basilar trunk close to the vertebrobasilar junction and may harbor saccular aneurysms. Surgical treatment of such aneurysms has been reported in several cases previously, despite the difficulty of the surgical approach. Endovascular treatment may provide a more convenient treatment alternative in such cases. This case is also interesting in that two discrete aneurysms arise from each limb of the fenestration. A 20-year-old man presented with acute subarachnoid hemorrhage. He had two kissing aneurysms at the fenestrated proximal basilar artery as demonstrated by MRA and selective angiography. The two aneurysms were successfully treated with GDCs via the contralateral vertebral arteries. One-year control angiogram showed stable occlusion. Aneurysms at the fenestrated basilar artery may be effectively treated with endovascular coil occlusion. The occurrence of multiplicity and the treatment alternatives are discussed, with relevant literature review.
    Surgical Neurology 08/2002; 58(1):54-8; discussion 58. · 1.67 Impact Factor
  • Acta Neurochirurgica 04/2002; 144(3):285-8. · 1.79 Impact Factor
  • H H Oruckaptan, O E Ozcan
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    ABSTRACT: Otolaryngol Head Neck Surg 2001;125:571-3.
    Otolaryngology Head and Neck Surgery 12/2001; 125(5):571-3. · 1.72 Impact Factor
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    ABSTRACT: Although lumbar spinal stenosis syndrome is extremely common, considerable controversy continues to surround its classification, diagnosis, and treatment. In this article, we retrospectively analyzed the clinical, radiological, and surgical characteristics of 300 patients operated on in our clinics with the diagnosis of lumbar spinal stenosis. Surgical therapy and outcome are discussed with respect to the known facts. After clinical and radiological evaluation, 300 patients were diagnosed with lumbar spinal stenosis. All patients underwent laminectomy and bilateral foraminotomy at the stenotic level. Surgical outcomes were evaluated as very good, good, same, and poor according to the clinical findings. Ninety percent of the surgically treated patients demonstrated very good and good outcomes. Our conclusion in lumbar spinal stenosis diagnosed by objective clinical and radiological findings is that decompressive laminectomy and extensive foraminotomy without instrumentation allow a good outcome.
    Neurosurgical Review 08/2001; 24(2-3):80-2. · 1.86 Impact Factor
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    ABSTRACT: Intracranial chondroid tumors are infrequently seen in neurosurgical practice. These tumors usually arise from cartilaginous synchondroses at the base of the skull, but occasionally from the pluripotential mesenchymal cells of the meninges. We present here a case of classic low-grade giant chondrosarcoma of the falx cerebri. This is only the second case of this variant reported in this location, and we summarize the diagnostic criteria with a brief review of literature. A 56-year-old female patient was admitted to the hospital with a history of progressive right-sided weakness occurring in the last 8 months and a recent grand mal seizure. Radiological evaluation demonstrated a large extra-axial mass in the left parafalcine area, suggesting a possible meningioma. An anterior interhemispheric approach enabled gross total removal of the tumor and a histologic diagnosis of a low-grade classic chondrosarcoma was made. The patient is currently stable and has shown no evidence of recurrence in more than 3 years without any adjuvant treatment. Intracranial cartilaginous tumors include classical, mesenchymal and myxoid chondrosarcomas in addition to benign chondromas. Parafalcine localization should be considered for all these variants as well as for meningiomas, hemangiopericytomas, solitary fibrous tumors, and meningeal metastatic carcinomas. Detailed radiological evaluation, light microscopic and ultrastructural analyses, and immunocytochemistry are essential for correct diagnosis. In contrast to mesenchymal and myxoid types, the prognosis of classic variants is usually good and does not require adjuvant treatment modalities if a radical resection of the tumor can be obtained. Increased documentation of clinical, radiological, and histologic findings as well as response to treatment modalities will provide a better understanding of the pathophysiology of these rare tumors, and highlight the optimum treatment strategies
    Surgical Neurology 04/2001; 55(3):174-9. · 1.67 Impact Factor
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    ABSTRACT: The outcome of patients with pituitary adenomas who were treated surgically with or without postoperative radiotherapy was analyzed. The purpose of this study was to determine the factors that strongly influence (A) tumor control, (B) the efficacy of surgery, and (C) radiotherapy based on the hormonal activity of adenomas and its invasion characteristics. Between 1982-1996, 684 patients with the diagnosis of pituitary adenoma were operated on. The mean age was 38 years and the mean follow-up time was 40.5 months. A total of 516 patients who were followed for more than 1 year were studied to analyze the effect of treatment modalities and invasion characteristics on tumor control. There were 297 patients with prolactinomas, 118 patients with somatotropinomas, 45 with corticotropinomas, 17 with mixed adenomas, two with thyrotropinomas, and 205 with null cell adenomas. All patients were classified according to Hardy's modified radiological classification scheme and analyzed in invasive and noninvasive groups individually based on this classification system. In the early postoperative period, 230 of these patients were given conventional radiotherapy with a mean dose of 4400 cGy. The following factors were analyzed for prognostic significance in tumor control: the effects of surgery and radiotherapy based on tumor types and invasion characteristics, the existence of histologically proven invasion of the dura mater overlying the sellar floor, and the early results of topical bromocriptine application in macroprolactinoma patients. Overall surgical complications and mortality rate were similar to those of large series reported in the literature. Except for the invasive somatotropinomas and null cell adenomas, statistical analysis demonstrated the ineffectiveness of radiotherapy on tumor control. We did not detect any positive correlation between the recurrence rate and mean recurrence time or dural invasion of the sellar floor. Topical bromocriptine application seemed to improve tumor control in 21 selected macroprolactinoma patients. Conventional radiotherapy is not as effective as expected, considering its adverse effects. The increased side effects of radiotherapy in cases with supra-parasellar extension, especially to the optic pathway and hypothalamus, limit its benefits, which could be demonstrated only in invasive somatotropinomas and null cell adenomas. In contrast with our current beliefs, tumoral infiltration of the sellar dura mater is not a prognostic factor for recurrence and therefore should not be a criterion for radiotherapy after surgery. Topical application of bromocriptine into the sellar cavity after tumor removal seems to provide superior results compared with the conventional treatment modalities.
    Surgical Neurology 04/2000; 53(3):211-9. · 1.67 Impact Factor
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    ABSTRACT: Spinal extradural angiolipomas are distinct, benign, and rare lesions composed of mature lipocytes admixed with abnormal blood vessels. They account for 0.14% of all spinal axis tumors. The case described here was a 72-year-old patient presenting with a history of paraparesis, hypoesthesia under the T2 level, hyperreflexia, and urinary overflow incontinence that appeared within 7 days after the administration of a coronary vasodilator drug regimen. The spinal magnetic resonance scan showed a lipomatous mass with signal void lesions, suggesting a vascular component of the tumor. The patient improved rapidly after surgical resection of the epidural tumor and decompression of the cord. According to the present literature, the duration of neurological symptoms ranges from 1 to 180 months (mean 28 months). But this patient's neurological deterioration took place 4 days before hospitalization. We believe that this can be explained by the increased tumor blood volume caused by vasodilator drugs, which in turn exerted a pulsatile compressive effect on the cord.
    Journal of Spinal Disorders 09/1999; 12(4):353-6. · 1.21 Impact Factor
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    ABSTRACT: We performed this retrospective analysis to determine the efficacy of surgery and radiotherapy over hormonal and volumetric control of prolactinomas, many of which had failed during dopa-agonist therapy. In the same analysis, the efficiency of topical bromocriptine application as a preliminary study was compared with standard treatment modalities. Between 1982-1997, 429 prolactinoma patients who underwent surgery at Hacettepe University Neurosurgery Department and at Bayindir Medical Center were included in this study. All patients were classified according to Hardy's classification scheme and were further divided into 'invasive' and 'non-invasive' groups based on this radiological classification system. The mean follow-up time was 38.4 months. One hundred and thirty five patients had peroperative bromocriptine application into the sellar cavity and these, either receiving radiotherapy (RT) or not, were analysed separately from the other 294 patients. In the early post-operative period, 104 of these patients were given conventional radiotherapy with median dose of 4500 cGy. We focused on the effects of surgery and radiotherapy over volumetric and hormonal tumour control on the basis of invasion characteristics and the early results of topical bromocriptine application in macroprolactinoma patients; and compared our results with the literature. Statistical analysis revealed that radiotherapy was not effective over hormonal and volumetric tumour control for prolactinomas. We did not observe any correlation to dural invasion of the sellar floor, recurrence, and the disease-free survival time. Topical bromocriptine application seemed to improve the volumetric control in 135 selected macroprolactinoma patients but not hormonal response compared with the standard treatment modalities. Conventional radiotherapy is not as effective as expected for prolactinomas and should not be preferred considering its adverse effects. Tumoural infiltration of the sellar dura mater is not a prognostic criterion for recurrence expectation and, therefore, should not be a criterion for radiotherapy after surgery. After subtotal removal, postoperative dopa-agonist therapy should be considered even if the patient was intolerant or resistant to previous treatment since surgery seems to improve patients' drug tolerance and cooperation due probably to the lower dose requirement. The early results of topical bromocriptine application seem to improve volumetric tumour control but this should not be accepted as a judgement since we need to wait for later results and to expand the sample size for more reliable interpretation.
    Acta Neurochirurgica 02/1999; 141(12):1287-94. · 1.79 Impact Factor
  • Mehmet Turgut, Ösman Ekin Ozcan, Can Zafer Karaman
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    ABSTRACT: Clinical, radiographic, and operative findings in two children with intra-osseous pseudomeningocele of the occipital bone due to cranial trauma are presented here, along with a literature review of this uncommon radiologic entity.
    Australasian Radiology 09/1998; 42(3):262-3. · 0.51 Impact Factor
  • S Inci, O E Ozcan, K Kilinç
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    ABSTRACT: Oxygen free radical-mediated lipid peroxidation has been proposed to be one of the major mechanisms of secondary damage in traumatic brain injury. The first purpose of this study was to establish the time-level relationship for lipid peroxidation in injured brain tissue. The second purpose was to examine the protective effect of alpha-tocopherol against lipid peroxidation. For this study, 65 guinea pigs in five groups were studied. Five of the animals were identified as a control group, and the remaining 60 animals were divided equally into four groups (Groups A, B, C, and D). Mild injury (200 g x cm) (Groups A and C) and severe injury (1000 g x cm) (Groups B and D) were produced by the method of Feeney et al. Alpha-tocopherol (100 mg/kg) was administered intraperitoneally before brain injury in Groups C and D. Five animals from each group were killed immediately after trauma, five after 1 hour, and the remaining five animals after 36 hours. Lipid peroxidation in traumatized brain tissues was assessed using the thiobarbituric acid method. In all groups with traumatic brain injuries, levels of malondialdehyde, a lipid peroxidation product, were higher than in the control group. The amount of lipid peroxidation was increased by the severity of the trauma. Alpha-tocopherol significantly suppressed the rise in lipid peroxide levels in traumatized brain tissues. This study demonstrates that lipid peroxidation is increased by the severity of trauma and that alpha-tocopherol has a protective effect against oxygen free radical-mediated lipid peroxidation in mild and severe brain injury.
    Neurosurgery 09/1998; 43(2):330-5; discussion 335-6. · 3.03 Impact Factor
  • M Turgut, K Tahta, O E Ozcan, B Onol
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    ABSTRACT: Oligodendrogliomas are relatively rare tumors that arise from the oligodendrocyte or its precursors. The role of postoperative radiotherapy (RT) in these tumors still remains unclear. Data concerning a study on 77 histologically verified cases of oligodendrogliomas of the brain among a total number of 1884 cases of an intracranial glioma treated at the Hacettepe Medical Centre between 1964 and 1991 were reviewed and analyzed (6.5%). One patient died in the early postoperative period and 8 patients in pediatric age group with an aggressive from of the tumor died within 6 months of treatment. The results suggest that oligodendrogliomas which arise in childhood primarily in the intraventricular region should be considered potentially more malignant than other lesions of this type. Because of this, we believe that postoperative radiotherapy is necessary to prevent the recurrences.
    Neurosurgical Review 02/1998; 21(2-3):138-46. · 1.86 Impact Factor
  • M Turgut, O Ertürk, S Saygi, O E Ozcan
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    ABSTRACT: A review of nasopharyngeal carcinomas (NPCs) treated in the Hacettepe University Hospitals is presented. One hundred twenty-four patients between the ages of 3 years and 72 years were managed in the period 1968-1992. Of these cases, 48 had only cranial nerve (CN) involvement on admission. The most commonly affected CNs were the VIth and the Vth, in that order. The prognostic significance of this finding is obvious, because early diagnosis and treatment is vital in a cancer patient. This study includes retrospective analysis of 124 patients with NPC. The patients were investigated with respect to clinical and radiological diagnosis and outcome. Our results also show that CN involvement in NPC usually requires careful neuro-otological examination. It is suggested that increased knowledge and understanding of the disease among neurosurgeons, neurologists and ENT surgeons would improve the prognosis of patients with NPC.
    Neurosurgical Review 02/1998; 21(4):243-8. · 1.86 Impact Factor

Publication Stats

650 Citations
109.22 Total Impact Points

Institutions

  • 1989–2007
    • Hacettepe University
      • • Department of Neurosurgery
      • • Department of Radiology
      • • 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