Abnormal cognitive dysfunction in patients with restless legs syndrome: A event-related potential study

Recent study reported that patients with restless legs syndrome (RLS) may have cognitive deficit, particularly prefrontal lobe dysfunction (Pearson et al., 2006). The cognitive dysfunction may be attributed to either secondary to daytime sleepiness and/or attention deficit due to RLS symptoms, or primary to intrinsic brain dysfunction underneath RLS syndrome. Event-related potential (ERP), which offers high temporal resolution, provides information about the precise timing of dynamic neural mechanisms of different cognitive processes. ERP involved in stimulus categorization, probability sequence, attention resource allocation, and memory processing. To identify cognitive dysfunction in patients with RLS, event-related potential (ERP) study was performed. Daytime sleepiness and RLS symptoms were checked to delineate underlying mechanism of cognitive dysfunction in RLS.OAIID:oai:osos.snu.ac.kr:snu2009-01/104/2014017262/9SEQ:9PERF_CD:SNU2009-01EVAL_ITEM_CD:104USER_ID:2014017262ADJUST_YN:NEMP_ID:A079623DEPT_CD:801CITE_RATE:0FILENAME:abnormal cognitive dysfunction in patients with restless legs syndrome.pdfDEPT_NM:의학과CONFIRM:

Theta Oscillation Related to the Auditory Discrimination Process in Mismatch Negativity: Oddball versus Control Paradigm

Background and Purpose The aim of this study was to identify the mechanism underlying the auditory discriminatory process reflected in mismatch negativity (MMN), using time-frequency analysis of single-trial event-related potentials (ERPs).Methods Two auditory tones of different probabilities (oddball paradigm) and the same probability (control paradigm) were used. The average dynamic changes in amplitude were evaluated, and the in-phase consistency of the EEG spectrum at each frequency and time window across trials, event-related spectral perturbations (ERSPs), and inter-trial phase coherence (ITC) were computed.Results Subtraction of the ERPs of standard stimuli from the ERPs of deviant stimuli revealed a clear MMN component in the oddball paradigm. However, no discernible MMN component was observed in the control paradigm. Statistical tests showed that in the oddball paradigm, deviant tones produced significant increases of theta ERSPs and ITC at around 250 ms as compared with the standard tone, while no significant difference between the two stimuli was observed in the control paradigm.Conclusions Our results confirm that the auditory discriminatory process reflected in MMN is accompanied by phase resetting and power modulation at the theta frequency.OAIID:oai:osos.snu.ac.kr:snu2012-01/102/2014017262/2SEQ:2PERF_CD:SNU2012-01EVAL_ITEM_CD:102USER_ID:2014017262ADJUST_YN:YEMP_ID:A079623DEPT_CD:801CITE_RATE:1.892DEPT_NM:의학과SCOPUS_YN:YCONFIRM:

Cognitive functions and stereopsis in patients with Parkinson's disease and Alzheimer's disease using 3-dimensional television: a case controlled trial.

Stereopsis or depth perception is an awareness of the distances of objects from the observer, and binocular disparity is a necessary component of recognizing objects through stereopsis. In the past studies, patients with neurodegenerative disease (Alzheimer dementia, AD; Parkinson's disease IPD) have problems of stereopsis but they did not have actual stimulation of stereopsis. Therefore in this study, we used a 3-dimensional (3D) movie on 3D television (TV) for actual stereopsis stimulation. We propose research through analyzing differences between the three groups (AD, IPD, and Controls), and identified relations between the results from the Titmus Stereo Fly Test, and the 3D TV test. The study also looked into factors that affect the 3D TV test. Before allowing the patients to watch TV, we examined Titmus stereo Fly Test and cognitive test. We used the 3D version of a movie, of 17 minutes 1 second duration, and carried out a questionnaire about stereopsis. The scores of the stereopsis questionnaire were decreased in AD patients, compared with in IPD and controls, although they did not have any difference of Titmus Stereo Fly Test scores. In IPD patients, cognitive function (Montreal cognitive assessment, MoCA) scores were correlated with the scores of the stereopsis questionnaire. We could conclude that Titmus fly test could not distinguish between the three groups and cognitive dysfunction contributes to actual stereopsis perception in IPD patients. Therefore the 3D TV test of AD and IPD patients was more effective than Titmus fly test

A dry and flexible electrode for continuous-EEG monitoring using silver balls based polydimethylsiloxane(PDMS)

Purpose : Continuous-electroencephalograph (cEEG) monitoring has become one of the hottest issues in the neurology field. However, the conventional EEG electrode is unsuitable for EEG monitoring because drying conductive paste leads to increase in impedance and skin trouble. Therefore, we manufactured and tested a new dry and flexible surface electrode for cEEG monitoring. Methods : The electrode was constructed using a nontoxic, nonflammable polydimethylsiloxane (PDMS) substrate and a contacting silver balls electrode. A patient in a comatose state due to subarachnoid hemorrhage in the intensive care unit was studied over 48 h, and EEG data were recorded for 10 minutes every hour. The proposed electrode was evaluated using impedance, power spectral density, and coherence. Results : The fabricated electrode is sufficiently flexible and biocompatible. Impedance of the dry and flexible electrode (10.6±2.7 kΩ) was higher than that of the conventional Ag/AgCl electrode (2.8±0.4 kΩ). However, the power spectral characteristics of the developed dry and flexible electrode and conventional Ag/AgCl electrode are similar throughout 36 h of recording. Conclusions : Our dry and flexible electrode, compared with a conventional wet electrode, showed comparable data quality in terms of impedance, visual interpretation, and spectral characteristics during cEEG monitoring.OAIID:oai:osos.snu.ac.kr:snu2012-01/102/2014017262/5SEQ:5PERF_CD:SNU2012-01EVAL_ITEM_CD:102USER_ID:2014017262ADJUST_YN:NEMP_ID:A079623DEPT_CD:801CITE_RATE:0DEPT_NM:의학과SCOPUS_YN:NCONFIRM:

Reduced neural synchrony in patients with restless legs syndrome during a visual oddball task.

BACKGROUND: Restless legs syndrome (RLS) is a sensorimotor neurological disorder characterized by an irresistible urge to move the legs. It has been reported that RLS patients show cognitive deficits, presumably due to hyperactivity causing loss of attention, or malfunctions in the frontal region resulting from sleep deprivation. However, the mechanism underlying cognitive deficits in RLS patients is mostly unknown. As an effort to clarifying this, we investigated the differences in neural activity and phase synchrony between healthy controls and RLS patients during cognitive task performances. METHODOLOGY/PRINCIPAL FINDINGS: Seventeen female drug-naive RLS patients were enrolled in the study, and an age-matched group of thirteen healthy female volunteers served as controls. Multichannel event-related potentials (ERPs) were recorded from RLS patients and normal controls while performing a visual oddball task. In addition to conventional analyses of ERP waveforms and spectra, interregional gamma-band phase synchrony (GBPS) was investigated to observe the differences in interregional neural synchronies between normal and RLS patient groups. Strong GBPS was observed primarily between anterior and posterior regions along the midline for both groups. Along with significant reduction and delay of P300 ERP and induced gamma-band activity (GBA), the GBPS was considerably decreased in RLS patients compared to normal subjects, especially at frontal region. CONCLUSIONS: Overall, our results support that cognitive dysfunction in RLS patients is associated with reduced interregional neural synchrony as well as alterations in local neural activity

Demographics, clinical data of idiopathic Parkinson disease patients, Alzheimer’s disease patients, and Controls.

<p>NS: Not significant, NA: Not analyzed, AD: Alzheimer’s disease, IPD: Idiopathic Parkinson’s disease.</p><p>* Statistical tests: ANOVA</p><p>^a: IPD vs AD</p><p>^b: IPD vs Controls</p><p>^c: AD vs Controls</p><p>Demographics, clinical data of idiopathic Parkinson disease patients, Alzheimer’s disease patients, and Controls.</p

Scores of stereopsis questionnaire in three groups.

<p>Number: Median value. IPD: Idiopathic Parkinson disease, AD: Alzheimer’s disease.</p

Correlations of stereopsis questionnaire scores, and Age, MoCA and the Titmus stereo Fly Test.

<p>AD: Alzheimer’s disease, IPD: Idiopathic Parkinson’s disease.</p><p>Total: IPD+AD+Controls, Montreal cognitive assessment</p><p>* p<0.05</p><p>**p<0.01</p><p>Correlations of stereopsis questionnaire scores, and Age, MoCA and the Titmus stereo Fly Test.</p

The number of patients, according to the Titmus stereo Fly Test, in three groups.

<p>IPD: Idiopathic Parkinson’s disease, AD: Alzheimer’s disease.</p

The number of patients, according to stereopsis questionnaire scores, in three groups.

<p>IPD: Idiopathic Parkinson’s disease, AD: Alzheimer’s disease.</p