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Dive into the research topics where Ayse Oytun Bayrak is active.

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Featured researches published by Ayse Oytun Bayrak.


Muscle & Nerve | 2009

Ultrasonography in patients with ulnar neuropathy at the elbow: Comparison of cross‐sectional area and swelling ratio with electrophysiological severity

Ayse Oytun Bayrak; Ilkay Koray Bayrak; Hande Türker; Muzaffer Elmali; Mehmet Selim Nural

The aim of this study was to determine the diagnostic value of ultrasonographic measurements in ulnar neuropathy at the elbow (UNE) and to assess the relationship between the measurements and the electrophysiological severity. The largest anteroposterior diameter (LAPD) and cross‐sectional area (CSA) measurements of the ulnar nerve were noted at multiple levels along the arm, and the distal‐to‐proximal ratios were calculated. Almost all of the measurements and swelling ratios between patients and controls showed statistically significant differences. The largest CSA, distal/largest CSA ratio, CSA at the epicondyle, and proximal LAPD had larger areas under the curve than other measurements. The sensitivity and specificity in diagnosing UNE were 95% and 71% for the largest CSA, 83% and 85% for the distal/largest CSA ratio, 83% and 81% for the CSA at the epicondyle, and 93% and 43% for the proximal LAPD, respectively. There was a statistically significant correlation between the electrophysiological severity scale score (ESSS) and the largest CSA, the CSA at the epicondyle and 2 cm proximal to the epicondyle, and the LAPD at the level of the epicondyle (P < 0.05). None of the swelling ratios showed a significant correlation with the ESSS. The largest CSA measurement is the most valuable ultrasonographic measurement both for diagnosis and determining the severity of UNE. Muscle Nerve, 2010


Muscle & Nerve | 2007

Ultrasonography in carpal tunnel syndrome: comparison with electrophysiological stage and motor unit number estimate.

Ilkay Koray Bayrak; Ayse Oytun Bayrak; Hacer Erdem Tilki; Mehmet Selim Nural; Tevfik Sunter

The purpose of this study was to document the ultrasonographic measurement differences in median nerve size between patients with carpal tunnel syndrome (CTS) and controls, and to correlate these findings with electrophysiological stage and motor unit number estimation (MUNE), thereby allowing us to test the validity of ultrasound as a diagnostic modality for assessing the severity of CTS. High‐resolution sonography and electrophysiological studies were performed on 41 wrists of 27 patients and compared with findings on 40 wrists of 20 healthy individuals. On ultrasonographic views, cross‐sectional area and flattening ratio in proximal, middle, and distal tunnel segments of the median nerve were measured both by calculating ellipsoid area by large and small cross‐sectional diameters and by automated ellipsoid area calculation. We compared electrophysiological stage and MUNE with proximal, middle, and distal cross‐sectional area and other ultrasonographic findings. All correlations between electrophysiological stage and cross‐sectional areas in these different segments of the median nerve were significant with both measurement methods. Negative correlations were seen between MUNE and cross‐sectional area in the proximal and middle segments, whereas no significant correlation was detected in the distal segment. Our results indicate that there are close correlations between the ultrasonographic findings and electrophysiological stage. Ultrasound also reflects the reduction in the number of axons estimated by the MUNE method. Therefore, we suggest that the ultrasonographic findings reflect the severity of disease in patients with CTS. Muscle Nerve, 2006


Journal of Ultrasound in Medicine | 2008

Bifid Median Nerve in Patients With Carpal Tunnel Syndrome

Ilkay Koray Bayrak; Ayse Oytun Bayrak; Melike Kale; Hande Türker; Baris Diren

Objective. The aim of this study was to investigate the frequency of the anatomic variation of a bifid median nerve in patients with carpal tunnel syndrome (CTS) and to determine the size criteria for sonography. Methods. On axial sonograms of 320 hands of 170 patients with CTS and 240 hands of 120 unaffected individuals, the median nerve was evaluated morphologically for a bifid median nerve, and the cross‐sectional area was measured at 3 levels (radial‐ulnar junction, pisiform, and hook of the hamate). Electrophysiologic studies were performed in addition to clinical and sonographic evaluations in all patients, controls with a bifid median nerve, and controls with a cross‐sectional area of greater than 0.09 cm2. Results. A bifid median nerve was seen in 32 (19%) of 170 patients and 11 (9%) of 120 controls. It occurred relatively frequently in patients with CTS (P < .01). The cross‐sectional area of the bifid median nerve was relatively higher than that of the nonbifid median nerve in controls at 2 of the 3 levels (P < .001; P = .226; P < .01). The cutoff values for the cross‐sectional area at the level of the pisiform were 0.11 cm2 (sensitivity, 90%; specificity, 99%; P < .001) for patients with a bifid median nerve and 0.10 cm2 (sensitivity, 98%; specificity, 81%; P < .001) for patients with a nonbifid median nerve. Conclusions. A bifid median nerve occurs relatively frequently in patients with CTS. It may facilitate compression of the median nerve in the carpal tunnel because of its relatively higher cross‐sectional area compared with a nonbifid median nerve. The size criterion for CTS in patients with a bifid median nerve is slightly higher than in those with a nonbifid median nerve.


Pediatric Hematology and Oncology | 2007

Pyridoxine and pyridostigmine treatment in vincristine-induced neuropathy.

Hamit Özyürek; Hande Türker; Mehtap Akbalik; Ayse Oytun Bayrak; Hülya Ince; Feride Duru

Vincristine is a commonly used antineoplastic drug and frequently causes neurotoxicity. Here the authors report a 4-year-old boy with acute lymphoblastic leukemia in whom vincristine-induced peripheral and cranial neuropathy developed during remission induction therapy. The patient seemed to benefit from pyridoxine and pyridostigmine therapy greatly and this therapy is recommended in patients with severe vincristine-induced neuropathy.


Clinical Rheumatology | 2009

Effect of cervical spondylosis on vertebral arterial flow and its association with vertigo

Ilkay Koray Bayrak; Dilek Durmus; Ayse Oytun Bayrak; Baris Diren; Feryal Canturk

The aim in this study was to evaluate the effect of cervical spondylosis on vertebral arterial flow. The flow changes on Doppler measurements in patients with vertigo were also assessed. Ninety-one patients with different grades of degeneration on disks and apophysis were evaluated. The severity of degeneration was determined by two observers, and the effect of cervical degeneration on vertebral arterial flow was assessed. The relation between vertigo and changes in Doppler measurements of vertebral artery in neck and cranium was analyzed. As total degeneration increases, the flow volume decreases in the right vertebral artery but increases in the left. No other correlation between degeneration scores, cervical curve measurements, and Doppler measurements was noted. According to the total degeneration scores, no differences were noted between the patients with and without vertigo. In patients with vertigo, the resistive index was higher in the neck before the vertebral foramina. In correlations of the ratios of the intra/extracranial vertebral artery with Doppler measurements, the only change was observed in the left flow volume. The severity of degeneration in disks and apophysis does not cause a considerable change in vertebral arterial flow, and also no significant finding on Doppler measurements were noted in patients with vertigo.


Brain & Development | 2009

Hereditary neuropathy with liability to pressure palsy (HNPP) in childhood: A case study emphasizing the relevance of detailed electrophysiological examination for suspected HNPP in the first decade

Ayse Oytun Bayrak; Esra Battaloglu; Hande Türker; Ibrahim Baris; Gurkan Oztas

Hereditary neuropathy with liability to pressure palsy (HNPP) is an autosomal dominant disorder characterized by recurrent mono-neuropathies secondary to minor trauma or compression. Whilst typical episodes of palsy generally become apparent during the second and the third decades, HNPP is rarely diagnosed in the first decade. We present the case of a 6-year-old patient to draw attention to the possibility of HNPP attacks in the first decade and the importance of detailed electrophysiological examination.


Neurological Research | 2010

Electrophysiological assessment of polyneuropathic involvement in rheumatoid arthritis: relationships among demographic, clinical and laboratory findings

Ayse Oytun Bayrak; Dilek Durmus; Yunus Durmaz; İlknur Demir; Ferhan Canturk; Musa Onar

Abstract Objectives: The aims of this study were to electrophysiologically evaluate polyneuropathy in rheumatoid arthritis (RA) patients and to examine the relationships among polyneuropathy and demographic, clinical and laboratory findings. Patients and methods: Sixty consecutive patients (51 women and nine men) with a clinical diagnosis of RA were examined electrophysiologically for the evidence of polyneuropathy. Parameters including age, gender, subcutaneous nodules, erosions, joint deformities, laboratory parameters, duration of RA, as well as dose, duration and type of disease modifying anti-rheumatic drug (DMARD) and steroid usage were recorded. RA activity was assessed using a 28-joint disease activity score (DAS28). The functional status of patients was measured using the health assessment questionnaire (HAQ). The symptoms and signs of polyneuropathy were quantified using the neuropathy symptoms score (NSS) and the neuropathy disability score (NDS), respectively. Results: Ten patients (17%, eight women and two men) had polyneuropathic involvement as defined by nerve conduction studies (NCS). Two patients had mild symmetric sensory neuropathy and eight patients had mild symmetric sensorimotor axonal polyneuropathy. There was no significant difference in age, gender, subcutaneous nodules, erosions, joint deformities, rheumatoid factor, as well as dose, duration and type of DMARD and steroid therapy administered. We found a significant relationship among polyneuropathy and duration of RA, DAS28, HAQ, as well as abnormal NSS and NDS values. The durations of RA and DAS28 were also associated with a four- and three-fold increase in the risk of polyneuropathy, respectively. Conclusion: Mild symmetric sensory or sensorimotor axonal polyneuropathies are common in RA patients and it is difficult to distinguish the symptoms of polyneuropathy from those of arthritis. An electrophysiological examination should be routinely carried out especially when patients have had a long disease duration and high scores for DAS28, HAQ, NSS and NDS.


Neurological Research | 2017

Diagnosing carpal tunnel syndrome with Doppler ultrasonography: a comparison of ultrasonographic measurements and electrophysiological severity

Nihal Kutlar; Ayse Oytun Bayrak; Ilkay Koray Bayrak; Sevgi Canbaz; Hande Türker

Abstract Introduction: Carpal tunnel syndrome (CTS) is the most common entrapment neuropathy. Diagnosis is based on clinical history, physical examination, and electrophysiological studies. Imaging techniques are performed for difficult-to-diagnose cases because they provide information about the morphology of the median nerve. More recently, it has been shown that Doppler ultrasonography can detect increased intraneural blood flow in CTS. The aim of our study is to evaluate the relationship between the severity of CTS, hypervascularization, and cross-sectional area (CSA) to determine the diagnostic value of Doppler ultrasonography. Patients and methods: The study group comprised 125 wrists of 75 patients who had been diagnosed with CTS, both clinically and electrophysiologically. The control group comprised 100 wrists of 50 healthy volunteers. Wrists were classified into five stages of CTS severity based on electrophysiologic studies. A radiologist examined the wrists blindly with grayscale images and Doppler ultrasonography to assess CSA and hypervascularization. Results: A total of 121 wrists were included. There were 28 wrists with minimal CTS severity stage, 36 with mild, 36 with moderate, and 21 with severe. The sensitivity and specificity of CSA and hypervascularization in detecting CTS was 90.9, 94.0, 93.4, and 90.0%, respectively. There was a significant correlation between CTS severity and hypervascularization (p < 0.005) for all stages. Conclusion: Our study shows that Doppler ultrasonography results strongly correlate with CTS severity. Hence, this is a useful method for diagnosing CTS and estimating its severity.


Neurological Research | 2015

Ultrasonographic findings in hereditary neuropathy with liability to pressure palsies

Ayse Oytun Bayrak; Ilkay Koray Bayrak; Esra Battaloglu; Burcak Ozes; Onur Yildiz; Musa Onar

Abstract Objectives: The aims of this study were to evaluate the sonographic findings of patients with hereditary neuropathy with liability to pressure palsies (HNPP) and to examine the correlation between sonographic and electrophysiological findings. Methods: Nine patients whose electrophysiological findings indicated HNPP and whose diagnosis was confirmed by genetic analysis were enrolled in the study. The median, ulnar, peroneal, and tibial nerves were evaluated by ultrasonography. Results: We ultrasonographically evaluated 18 median, ulnar, peroneal, and tibial nerves. Nerve enlargement was identified in the median, ulnar, and peroneal nerves at the typical sites of compression. None of the patients had nerve enlargement at a site of noncompression. None of the tibial nerves had increased cross-sectional area (CSA) values. There were no significant differences in median, ulnar, and peroneal nerve distal motor latencies (DMLs) between the patients with an increased CSA and those with a normal CSA. In most cases, there was no correlation between electrophysiological abnormalities and clinical or sonographic findings. Discussion: Although multiple nerve enlargements at typical entrapment sites on sonographic evaluation can suggest HNPP, ultrasonography cannot be used as a diagnostic tool for HNPP. Ultrasonography may contribute to the differential diagnosis of HNPP and other demyelinating polyneuropathies or compression neuropathies; however, further studies are required.


International Journal of Neuroscience | 2010

Manifestation of Lambert–Eaton Myasthenic Syndrome During Last Trimester of Pregnancy

Ayse Oytun Bayrak; Ufuk Sandıkçı; Serpil Yon; Musa Onar

ABSTRACT Lambert–Eaton myasthenic syndrome (LEMS) is a rare immune-mediated disorder of neuromuscular junctions. The knowledge of the effects of pregnancy on the course of patients with LEMS is limited. Here we describe a patient without a history of previous known illness who has complained of weakness during the last trimester of her pregnancy, delivered a healthy baby and was diagnosed with non-paraneoplastic LEMS during the postpartum period. With this case we wanted to emphasize the effects of pregnancy on the course of patients with LEMS.

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Hande Türker

Ondokuz Mayıs University

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Musa Onar

Ondokuz Mayıs University

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İlknur Demir

Ondokuz Mayıs University

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Ahmet Yılmaz

Turkish Ministry of Health

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Baris Diren

Ondokuz Mayıs University

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Dilek Durmus

Ondokuz Mayıs University

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