Deniz Belen - Independent Researcher (original) (raw)
Papers by Deniz Belen
Flow Diversion in Middle Cerebral Artery Aneurysms: Is It Really an All-Purpose Treatment?
World Neurosurgery, Mar 1, 2016
The outcome of flow diversion for middle cerebral artery (MCA) aneurysms, one of the most common ... more The outcome of flow diversion for middle cerebral artery (MCA) aneurysms, one of the most common sites for intracranial aneurysms, has not been defined thoroughly. We assessed our outcomes in MCA aneurysms (MCAAs) treated by flow diversion, i.e., with either dedicated flow diverters or telescopic stents. Patients with MCAAs were treated by flow diversion if surgical or other endovascular treatment modalities had failed or were deemed likely to fail. Angiographic and clinical outcome of these patients was assessed retrospectively. Aneurysm location on MCA was defined as M1 segment, "true bifurcation" (classical bifurcation of MCA into superior and inferior trunks), "variant bifurcation" (bifurcation of early frontal or early/distal temporal branches), or M2 segment. Aneurysm morphology was classified as saccular versus dissecting/fusiform. Treatment was attempted in 29 MCAAs. Technical failure rate was 3.4% (1/29). Thirteen of aneurysms were fusiform. Of the bifurcation aneurysms, most (10/16) were the variant type. Overall and procedure-related mortality/permanent morbidity rates were 10.3% (3/29) and 3.5% (1/29). Total occlusion rates (mean angiographic follow-up 10.3 months) for saccular and fusiform aneurysms were 40% and 75%, respectively. In bifurcation aneurysms, occlusion was strongly associated with side-branch occlusion (P < 0.005). In this series, flow diversion for the treatment of MCAAs was safe, was effective in the treatment of fusiform MCAAs, and was not as effective at mid-term for MCA bifurcation aneurysms. Unsatisfactory occlusion rate in bifurcation aneurysms likely results from residual filling of the aneurysms in cases in which the jailed side branch remains patent.
Does brain activity differ between the genders?
PubMed, 2014
Averroës in the School of Athens
Neurosurgery, Feb 1, 2009
The European Renaissance was a revolutionary movement in human history. In this era of the rebirt... more The European Renaissance was a revolutionary movement in human history. In this era of the rebirth of humanity, a great number of valuable artworks were created. One of these masterpieces is the magnificent wall painting The School of Athens, by Raphael, which is also known as a "visualization of knowledge." Raphael depicted almost all ancient Greek philosophers in this fresco. The painting displays one noticeable figure among the scholars: the philosopher/scientist Averroës from Andalusia. Western thought was greatly influenced by Averroës' philosophy. Averroës was as extraordinary a physician as he was a philosopher. His medical works presented novel concepts such as the discovery of the photoreceptor function of the retina, describing symptoms and signs of Parkinson's disease, and proposing a cardiac/vascular origin of cerebral stroke. In this article, we aimed to introduce Averroës' works and his contribution to neuroscience in the context of art, framed particularly with Raphael's masterwork The School of Athens.
Neuroscience, Apr 1, 2019
Schweizerische Medizinische Wochenschrift, Jul 12, 2008
Questions under study: General and local uses of anaesthesia are the preferred common methods in ... more Questions under study: General and local uses of anaesthesia are the preferred common methods in the surgical treatment of chronic subdural haematoma (CSDH). The literature provides no information regarding monitored anaesthesia care during surgery of CSDH. In this report we evaluate the clinical results of surgical treatment for CSDH under monitored anaesthesia care. Method: Between 2001 and 2006 twenty consecutive patients with 24 CSDHs were surgically treated under monitored anaesthesia care at one institution. The clinical success of the procedure under monitored anaesthesia care, patient satisfaction, length of hospitalisation, anaesthesia-related complications and neurological outcome were analysed. Results: Mean age was 60.9 years, with 15 patients aged over 60. ASA physical condition score was IV in 11 patients, III in 1, II in 4 and I in 4. In all patients CSDH was successfully drained by burr hole craniotomy under monitored anaesthesia care. There was no anaesthesia-related morbidity or mortality. Mean hospital stay was 4.5 days. Conclusion: Preliminary results indicate that surgery for CSDH under monitored anaesthesia care is safe and effective. Conscious sedation using monitored anaesthesia care, that is a middle ground between general anaesthesia and local anaesthesia, may facilitate patient comfort and surgical competence during surgery for CSDH.
Neurosurgery, Dec 1, 2007
Turkish Neurosurgery, 2017
groups, researchers have explored certain gene mutations that have guided them to search for spec... more groups, researchers have explored certain gene mutations that have guided them to search for specific therapeutic options (6). There is no question that scientists should refrain from using discriminative expressions when specifying any ethnicity. Nonetheless, some authors continue to prefer such terms without knowing their racialist background. One such illreputed term is the Caucasian that has its root in a medical thesis written in 1775 by Johann Friedrich Blumenbach, who suggested the diversity of human race by considering cranial shapes (2). However, his conclusion was later used for spreading scientific racism that has continued until now (13). Neuroscience studies have proved that there is no relationship between cranial shape and intellectuality, as with any other physical characteristic (5). While contemporary ethnic classification originated simply from the qualification of cranial shapes and misused later for scientific racism, this issue may be reconsidered for improvement. In this report, the historical background of such ethnic definitions is presented and discussed, and more suitable terminology is proposed.
Turkiye Klinikleri Tip Bilimleri Dergisi, 2006
Spinal Cord, May 30, 2006
Method: A 31-year-old man was referred to our department with a diagnosis of Pott's disease, a co... more Method: A 31-year-old man was referred to our department with a diagnosis of Pott's disease, a complaint of back pain and gait difficulty for 2 weeks. Neurological examination showed spastic paraparesis and hypoesthesia below the L2 dermatome level. He also had urinary incontinence. Abdominal computed tomography and lumbar magnetic resonance imaging study revealed a giant cystic mass lesion located in the psoas muscle. Posteriorly, the third lumbar vertebral body was destructed and the tumor was compressing the dural sac. A combined anterior and posterior approach was performed. Pathological diagnosis was a yolk sac tumor. Result: His neurological status improved during the postoperative course. A chemotherapy protocol was given including bleomycin, etoposide and cisplatin. Five months after the last chemotherapy, he was brought to the emergency unit in sepsis and died despite antibiotherapy. Conclusion: Yolk sac tumor should be considered in young adult male patients presenting with acute paraparesis even without any signs or medical history of a testis tumor. These tumors may be unresectable; however, decompression of neural structures and stabilization of the spine with instrumentation may cause substantial improvement in neurological deficit and pain relief.
Surgical Neurology, Feb 1, 2009
Background: Currently, there are various antiseptics used for cleaning the skin before surgery, b... more Background: Currently, there are various antiseptics used for cleaning the skin before surgery, but there is no standard procedure in practice. Chlorhexidine and povidone-iodine are the most preferred compounds among antiseptics. Both are proved to be safe and effective for skin disinfection. In this study, our aim was to investigate the combined effects of chlorhexidine and povidone-iodine on the skin's flora before neurosurgical intervention, consecutively. Methods: Randomly, 50 cranial and 50 spine neurosurgery cases were assigned to the study. The first culture was obtained after hair removal and before cleaning the skin with any antiseptic. The second culture was obtained after the skin had been cleaned with chlorhexidine for 3 minutes. Then, the skin was cleaned twice with povidone-iodine for 30 seconds, and the third and fourth cultures were taken from the skin incision area. Bacteria were identified by means of standard laboratory identification methods. Positive culture results were compared statistically among order of cultures obtained. Results: In the first culture evaluation, 39 (33 cnS, 6 Stapylococcus aureus) of 50 cranial samples and 37 (33 cnS, 4 S aureus) of 50 spine samples showed reproduction. In the second culture, 9 cranial and 5 spine samples showed reproduction of cnS. In the third and fourth cultures, no growth was observed (P b .001). Conclusion: Three minutes' cleaning of the incision area with chlorhexidine, followed by 30-second cleaning with povidone-iodine, could be a sufficient disinfection procedure for preoperative preparation of the skin in patients undergoing a neurosurgical procedure.
Exogenous contrast agent improves sensitivity of gradient-echo functional magnetic resonance imaging at 9.4 T
Magnetic Resonance in Medicine, 2004
Relative to common clinical magnetic field strengths, higher fields benefit functional brain imag... more Relative to common clinical magnetic field strengths, higher fields benefit functional brain imaging both by providing additional signal for high-resolution applications and by improving the sensitivity of endogenous contrast due to the blood oxygen level dependent (BOLD) mechanism, which has limited detection power at low magnetic fields relative to the use of exogenous contrast agent. This study evaluates the utility of iron oxide contrast agent for gradient echo functional MRI at 9.4 T in rodents using cocaine and methylphenidate as stimuli. Relative to the BOLD method, the use of high iron doses and short echo times provided a roughly twofold global increase in functional sensitivity, while also suppressing large vessel signal and reducing susceptibility artifacts. Furthermore, MRI measurements of the functional percentage change in cerebral blood volume (CBV) showed excellent agreement with results obtained at much lower magnetic field strengths, demonstrating that MRI estimates of this quantity are roughly independent of magnetic field when appropriate techniques are employed. The derived field dependencies for relative sensitivity and MRI estimates of the percentage change in CBV suggest that the benefits provided by exogenous agents will persist even at much higher magnetic fields than 9.4 T.
Two different approaches regarding hydrocephalus treatment in the islamic world during the middle ages
Turkish Neurosurgery, 2022
Journal of Clinical Neuroscience, 2007
Aneurysms are seen rarely at the P2-P3 junction of the posterior cerebral artery (PCA). P2-P3 jun... more Aneurysms are seen rarely at the P2-P3 junction of the posterior cerebral artery (PCA). P2-P3 junction aneurysm surgery is challenging. Here, a successful clipping of a large P2-P3 junction aneurysm via a subtemporal approach is reported. A 26-year-old woman presented with a 6-month history of left occipito-parietal headache. Computed tomography (CT) scan, magnetic resonance imaging (MRI) and cerebral angiography revealed a 2-cm aneurysm at the P2-P3 junction of the left PCA. Successful neck clipping of the aneurysm was performed via a subtemporal approach without additional neurological deficits or surgical complications. Coil embolization has been suggested as the treatment of choice but PCA aneurysms are also good candidates for microsurgical clipping. The subtemporal approach is simple and safe in experienced hands. P2-P3 junction PCA aneurysms can be successfully clipped via the subtemporal approach without excessive brain retraction, resection of brain tissue or disruption of surface veins.
One of the Earliest Accounts of Head Wounds in Firdaws al-Ḥikma by al-Ṭabarī from the 9th Century
World Neurosurgery, Nov 1, 2017
To present the first Arabic text on suturing scalp wounds. A related section entitled "O... more To present the first Arabic text on suturing scalp wounds. A related section entitled "On the wounds in the head" from the book Firdaws al-Ḥikma (Paradise of the Wisdom) written by al-Ṭabarī in the 9th century was identified and analyzed. This work was one of the earliest medical compendiums in the Islamic world during the medieval period. A printed copy of Firdaws al-Ḥikma edited by Muḥammad Zubayr al-Ṣiddīqī was examined, and findings were compared with relevant knowledge in the literature. A notable part of this text is based on appropriate closure of scalp wounds using sutures. Before this work, only the well-known Indian medical book Suśruta-Saṃhitā had mentioned closure of scalp wounds using sutures. In his work, al-Ṭabarī recommended using materials made of silk or linen for suturing. He additionally proposed some recipes that have a coating feature that prevents bleeding from the wound after it was closed properly. He also dealt with persistent swelling and provided formulas for solving the problem with special compositions. Firdaws al-Ḥikma is a noteworthy work in the history of medicine, and it includes a unique chapter on head wounds. To the best of our knowledge, this is the first mention of suturing scalp cuts in Arabic literature and the second reference in medical literature after the Indian work Suśruta-Saṃhitā.
Turkish Neurosurgery, 2013
AIm: This study aimed to investigate the effects of a new generation antiepileptic agent, levetir... more AIm: This study aimed to investigate the effects of a new generation antiepileptic agent, levetiracetam, on the neural tube development in a chick embryo model that corresponds to the first month of vertebral development in mammals. mAteRIAl and methods: Forty-five Atabey® breed fertilized chicken eggs with no specific pathogens were randomly divided into 5 groups. All of the eggs were incubated at 37.8±2°C and 60±5 % relative humidity in an incubator. Group A was control group. The other eggs were applied physiological saline and drugs at a volume of 10 µL by the in ovo method at the 28th hour of the incubation period. Group B was given distilled water; Group C, physiological saline; Group D, Levetiracetam (L8668) at a dose equivalent to the treatment dose for humans (10 mg/ kg), and Group E, Levetiracetam (L8668) at a dose of 10 times the treatment dose. The embryos in all of the groups were removed from the shells at the 48th hour and morphologically and histologically evaluated. Results: Of the 45 embryos incubated, neural tubes of 41 were closed and the embryos displayed normal development. ConClusIon: Levetiracetam, at a dose equivalent to human treatment dose and 10 times the treatment dose, was shown not to cause neural tube defects in chick embryos.
Asian Spine Journal, 2015
The study retrospectively investigated 15 cases with multilevel noncontiguous spinal fractures (M... more The study retrospectively investigated 15 cases with multilevel noncontiguous spinal fractures (MNSF). Purpose: To clarify the evaluation of true diagnosis and to plane the surgical treatment. Overview of Literature: MNSF are defined as fractures of the vertebral column at more than one level. High-energy injuries caused MNSF, with an incidence ranging from 1.6% to 16.7%. MNSF may be misdiagnosed due to lack of detailed neurological and radiological examinations. Methods: Patients with metabolic, rheumatologic diseases and neoplasms were excluded. Despite the presence of a spinal fracture associated clearly with the clinical picture, all patients were scanned within spinal column by direct X-rays, computed tomography and magnetic resonance imaging. When there were ≥5 intact vertebrae between two fractured vertebral segments, each fracture region was managed with a separated stabilization. In cases with ≤4 intact segments between two fractured levels, both fractures were fixed with the same rod and screw system. Results: There were 32 vertebra fractures in 15 patients. Eleven (73.3%) patients were male and age ranged from 20 to 64 years (35.9±13.7 years). Eleven cases were the American Spinal Injury Association (ASIA) E, 3 were ASIA A, and one was ASIA D. Ten of the 15 (66.7%) patients returned to previous social status without additional deficit or morbidity. The remaining 5 (33.3%) patients had mild or moderate improvement after surgery. Conclusions: The spinal column should always be scanned to rule out a secondary or tertiary vertebra fracture in vertebral fractures associated with high-energy trauma. In MNSF, each fracture should be separately evaluated for decision of surgery and planned approach needs particular care. In MNSF with ≤4 intact vertebra in between, stabilization of one segment should prompt the involvement of the secondary fracture into the system.
Turkish Neurosurgery, 2015
studies, experimental studies in the literature consist of studies where other adjunct devices ot... more studies, experimental studies in the literature consist of studies where other adjunct devices other than flow diverters are not used and they do not represent the small narrownecked aneurysms frequently seen in routine daily practice. In these studies, flow diverter stents direct the blood flow along the parent artery (13) and provide stasis of the blood inside the aneurysm to promote thrombosis of the aneurysm █ INTRODUCTION Flow diverter (FD) devices have been the current endovascular treatment option for the hardly treated intracranial widenecked, fusiform and giant aneurysms (7). Recently, flow diverter stents have been the most important treatment modality because of acceptable morbidity, mortality and high aneurysm occlusion rates (5). Except for a few small AIM: To report patient and procedure-related factors affecting the angiographic and clinical outcome in patients treated with the Silk device. MATERIAL and METHODS: All patients with intracranial aneurysms in whom treatment was attempted with the Silk flow diverter by our neurovascular team between October 2010 and November 2013 were included consecutively. The data was analyzed by an independent stroke neurologist not involved in the treatment of the patients. RESULTS: A total of 96 patients (64 female) with ages range from 3 to 78 were included in this study. We found that 54 of the patients were asymptomatic and 42 of them symptomatic, while 21 had a prior history of subarachnoid hemorrhage (SAH). Mean aneurysm size was 10.2 mm (range 2 to 40 mm). 2 patients died due to consequences of SAH. 3 patients developed visual decline on the follow-up, 2 of these were procedure-related. Symptomatic thromboembolic events were noted in 7 cases. Patients with aneurysms smaller than 13 mm had significantly less complications and higher occlusion rates. The complication rate was significantly high in patients admitted with symptoms. Adjunctive coiling had no impact on outcome. CONCLUSION: Safety and efficacy of flow diversion in this series was closely related to aneurysm size and presenting symptoms. A size cutoff for safety and efficacy has not been reported before and will be useful not only for future studies but also for patient counseling in daily practice. The futility of adjunctive coiling in this series calls for reappraisal of the current recommendations for this specific device.
Neurosurgical Review, 1996
We present 23 cases of Langerhans cell histiocytosis with cen~raI nervous system (CNS) involvemen... more We present 23 cases of Langerhans cell histiocytosis with cen~raI nervous system (CNS) involvement. The major complaints were a mass on the cranial vault in fifteen (65 %), visual disturbance in four (16 %), polyurea-polydipsia in three (13 %), and progressive weakness in all extremities in one patient (4 %). Neurological examination revealed no abnormality in sixteen patients (70 %), cranial nerve palsy, visual field defect and optic atrophy in six (26 %) and paraparesis in one (4 %). Tumoral mass was found to be located on the cranial vault (65 %), in the suprasellar region (21%) and in the spinal column (8 %). The cranium and spinal column were both involved in one patient. All patients underwent surgery; craniectomy with grossly total tumor excision plus cranioplasty (65 %), craniotomy with subtotal tumor excision (26 %), and vertebrectomy with grafting (13 %) were performed. The clinical, radiological and histopathological features, as well as therapeutical considerations are discussed and the pertinent literature is reviewed.
Asian Spine Journal, 2014
A 47-year-old woman was admitted with complaints of progressive weakness in the lower extremities... more A 47-year-old woman was admitted with complaints of progressive weakness in the lower extremities and pain in the back and left leg. Thoracic magnetic resonance imaging (MRI) revealed a spinal intramedullary tumor between the T9 and L1 levels, which were iso-to hypointense on T2 and slightly hyperintense on T1-weighted images. The tumor was resected as total, and the diagnosis was malignant melanoma confirmed with histopathology. Neurological findings improved at the postoperative period and no residual or recurrence was noted on postoperative MRI at the 9-month follow-up. Primary melanoma of the spinal cord, particularly intramedullar localization, is seldomly reported in the literature. We report a primary malignant melanoma of the spinal cord and emphasize the diagnostic and prognostic challenges.
Flow Diversion in Middle Cerebral Artery Aneurysms: Is It Really an All-Purpose Treatment?
World Neurosurgery, Mar 1, 2016
The outcome of flow diversion for middle cerebral artery (MCA) aneurysms, one of the most common ... more The outcome of flow diversion for middle cerebral artery (MCA) aneurysms, one of the most common sites for intracranial aneurysms, has not been defined thoroughly. We assessed our outcomes in MCA aneurysms (MCAAs) treated by flow diversion, i.e., with either dedicated flow diverters or telescopic stents. Patients with MCAAs were treated by flow diversion if surgical or other endovascular treatment modalities had failed or were deemed likely to fail. Angiographic and clinical outcome of these patients was assessed retrospectively. Aneurysm location on MCA was defined as M1 segment, "true bifurcation" (classical bifurcation of MCA into superior and inferior trunks), "variant bifurcation" (bifurcation of early frontal or early/distal temporal branches), or M2 segment. Aneurysm morphology was classified as saccular versus dissecting/fusiform. Treatment was attempted in 29 MCAAs. Technical failure rate was 3.4% (1/29). Thirteen of aneurysms were fusiform. Of the bifurcation aneurysms, most (10/16) were the variant type. Overall and procedure-related mortality/permanent morbidity rates were 10.3% (3/29) and 3.5% (1/29). Total occlusion rates (mean angiographic follow-up 10.3 months) for saccular and fusiform aneurysms were 40% and 75%, respectively. In bifurcation aneurysms, occlusion was strongly associated with side-branch occlusion (P < 0.005). In this series, flow diversion for the treatment of MCAAs was safe, was effective in the treatment of fusiform MCAAs, and was not as effective at mid-term for MCA bifurcation aneurysms. Unsatisfactory occlusion rate in bifurcation aneurysms likely results from residual filling of the aneurysms in cases in which the jailed side branch remains patent.
Does brain activity differ between the genders?
PubMed, 2014
Averroës in the School of Athens
Neurosurgery, Feb 1, 2009
The European Renaissance was a revolutionary movement in human history. In this era of the rebirt... more The European Renaissance was a revolutionary movement in human history. In this era of the rebirth of humanity, a great number of valuable artworks were created. One of these masterpieces is the magnificent wall painting The School of Athens, by Raphael, which is also known as a "visualization of knowledge." Raphael depicted almost all ancient Greek philosophers in this fresco. The painting displays one noticeable figure among the scholars: the philosopher/scientist Averroës from Andalusia. Western thought was greatly influenced by Averroës' philosophy. Averroës was as extraordinary a physician as he was a philosopher. His medical works presented novel concepts such as the discovery of the photoreceptor function of the retina, describing symptoms and signs of Parkinson's disease, and proposing a cardiac/vascular origin of cerebral stroke. In this article, we aimed to introduce Averroës' works and his contribution to neuroscience in the context of art, framed particularly with Raphael's masterwork The School of Athens.
Neuroscience, Apr 1, 2019
Schweizerische Medizinische Wochenschrift, Jul 12, 2008
Questions under study: General and local uses of anaesthesia are the preferred common methods in ... more Questions under study: General and local uses of anaesthesia are the preferred common methods in the surgical treatment of chronic subdural haematoma (CSDH). The literature provides no information regarding monitored anaesthesia care during surgery of CSDH. In this report we evaluate the clinical results of surgical treatment for CSDH under monitored anaesthesia care. Method: Between 2001 and 2006 twenty consecutive patients with 24 CSDHs were surgically treated under monitored anaesthesia care at one institution. The clinical success of the procedure under monitored anaesthesia care, patient satisfaction, length of hospitalisation, anaesthesia-related complications and neurological outcome were analysed. Results: Mean age was 60.9 years, with 15 patients aged over 60. ASA physical condition score was IV in 11 patients, III in 1, II in 4 and I in 4. In all patients CSDH was successfully drained by burr hole craniotomy under monitored anaesthesia care. There was no anaesthesia-related morbidity or mortality. Mean hospital stay was 4.5 days. Conclusion: Preliminary results indicate that surgery for CSDH under monitored anaesthesia care is safe and effective. Conscious sedation using monitored anaesthesia care, that is a middle ground between general anaesthesia and local anaesthesia, may facilitate patient comfort and surgical competence during surgery for CSDH.
Neurosurgery, Dec 1, 2007
Turkish Neurosurgery, 2017
groups, researchers have explored certain gene mutations that have guided them to search for spec... more groups, researchers have explored certain gene mutations that have guided them to search for specific therapeutic options (6). There is no question that scientists should refrain from using discriminative expressions when specifying any ethnicity. Nonetheless, some authors continue to prefer such terms without knowing their racialist background. One such illreputed term is the Caucasian that has its root in a medical thesis written in 1775 by Johann Friedrich Blumenbach, who suggested the diversity of human race by considering cranial shapes (2). However, his conclusion was later used for spreading scientific racism that has continued until now (13). Neuroscience studies have proved that there is no relationship between cranial shape and intellectuality, as with any other physical characteristic (5). While contemporary ethnic classification originated simply from the qualification of cranial shapes and misused later for scientific racism, this issue may be reconsidered for improvement. In this report, the historical background of such ethnic definitions is presented and discussed, and more suitable terminology is proposed.
Turkiye Klinikleri Tip Bilimleri Dergisi, 2006
Spinal Cord, May 30, 2006
Method: A 31-year-old man was referred to our department with a diagnosis of Pott's disease, a co... more Method: A 31-year-old man was referred to our department with a diagnosis of Pott's disease, a complaint of back pain and gait difficulty for 2 weeks. Neurological examination showed spastic paraparesis and hypoesthesia below the L2 dermatome level. He also had urinary incontinence. Abdominal computed tomography and lumbar magnetic resonance imaging study revealed a giant cystic mass lesion located in the psoas muscle. Posteriorly, the third lumbar vertebral body was destructed and the tumor was compressing the dural sac. A combined anterior and posterior approach was performed. Pathological diagnosis was a yolk sac tumor. Result: His neurological status improved during the postoperative course. A chemotherapy protocol was given including bleomycin, etoposide and cisplatin. Five months after the last chemotherapy, he was brought to the emergency unit in sepsis and died despite antibiotherapy. Conclusion: Yolk sac tumor should be considered in young adult male patients presenting with acute paraparesis even without any signs or medical history of a testis tumor. These tumors may be unresectable; however, decompression of neural structures and stabilization of the spine with instrumentation may cause substantial improvement in neurological deficit and pain relief.
Surgical Neurology, Feb 1, 2009
Background: Currently, there are various antiseptics used for cleaning the skin before surgery, b... more Background: Currently, there are various antiseptics used for cleaning the skin before surgery, but there is no standard procedure in practice. Chlorhexidine and povidone-iodine are the most preferred compounds among antiseptics. Both are proved to be safe and effective for skin disinfection. In this study, our aim was to investigate the combined effects of chlorhexidine and povidone-iodine on the skin's flora before neurosurgical intervention, consecutively. Methods: Randomly, 50 cranial and 50 spine neurosurgery cases were assigned to the study. The first culture was obtained after hair removal and before cleaning the skin with any antiseptic. The second culture was obtained after the skin had been cleaned with chlorhexidine for 3 minutes. Then, the skin was cleaned twice with povidone-iodine for 30 seconds, and the third and fourth cultures were taken from the skin incision area. Bacteria were identified by means of standard laboratory identification methods. Positive culture results were compared statistically among order of cultures obtained. Results: In the first culture evaluation, 39 (33 cnS, 6 Stapylococcus aureus) of 50 cranial samples and 37 (33 cnS, 4 S aureus) of 50 spine samples showed reproduction. In the second culture, 9 cranial and 5 spine samples showed reproduction of cnS. In the third and fourth cultures, no growth was observed (P b .001). Conclusion: Three minutes' cleaning of the incision area with chlorhexidine, followed by 30-second cleaning with povidone-iodine, could be a sufficient disinfection procedure for preoperative preparation of the skin in patients undergoing a neurosurgical procedure.
Exogenous contrast agent improves sensitivity of gradient-echo functional magnetic resonance imaging at 9.4 T
Magnetic Resonance in Medicine, 2004
Relative to common clinical magnetic field strengths, higher fields benefit functional brain imag... more Relative to common clinical magnetic field strengths, higher fields benefit functional brain imaging both by providing additional signal for high-resolution applications and by improving the sensitivity of endogenous contrast due to the blood oxygen level dependent (BOLD) mechanism, which has limited detection power at low magnetic fields relative to the use of exogenous contrast agent. This study evaluates the utility of iron oxide contrast agent for gradient echo functional MRI at 9.4 T in rodents using cocaine and methylphenidate as stimuli. Relative to the BOLD method, the use of high iron doses and short echo times provided a roughly twofold global increase in functional sensitivity, while also suppressing large vessel signal and reducing susceptibility artifacts. Furthermore, MRI measurements of the functional percentage change in cerebral blood volume (CBV) showed excellent agreement with results obtained at much lower magnetic field strengths, demonstrating that MRI estimates of this quantity are roughly independent of magnetic field when appropriate techniques are employed. The derived field dependencies for relative sensitivity and MRI estimates of the percentage change in CBV suggest that the benefits provided by exogenous agents will persist even at much higher magnetic fields than 9.4 T.
Two different approaches regarding hydrocephalus treatment in the islamic world during the middle ages
Turkish Neurosurgery, 2022
Journal of Clinical Neuroscience, 2007
Aneurysms are seen rarely at the P2-P3 junction of the posterior cerebral artery (PCA). P2-P3 jun... more Aneurysms are seen rarely at the P2-P3 junction of the posterior cerebral artery (PCA). P2-P3 junction aneurysm surgery is challenging. Here, a successful clipping of a large P2-P3 junction aneurysm via a subtemporal approach is reported. A 26-year-old woman presented with a 6-month history of left occipito-parietal headache. Computed tomography (CT) scan, magnetic resonance imaging (MRI) and cerebral angiography revealed a 2-cm aneurysm at the P2-P3 junction of the left PCA. Successful neck clipping of the aneurysm was performed via a subtemporal approach without additional neurological deficits or surgical complications. Coil embolization has been suggested as the treatment of choice but PCA aneurysms are also good candidates for microsurgical clipping. The subtemporal approach is simple and safe in experienced hands. P2-P3 junction PCA aneurysms can be successfully clipped via the subtemporal approach without excessive brain retraction, resection of brain tissue or disruption of surface veins.
One of the Earliest Accounts of Head Wounds in Firdaws al-Ḥikma by al-Ṭabarī from the 9th Century
World Neurosurgery, Nov 1, 2017
To present the first Arabic text on suturing scalp wounds. A related section entitled "O... more To present the first Arabic text on suturing scalp wounds. A related section entitled "On the wounds in the head" from the book Firdaws al-Ḥikma (Paradise of the Wisdom) written by al-Ṭabarī in the 9th century was identified and analyzed. This work was one of the earliest medical compendiums in the Islamic world during the medieval period. A printed copy of Firdaws al-Ḥikma edited by Muḥammad Zubayr al-Ṣiddīqī was examined, and findings were compared with relevant knowledge in the literature. A notable part of this text is based on appropriate closure of scalp wounds using sutures. Before this work, only the well-known Indian medical book Suśruta-Saṃhitā had mentioned closure of scalp wounds using sutures. In his work, al-Ṭabarī recommended using materials made of silk or linen for suturing. He additionally proposed some recipes that have a coating feature that prevents bleeding from the wound after it was closed properly. He also dealt with persistent swelling and provided formulas for solving the problem with special compositions. Firdaws al-Ḥikma is a noteworthy work in the history of medicine, and it includes a unique chapter on head wounds. To the best of our knowledge, this is the first mention of suturing scalp cuts in Arabic literature and the second reference in medical literature after the Indian work Suśruta-Saṃhitā.
Turkish Neurosurgery, 2013
AIm: This study aimed to investigate the effects of a new generation antiepileptic agent, levetir... more AIm: This study aimed to investigate the effects of a new generation antiepileptic agent, levetiracetam, on the neural tube development in a chick embryo model that corresponds to the first month of vertebral development in mammals. mAteRIAl and methods: Forty-five Atabey® breed fertilized chicken eggs with no specific pathogens were randomly divided into 5 groups. All of the eggs were incubated at 37.8±2°C and 60±5 % relative humidity in an incubator. Group A was control group. The other eggs were applied physiological saline and drugs at a volume of 10 µL by the in ovo method at the 28th hour of the incubation period. Group B was given distilled water; Group C, physiological saline; Group D, Levetiracetam (L8668) at a dose equivalent to the treatment dose for humans (10 mg/ kg), and Group E, Levetiracetam (L8668) at a dose of 10 times the treatment dose. The embryos in all of the groups were removed from the shells at the 48th hour and morphologically and histologically evaluated. Results: Of the 45 embryos incubated, neural tubes of 41 were closed and the embryos displayed normal development. ConClusIon: Levetiracetam, at a dose equivalent to human treatment dose and 10 times the treatment dose, was shown not to cause neural tube defects in chick embryos.
Asian Spine Journal, 2015
The study retrospectively investigated 15 cases with multilevel noncontiguous spinal fractures (M... more The study retrospectively investigated 15 cases with multilevel noncontiguous spinal fractures (MNSF). Purpose: To clarify the evaluation of true diagnosis and to plane the surgical treatment. Overview of Literature: MNSF are defined as fractures of the vertebral column at more than one level. High-energy injuries caused MNSF, with an incidence ranging from 1.6% to 16.7%. MNSF may be misdiagnosed due to lack of detailed neurological and radiological examinations. Methods: Patients with metabolic, rheumatologic diseases and neoplasms were excluded. Despite the presence of a spinal fracture associated clearly with the clinical picture, all patients were scanned within spinal column by direct X-rays, computed tomography and magnetic resonance imaging. When there were ≥5 intact vertebrae between two fractured vertebral segments, each fracture region was managed with a separated stabilization. In cases with ≤4 intact segments between two fractured levels, both fractures were fixed with the same rod and screw system. Results: There were 32 vertebra fractures in 15 patients. Eleven (73.3%) patients were male and age ranged from 20 to 64 years (35.9±13.7 years). Eleven cases were the American Spinal Injury Association (ASIA) E, 3 were ASIA A, and one was ASIA D. Ten of the 15 (66.7%) patients returned to previous social status without additional deficit or morbidity. The remaining 5 (33.3%) patients had mild or moderate improvement after surgery. Conclusions: The spinal column should always be scanned to rule out a secondary or tertiary vertebra fracture in vertebral fractures associated with high-energy trauma. In MNSF, each fracture should be separately evaluated for decision of surgery and planned approach needs particular care. In MNSF with ≤4 intact vertebra in between, stabilization of one segment should prompt the involvement of the secondary fracture into the system.
Turkish Neurosurgery, 2015
studies, experimental studies in the literature consist of studies where other adjunct devices ot... more studies, experimental studies in the literature consist of studies where other adjunct devices other than flow diverters are not used and they do not represent the small narrownecked aneurysms frequently seen in routine daily practice. In these studies, flow diverter stents direct the blood flow along the parent artery (13) and provide stasis of the blood inside the aneurysm to promote thrombosis of the aneurysm █ INTRODUCTION Flow diverter (FD) devices have been the current endovascular treatment option for the hardly treated intracranial widenecked, fusiform and giant aneurysms (7). Recently, flow diverter stents have been the most important treatment modality because of acceptable morbidity, mortality and high aneurysm occlusion rates (5). Except for a few small AIM: To report patient and procedure-related factors affecting the angiographic and clinical outcome in patients treated with the Silk device. MATERIAL and METHODS: All patients with intracranial aneurysms in whom treatment was attempted with the Silk flow diverter by our neurovascular team between October 2010 and November 2013 were included consecutively. The data was analyzed by an independent stroke neurologist not involved in the treatment of the patients. RESULTS: A total of 96 patients (64 female) with ages range from 3 to 78 were included in this study. We found that 54 of the patients were asymptomatic and 42 of them symptomatic, while 21 had a prior history of subarachnoid hemorrhage (SAH). Mean aneurysm size was 10.2 mm (range 2 to 40 mm). 2 patients died due to consequences of SAH. 3 patients developed visual decline on the follow-up, 2 of these were procedure-related. Symptomatic thromboembolic events were noted in 7 cases. Patients with aneurysms smaller than 13 mm had significantly less complications and higher occlusion rates. The complication rate was significantly high in patients admitted with symptoms. Adjunctive coiling had no impact on outcome. CONCLUSION: Safety and efficacy of flow diversion in this series was closely related to aneurysm size and presenting symptoms. A size cutoff for safety and efficacy has not been reported before and will be useful not only for future studies but also for patient counseling in daily practice. The futility of adjunctive coiling in this series calls for reappraisal of the current recommendations for this specific device.
Neurosurgical Review, 1996
We present 23 cases of Langerhans cell histiocytosis with cen~raI nervous system (CNS) involvemen... more We present 23 cases of Langerhans cell histiocytosis with cen~raI nervous system (CNS) involvement. The major complaints were a mass on the cranial vault in fifteen (65 %), visual disturbance in four (16 %), polyurea-polydipsia in three (13 %), and progressive weakness in all extremities in one patient (4 %). Neurological examination revealed no abnormality in sixteen patients (70 %), cranial nerve palsy, visual field defect and optic atrophy in six (26 %) and paraparesis in one (4 %). Tumoral mass was found to be located on the cranial vault (65 %), in the suprasellar region (21%) and in the spinal column (8 %). The cranium and spinal column were both involved in one patient. All patients underwent surgery; craniectomy with grossly total tumor excision plus cranioplasty (65 %), craniotomy with subtotal tumor excision (26 %), and vertebrectomy with grafting (13 %) were performed. The clinical, radiological and histopathological features, as well as therapeutical considerations are discussed and the pertinent literature is reviewed.
Asian Spine Journal, 2014
A 47-year-old woman was admitted with complaints of progressive weakness in the lower extremities... more A 47-year-old woman was admitted with complaints of progressive weakness in the lower extremities and pain in the back and left leg. Thoracic magnetic resonance imaging (MRI) revealed a spinal intramedullary tumor between the T9 and L1 levels, which were iso-to hypointense on T2 and slightly hyperintense on T1-weighted images. The tumor was resected as total, and the diagnosis was malignant melanoma confirmed with histopathology. Neurological findings improved at the postoperative period and no residual or recurrence was noted on postoperative MRI at the 9-month follow-up. Primary melanoma of the spinal cord, particularly intramedullar localization, is seldomly reported in the literature. We report a primary malignant melanoma of the spinal cord and emphasize the diagnostic and prognostic challenges.