Browsing by Author "Tanrikulu, Bahattin"

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Changes in Callosal Angle After Successful Endoscopic Third Ventriculostomy Procedure in Pediatric Patients
(TURKISH NEUROSURGICAL SOC, 2020-01-01) Tanrikulu, Bahattin; Ozek, M. Memet
AIM: To determine whether callosal angle (CA) measurement, a diagnostic and prognostic tool used for normal-pressure hydrocephalus in adults, is a reliable radiological parameter for evaluating endoscopic third ventriculostomy (ETV) outcomes in pediatric patients. MATERIAL and METHODS: Forty-seven pediatric patients with hydrocephalus who underwent successful EN in our clinic between 2011 and 2015 were included in this study. Preoperative and postoperative three-month CA, lateral ventricle frontal horn (LVFH) width, Evans' index (El), and frontal-occipital horn ratio (FOR) parameters were recorded, with changes analyzed using a paired-samples t-test. RESULTS: There were 29 male and 18 female patients included within the cohort. For mean preoperative values, LVFH width was 58.8 +/- 14.9 mm, El was 0.43 +/- 0.09, FOR was 0.51 +/- 0.74, and CA was 78.5 degrees +/- 36.4 degrees. Separately, for mean postoperative values, LVFH width was 54 +/- 14.2 mm, El was 0.39 +/- 0.09, FOR was 0.47 +/- 0.07, and CA was 104.5 degrees +/- 32.6 degrees. The CA was increased and the LVFH width, El, and FOR were decreased in all patients within three months after surgery. The postoperative three-month change in CA was higher than those observed in the other parameters. CONCLUSION: Changes in CA after successful EN were dramatically higher than those in the other ventricular parameters. For this reason, we suggest CA be used as a radiological criterion during early radiological follow-up of patients after ETV.
Current Clinical Practice About Pediatric Midline Gliomas in the Scope of Molecular Era
(TURKISH NEUROSURGICAL SOC, 2020-01-01) Tanrikulu, Bahattin; Ozek, M. Memet
AIM: To share our clinical experience with surgical and adjuvant treatment strategies followed during the treatment of midline gliomas. MATERIAL and METHODS: Pediatric patients with midline gliomas who underwent surgery in our clinic between March 2016 and November 2019 were included. Tissue samples were obtained through surgical excision, open biopsy, or stereotactic biopsy. All samples were analyzed for ATRX, BRAFV600E, IDH1/2, H3K27M, and H3G34R mutations, EGFR and PGFRA amplifications, and PTEN loss. RESULTS: There were 7 (43.8\%) female and 9 (56.2\%) male pediatric patients in the study. Eight patients had thalamic, 5 patients had pontine, 2 patients had medulla oblongata and one patient had brachium pontis tumors. Presenting symptoms were headache, disequilibrium, ophthalmoplegia, and panic attack. Eleven tumors showed H3K27M mutation and were diagnosed as diffuse midline gliomas. BRAFV600E, ATRX mutations, PTEN loss, and EGFR amplifications were other molecular alterations detected within tumor samples. Patients with H3K27M mutant tumors had a shorter life span. Five patients were enrolled in an ONC201 trial. CONCLUSION: Although most midline gliomas are not amenable to gross total excision, obtaining tissue samples is mandatory for determining patients' exact diagnoses, tailored treatment plans, and eligibility for clinical trials. Stereotactic biopsy for midline gliomas is a safe and effective method.
Epilepsy Surgery in Pediatric Patients: A Single-Center Experience
(KARE PUBL, 2019-01-01) Tanrikulu, Bahattin; Isik, Ugur; Ozek, Memet Metin
Objectives: Epilepsy surgery is one of the treatment options in pediatric patients with drug-resistant epilepsy. Our aim is to share demographic data, surgical outcome, possible surgical complications, and factors that affect surgical outcome in pediatric patients with drug-resistant epilepsy who were operated in our clinic. Methods: In this retrospective study, 85 patients who were operated in Acibadem Hospital Pediatric Epilepsy Surgery Clinic between years 2005 and 2017 were included. We investigated the influence of sex, age at seizure onset, side and frequency of seizures, time to surgery, type of epilepsy surgery, and histopathology on pediatric epilepsy surgery outcome. Surgical outcome was assessed by Engel classification system. Statistical analysis was performed with SPSS 20.0 software. Results: There were 56 male (66\%) and 29 female (34\%) participants. Median of the age of seizure onset is 2 years (1 day-15 years). Median of age at operation is 6.2 years (3 months-16 years). Median of the duration of seizure until surgery is 3.2 years (3 months-15.5 years). Median follow-up is 5.6 years (3 months-13.5 years). There were permanent motor neurological deficits in 3 patients (3.5\%). The best surgical outcome was achieved in patients with resective surgeries (p<0.01). Age at seizure onset was the most important factor that influences surgical outcome in our patients (p<0.05). Conclusion: Epilepsy surgery is one of the safe and effective treatment options in pediatric patients with drug-resistant epilepsy.
Genomic Analysis of Non-NF2 Meningiomas Reveals Mutations in TRAF7, KLF4, AKT1, and SMO
(AMER ASSOC ADVANCEMENT SCIENCE, 2013-01-01) Clark, Victoria E.; Erson-Omay, E. Zeynep; Serin, Akdes; Yin, Jun; Cotney, Justin; Oezduman, Koray; Avsar, Timuin; Li, Jie; Murray, Phillip B.; Henegariu, Octavian; Yilmaz, Saliha; Guenel, Jennifer Moliterno; Carrion-Grant, Geneive; Yilmaz, Baran; Grady, Conor; Tanrikulu, Bahattin; Bakircioglu, Mehmet; Kaymakcalan, Hande; Caglayan, Ahmet Okay; Sencar, Leman; Ceyhun, Emre; Atik, A. Fatih; Bayri, Yasar; Bai, Hanwen; Kolb, Luis E.; Hebert, Ryan M.; Omay, S. Bulent; Mishra-Gorur, Ketu; Choi, Murim; Overton, John D.; Holland, Eric C.; Mane, Shrikant; State, Matthew W.; Bilguevar, Kaya; Baehring, Joachim M.; Gutin, Philip H.; Piepmeier, Joseph M.; Vortmeyer, Alexander; Brennan, Cameron W.; Pamir, M. Necmettin; Kilic, Tuerker; Lifton, Richard P.; Noonan, James P.; Yasuno, Katsuhito; Guenel, Murat
We report genomic analysis of 300 meningiomas, the most common primary brain tumors, leading to the discovery of mutations in TRAF7, a proapoptotic E3 ubiquitin ligase, in nearly one-fourth of all meningiomas. Mutations in TRAF7 commonly occurred with a recurrent mutation ( K409Q) in KLF4, a transcription factor known for its role in inducing pluripotency, or with AKT1(E17K), a mutation known to activate the PI3K pathway. SMO mutations, which activate Hedgehog signaling, were identified in similar to 5\% of non-NF2 mutant meningiomas. These non-NF2 meningiomas were clinically distinctive-nearly always benign, with chromosomal stability, and originating from the medial skull base. In contrast, meningiomas with mutant NF2 and/or chromosome 22 loss were more likely to be atypical, showing genomic instability, and localizing to the cerebral and cerebellar hemispheres. Collectively, these findings identify distinct meningioma subtypes, suggesting avenues for targeted therapeutics.
Hereditary spastic paraplegia with recessive trait caused by mutation in KLC4 gene
(NATURE PUBLISHING GROUP, 2015-01-01) Bayrakli, Fatih; Poyrazoglu, Hatice Gamze; Yuksel, Sirin; Yakicier, Cengiz; Erguner, Bekir; Sagiroglu, Mahmut Samil; Yuceturk, Betul; Ozer, Bugra; Doganay, Selim; Tanrikulu, Bahattin; Seker, Askin; Akbulut, Fatih; Ozen, Ali; Per, Huseyin; Kumandas, Sefer; Torun, Yasemin Altuner; Bayri, Yasar; Sakar, Mustafa; Dagcinar, Adnan; Ziyal, Ibrahim
We report an association between a new causative gene and spastic paraplegia, which is a genetically heterogeneous disorder. Clinical phenotyping of one consanguineous family followed by combined homozygosity mapping and whole-exome sequencing analysis. Three patients from the same family shared common features of progressive complicated spastic paraplegia. They shared a single homozygous stretch area on chromosome 6. Whole-exome sequencing revealed a homozygous mutation (c.853\_871del19) in the gene coding the kinesin light chain 4 protein (KLC4). Meanwhile, the unaffected parents and two siblings were heterozygous and one sibling was homozygous wild type. The 19 bp deletion in exon 6 generates a stop codon and thus a truncated messenger RNA and protein. The association of a KLC4 mutation with spastic paraplegia identifies a new locus for the disease.
In Vitro Effects of Mesenchymal Stem Cells and Various Agents on Apoptosis of Glioblastoma Cells
(TURKISH NEUROSURGICAL SOC, 2019-01-01) Tanrikulu, Bahattin; Ziyal, Ibrahim; Bayri, Yasar
AIM: To investigate a new anti-tumor treatment method using stem cells transfected with specific genes and proteins that induce apoptosis in tumor cells. MATERIAL and METHODS: We used glioblastoma (GBM) cells and human adipose tissue-derived mesenchymal stem cells (AD-MSCs) in this study. The AD-MSCs were transfected with the tumor necrosis factor-related apoptosis-inducing ligand (TRAIL). To overcome apoptosis resistance in tumor cells, we used suberoylanilide hydroxamic acid (SAHA) as the histone deacetylase inhibitor and embelin as the X-linked inhibitor of apoptosis protein (XIAP). In addition, we silenced the XIAP gene on GBM cells with the shXIAP plasmid. Following the determination of half-maximal effective concentration (EC50\%) doses of SAHA and embelin, GBM cells were incubated with them for 24 hours. XIAP-silenced and XIAP-non-silenced GBM cells were cultured with TRAIL-non-transfected and TRAIL-transfected stem cells for 24 hours. Viability and cell cycle analysis of all groups were determined using annexin V/propidium iodide and cell cycle method via flow cytometry. RESULTS: TRAIL-transfected AD-MSCs, XIAP silencing, embelin, and SAHA induced apoptosis in GBM cells and decreased their proliferation, whereas TRAIL-non-tranfected AD-MSCs did not. CONCLUSION: Engineered stem cell therapies and molecular studies show promise in developing combination therapies for effective treatment of GBM.
Surgical Results of Pediatric Patients with Hamartoma
(KARE PUBL, 2020-01-01) Tanrikulu, Bahattin; Ozek, M. Memet
Objectives: Hypothalamic hamartomas (HH) are congenital lesions present with gelastic seizures and precocious puberty. Disconnective surgery is a safe and effective treatment method in patients with HH. In this study, we aim to share demographic information, presenting symptoms, surgical complications and surgical outcomes in pediatric patients with HH who were operated in our clinic. Methods: In this retrospective study, 12 pediatric patients with HH, who were operated in Acibadem University, School of Medicine, Department of Neurosurgery, Division of Pediatric Neurosurgery and Epilepsy Surgery Clinic between years 2007-2018 were included. All clinical materials, including patient notes, cranial magnetic resonance imaging, electroencephalogram recordings and endocrinological data of patients, were collected. Variables evaluated in the statistical analysis were age, sex, presenting symptom, radiological appearance, treatment outcome. Surgical outcome was evaluated by the Engel classification system. Statistical analysis was performed using SPSS 20.0 software. Results:There were eight (66.7) males and four (33.3\%) females within the patient cohort. Median age at the time of diagnosis was 3.1 years (4 months-6 years). Median follow-up period was 98.3 months (24-177 months). Presenting symptoms were gelastic seizures in six (50\%) patients, precocious pu-berty in three (25\%) patients and both gelastic seizures and precocious puberty in three patients. All patients had disconnective surgery for HH. None of the patients had a postoperative neurological deficit. The seizure outcome in seven (77\%) of the nine patients with seizure were Engel class 1 after the surgery. Signs and symptoms of precocious puberty persist after surgery in three (50\%) of six patients who had presented with precocious puberty in the preoperative period. There was no statistically significant relationship between age, sex and type of HH (p 0.05). There was also no significant relationship between the type of HH and presenting symptom, operation route or treatment outcome (p>0.05). Conclusion: Disconnective surgery is a safe and effective treatment method in pediatric patients with HH. Since most of the patients presents with seizures and/or endocrinological problems, thorough preoperative and postoperative neurological and endocrinological follow-up is recommended.