Brain function assessment in different conscious states

Background: The study of brain functioning is a major challenge in neuroscience fields as human brain has a dynamic and ever changing information processing. Case is worsened with conditions where brain undergoes major changes in so-called different conscious states. Even though the exact definition of consciousness is a hard one, there are certain conditions where the descriptions have reached a consensus. The sleep and the anesthesia are different conditions which are separable from each other and also from wakefulness. The aim of our group has been to tackle the issue of brain functioning with setting up similar research conditions for these three conscious states.Methods: In order to achieve this goal we have designed an auditory stimulation battery with changing conditions to be recorded during a 40 channel EEG polygraph (Nuamps) session. The stimuli (modified mismatch, auditory evoked etc.) have been administered both in the operation room and the sleep lab via Embedded Interactive Stimulus Unit which was developed in our lab. The overall study has provided some results for three domains of consciousness. In order to be able to monitor the changes we have incorporated Bispectral Index Monitoring to both sleep and anesthesia conditions.Results: The first stage results have provided a basic understanding in these altered states such that auditory stimuli have been successfully processed in both light and deep sleep stages. The anesthesia provides a sudden change in brain responsiveness; therefore a dosage dependent anesthetic administration has proved to be useful. The auditory processing was exemplified targeting N1 wave, with a thorough analysis from spectrogram to sLORETA. The frequency components were observed to be shifting throughout the stages. The propofol administration and the deeper sleep stages both resulted in the decreasing of N1 component. The sLORETA revealed similar activity at BA7 in sleep (BIS 70) and target propofol concentration of 1.2 μg/mL.Conclusions: The current study utilized similar stimulation and recording system and incorporated BIS dependent values to validate a common approach to sleep and anesthesia. Accordingly the brain has a complex behavior pattern, dynamically changing its responsiveness in accordance with stimulations and states. © 2010 Ozgoren et al; licensee BioMed Central Ltd

Childhood and juvenile onset multiple sclerosis: clinical and paraclinical features

It is well known that multiple sclerosis (MS) is a demyelinating disease of the central nervous system that mostly starts in the second to third decade. In the present study, we reviewed our own observations of the clinical and paraclinical features in the 36 of 890 (4.04%) MS patients whose symptoms started before 16 years of age. The average age at onset of the disease in these 36 patients was 12.9 years. In 18 patients, the disease onset was monosymptomatic. Diplopia and sensory disturbances were the most common initial manifestations and occurred in 27.7% of cases. Twenty-one patients (59%) had a relapsing and 11 patients (30.5%) had a secondary progressive course. On the last evaluation, the EDSS score was above 5 in 11 patients and it was below 5 in 21 patients. As a result of this study, we concluded that childhood onset MS does not significantly differ from that it has been typically seen in adults in terms of major clinical manifestations and course of disease. (C) 2003 Elsevier Science B.V. All rights reserved

Motor cortical thresholds and cortical silent periods in epilepsy

We studied motor cortical thresholds (TIs) and cortical silent periods (SPs) evoked by transcranial magnetic stimulation (TMS) in 110 epileptic patients. Sixty-two had primary generalised, 48 had partial type seizures. Fifteen out 110 patients were analysed both before and after anticonvulsant medication. Our aims were to evaluate the TI levels and the duration of SPs in patients with epilepsy and to determine the reliability of TMS in patients with epilepsy. There was no negative effect of TMS on the clinical status and EEG findings in patients with epilepsy. TIs obtained from patients with partial epilepsy were higher than those obtained from both controls and primary epileptics. The duration of SPs in patients with primary epileptics was more prolonged than those obtained from controls. There was no correlation between EEG lateralisation and both SP duration and TI values. In de novo patient group, SP duration was significantly prolonged after anticonvulsant medication. We concluded that TMS is a reliable electrophysiological investigation in patients with epilepsy. The analysis of SP duration may be an appropriate investigation in monitoring the effect of anticonvulsant medication on the cortical inhibitory activity. (C) 2003 BEA Trading Ltd. Published by Elsevier Ltd. All rights reserved

Circadian Distribution of Epileptic Seizures

31st International Epilepsy Congress -- SEP 05-09, 2015 -- Istanbul, TURKEY[No Abstract Available

Neuropathy and dysautonomia in patients with obstructive sleep apnea syndrome [Obstruktif uyku apne sendromunda nöropati ve disotonomi]

Introduction: The aim of our study is to search for the existence of neuropathy, dysautonomia and to identify the correlations of sickness level of patients with Obstructive Sleep Apnea Syndrome (OSAS). Methods: The research is based on the real cases at Dokuz Eylul University of Medicine Sleep and Epilepsy Center, observed during September 2008- May 2009. The patients were selected by polysomnography samples based on 20 persons at same ages with following criteria; high leveled OSAS (AHİ?30), low OSAS (5?AHİ<30) and healthy participants. Classical ENMG protocol, symphatic skin response and R-R interval variation test were performed on these samples. Results: High and low leveled OSAS patients had a statistically significant (p<0.05) decrease in the average velocity of motor conduction in right tibialis posterior when compared to the control group. Besides we observed an statistically significant (p<0.05) increase in the average amplitud of symphatic skin responses in high leveled OSAS patients than control group. Conclusion: OSAS indicates a risk of possible peripheral neuropathy and autonomic dysfunction risk increases in positive correlation with level of OSAS. © 2015 by Turkish Association of Neuropsychiatry