Person: KAHRAMAN KOYTAK, PINAR
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KAHRAMAN KOYTAK
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Publication Metadata only Peripheral nervous system assessment in acromegaly patients under somatostatin analogue therapy(SPRINGER, 2017) YAVUZ, DİLEK; Alibas, H.; Yavuz, D. Gogas; Koytak, P. Kahraman; Uygur, M.; Tanridag, T.; Uluc, K.Purpose Acromegaly is known to affect peripheral nervous system (PNS) causing carpal tunnel syndrome (CTS) and polyneuropathy. The frequency of these disorders and the evaluation methods vary among studies. In the present study, we aimed to examine PNS of acromegaly patients under somatostatin analogue (SSA) therapy. Methods Forty-eight acromegaly patients (26 F/22 M, 45.58 +/- 11.6 years) under SSA treatment and 44 healthy controls (25 F/19 M, 47.46 +/- 8.7 years) were assessed by symptom questionnaires, neurologic examination and electrophysiological studies. Results 87.5 % of the acromegaly patients had at least one abnormal finding regarding PNS. With the incorporation of palm-wrist median nerve conduction velocity method, we detected CTS in 50 % of patients. Polyneuropathy was less frequent (29.2 %). Both conditions were independent from the coexisting diabetes mellitus (p = 0.22 for CTS, p = 0.71 for polyneuropathy). Polyneuropathy but not CTS was more common among biochemically uncontrolled acromegaly patients rather than those under control (p = 0.03; p = 0.68, respectively). Conculsion Our findings emphasize the high prevalence of peripheral nervous system involvement in acromegaly patients under SSA therapy and importance of neurological evaluation of these patients. Early diagnosis and treatment of the disease may reduce the PNS involvement.Publication Metadata only Medial plantar-to-radial amplitude ratio: does it have electrodiagnostic utility in distal sensory polyneuropathy?(TAYLOR & FRANCIS LTD, 2017) ULUÇ, KAYIHAN; Koytak, Pinar Kahraman; Alibas, Hande; Ozden, Hatice Omercikoglu; Tanridag, Tulin; Uluc, KayihanPurpose of the study: We proposed a new electrophysiological parametermedial plantar (MP)-to-radial amplitude ratio (MPRAR), similar to sural-to-radial amplitude ratio (SRAR), in the diagnosis of distal sensory polyneuropathy (DSP), based on the concept that distal nerves are affected more and earlier than proximal nerves in axonal neuropathies. We aimed to investigate the diagnostic sensitivity of this parameter in diabetic DSP, together with sensitivities of SRAR and MP nerve action potential (NAP) amplitude. Materials and Methods: In 124 healthy controls and 87 diabetic patients with clinically defined DSP and normal sural responses, we prospectively performed sensory nerve conduction studies (NCS), and evaluated the MP NAP amplitude, MPRAR and SRAR values. We determined the lower limits of normal (LLN) of these parameters in the healthy controls and calculated their sensitivities and specificities in detecting DSP in diabetic patients. Results: MP nerve amplitude and MPRAR values were significantly lower in the patient group, compared to controls. However, SRAR values did not differ significantly between the two groups. The LLN of MP NAP amplitude was found to be 4.1 mu V. The cutoff values for SRAR and MPRAR were determined as 0.24 and 0.16, respectively. MPRAR was abnormal in 21.8% of patients. However, the most sensitive parameter in detection of DSP was MP NAP amplitude, which showed a sensitivity of 31% and a specificity of 100%. Conclusions: Although MPRAR is more sensitive than SRAR in detecting DSP, it does not provide additional diagnostic yield to the assessment of MP NCS alone in diabetic DSP patients with normal sural responses.Publication Metadata only The reliability of medial and lateral plantar nerve recordings in healthy elderly individuals(SPRINGER-VERLAG ITALIA SRL, 2015) ULUÇ, KAYIHAN; Keskin, Gokce; Koytak, Pinar Kahraman; Bastan, Birgul; Tanridag, Tulin; Us, Onder; Uluc, KayihanThe aim of this study was to investigate the reliability of medial plantar (MP) and lateral plantar (LP) nerve conduction studies (NCS) in healthy individuals aged > 65 years, and to obtain reference values for this age group. The study included 81 healthy subjects. MP response was absent in only 2 subjects, but LP response could not be obtained bilaterally in 43 of the 81 subjects. Regression analysis showed that MP NCS could be reliably performed in those aged a parts per thousand currency sign72 years and normal values for MP nerve in individuals aged 66-72 years would be strongly against a large-fiber neuropathy. However, LP response was absent in 53.1 % of the healthy elderly subjects; therefore, we think it is unreliable to study the LP nerve in this age group.Publication Open Access Brainstem Reflexes in Systemic Lupus Erythematosus Patients Without Clinical Neurological Manifestations(AVES, 2017-05-08) SÜNTER, GÜLİN; Salcini, Celal; Bastan, Birgul; Sunter, Gulin; Kahraman Koytak, Pinar; Yilmaz, Orhan; Tanridag, Tlin; Us, Onder; Uluc, KayihanIntroduction: We aimed to assess central and peripheral nervous system involvement in systemic lupus erythematosus (SLE) patients without any neurological signs and symptoms by performing electrophysiological investigations. Methods: Thirty-eight SLE patients and 35 healthy volunteers participated in this study. Peripheral nerve conduction and brainstem reflexes were evaluated by performing nerve conduction studies (NCSs) and blink reflex (BR) and masseter inhibitory reflex (MIR) recordings. Results: Eleven patients (29%) had an abnormality in at least 1 NCS parameter, and 1 (2.6%) patient was diagnosed with polyneuropathy. The number of patients with abnormal BR and MIR was 23 (60.5%) and 14 (37%), respectively. The contralateral R2 latency of BR and the silent period 1 (SP1) latency of MIR were significantly prolonged in the patients compared with the controls (p=0.015 and p<0.001, respectively). Conclusion: This study showed that irrespective of peripheral nervous system involvement, brainstem reflexes could be affected in SLE patients even without clinical neurological findings. Brainstem reflex abnormalities suggested that the functional integrity of the inhibitory or excitatory interneurons in the lateral caudal pons and lateral medulla is disturbed in SLE patients.Publication Metadata only Headache During Air Travel: An Unusual Cause of Reversible Cerebral Vasoconstriction Syndrome(WILEY-BLACKWELL, 2015) MİDİ, İPEK; Alibas, Hande; Ceferova, Shebnem; Koytak, Pinar Kahraman; Uluc, Kayihan; Midi, Ipek; Elmaci, Nese Tuncer; Aktan, Sevinc; Tanridag, TulinPublication Open Access Motor-Unit Number Estimation Is Sensitive in Detecting Motor Nerve Involvement in Patients with Carpal Tunnel Syndrome(KOREAN NEUROLOGICAL ASSOC, 2016) SÜNTER, GÜLİN; Yilnnaz, Orhan; Sunter, Gulin; Salcini, Celal; Koytak, Pinar Kahraman; Tanridag, Tulin; Us, Onder; Uluc, KayihanBackground and Purpose We compared the motor-unit number estimation (MUNE) findings in patients who presented with signs and/or findings associated with carpal tunnel syndrome (CTS) and healthy controls, with the aim of determining if motor-unit loss occurs during the clinically silent period and if there is a correlation between clinical and MUNE findings in CTS patients. Methods The study investigated 60 hands of 35 patients with clinical CTS and 60 hands of 34 healthy controls. Routine median and ulnar nerve conduction studies and MUNE analysis according to the multipoint stimulation method were performed. Results The most common electrophysiological abnormality was reduced conduction velocity in the median sensory nerve (100% of the hands). The MUNE value was significantly lower for the patient group than for the control group (p=0.0001). ROC analysis showed that a MUNE value of 121 was the optimal cutoff for differentiating between patients and controls, with a sensitivity of 63.3% and a specificity of 68.3%. MUNE values were lower in patients with complaints of numbness, pain, and weakness in the median nerve territory (p<0.05, for all comparisons), and lower in patients with hypoesthesia than in patients with normal neurological findings (p=0.023). Conclusions The MUNE technique is sensitive in detecting motor nerve involvement in CTS patients who present with sensorial findings, and it may be useful in detecting the loss of motor units during the early stages of CTS. Larger-scale prospective clinical trials assessing the effect of early intervention on the outcome of these patients would help in confirming the possible benefit of detecting subclinical motor-unit loss in CTS.Publication Metadata only Reference jitter values for the sternocleidomastoid muscle with concentric needle electrodes(WILEY, 2021) ULUÇ, KAYIHAN; Kula, Ezgi; Tanridag, Tulin; Kahraman Koytak, Pinar; Uluc, KayihanBackground The aim of this study was to establish reference jitter values for the voluntary activated sternocleidomastoid (SCM) muscle using a concentric needle electrode (CNE). Methods The study included 39 healthy participants (20 female and 19 male) aged 18-77 y. Jitter was expressed as the mean consecutive difference (MCD) of 80-100 consecutive discharges. Filters were set at 1 and 10 kHz. The mean MCDs for all participants were pooled, and the mean value +2.5 SD was accepted as the upper limit for the mean MCD. The upper limit for individual MCD was calculated using +2.5 SD of the upper 10th percentile MCD for individual participants. Results Mean age of the participants was 45 +/- 14.5 y. Mean MCD was 16.20 +/- 2.23 mu s (range: 12-21 mu s), and the upper limit of normal for mean MCD was 21.8 mu s. The mean value for 823 individual jitters was 23.3 +/- 4.61 mu s (range: 6.6-36.9 mu s), and the upper limit of normal for each individual jitter was 34.6 mu s. Conclusions The present findings indicate that upper normal limit for mean MCD is 22 mu s and for individual data it is 35 mu s.Publication Metadata only Topiramate and accommodation: Does topiramate cause accommodative dysfunction?(CANADIAN OPHTHAL SOC, 2017) ÇERMAN, EREN; Cerman, Eren; Turhan, Semra Akkaya; Eraslan, Muhsin; Koytak, Pinar Kahraman; Kilinc, Ozden; Tanridag, TlinObjective: To investigate the accommodation function in topiramate users. Design:Case-control clinical study. Participants:The participants included 16 controls and 22 patients using 100 mg/kg topiramate who were diagnosed with migraine according to the International Classification of Headache Disorders, second edition criteria. Methods:One-minute dynamic measurements of refraction with accommodation stimuli of 0 D, 2 D, 2.5 D, 3 D, 4 D, and 5 D were obtained using the open field refractometer WAM-5500 in. Results:In most of the accommodation stimuli ranges (0 D, 2.5 D, 3 D, and 5 D), topiramate users had a significantly higher accommodative lag compared with controls (p=0.028, p =0.014, p=0.011, and p=0.011, respectively). The most important causes of accommodative lag were found to be accommodation stimulus and inclusion in the topiramate group (p<0.001, R-2=0.32, 95% CI 0.22-0.37 and 0.42-0.91, respectively). Multivariate linear regression analysis revealed that the 2 most important predictors of accommodative lag were accommodation stimulus and age (p<0.001, r=0.51, 95% CI 0.31-0.32 and 0.67-0.69, respectively) CONCLUSIONS: Even after adjustment for age, accommodative lag is greater across several accommodative stimulus levels in patients using topiramate, which may be related to visual symptoms in topiramate users.Publication Metadata only Evaluation of depressive mood and cognitive functions in patients with acromegaly under somatostatin analogue therapy(SPRINGER, 2017) YAVUZ, DİLEK; Alibas, H.; Uluc, K.; Koytak, P. Kahraman; Uygur, M. M.; Tuncer, N.; Tanridag, T.; Yavuz, D. GogasAims Acromegaly is caused by a pituitary adenoma that releases excess growth hormone (GH) and a concomitant increase in insulin-like growth factor 1 (IGF-1). Acromegaly results not only in phenotypic changes, but also in neurologic complications as peripheral neuropathy and cognitive dysfunction. This study aimed to compare depressive mood and cognitive function in patients with acromegaly and in healthy controls as well as to determine the factors underlying cognitive dysfunction in the acromegalic patients. Materials and methods This study included 42 patients with acromegaly that were receiving somatostatin analogue therapy and 44 healthy controls. Memory, attention, visuospatial function, inhibitory function, abstract thinking, verbal fluency, and depressive mood were measured in the patients and controls. Results Patients with acromegaly had lower learning (p = 0.01), planning (p = 0.03), complex attention and inhibitory function (p = 0.04) scores than the controls. There was no significant difference in depressive mood between the patients and controls (p > 0.05). Gamma knife radiosurgery did not negatively affect cognitive function (p > 0.05). Conclusion The present findings show that acromegaly negatively affects learning, attention, and planning.Publication Metadata only Dental Follicle Mesenchymal Stem Cells Enhance CD4+Foxp3+ Regulatory T Cells in the Lymphocytes of Amyotrophic Lateral Sclerosis Patients(MARMARA UNIV, INST HEALTH SCIENCES, 2017) KAHRAMAN KOYTAK, PINAR; Genc, Deniz; Zibandeh, Noushin; Uluc, Kayihan; Koytak, Pinar Kahraman; Gokalp, Muazzez; Tanridag, Tulin; Akkoc, TuncObjective: Amyotrophic lateral sclerosis (ALS) is a disorder that causes the degeneration of motor neurons. Currently, riluzole is the only effective drug used to treat ALS; however, it has limited clinical benefits. Stem cell-based therapy has been studied as a potential novel treatment strategy for ALS and has shown to have an anti-inflammatory effects when treating this disease. In this study, we studied the immunosuppressive effect of dental follicle mesenchymal stem cells (DFSCs) on peripheral blood mononuclear cells (PBMCs) of ALS patients. Methods: DFSCs were isolated from the third molar teeth of healthy individuals, and cells were seeded in the 48 well plate 48 hours prior to PBMC isolation. PBMCs were isolated from venous blood samples of ALS patients and healthy volunteers and were cultured in the presence or absence of DFSCs. After 72 h of culture period lymphocyte proliferation, apoptosis and CD4+FoxP3+ regulatory T-cell ratios were analyzed. Results: Analysis revealed an increase in the number of CD4+FoxP3+ regulatory T cells and a decrease in the proliferative responses of lymphocytes with DFSCs. In addition, DFSCs enhanced the apoptotic effect of the lymphocytes of ALS patients, but increased cell survival in healthy individuals. Conclusion: Our study showed that DFSCs regulate inflammatory responses of lymphocytes in ALS patients and that they can be a novel therapeutic approach for treating neuroinflammatory diseases including ALS.