Local and Widely Distributed EEG Activity in Schizophrenia With Prevalence of Negative Symptoms

2017 ◽  
Vol 48 (5) ◽  
pp. 307-315 ◽  
Author(s):  
Vera A. Grin-Yatsenko ◽  
Valery A. Ponomarev ◽  
Marina V. Pronina ◽  
Yury I. Poliakov ◽  
Irina V. Plotnikova ◽  
...  
Keyword(s):  
Negative Symptoms ◽  
Current Source ◽  
Low Frequency ◽  
Chronic Schizophrenia ◽  
Control Group ◽  
Beta Activity ◽  
Eyes Closed ◽  
Distributed Components ◽  
Spatially Distributed ◽  
Eyes Open

We evaluated EEG frequency abnormalities in resting state (eyes closed and eyes open) EEG in a group of chronic schizophrenia patients as compared with healthy subjects. The study included 3 methods of analysis of deviation of EEG characteristics: genuine EEG, current source density (CSD), and group independent component (gIC). All 3 methods have shown that the EEG in schizophrenia patients is characterized by enhanced low-frequency (delta and theta) and high-frequency (beta) activity in comparison with the control group. However, the spatial pattern of differences was dependent on the type of method used. Comparative analysis has shown that increased EEG power in schizophrenia patients apparently concerns both widely spatially distributed components and local components of signal. Furthermore, the observed differences in the delta and theta range can be described mainly by the local components, and those in the beta range mostly by spatially widely distributed ones. The possible nature of the widely distributed activity is discussed.

scholarly journals EEG Data Quality: Determinants and Impact in a Multicenter Study of Children, Adolescents, and Adults with Attention-Deficit/Hyperactivity Disorder (ADHD)

2021 ◽  
Vol 11 (2) ◽  
pp. 214
Author(s):  
Anna Kaiser ◽  
Pascal-M. Aggensteiner ◽  
Martin Holtmann ◽  
Andreas Fallgatter ◽  
Marcel Romanos ◽  
...  
Keyword(s):  
Data Quality ◽  
Large Scale ◽  
Linear Models ◽  
Spectral Power ◽  
Control Group ◽  
Continuous Performance Task ◽  
Related Data ◽  
Eyes Closed ◽  
Eeg Data ◽  
Eyes Open

Electroencephalography (EEG) represents a widely established method for assessing altered and typically developing brain function. However, systematic studies on EEG data quality, its correlates, and consequences are scarce. To address this research gap, the current study focused on the percentage of artifact-free segments after standard EEG pre-processing as a data quality index. We analyzed participant-related and methodological influences, and validity by replicating landmark EEG effects. Further, effects of data quality on spectral power analyses beyond participant-related characteristics were explored. EEG data from a multicenter ADHD-cohort (age range 6 to 45 years), and a non-ADHD school-age control group were analyzed (ntotal = 305). Resting-state data during eyes open, and eyes closed conditions, and task-related data during a cued Continuous Performance Task (CPT) were collected. After pre-processing, general linear models, and stepwise regression models were fitted to the data. We found that EEG data quality was strongly related to demographic characteristics, but not to methodological factors. We were able to replicate maturational, task, and ADHD effects reported in the EEG literature, establishing a link with EEG-landmark effects. Furthermore, we showed that poor data quality significantly increases spectral power beyond effects of maturation and symptom severity. Taken together, the current results indicate that with a careful design and systematic quality control, informative large-scale multicenter trials characterizing neurophysiological mechanisms in neurodevelopmental disorders across the lifespan are feasible. Nevertheless, results are restricted to the limitations reported. Future work will clarify predictive value.

scholarly journals Maximal stability limits in adolescents with Tourette syndrome

2021 ◽  
Vol 4 (1) ◽  
pp. 013-022
Author(s):  
Blanchet Mariève ◽  
Prince François ◽  
Lemay Martin ◽  
Chouinard Sylvain ◽  
Messier Julie
Keyword(s):  
Postural Control ◽  
Tourette Syndrome ◽  
Center Of Pressure ◽  
Phase 1 ◽  
Sensory Information ◽  
Control Group ◽  
Eyes Closed ◽  
Highly Sensitive ◽  
Eyes Open ◽  
Stability Limits

We explored if adolescents with Gilles de la Tourette syndrome (GTS) had functional postural control impairments and how these deficits are linked to a disturbance in the processing and integration of sensory information. We evaluated the displacements of the center of pressure (COP) during maximal leaning in four directions (forward, backward, rightward, leftward) and under three sensory conditions (eyes open, eyes closed, eyes closed standing on foam). GTS adolescents showed deficits in postural stability and in lateral postural adjustments but they had similar maximal COP excursion than the control group. The postural performance of the GTS group was poorer in the eyes open condition (time to phase 1 onset, max-mean COP). Moreover, they displayed a poorer ability to maintain the maximum leaning position under the eyes open condition during mediolateral leaning tasks. By contrast, during forward leaning, they showed larger min-max ranges than control subjects while standing on the foam with the eyes closed. Together, these findings support the idea that GTS produces subclinical postural control deficits. Importantly, our results suggest that postural control disorders in GTS are highly sensitive to voluntary postural leaning tasks which have high demand for multimodal sensory integration.

Tardive Dyskinesia and Type II Schizophrenia

1992 ◽  
Vol 160 (2) ◽  
pp. 253-256 ◽  
Author(s):  
Elizabeth J. B. Davis ◽  
Milind Borde ◽  
L. N. Sharma
Keyword(s):  
Cognitive Impairment ◽  
Negative Symptoms ◽  
Chronic Schizophrenia ◽  
Thought Disorder ◽  
Control Group ◽  
Positive Symptoms ◽  
Type Ii ◽  
Formal Thought Disorder ◽  
Schizophrenic Patients ◽  
Male Patients

Cognitive impairment, negative and positive symptoms, primitive release reflexes, and age/temporal disorientation were assessed in 20 male patients meeting the DSM–III–R criteria for chronic schizophrenia and Schooler & Kane's criteria for TD. The control group comprised 20 age-matched male chronic schizophrenic patients without TD. Significant associations were found between TD, cognitive impairment, some negative symptoms, and formal thought disorder. These associations were independent of other illness and treatment variables. The severity of TD correlated significantly with that of cognitive impairment.

scholarly journals Increased Beta Activity Links to Impaired Emotional Control in ADHD Adults With High IQ

2017 ◽  
Vol 23 (7) ◽  
pp. 754-764 ◽  
Author(s):  
Hui Li ◽  
Qihua Zhao ◽  
Fang Huang ◽  
Qingjiu Cao ◽  
Qiujin Qian ◽  
...  
Keyword(s):  
Resting State ◽  
Emotional Control ◽  
Control Group ◽  
Beta Activity ◽  
Adhd Group ◽  
Eeg Signals ◽  
Eyes Closed ◽  
Beta Power ◽  
Eeg Power ◽  
Iq Method

Objective: The present study investigated the neuropathology of everyday-life executive function (EF) deficits in adults with ADHD with high IQ. Method: Forty adults with ADHD with an IQ ≥ 120 and 40 controls were recruited. Ecological EFs were measured, and eyes-closed Electroencephalograph (EEG) signals were recorded during a resting-state condition; EEG power and correlations with impaired EFs were analyzed. Results: Compared with controls, the ADHD group showed higher scores on all clusters of EF. The ADHD group showed globally increased theta, globally decreased alpha, and increased central beta activity. In the ADHD group, central beta power was significantly related to emotional control ratings, while no such correlation was evident in the control group. Conclusion: The results suggest that resting-state beta activity might be involved in the neuropathology of emotional control in adults with ADHD with high IQ.

scholarly journals Postural Balance Ability and the Effect of Visual Restriction on Older Dancers and Non-Dancers

2021 ◽  
Vol 3 ◽  
Author(s):  
Maria-Elissavet Nikolaidou ◽  
Vasilios Karfis ◽  
Maria Koutsouba ◽  
Arno Schroll ◽  
Adamantios Arampatzis
Keyword(s):  
Repeated Measures ◽  
Postural Balance ◽  
Path Length ◽  
Performance Test ◽  
Control Group ◽  
Quiet Stance ◽  
Balance Performance ◽  
Visual Channel ◽  
Eyes Closed ◽  
Eyes Open

Dance has been suggested to be an advantageous exercise modality for improving postural balance performance and reducing the risk of falls in the older population. The main purpose of this study was to investigate whether visual restriction impacts older dancers and non-dancers differently during a quiet stance balance performance test. We hypothesized higher balance performance and greater balance deterioration due to visual restriction in dancers compared with non-dancers, indicating the superior contribution of the visual channel in the expected higher balance performances of dancers. Sixty-nine (38 men, 31 women, 74 ± 6 years) healthy older adults participated and were grouped into a Greek traditional dance group (n = 31, two to three times/week for 1.5 h/session, minimum of 3 years) and a non-dancer control group (n = 38, no systematic exercise history). The participants completed an assessment of one-legged quiet stance trials using both left and right legs and with eyes open while standing barefoot on a force plate (Wii, A/D converter, 1,000 Hz; Biovision) and two-legged trials with both eyes open and closed. The possible differences in the anthropometric and one-legged balance parameters were examined by a univariate ANOVA with group and sex as fixed factors. This ANOVA was performed using the same fixed factors and vision as the repeated measures factor for the two-legged balance parameters. In the one-legged task, the dance group showed significantly lower values in anteroposterior and mediolateral sway amplitudes (p = 0.001 and p = 0.035) and path length measured in both directions (p = 0.001) compared with the non-dancers. In the two-legged stance, we found a significant vision effect on path length (p < 0.001) and anteroposterior amplitude (p < 0.001), whereas mediolateral amplitude did not differ significantly (p = 0.439) between closed and open eyes. The dance group had a significantly lower CoP path length (p = 0.006) and anteroposterior (p = 0.001) and mediolateral sway amplitudes (p = 0.003) both in the eyes-open and eyes-closed trials compared with the control group. The superior balance performance in the two postural tasks found in the dancers is possibly the result of the coordinated, aesthetically oriented intersegmental movements, including alternations between one- and two-legged stance phases, that comes with dance. Visual restriction resulted in a similar deterioration of balance performance in both groups, thus suggesting that the contribution of the visual channel alone cannot explain the superior balance performance of dancers.

scholarly journals Effectiveness of an Unexpected Disturbance Program in the Early Stage of Rehabilitation in Athletes With Unilateral Knee Ligament Injury

2021 ◽  
Vol 30 (1) ◽  
pp. 43-48
Author(s):  
Joerg Teichmann ◽  
Rachel Tan ◽  
Kim Hébert-Losier ◽  
Yeo Wee Kian ◽  
Shabana Jalal Din ◽  
...  
Keyword(s):  
Early Stage ◽  
National Level ◽  
Isometric Strength ◽  
Return To Play ◽  
Ligament Injury ◽  
Control Group ◽  
Knee Ligament ◽  
Eyes Closed ◽  
Knee Ligament Injury ◽  
Eyes Open

Context: Sensorimotor, proprioceptive, and neuromuscular programs are critical for the successful rehabilitation of injured athletes, and these decrease reinjury rates. Objective: To investigate the effects of an unexpected disturbance program (UDP) on balance and unilateral strength metrics in athletes with unilateral knee ligament injury. Design: A 3-week parallel-group experimental design consisting of 9 rehabilitation sessions. Setting: National Sports Institute. Participants: Twenty-one national-level athletes (age 21.4 [4.4] y, body mass 63.9 [10.8] kg, height 169.0 [10.2] cm) who had sustained a unilateral knee ligament injury. Intervention: An UDP program designed to evoke rapid sensorimotor responses was compared with traditional training and a nonexercise control group. Main Outcome Measures: Unilateral total, anteroposterior, and mediolateral sway with eyes open and closed and unilateral isometric strength. Results: Traditional exercises tended to outperform the UDP when unilateral balance testing was performed with eyes open; however, balance improvement following UDP tended to be greater in the eyes-closed condition. Significant strength gains in both the injured and uninjured legs were only observed following the UDP. This increase in unilateral isometric strength was 23.4 and 35.1 kg greater than the strength improvements seen in the traditional rehabilitation and control groups (P < .05). Conclusions: UDP could improve neural aspects of rehabilitation to improve rehabilitation outcomes by improving strength, sensorimotor function, and proprioception. Given the complementary adaptations, an UDP could provide an effective adjunct to traditional rehabilitation protocols and improve return-to-play outcomes.

scholarly journals Effect of a “T-Band” Kick Training Protocol on Postural Sway

1998 ◽  
Vol 7 (2) ◽  
pp. 122-127 ◽  
Author(s):  
Andrew G. Baker ◽  
William G. Webright ◽  
David H. Perrin
Keyword(s):  
Postural Sway ◽  
Stability Index ◽  
Control Group ◽  
Eyes Closed ◽  
Before And After ◽  
Proprioceptive Training ◽  
Eyes Open ◽  
Potential Benefits ◽  
Experimental Group ◽  
Training Protocol

The purpose of this study was to examine the effects of a resistive tubing kick training protocol on postural sway in uninjured collegiate wrestlers. An experimental group (n= 10) performed a progressive resistive tubing kick training protocol three times per week for 6 weeks. A control group (n= 9) performed no resistive tubing training during the 6 weeks. Postural sway (stability index) was assessed before and after the 6-week training period. ANOVAs demonstrated no significant interactions, although significant main effects were found for group and eye condition. The experimental group demonstrated less postural sway than the control group regardless of training, and postural sway was greater with the eyes closed than with the eyes open. Resistive tubing kick training does not significantly improve postural sway in healthy collegiate wrestlers. Further research should examine the potential benefits of proprioceptive training using a greater intensity of training and/or using subjects who have a greater potential for improvement.

scholarly journals Balance Markers in Adolescents at 1 Month Postconcussion

2017 ◽  
Vol 5 (3) ◽  
pp. 232596711769550 ◽  
Author(s):  
Coralie Rochefort ◽  
Coren Walters-Stewart ◽  
Mary Aglipay ◽  
Nick Barrowman ◽  
Roger Zemek ◽  
...  
Keyword(s):  
Center Of Pressure ◽  
Age Distribution ◽  
Control Group ◽  
Level Of Evidence ◽  
Cross Sectional ◽  
Significant Group ◽  
Dual Task Condition ◽  
Eyes Closed ◽  
Eyes Open ◽  
Balance Deficits

Background: The Balance Error Scoring System (BESS) shows that balance tends to recover within days after a concussion, whereas measures of the movement of the center of pressure (COP) show that balance deficits can persist up to 1 month after concussion. While approximately 30% of adolescents suffering concussion have functional consequences including balance deficits, evidence of the use of different balance assessments for concussion is limited within this population. Purpose: To compare performance on a series of balance assessments between adolescents with a diagnosed concussion at 1 month postinjury and noninjured control participants within the same age distribution. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Thirty-three adolescents 1 month postconcussion and 33 control participants completed the BESS followed by two, 2-minute trials standing on a Nintendo Wii Balance Board (WBB), during which the COP under their feet was recorded using 2 testing protocols: (1) double-leg stance, eyes open (EO) and (2) double-leg stance, eyes closed (EC). Participants then completed a dual-task condition (DT) with eyes open combining a double-leg stance and a Stroop color and word test while standing on the WBB. Three commonly used COP variables, anterior-posterior (A/P) and mediolateral (M/L) velocity and 95% ellipse, were computed for each condition performed on the WBB. Results: Participants postconcussion swayed over a significantly larger ellipse area compared with the control group in the EO ( P = .008), EC ( P = .002), and DT ( P = .003) conditions and also performed the DT condition with faster COP velocity in the M/L direction ( P = .007). No significant group difference was identified for BESS total score. Conclusion: At 1 month postconcussion, participants continued to demonstrate balance deficits in COP control despite scoring similar to controls on the BESS. Simple COP measures of balance may identify subtle impairments not captured by the BESS.

scholarly journals Quantification of Trunk Postural Stability Using Convex Polyhedron of the Time-Series Accelerometer Data

2016 ◽  
Vol 2016 ◽  
pp. 1-9 ◽  
Author(s):  
Roman Melecky ◽  
Vladimir Socha ◽  
Patrik Kutilek ◽  
Lenka Hanakova ◽  
Peter Takac ◽  
...  
Keyword(s):  
Postural Stability ◽  
Convex Polyhedron ◽  
Human Movement ◽  
Control Group ◽  
Accelerometer Data ◽  
Eyes Closed ◽  
Significant Difference ◽  
Eyes Open ◽  
Novel Method ◽  
Well Correlation

Techniques to quantify postural stability usually rely on the evaluation of only two variables, that is, two coordinates of COP. However, by using three variables, that is, three components of acceleration vector, it is possible to describe human movement more precisely. For this purpose, a single three-axis accelerometer was used, making it possible to evaluate 3D movement by use of a novel method, convex polyhedron (CP), together with a traditional method, based on area of the confidence ellipse (ACE). Ten patients (Pts) with cerebellar ataxia and eleven healthy individuals of control group (CG) participated in the study. The results show a significant increase of volume of the CP (CPV) in Pts or CG standing on foam surface with eyes open (EO) and eyes closed (EC) after the EC phase. Significant difference between Pts and CG was found in all cases as well. Correlation coefficient indicates strong correlation between the CPV and ACE in most cases of patient examinations, thus confirming the possibility of quantification of postural instability by the introduced method of CPV.

scholarly journals Balance Performance in Irradiated Survivors of Nasopharyngeal Cancer with and without Tai Chi Qigong Training

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Shirley S. M. Fong ◽  
Louisa M. Y. Chung ◽  
William W. N. Tsang ◽  
Joyce C. Y. Leung ◽  
Caroline Y. C. Charm ◽  
...  
Keyword(s):  
Healthy Control Group ◽  
Control Group ◽  
Healthy Individuals ◽  
Balance Performance ◽  
Compliant Surface ◽  
Eyes Closed ◽  
Eyes Open ◽  
Healthy Control ◽  
The One ◽  
Minute Walk

This cross-sectional exploratory study aimed to compare the one-leg-stance time and the six-minute walk distance among TC Qigong-trained NPC survivors, untrained NPC survivors, and healthy individuals. Twenty-five survivors of NPC with TC Qigong experience, 27 survivors of NPC without TC Qigong experience, and 68 healthy individuals formed the NPC-TC Qigong group, NPC-control group, and healthy-control group, respectively. The one-leg-stance (OLS) timed test was conducted to assess the single-leg standing balance performance of the participants in four conditions: (1) standing on a stable surface with eyes open, (2) standing on a compliant surface with eyes open, (3) standing on a stable surface with eyes closed, and (4) standing on a compliant surface with eyes closed. The six-minute walk test (6MWT) was used to determine the functional balance performance of the participants. Results showed that the NPC-control group had a shorter OLS time in all of the visual and supporting surface conditions than the healthy control group(P<0.05). The OLS time of the TC Qigong-NPC group was comparable to that of the healthy control group in the somatosensory-challenging condition (condition 3)(P=0.168)only. Additionally, there was no significant difference in the 6MWT distance among the three groups(P>0.05). TC Qigong may be a rehabilitation exercise that improves somatosensory function and OLS balance performance among survivors of NPC.

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