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Publication Open Access A novel modular dynamic stabilization system for the treatment of degenerative spinal pathologies(Turkish Neurosurgical Society, 2019) Çevik, Orhun Mete; Erbulut, Deniz Ufuk; Goel, Vijay; N/A; Özer, Ali Fahir; Yaman, Onur; Şentürk, Salim; Öktenoğlu, Bekir Tunç; Sasani, Mehdi; Süzer, Süleyman Tuncer; Faculty Member; Doctor; Doctor; Faculty Member; School of Medicine; 1022; N/A; N/A; N/A; N/A; 221691Aim: to show the preliminary clinical results of the Orthrus modular dynamic stabilization system that is a new instrumentation system intended for degenerative diseases of the lumbar spine. Material and methods: the system utilizes two different types of screws that can be used in conjunction with different types of rods such as titanium, carbon fiber or PEEK. The first type of screw is a double headed screw to interconnect to the upper and lower level with independent rods. The second type of screw is a sliding screw to be used on a immovable vertebrae that allows movement in two planes on the tip. Results: the system has been used on 36 patients with pathology varying from degenerative disc disease to degenerative lumbar scoliosis. Satisfactory results have been obtained in a all 36 patients in the 12-month follow-up period. Conclusion: the Orthrus dynamic system shows better clinical results than the available dynamic systems on the market. It also proves to provide similar fusion with considerably less postoperative morbidity which makes it a better method to treat adult degenerative spine diseases for carefully chosen patients.Publication Open Access An investigation into the correlation of scalp electrophysiological findings with preoperative clinical and imaging findings in patients with focal cortical dysplasia(Turkish Neurosurgical Society, 2022) Gürkan, Zahide Mail; Kapar, Özge; Yeni, Seher Naz; Bilgiç, Bilge; Gürses, Rabia Candan; Faculty Member; School of Medicine; 110149Aim: to evaluate the patients who had epilepsy surgery and pathologically proven focal cortical dysplasia (FCD) in order to further classify and discuss electroencephalography (EEG) findings in different pathological subtypes. Material and methods: this study included 19 refractory epilepsy patients who underwent surgery between 1999 and 2017 in the Istanbul Faculty of Medicine. Demographic data, preoperative examinations, scalp video EEGs, and postoperative outcomes were evaluated retrospectively. Results: In this study, 36.8% of the patients were female. The mean age was 21.89 ± 14.64 years. Rhythmic epileptiform discharges (RED) were observed in 31.6%. 37.5% of the patients with isolated intermittent spike/sharp waves were type I, 50% were type II, and 12.5% were type III. 100% of the patients with normal background activity were FCD type II. 67% of the patients with asymmetric slowing were FCD type I, 22% was FCD type II, 11% were FCD type III. 71% of the patients with symmetrical slowing were FCD type I, 29% were FCD type II. One patient had Frontal Intermittent Rhythmic Activity, one patient had Electrical Status Epilepticus in Slow Sleep, two patients had “burst suppression,” and one patient had a “switch of” sign. The frequency of focal epileptogenic activity was higher when there was an FCD lesion on magnetic resonance imaging. Conclusion: the findings obtained in this study did not reveal any distinctive electrophysiological features in FCD and subgroups of FCD. The incidence of REDs did not differ between types. The frequency of isolated intermittent sharp/spike waves was higher in type II than I. Intermittent and continuous EEG slowing was more commonly seen among FCD Type I patients.Publication Open Access Anti-pan-neurofascin IgG3 as a marker of fulminant autoimmune neuropathy(Lippincott Williams and Wilkins (LWW), 2019) Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM)Objective: to identify and characterize patients with autoantibodies against different neurofascin (NF) isoforms. Methods: screening of a large cohort of patient sera for anti-NF autoantibodies by ELISA and further characterization by cell-based assays, epitope mapping, and complement binding assays. Results: two different clinical phenotypes became apparent in this study: The well-known clinical picture of subacute-onset severe sensorimotor neuropathy with tremor that is known to be associated with IgG4 autoantibodies against the paranodal isoform NF-155 was found in 2 patients. The second phenotype with a dramatic course of disease with tetraplegia and almost locked-in syndrome was associated with IgG3 autoantibodies against nodal and paranodal isoforms of NF in 3 patients. The epitope against which these autoantibodies were directed in this second phenotype was the common Ig domain found in all 3 NF isoforms. In contrast, anti-NF-155 IgG4 were directed against the NF-155-specific Fn3Fn4 domain. The description of a second phenotype of anti-NF-associated neuropathy is in line with some case reports of similar patients that were published in the last year. Conclusions: our results indicate that anti-pan-NF-associated neuropathy differs from anti-NF-155-associated neuropathy, and epitope and subclass play a major role in the pathogenesis and severity of anti-NF-associated neuropathy and should be determined to correctly classify patients, also in respect to possible differences in therapeutic response.Publication Open Access Antimuscarinic-induced convulsions in fasted rats after food intake: EEG patterns of fasting, scopolamine treatment, and convulsions(Galenos Yayınevi, 2022) Türkmen, Aslı Zengin; Nurten, Asiye; Edis, Bilge Özerman; Özen, İlknur; Kara, İhsan; Karamürsel, Sacit; Faculty Member; School of Medicine; 19597Objective: antimuscarinic treatment in fasted mice and rats causes clonic convulsion soon after food intake. This study was designed to evaluate the electrophysiological markers of these convulsions and fasting in electrocorticograms in rats. Methods: Male Wistar albino rats were stereotaxically implanted with 10 cortical electrodes, and baseline electroencephalogram recordings were taken for 10 minutes. After weighing, rats were deprived of food for 52 hours. At the 24th and 52nd hours of deprivation, continuous electroencephalogram recordings were repeated. After the deprivation period, animals were treated with saline or scopolamine (3 mg/kg). Twenty minutes after injections, animals were given food pellets. After eating food, electroencephalogram recordings were taken for 60 minutes and all animals were observed simultaneously to determine the incidence and onset of convulsions. Results: these results show that food deprivation for 52 hours decreased the amplitude of the gamma band when compared to basal (P <.05) and 24 hours (P <.008) food deprivation. And the amplitude of the beta band in the 52nd hour decreased when compared to the 24th hour of food deprivation (P <.05). The treatment with scopolamine changes the effects of food deprivation on the electroencephalogram. As a typical epileptiform manifestation, refeeding after scopolamine treatment caused a series of high-voltage polyspikes and synchronized spikes with a predominant frequency in the 1-3 Hz range. Conclusions: it was revealed that the behavioral patterns of rats and the electroencephalogram properties in these convulsions are in accordance with each other.Publication Open Access Behavioral functioning of school-aged children with non-syndromic craniosynostosis(Springer, 2020) Zeytinoğlu Saydam, Senem; Özek, M. Memet; Crerand, Canice; Department of Business Administration; Department of Business Administration; Marcus, Justin; Faculty Member; College of Administrative Sciences and Economics; 124653Purpose: this study investigated the risk for children with non-syndromic craniosynostosis to develop behavioral problems during school age determined by the type of craniosynostisis, age at first surgery, and number of surgeries. Method: final sample consisted of 43 children aged between 6 years and 8 months and 17 years and 1 month (M = 10 years and 5 months). Behavioral problems were assessed with Child Behavioral Checklist (CBCL). Results: our sample had higher scores on the CBCL than the general population; specific elevations were observed including somatic complaints, aggressive behavior, social problems, attention problems, and thought problems and rule-breaking behavior. Behavioral functioning varied by number of surgical procedures, type of craniosynostosis, and age at first surgery. Conclusion: for school-aged NSC children's behavioral functioning, diagnosis specific patterns especially impacted by the first age of the surgery and number of surgeries.Publication Open Access Bi-allelic variants in HOPS complex subunit VPS41 cause cerebellar ataxia and abnormal membrane trafficking(Oxford University Press (OUP), 2021) Sanderson, L.E.; Lanko, K.; Alsagob, M.; Almass, R.; Al-Ahmadi, N.; Najafi, M.; Al-Muhaizea, M.A.; Alzaidan, H.; AlDhalaan, H.; Perenthaler, E.; van der Linde, H.C.; Nikoncuk, A.; Kühn, N. A.; Antony, D.; Owaidah, T.M.; Raskin, S.; Vieira, L. G. D. R.; Mombach, R.; Ahangari, N.; Silveira, T. R. D.; Ameziane, N.; Rolfs, A.; Alharbi, A.; Sabbagh, R. M.; AlAhmadi, K.; Alawam, B.; Ghebeh, H.; AlHargan, A.; Albader, A. A.; Binhumaid, F. S.; Goljan, E.; Monies, D.; Mustafa, O. M.; Aldosary, M.; AlBakheet, A.; Alyounes, B.; Almutairi, F.; Al-Odaib, A; Aksoy, D. B.; Trabzuni, D.; Rosenfeld, J. A.; Karimiani, E. G.; Meyer, B. F.; Karakaş, B.; Al-Mohanna, F.; Arold, S. T.; Çolak, D.; Maroofian, R.; Houlden, H.; Bertoli-Avella, A. M.; Schmidts, M.; Barakat, T. S.; van Ham, T. J.; Kaya, N.; Başak, Ayşe Nazlı; Palvadeau, Robin Jerome; Faculty Member; Koç University Research Center for Translational Medicine (KUTTAM) / Koç Üniversitesi Translasyonel Tıp Araştırma Merkezi (KUTTAM); School of Medicine; 1512; N/AMembrane trafficking is a complex, essential process in eukaryotic cells responsible for protein transport and processing. Deficiencies in vacuolar protein sorting (VPS) proteins, key regulators of trafficking, cause abnormal intracellular segregation of macromolecules and organelles and are linked to human disease. VPS proteins function as part of complexes such as the homotypic fusion and vacuole protein sorting (HOPS) tethering complex, composed of VPS11, VPS16, VPS18, VPS33A, VPS39 and VPS41. The HOPS-specific subunit VPS41 has been reported to promote viability of dopaminergic neurons in Parkinson's disease but to date has not been linked to human disease. Here, we describe five unrelated families with nine affected individuals, all carrying homozygous variants in VPS41 that we show impact protein function. All affected individuals presented with a progressive neurodevelopmental disorder consisting of cognitive impairment, cerebellar atrophy/hypoplasia, motor dysfunction with ataxia and dystonia, and nystagmus. Zebrafish disease modelling supports the involvement of VPS41 dysfunction in the disorder, indicating lysosomal dysregulation throughout the brain and providing support for cerebellar and microglial abnormalities when vps41 was mutated. This provides the first example of human disease linked to the HOPS-specific subunit VPS41 and suggests the importance of HOPS complex activity for cerebellar function.Publication Open Access Censoring distances based on labeled cortical distance maps in cortical morphometry(Frontiers, 2013) Nishino, Tomoyuki; Alexopolous, Dimitrios; Todd, Richard D.; Botteron, Kelly N.; Miller, Michael I.; Ratnanather, J. Tilak; Department of Mathematics; Department of Mathematics; Ceyhan, Elvan; Undergraduate Student; Faculty Member; College of SciencesIt has been demonstrated that shape differences in cortical structures may be manifested in neuropsychiatric disorders. Such morphometric differences can be measured by labeled cortical distance mapping (LCDM) which characterizes the morphometry of the laminar cortical mantle of cortical structures. LCDM data consist of signed/labeled distances of gray matter (GM) voxels with respect to GM/white matter (VW) surface. Volumes and other summary measures for each subject and the pooled distances can help determine the morphometric differences between diagnostic groups, however they do not reveal all the morphometric information contained in LCDM distances. To extract more information from LCDM data, censoring of the pooled distances is introduced for each diagnostic group where the range of LCDM distances is partitioned at a fixed increment size; and at each censoring step, the distances not exceeding the censoring distance are kept. Censored LCDM distances inherit the advantages of the pooled distances but also provide information about the location of morphometric differences which cannot be obtained from the pooled distances. However, at each step, the censored distances aggregate, which might confound the results. The influence of data aggregation is investigated with an extensive Monte Carlo simulation analysis and it is demonstrated that this influence is negligible. As an illustrative example, GM of ventral medial prefrontal cortices (VMPFCs) of subjects with major depressive disorder (MDD), subjects at high risk (HR) of MDD, and healthy control (Ctrl) subjects are used. A significant reduction in laminar thickness of the VMPFC in MDD and HR subjects is observed compared to Ctrl subjects. Moreover, the GM LCDM distances (i.e., locations with respect to the GM/WM surface) for which these differences start to occur are determined. The methodology is also applicable to LCDM-based morphometric measures of other cortical structures affected by disease.Publication Open Access Changes in the expression of c-fos and AQP4 in the hippocampus and amygdala regions of rats with kainic acid-induced temporal lobe epilepsy and their role in the pathogenesis of disease(Galenos Yayınevi, 2022) Taşkıran, Emine; Yılmaz, Canan Uğur; Orhan, Nurcan; Kaya, Mehmet; Arıcan, Nadir; Bahçeci, Metin Berkant; Kaya, Mehmet; Gürses, Rabia Candan; Ahıshalı, Bülent; Faculty Member; Faculty Member; Faculty Member; School of Medicine; 10486; 110149; N/AObjective: aquaporin4 is the main water channel in the brain that is associated with neurological disorders. The role and the expressive changes of aquaporin4 in epilepsy are still limited and controversial. The study aims to evaluate the expression of c-fos and aquaporin4 during epileptogenesis after systemic kainic acid-induced status epilepticus in the temporal lobe epilepsy animal model and to investigate their alterations in both hippocampus and amygdala. Methods: intraperitoneal injections of kainic acid (5-15 mg/kg) by repeated low kainic acid protocol were given to young adult 32 Wistar albino rats for status epilepticus. Aquaporin4 and c-fos were investigated in the hippocampus and amygdala on days 1 and 60 after status epilepticus by immunostaining methods in brain slices. Results: the intensity of c-fos immunostaining rose considerably in the hippocampus CA1 area of rats during the acute period (P < 0.05) and in the amygdala during the chronic period. The immunostaining intensity of aquaporin4in the hippocampus of rats with acute kainic acid increased significantly (P <.05). It was also raised in the hippocampal region of the rats in the acute sham and chronic kainic acid groups. Discussion: the results of this study support a link between aquaporin4 and epilepsy. It can be speculated that aquaporin4 change is primarily a defense mechanism immediately after status epilepticus, and then, it can evolve into a causal factor with exhaustion as a result of overuse.Publication Open Access Chitosan channels stuffed with mesenchyme originated stem/progenitor cells for renovate axonal regeneration in complete spinal cord transection(Turkish Neurosurgical Society, 2021) Çakıcı, Nazlı; Bozkurt, Gökhan; Puralı, Nuhan; Denkbaş, Emir Baki; Korkusuz, Petek; Uçkan Çetinkaya, Duygu; Başak, Ahmet Tulgar; Doctor; Koç University HospitalAim: to examine the implantation of chitosan channels stuffed with mesenchyme-originated stem/progenitor cells (MSPCs) derived from adult rats in a spinal cord transection model. The level of axonal regeneration, the effect of chitosan channels on the survival of MSPCs, and the functional recovery results were also evaluated. Material and methods: chitosan channels stuffed with MSPCs were implanted at the level of T8 in a transected rat spinal cord. MSPCs were harvested from the pelvic bone marrow of adult rats, and the MSPC-chitosan channel group was compared with three control groups. The axonal regeneration capacity, the effect of chitosan channels on the survival of MSPCs, and the functional recovery results were compared among four groups. The survival of MSPCs was evaluated using histopathological techniques and electron microscopy, axonal regeneration/germination was evaluated by confocal microscopy, and locomotor function was assessed for 4 weeks using the Basso, Beattie, and Bresnahan locomotor score. Results: the MSPC-chitosan channel group exhibited enhanced survival of transplanted MSPCs compared with MSPCs transplanted directly into the lesion cavity, although no significant difference was detected in locomotor function between the treatment and control groups. The MSPC-chitosan channel group demonstrated thicker myelination of axons than the other groups. Conclusion: chitosan channels promoted the survival of transplanted MSPCs and created a tissue bridge after complete spinal cord transection. They also induced axonal regeneration and germination. No significant improvement in functional recovery was found between the groups.Publication Open Access Clinical and molecular genetic findings of cerebral arteriopathy with subcortical infarcts and leukoencephalopathy(Galenos Yayınevi, 2021) Rüstemoğlu, Burcu Sevinç; Samancı, Bedia; Tepgeç, Fatih; Kürtüncü, Murat; Gündüz, Tuncay; Sayın, Gözde Yeşil; Gürvit, Hakan; Bilgiç, Başar; Toksoy, Güven; Eraksoy, Mefkure; Hanagasi, Hasmet; Uyguner, Zehra Oya; Altunoğlu, Umut; Avcı, Şahin; Faculty Member; Faculty Member; School of Medicine; Koç University Hospital; 126174; N/AObjective: most lacunar strokes are sporadic, and hypertension, diabetes, smoking, and cardiovascular diseases are among its main risk factors. Strokes caused by small vessel diseases are generally associated with single-gene disorders with familial dominant and recessive inheritance. The most common condition is cerebral autosomal dominant arteriopathy, with subcortical infarcts and leukoencephalopathy (CADASIL), associated with the NOTCH3 gene. An infrequent form of this disease is the cerebral autosomal recessive arteriopathy with subcortical infarcts and leukoencephalopathy (CARASIL), revealed with pathogenic HTRA1 gene variants related to distinct molecular pathways. The neurological and cranial magnetic resonance imaging (MRI) findings are very similar to CADASIL; however, earlier than expected onset of common alopecia in man, low back pain, and more severe memory impairment are the differences in terms of clinical presentations. Clinical findings of 22 patients from 16 families with widespread white matter lesions in the periventricular field in the brain were investigated with molecular genetic findings. Materials and Methods: clinical examination results and cranial MRI findings are reported, and NOTCH3 and HTRA1 genes are sequenced stepwise by Sanger and next-generation sequencing techniques. Results: missense changes in epidermal growth factor (EGF)-like domain in the NOTCH3 are found in 18 cases from 14 families. Two different homozygous pathogenic missense and non-sense variants, in the HTRA1 gene, were detected in four patients from two families. The disease onset age was approximately 16 years earlier in cases carrying pathogenic variants located in the encoding region of EGF-like domains 1-6 of NOTCH3. Conclusion: In the NOTCH3 gene with c.382T>C (p.C128R), c.555T>G (p.C185W), and c.1903C>T (p.R635C) and in the HTRA1 gene c.235C>T (p.Q79*) are presented for the first time in this study. Molecular genetic investigation of CADASIL and CARASIL is important to support the clinical diagnosis, determine the inheritance model, provide patient and family counseling, manage disease process, and evaluate possible treatment strategies.