Rahsan Kemerdere

Cerebrospinal fluid superoxide dismutase and serum malondialdehyde levels in patients with aneurysmal subarachnoid hemorrhage : preliminary results

Abstract Objectives: Experimental studies provide evidence that oxidative damage plays a role in the development of vasospasm after aneurysmal subarachnoid hemorrhage (SAH) but data from human studies is still limited. The purpose of this study was to investigate the time course of cerebrospinal fluid (CSF) superoxide dismutase (SOD) and serum malondialdehyde (MDA) changes in patients with aneurysmal SAH. Methods: SOD in CSF and MDA in the serum were detected on days 1–3, 5 and 7 after aneurysmal SAH in 21 patients, and the results were compared with 15 patients with hydrocephalus. The results were also compared with those of clinical parameters including the patients outcome at 6 months. Results: The mean CSF SOD levels were lower and serum MDA levels were higher than the controls. Patients with a high amount of blood within the cisterns had a trend to decreased SOD while increasing MDA levels. Conclusion: These preliminary results suggest that the levels of antioxidants are decreased after the onset of SAH in the early period, possibly because of increased oxidative stress. Reactive oxygen-mediated oxidative damage may play an important role in inflammation after SAH.

Expression of hypoxia inducible factor-1α in tumors of patients with glioblastoma multiforme and transitional meningioma

Hypoxia-inducible factor-1 alpha (HIF-1alpha) is the major transcriptional factor involved in the adaptive response to hypoxia. The aim of this study was to assess HIF-1alpha in 22 patients with transitional meningioma (TM) and 26 patients with glioblastoma multiforme (GBM). HIF-1alpha was assessed using a commercially available enzyme-linked immunosorbent assay-based HIF-1 transcription factor assay. Levels of HIF-1alpha in TM and GBM were measured using optical density at 450nm, and median values were found to be 0.35 for TM and 0.37 OD for GBM, respectively. There was no statistically significant difference between the two types of tumor (p=0.264). These findings indicate that HIF-1alpha is elevated in both TM and GBM, suggesting that although hypoxia is one of the most important and powerful stimuli for HIF-1alpha elevation and consequently angiogenesis, other mechanisms may play roles in HIF-1alpha stimulation in benign brain tumors such as TM.

Expressions of some vital molecules: glioblastoma multiforme versus normal tissues

Abstract Objective: The aim of this study was to assess plasma and/or tissue levels of adhesion and apoptotic molecules, cytokines, nitric oxide metabolites, levels of lipid peroxidation, myeloperoxidase and superoxide dismutase in patients with glioblastoma multiforme and controls. Methods: All the molecules were evaluated in 25 tumors and 30 controls: 15 were normal healthy subjects for plasma and 15 were normal brain tissues that were collected during autopsy. Commercially available kits for measurements were used. Results: Superoxide dismutase was significantly lower in tumors, while all other molecules were significantly elevated compared to the controls (p=0·0001). Superoxide dismutase negatively correlated with plasma interleukin-1beta (p=0·04) and plasma Fas (p=0·016). Plasma intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 correlated positively with plasma 3-nitrotyrosine (p=0·019) and nitrite/nitrate (p=0·019), respectively. Furthermore, plasma interleukin-1beta also positively correlated with plasma nitrite/nitrate (p=0·003). Discussion: These results suggest that there is a complex relationship between pro- and anti-apoptotic molecules in glioblastoma multiforme pathogenesis. Thus, targeting multiple pathways with advanced chemotherapeutic agents or radiotheraupetic regimens following total resections might be helpful in patients with glioblastoma multiforme since preventing a single pathway does not seem to be reasonable.

Low-grade temporal gliomas: Surgical strategy and long-term seizure outcome

Low-grade gliomas (LGGs) are generally located in temporal lobe and cause medically-intractable seizure so that surgical treatment becomes inevitable. This study includes a retrospective analysis of our patients with temporal LGGs retrieved from our epilepsy surgery data base and tries to present appropriate surgical approach and long-term seizure and anti-epileptic drug (AED) outcomes. Fifty-three patients including children and adults underwent surgery on temporal lobe LGGs and 35 patients were reached to report seizure and AED outcomes. On the non-dominant temporal lobe, anterior temporal resection with hippocampectomy whether mesial structure are involved or not is the appropriate approach. On the dominant temporal lobe mesial structures should be respected. However, total resection of the tumor should be the goal of surgery. Mean follow-up period was 8.3 years and favorable seizure outcome was found to be 91.4%. Surgery decreased AED usage and mean number of AED significantly decreased. Children also benefited from surgery as adults. Surgical treatment of tumor-related epilepsy from temporal lobe controls seizures, and total removal should be the main goal of surgery as neuropsychological testing permit.

Tissue and plasma thioredoxin reductase expressions in patients with glioblastoma multiforme.

BACKGROUND AND STUDY AIMS Thioredoxin reductase (TrxR) is a redox protein that is considered to play a role in tumor progression. The purpose of this study was to assess the expression of TrxR in blood and tumor samples of glioblastoma multiforme (GBM) patients. PATIENTS TrxR levels were evaluated in blood and GBM tissues extracted from 27 patients, in normal brain tissues of 12 autopsy cases, and in blood samples of 12 healthy subjects. The results were compared between tumor and control groups. RESULTS The mean level of TrxR in GBM tissues (74.5 ± 14.9 U/g wet tissue) was remarkably higher than in normal brain tissues (14.8 ± 3.4 U/g wet tissue). The mean TrxR levels in blood were significantly higher in GBM patients (296.3 ± 43.6 U/mL) than in the controls (203.0 ± 11.3 U/mL). CONCLUSIONS These findings suggest that high levels of TrxR may be related to progression of GBM.

Dynamic thiol-disulphide homeostasis in low-grade gliomas: Preliminary results in serum

OBJECTIVE Maintaining of precise balance between oxidation and anti-oxidation is important in both physiological and pathological states. Knowledge about this balance may give an idea about the process of the disease. The aim of this study was to investigate dynamic thiol-disulfide homeostasis in patients with low-grade gliomas. PATIENTS AND METHODS Serial serum samples were collected in 13 patients operated on low-grade gliomas before and after surgery. Control serum samples were obtained from venous cord blood from 13 healthy women during cesarean section. Total thiol, native thiol, and disulfide bond formation were measured and compared with the controls. RESULTS Total thiols, native thiols, and disulfide bond formation were significantly elevated in patients before the surgery compared to the controls (p<0.05). Even after the surgery, these three parameters were still high in patients, and the differences were significant (p<0.05). Although no significant difference was found between patients and controls regarding the ratios of disulfide/total thiol, disulfide/native thiol, and native thiol/total thiol (p>0.05), the balance seemed to shift to oxidative side. CONCLUSIONS Thiol-disulfide homeostasis was disrupted in patients with low-grade gliomas, and oxidation may play a role in the process of this disease. Supplementation with antioxidants before and after surgery may be taken into consideration.

Antiepileptic Drug Prophylaxis in Unruptured Intracranial Aneurysms

Aim:Postoperative seizure disorder can affect the outcome of patients with unruptured intracranial aneurysms. The objective of this study is to evaluate the frequency of postoperative seizures and the need for antiepileptic prophylaxis after the surgery of unruptured intracranial aneurysms. Methods:The medical data of 30 patients who were operated for unruptured intracranial aneurysms were reviewed for age and sex of the patients, location of the aneurysms, length of hospital stay, postoperative complications, and history of preoperative seizures. Postoperative early and late seizures were investigated through their relation with antiepileptic drug usage. Results:Postoperative seizures were observed in 2 patients (7.14%): 1 early seizure in the first week and 1 late seizure occurred 2 years after the surgery. All seizures were generalized tonic clonic in type. The patient with early seizure had left internal capsule ischemia. The patient with late seizure had encephalomalacia in the operative field on magnetic resonance imaging. Conclusions:Antiepileptic prophylaxis in unruptured intracranial aneurysms should be ceased if the patient has no history of preoperative epilepsy and if no seizure is observed at the end of 3 months.

Surgical and neurological complications in temporal lobe epilepsy surgery in modern era

Background: Temporal lobe epilepsy is the most common form of focal epilepsy, and surgical treatment has been proven to be an effective and safe management. Despite its safety, it is important to know that some complications and/or even death can be seen after surgery. Neurosurgeons should be able to precisely inform epilepsy surgery candidates about the possible unwanted/unexpected conditions after surgery. Methods: Fifty-three patients who underwent anterior temporal lobe resection due to temporal lobe epilepsy by a single surgeon were investigated retrospectively regarding postoperative surgical and neurological complications. Results: Overall complication rate was found to be 19%, surgical complications comprised 13.2% whereas neurological complications were 5.8%. Three patients underwent a second surgery whereas the rest had medical treatment or recovered spontaneously. Fortunately persistent complication rate was found to be 0%, and there was no mortality. Conclusions: Anterior temporal lobe resection is a safe and very effective surgical modality for the treatment of temporal lobe epilepsy. However, unexpected complications may be possible in this modern era and a surgeon should trust in him/herself not in modern equipments.

Acute tetraplegia following laryngotracheal reconstruction surgery

Background: Paraplegia following thoracic spinal surgery or abdominal operations is usually attributed to spinal cord ischemia due to interruption of the segmental spinal vascular supply. Alternatively, the etiology of spinal cord ischemia following cervical surgery is less clear. Case Description: A 14-year-old male became acutely tetraplegic with a C4 sensory level and sphincteric dysfunction 12 h following surgery for tracheal stenosis due to prior intubation. Signs included loss of pain and temperature below the level of C4 with preservation of deep sensations (position and vibration) and mute plantar responses. The cervical magnetic resonance imaging revealed diffuse intramedullary cord swelling between C2-C7 and hyperintense signal changes in the anterior and posterior columns of the cord on T2-weighted images. Various etiologies for this finding included a cervical hyperextension or hyperflexion injury vs. anterior spinal artery syndrome. Conclusions: Postoperative treatment of spinal cord ischemia attributed to cervical and thoracoabdominal surgery is largely ineffective in reversing major neurological deficits. Therefore, it is critical to prevent ischemia during these procedures by the avoidance of coagulopathies, anemia, hypotension, and hyperflexion/hyperextension maneuvers.

Long-term clinical and seizure outcomes of insular gliomas via trans-opercular approach

OBJECTIVE To report long-term clinical and seizure outcomes of patients who were operated upon insular gliomas via trans-opercular approach. PATIENTS AND METHODS Since 2010, surgical resection of insular gliomas was performed via trans-opercular approach by our group. Clinical, surgical and follow-up results were analyzed retrospectively. RESULTS The majority were low-grade (81.8%) and among them oligodendroglioma was the most common (n = 8). Half of the patients underwent awake craniotomy with cortical electrical stimulation and total removal was achieved in 6 patients. Long-term follow-up showed the majority of patients (90.9 %) were completely seizure free. Only one patient showed slight paresis on one upper extremity at the long-term follow-up. CONCLUSIONS Trans-opercular approach for insular gliomas is safe and maximal resection with minimal neurological deficits is possible. Use of ultrasonic aspirator and neuronavigation make surgery safer. Surgery-related complication is very rare. Future studies should contain larger number of patient and long-term follow-up in order to provide more accurate data.