Ahmet Bekar - Academia.edu (original) (raw)

Papers by Ahmet Bekar

The European Research Journal

Objectives: Aquaductal web (AW) is a special form of aqueductal stenosis with similar clinical pr... more Objectives: Aquaductal web (AW) is a special form of aqueductal stenosis with similar clinical presentation with idiopathic normal pressure hydrocephalus (iNPH). iNPH is indeed a communicating hydrocephalus syndrome whereas AW is a noncommunicating subtype. Here, we aimed to investigate the similarities and differences between these two different chronic hydrocephalus syndromes in terms of clinical signs and symptoms, response to shunt treatment and postoperative complications. Methods: Forty-one patients who underwent shunt operation with the diagnosis of iNPH or AW at our clinic between January 2010-May 2019 were retrospectively analyzed. Patients were evaluated by age, gender, clinical sign and symptoms, comorbidities, intraoperative and postoperative complications, and early and late postoperative outpatient follow-up findings. Results: Twenty-six patients were classified as iNPH group and 15 patients as AW group. Patients in the AW group were significantly younger (45.5 ± 15.6 ...

Journal of Neurosurgical Anesthesiology, Apr 1, 1999

A case of solitary cervical intra and extramedullary schwannoma diagnosed by magnetic resonance i... more A case of solitary cervical intra and extramedullary schwannoma diagnosed by magnetic resonance imaging and treated surgically is reported.

Arquivos De Neuro-psiquiatria, Dec 1, 2022

Background Gelastic seizures are extremely rare, short-lasting, unprovoked, and uncontrollable la... more Background Gelastic seizures are extremely rare, short-lasting, unprovoked, and uncontrollable laughing attacks. We conducted this retrospective evaluation to determine whether these symptoms, manifesting in different forms, such as cheerful laughter, laughing, smiling, and sobbing had any value in terms of etiology or localization. Methods A total of 31 patients who exhibited bouts of laughing or crying and who were under follow-up between 2000 and 2019 at tertiary epilepsy centers were included in the study. Laughing seizures were divided into three groups in terms of semiology (i.e., laughter with mirth, laughter without mirth, and smile). Dacrystic seizures were accompanied by some gelastic seizures and were divided into two groups in terms of semiology (i.e., weeping loudly [motor and voice-sobbing] and crying). Results Of the 27 patients with laughing seizures, 12 had seizures that manifested with smiling, 7 had seizures that manifested with laughing and mirth, and 8 had seizures that manifested with laughter without mirth. Dacrystic-gelastic seizures were observed in four patients, among whom 2 patients had crying and laughter without mirth and 2 patients had weeping loudly and laughter without mirth episodes. Conclusion Gelastic and dacrystic seizures often suggest hypothalamic hamartomas, in the literature. This rare ictal behavior can originate from different cortical locations and lesions of a different nature. However, we found that gelastic seizures with smiling were a more homogenous group with regard to location in the temporal lobe, which we aimed to show by evaluating the patients included in this study.

Ulusal travma dergisi, 2002

Summary Objective. Reports of large series of patients who had undergone successful cranial neuro... more Summary Objective. Reports of large series of patients who had undergone successful cranial neurosurgery without hair removal led part of our team to abandon the practice of shaving patients' heads pre- operatively. The aim of this study was to assess whether this change in routine, which was implemented in 1992, has aected the rate of postoperative infection in our cranial surgery patients. Methods. A group of patients whose heads were shaved pre- operatively was compared to a group whose hair was not shaved prior to cranial surgery. The latter patients had their hair washed with shampoo and 4% chlorhexidine within 24 hours of their opera- tion. In the operating room, the surgical site was scrubbed for 8-10 minutes with 4% chlorhexidine diluted with water, and then cleansed with 10% povidone-iodine solution. Prophylactic antibiotics were administered for 3 days. Results. We performed 1.038 cranial procedures without hair re- moval. The procedures included craniotomy for tumour,...

Clinical EEG and Neuroscience, 2021

Introduction. Ulegyria results from perinatal hypoxic-ischemic brain injury in term infants. The ... more Introduction. Ulegyria results from perinatal hypoxic-ischemic brain injury in term infants. The specific mushroom-shaped configuration of ulegyria results from small atrophic circumvolutions at the bottom of a sulcus underlying an intact gyral apex. Clinically, ulegyria is generally associated with epilepsy. Here, we aimed to delineate the characteristics of patients with ulegyria and the epileptic seizures they experience. Material and methods. Medical records including radiology and pathology reports, video-electroencephalographic (EEG) analysis, operative notes, hospital progress and outpatient clinic notes were reviewed retrospectively in a total of 10 ulegyria patients. Results. Patients ages ranged between 24 and 58 years (mean, 32 ± 9.8 years). Past medical history was confirmed for neonatal asphyxia in 2 (20%). Neurological examination was remarkable for spastic hemiparesis in 1 (10%) patient with perisylvian ulegyria and for visual field deficits in 2 patients (20%) with o...

Uludağ Üniversitesi Tıp Fakültesi Dergisi, 2020

Küçük hücreli dışı akciğer kanseri (KHDAK)’nin en sık metastaz yaptığı organlardan biri beyindir.... more Küçük hücreli dışı akciğer kanseri (KHDAK)’nin en sık metastaz yaptığı organlardan biri beyindir. Beyin metastazı olan hastalar tedavi edilmediğinde ortalama yaşam süresi aylarla sınırlıdır. Bu çalışmanın amacı beyin metastazı yapmış evre 4 KHDAK hastalarda beyin metastazı için cerrahi tedavi uygulamasının onkolojik sonuçlarını göstermektir. Kliniğimizde 2004-2012 yılları arasında KHDAK tanısı konan ve BM nedeniyle cerrahi tedavi uygulanan 59 hastanın verileri prospektif olarak kaydedildi ve retrospektif olarak incelendi. Hastaların cerrahi ve onkolojik sonuçları irdelendi. Sağ kalım süresi beyin metastazı tanısı konulduğu tarih ile ölüm tarihi veya mevcut en son takip arasındaki zaman olarak hesaplandı. Hastaların 51’i erkek, 8’i kadın, ortalama yaş 56.92 (37-81) yıl idi. Cerrahi olarak 55 hastaya total eksizyon, 4 hastaya subtotal eksizyon yapıldı. Ameliyat sonrası mortalite saptanmadı. Patolojik inceleme sonucunda 55 hastada cerrahi sınırlar tümörsüz, 4 hastada ise cerrahi sınır ...

Transplantation Proceedings, 2005

Bardet-Biedl syndrome (BBS) is a rare autosomal recessive disorder. End-stage renal failure has b... more Bardet-Biedl syndrome (BBS) is a rare autosomal recessive disorder. End-stage renal failure has been reported as the most frequent cause of death in this disorder. There are few reports of kidney transplantation in these patients. Renal transplant patients are known to be at increased risk for the development of malignancies. Although a few patients with BBS have been described to develop malignant disease, there was no previous association with lymphoma. We report a 20-year-old patient in whom primary central nervous system lymphoma was diagnosed 20 months after renal transplantation.

Turkish journal of medical sciences, 2024

Introduction Brain metastases are the most common malignancies observed in the central nervous sy... more Introduction Brain metastases are the most common malignancies observed in the central nervous system (CNS), and up to 20%-30% of cancer patients develop them at some point during the course of their disease [1-3]. Several types of malignant tumors can metastasize to the CNS. The most common primary tumors responsible for brain metastases are lung cancer, melanoma, renal cell carcinoma, breast cancer, and colorectal carcinoma [3-5]. Surgical total resection of brain metastases is crucial in improving patients' quality of life and survival [5-7]. Therefore, surgery should be considered the first treatment option for such individuals. However, surgical resection of metastases located in functional brain regions or those near the eloquent areas is a challenge encountered during neurosurgery because, in addition to total resection, preservation of neurologic functions should be the primary goal during surgical planning [8,9],primary. Therefore, effective surgical methods and resection strategies to preserve neurological functions continue to evolve daily. Awake craniotomy (AC) is a modern and advanced method in neurosurgery and plays an important role in the treatment of brain tumors. This surgical technique aims to preserve the functional regions of the brain and improve these functions during the removal of brain tumors [10]. There is increasing evidence that AC is an effective method for tumor removal in or near functional regions, resulting in a higher rate of resection, lower rates of neurological complications, and better overall survival [10-13]. Background/aim: Awake craniotomy (AC) maximizes the resection of lesions in eloquent brain areas while preserving functionality. Tumor delineation with intraoperative use of sodium fluorescein (NaFl) facilitates total resection. When used with AC, it may allow for safe resection without increasing the risk of postoperative neurologic deficits. This study investigated the efficacy and safety of the combined use of NaFl and AC for maximum safe resection in patients with brain metastases.

DergiPark (Istanbul University), Jun 1, 2010

ÖZET İntrakranial subdural ampiyem potansiyel yıkıcı komplikasyonlarla giden bir nöroşirürji acil... more ÖZET İntrakranial subdural ampiyem potansiyel yıkıcı komplikasyonlarla giden bir nöroşirürji acilidir. Erken tanı, erken cerrahi ve uygun antibiyotik tedavisi mortaliteyi azaltır. Bu makalede 1990-2009 yılları arasında opere edilen 31 hasta retrospektif olarak incelenmiş ve klinik prezentasyon, etyolojik faktörler ve tedavi stratejileri açısından karşılaştırılmıştır. En sık etken Stafilococcus aureus idi. En sık başvuru şikayeti ateşti ve tanı tüm olgularda konrastlı kranial BT ile konuldu. En sık yerleşim yeri frontal konveksite idi. Kraniotomi 24 olguya, sadece burr-hole 4 olguya, hem burr-hole hem kraniotomi 3 olguya uygulandı. Ortalama takip süresi 20 (±23.25) ay idi. 4 hastada rekürrens izlendi. Agresif tedaviye rağmen mortalite ve morbiditenin hala yüksek olduğu akıldan çıkarılmamalıdır. Kraniotomi ile ampiyem boşaltılması önerdiğimiz tedavi şeklidir.

Neurological Research, Apr 1, 2012

European Journal of Cancer, Jul 1, 2014

Turkish Neurosurgery, 2019

To determine the efficacy and safety of microvascular decompression (MVD) for hemifacial spasm (H... more To determine the efficacy and safety of microvascular decompression (MVD) for hemifacial spasm (HFS) by retrospectively reviewing our results. MATERIAL and METHODS: A total of 55 patients who underwent MVD in our clinic between 2003 and 2017 were retrospectively analyzed. Clinical outcome results, recurrence rates, and surgical complications were noted. RESULTS: Thirty-six patients were female (65%). The mean age of the patients was 51.3 years. The mean duration of the complaint was 46.4 months. In 45 patients (82%), HFS was completely resolved within the first 6 months after the surgery. Five patients (9%) with recurrent symptoms were reoperated within the first year of the surgery. HFS symptoms of five patients (9%) completely ceased initially, but started again and reoperation was required due to failure of alternative treatments. Delayed facial nerve palsy and hearing loss were noted in one patient for each (2%). Cerebrospinal fluid leak was observed in two patients (4%). No mortality was observed in this series. CONCLUSION: MVD is a safe and effective option for patients with HFS that is resistant to medical treatment.

Nutrition and Cancer, Jul 18, 2017

Unmethylated O6-methylguanine-DNA-methyltransferase (MGMT) promoter leads to Temozolomide (TMZ) r... more Unmethylated O6-methylguanine-DNA-methyltransferase (MGMT) promoter leads to Temozolomide (TMZ) resistance in most of the glioblastoma multiforme (GBM) patients. We previously investigated the synergistic effect of Olea europaea leaf extract (OLE) on TMZ cytotoxicity through modulating microRNA expression. To date, knowledge about the effect of OLE on MGMT methylation is insufficient. The aim of the current study was to evaluate the potential modulating effect of OLE on the TMZ response of GBM tumors through MGMT methylation. Exposure to 1 mg/mL OLE caused a significant induction of CpG island methylation in the MGMT gene using Methyl quantitative PCR assay (P &amp;amp;amp;lt; 0.001). In WST-1 analysis, the use of 350 µM TMZ plus 1 mg/mL OLE significantly increased the TMZ response of MGMT unmethylated cells (P = 0.003). Using the comet assay, the impact of 1 mg/mL OLE plus 350 µM TMZ on the formation of DNA strand breaks was significantly higher than that of 450 µM TMZ alone (P &amp;amp;amp;lt; 0.001) and Western blot analysis revealed that, when cells are treated with 1-mg/mL OLE, the total p53 protein levels tended to decrease. The results presented in this study uniquely demonstrated that OLE synergistically increased the TMZ response of GBM tumors by regulating MGMT gene methylation and p53 expression. However, further studies to validate our findings are required.

Neurocirugía, Jul 1, 2023

A ease of intramedullary metastatie cord tumour which originated from a bronehogenie earanoma is ... more A ease of intramedullary metastatie cord tumour which originated from a bronehogenie earanoma is presepted here with its rarity and difficulties in diagnosis.

Human & Experimental Toxicology, Jun 6, 2019

Glioblastoma (GBM) is the most prevalent and deadliest subtype of glioma. Despite current innovat... more Glioblastoma (GBM) is the most prevalent and deadliest subtype of glioma. Despite current innovations in existing therapeutic modalities, GBM remains incurable, and alternative therapies are required. Previously, we demonstrated that Olea europaea leaf extract (OLE) kills GBM cells by modulating miR-181b, miR-137, miR-153 and Let-7d expression. However, although oleuropein (OL) is the main compound in OLE, its role in the antitumour effect of OLE remains unknown. This study determined the effect of OL on GBM cell line T98G and compared the results with our previous findings regarding the effect of OLE on the same cell line. The antiproliferative activity of OL and its effect on temozolomide (TMZ) response were tested inT98G cells using WST-1 assay. OL inhibition was evaluated using one-way analysis of variance with Tukey's post hoc test. The effect of OL on miR-181b, miR-137, miR-153 and Let-7d expression was assessed using quantitative reverse transcription polymerase chain reaction. Fold differences in expression between untreated, OL or OL þ TMZtreated samples were calculated using 2 ÀDCt method. Significance was evaluated using an independent sample t-test. Treatment with 277.5 and 555 mM OL resulted in 39.51% and 75.40% reductions in T98G cells within 24 h. Coadministration of 325 mM TMZ and 277.5 or 555 mM, OL caused 2.08-and 2.83-fold increases, respectively, in the therapeutic effect of TMZ. OL þ TMZ significantly increased microRNA expression, particularly Let-7d, than OLE. In conclusion, OL has an antitumour effect on GBM cells mainly via regulation of Let-7d expression. The present results also indicate other minor compounds in OLE play important anticancer roles.