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 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 Metadata only Medial plantar and dorsal sural nerve conduction studies increase the sensitivity in the detection of neuropathy in diabetic patients(ELSEVIER IRELAND LTD, 2008) İŞAK, BARIŞ; Uluc, Kayihan; Isak, Baris; Borucu, Deniz; Temucin, Cagri Mesut; Cetinkaya, Yilmaz; Koytak, Pinar Kahraman; Tanridag, Tulin; Us, Onderobjective: Clinical utility of nerve conduction studies (NCS) of the medial plantar and dorsal sural nerves in the early detection of polyneuropathy have already been shown separately. However, at present, there is no data about the combined assessment of these two nerves in distal sensory neuropathy. In the present study, we aimed to evaluate the medial plantar and dorsal sural NCS in a group of diabetic patients with distal sensory neuropathy (DSN) and in healthy controls. Methods: Thirty healthy and 30 diabetic adult patients were included. In all subjects, peripheral motor and sensory NCS were performed bilaterally with surface electrodes on the lower limbs including medial plantar and dorsal sural nerves. In addition, motor and sensory nerves were studied unilaterally on the upper limb. Results: In all patients, nerve action potential (NAP) amplitudes of sural and superficial peroneal nerves were within normal ranges, but in the patient group mean value was significantly lower than in the controls. Among clinically defined 30 DSN patients, medial plantar NAP amplitude was abnormal in 18 (60%) and dorsal sural nerve amplitude was abnormal in 13 (40%) of the patients bilaterally. Additionally, the onset NCV of the dorsal sural nerve was significantly slower in patients than controls (P = 0.038). Evaluation of both of these nerves increased the sensitivity up to 70% in the detection of neuropathy. Conclusions: Bilateral NCS assessment of both of the medial plantar and dorsal sural nerves together increases the rate of diagnosis of diabetic distal sensory neuropathy compared to assessment of either of these nerves. Significance: Assessment of medial plantar in addition to dorsal sural NCS together increases the sensitivity in the detection of neuropathy and allows earlier diagnosis, especially when routine NCS are normal. (c) 2008 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.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.Publication Metadata only ASSESSMENT OF SYMPTOMATIC DIABETIC PATIENTS WITH NORMAL NERVE CONDUCTION STUDIES: UTILITY OF CUTANEOUS SILENT PERIODS AND AUTONOMIC TESTS(WILEY, 2011) İŞAK, BARIŞ; Koytak, Pinar Kahraman; Isak, Baris; Borucu, Deniz; Uluc, Kayihan; Tanridag, Tulin; Us, OnderEstablished electrophysiological methods have limited clinical utility in the diagnosis of small-fiber neuropathy (SFN). In this study, diabetic patients with clinically diagnosed SFN were evaluated with autonomic tests and cutaneous silent periods (CSPs). Thirty-one diabetic patients with clinically suspected SFN and normal nerve conduction studies were compared with 30 controls. In the upper extremities (UE), the CSP parameters did not differ statistically between the patient and control groups, whereas, in the lower extremities (LE), patients had prolonged CSP latencies (P = 0.018) and shortened CSP durations (P < 0.001). The sensitivity of the CSP duration was 32.6%, and the specificity was 96.7%. The expiration-to-inspiration ratios and amplitudes of the sympathetic skin responses in the lower extremities were also reduced. Our findings indicate that the diagnostic utility of CSPs was higher than that of the autonomic tests to support the clinically suspected diagnosis of SFN. Muscle Nerve 43: 317-323, 2011