Higher Perceived Stress Increases the Subjective Reporting of ADHD: A Sample of Medical Students

This study aimed to evaluate the subjective Attention-Deficit/Hyperactivity Disorder (ADHD) symptoms with self-reported ratings and objective neurocognitive tests among medical students. Also, we examined to identify the psychological factors that predict ADHD reporting among medical students. Medical students (N=57) completed self-report questionnaires, and neurocognitive tests were conducted for attention measures. Participants had a mean age of 20.3 years, and 69.0% were female. High levels of perceived stress, state-trait anxiety, and current and childhood ADHD symptoms were possible risk factors; however, only higher perceived stress was a risk factor for the possibility of reporting themselves as ADHD in medical school students [odds ratio [OR] =1.184, 95% confidence interval [CI] = [1.015; 1.381]]. Higher perceived stress levels, the more reported ADHD subjectively in medical students. Objective attention measures had no impact on reporting ADHD subjectively. Screening for perceived stress is necessary for medical students, especially those with subjective ADHD symptoms

Complexity Analysis of Resting-State fMRI in Adult Patients with Attention Deficit Hyperactivity Disorder: Brain Entropy

Objective. Complexity analysis of functional brain structure data represents a new multidisciplinary approach to examining complex, living structures. I aimed to construct a connectivity map of visual brain activities using resting-state functional magnetic resonance imaging (fMRI) data and to characterize the level of complexity of functional brain activity using these connectivity data. Methods. A total of 25 healthy controls and 20 patients with attention deficit hyperactivity disorder (ADHD) participated. fMRI preprocessing analysis was performed that included head motion correction, temporal filtering, and spatial smoothing process. Brain entropy (BEN) was calculated using the Shannon entropy equation. Results. My findings demonstrated that patients exhibited reduced brain complexity in visual brain areas compared to controls. The mean entropy value of the ADHD group was 0.56±0.14, compared to 0.64±0.11 in the control group. Conclusion. My study adds an important novel result to the growing literature pertaining to abnormal visual processing in ADHD that my ADHD patients had lower BEN values, indicating more-regular functional brain structure and abnormal visual information processing

Electrical source localization by LORETA in patients with epilepsy: Confirmation by postoperative MRI

Background: Few studies have been conducted that have compared electrical source localization (ESL) results obtained by analyzing ictal patterns in scalp electroencephalogram (EEG) with the brain areas that are found to be responsible for seizures using other brain imaging techniques. Additionally, adequate studies have not been performed to confirm the accuracy of ESL methods. Materials and Methods: In this study, ESL was conducted using LORETA (Low Resolution Brain Electromagnetic Tomography) in 9 patients with lesions apparent on magnetic resonance imaging (MRI) and in 6 patients who did not exhibit lesions on their MRIs. EEGs of patients who underwent surgery for epilepsy and had follow-ups for at least 1 year after operations were analyzed for ictal spike, rhythmic, paroxysmal fast, and obscured EEG activities. Epileptogenic zones identified in postoperative MRIs were then compared with localizations obtained by LORETA model we employed. Results: We found that brain areas determined via ESL were in concordance with resected brain areas for 13 of the 15 patients evaluated, and those 13 patients were post-operatively determined as being seizure-free. Conclusion: ESL, which is a noninvasive technique, may contribute to the correct delineation of epileptogenic zones in patients who will eventually undergo surgery to treat epilepsy, (regardless of neuroimaging status). Moreover, ESL may aid in deciding on the number and localization of intracranial electrodes to be used in patients who are candidates for invasive recording

Eriyik polimerin viskoz davranışının serbest hacim ile ilişkilendirilmesi

Serbest hacim büyüklüğünün bir fonksiyonu olarak viskoziteye ilişkin çalışmalar son dönemlerde oldukça popüler bir hale gelmiştir [1-2]. Utracki [1], Simha-Somcysky (SS) Boşluk Teorisinden [3] hesap edilen serbest hacim üyüklüğünün bir ölçüsü olarak basınç ve sıcaklığa bağımlı boşluk kesri h ile şeklinde bir bağıntıyı önermiştir. Burada ai {i=0, 1 ve 2}’ler uygunluk parametreleridir. Utracki, SS’deki hal denklemindeki basınç parametresinin iki katını reolojik parametre olarak kullanarak ( ), bazı polimerlerin viskozite verilerini lineer bir hale getirmiştir. Yahsi [4], Utracki’nin hal denklemini bazı dallanmış alkanlar için lineer bir hale getirmediğini göstermiştir. Bu amaçla, difüzyon işlemleri için modifiye edilmiş ve önerilmiş serbest hacim bağıntısı , polimerlerin viskoz davranışlarının incelenmesi için test edilmiştir, fakat buda verileri lineer bir hale getirmemiştir. Burada uf segmental molar serbest hacim ve u* ise bir segmentin atlaması için kritik serbest hacim olarak yorumlanabilir. Böylece serbest hacim modeli viskozite verilerinin yorumlanması için tutarlı bir model değildir. Bununla birlikte transport olaylarında boşluğun büyüklüğü mü yoksa serbest hacim kesri mi baskın rol oynamaktadır sorusu sorulabilir. Serbest hacim tek başına transport olayını açıklamakta yeterli değildir, buna karşılık serbest hacmin kesri baskın rolü üstlenmektedir, çünkü bir segmentin peş peşe olarak atlaması maddede bulunan boşlukların miktarına bağlıdır ki buna serbest hacim kesri denir. Bir molekülün geçişi için son durumu ele alacağız ve bunun üzerine modeli tesis edeceğiz. Sıvıların istatistik termodinamiği temel alan SS teorisi ve Eyring Significant Structure (ESS) geçiş teorilerini birleştirilerek Yahsi [2] tarafından öne sürülen geçiş olayı olarak teorik bir model, serbest hacim niceliğini bir ölçüsü, sıcaklık ve basınç bağımlı boşluk kesri h(P,T)’nin modelde baskın bir rol oynadığını vurgular. Neticede Polystyrene (PS), Polypropylene (PP) ve Acrylonitrile-butadiene-styrene (ABS) gibi polimerler için h(P,T) boşluk kesri cinsinden viskozite için düzenlenmiş bir model geliştirdik. %6 ya da daha düşük KOK (Karakök Ortalama Kare) değeri ile viskozitede yeterli bir uyum elde ettik. Temmuz 2006 Gülsüm Akdeniz The study of viscosity, h, as a function of free-volume quantity has been recently popular [1-2]. Utracki[1] proposed a relation where ai {i=0, 1 and 2} are fitting parameters and h is the pressure and temperature dependent hole fraction as a measure of free volume quantity, computed by using the Simha Somcysky (SS) Hole Theory [3]. He linearized the viscosity data for some polymers using the rheological pressure parameter twice the equation of state (eos) one ( ) in the SS. Yet Yahsi [4] showed that it did not linearize the data of some branched alkanes. For this purpose, a modified free volume relation, viz. proposed for diffusion processes is tested for the viscous behavior of the polymers, but it did not linearize the data. Here uf is segmental molar free volume and u* is interpreted as the critical free volume for jumping of a segment. Therefore such a free volume model is not consistent to interpret the viscosity data. However, question may be raised whether the hole (vacancy) size (free volume) or free volume fraction plays a dominant role for the transport phenomena. The free volume is not alone sufficient to explain the transportation, but rather the fraction of it plays a major role because successive jumping of a segment is attained with a quantity related with an amount of holes distributed in the matter so called the free volume fraction. We will consider the latter for the transport of a molecule and proceed to establish the model based upon this case. A theoretical model as transport phenomena, proposed by Yahsi [2], combining the Eyring Significant Structure (ESS) transport theory and the SS theory based on statistical thermodynamics of liquids[3]. exposes that the temperature and pressure dependent hole fraction, , as a measure of free volume quantity, plays a dominant role in the model. Thereby we have developed a simplified model for the viscosity in terms of for the polymer such as Polystyrene (PS), Polypropylene (PP), and Acrylonitrile-butadiene-styrene (ABS). The satisfactory agreement in viscosity is obtained with an rms value %6 or less. July 2006 Gülsüm AKDENİ

High Prevalence of Tarsal Tunnel Syndrome in Patients Diagnosed with Fibromyalgia Syndrome Hohe Prävalenz des Tarsaltunnelsyndroms bei Patienten mit Fibromyalgie-Syndrom

Objective To evaluate foot function and prevalence of tarsal tunnel syndrome in patients diagnosed with fibromyalgia syndrome as compared with healthy individuals. Methods This prospective study included 111 participants, including 63 female patients with fibromyalgia (mean age: 46.17 ± 6.64 years) and 48 female healthy controls (mean age: 46.16 ± 9.38 years) who met the selection criteria. The participants were evaluated for Tinel’s sign and asked about the presence of foot pain and paraesthesia in both groups. In addition, the participants were assessed using the Fibromyalgia Impact Questionnaire and Foot Function Index (FFI) for functionality. Bilateral electrophysiological studies of the tibial, peroneal, sural, medial and lateral plantar nerves were performed. Results Tarsal tunnel syndrome was present in 20 extremities of the patients with fibromyalgia (15.9 %) and four extremities of the controls (4.2 %)(p = 0.005). Paraesthesia was observed in 56 extremities in the fibromyalgia group (44.4 %) and 10 extremities in the control group (10.4 %)(p < 0.001). Tinel’s sign was positive in 69 extremities (54.8 %) in the fibromyalgia group and 17 in the control group (17.7 %)(p < 0.001). The total number of painful feet was 123 (97.6 %) in the fibromyalgia group and 22 (22.9 %) in the control group (p < 0.001). The mean total FFI was 66.26 ± 60.80 for the right foot and 66.28 ± 64.12 for the left foot in the FMS group; in the control group, it was 16.02 ± 31.01 and 16.87 ± 34.14, respectively. Both values exhibited a statistically significant difference between the two groups (p < 0.001) Conclusion In patients with fibromyalgia syndrome, paraesthesia and foot pain may be seen more frequently. Therefore, electrophysiological evaluation of the lower extremities may be recommended in these patients