Pain-related fear in adolescents with chronic musculoskeletal pain: process evaluation of an interdisciplinary graded exposure program.

BACKGROUND: For studying the effectiveness of treatment, it is important to check whether a new treatment is performed as originally described in the study-protocol. OBJECTIVES: To evaluate whether an interdisciplinary graded exposure program, for adolescents with chronic musculoskeletal pain reporting pain-related fear, was performed according to protocol, and whether it is feasible to implement the program in rehabilitation care. METHODS: A process evaluation where quantitative and qualitative data on participant characteristics (adolescents, parents and therapists), attendance and participants' opinion on the program were collected, by means of registration forms, questionnaires and group interviews. To evaluate treatment fidelity, audio and video recordings of program sessions were analyzed. RESULTS: Thirty adolescents were offered the program, of which 23 started the program. Adolescents attended on average 90% of the sessions. At least one parent per adolescent participated in the program. Analysis of 20 randomly selected recordings of treatment sessions revealed that treatment fidelity was high, since 81% of essential treatment elements were offered to the adolescents. The program was considered client-centered by adolescents and family-centered by parents. Treatment teams wished to continue offering the program in their center. CONCLUSION: The interdisciplinary graded exposure program was performed largely according to protocol, and therapists, adolescents and their parents had a favorable opinion on the program. Implementation of the program in rehabilitation care is considered feasible. TRIAL REGISTRATION: Clinicaltrials.gov ID: NCT02181725 (7 February 2014).

Preventing musculoskeletal complaints in music students: a randomized controlled trial.

BACKGROUND: Musculoskeletal complaints in music students are common. Little is known about effectiveness of interventions. AIMS: To assess whether a biopsychosocial prevention course is better at reducing disability due to musculoskeletal disorders compared with physical activity promotion. METHODS: This was a multicentre randomized controlled trial with intention-to-treat analysis. Participants were first- and second-year students from five conservatories, randomized to experimental or control groups. The experimental group participated in 11 classes on body posture playing the instrument according to postural exercise therapy, and performance-related psychosocial aspects. The control group participated in five classes promoting physical activity according to national guidelines. The primary outcome was disability using the Disabilities of the Arm, Shoulder and Hand (DASH) questionnaire, including the performing arts module. Secondary outcomes were pain, quality of life, playing-related musculoskeletal disorders and health behaviour. Outcomes were assessed at six points, from baseline until 2-year follow-up. RESULTS: One hundred and seventy participants were randomized to experimental (n = 84) or control (n = 86) groups. Loss to follow-up was 40% during the trial and 69% at 2-year follow-up. The dropout rate was equal in both groups. Overall, there were no significant differences between groups for any outcome adjusted for baseline characteristics: percentage disability, odds ratio was 1.31, 95% confidence interval (CI) 0.69-2.51; general DASH, ß = -0.57, 95% CI -3.23 to 2.09; and performing arts module, ß = -0.40, 95% CI 5.12-4.32. CONCLUSIONS: A biopsychosocial prevention course tailored for musicians was not superior to physical activity promotion in reducing disability. Large numbers lost to follow-up warrant cautious interpretation.

Anxiety affects disability and quality of life in patients with painful diabetic neuropathy.

BACKGROUND: Painful diabetic neuropathy (PDN) is known to negatively affect psychosocial functioning as expressed by enhanced levels of anxiety and depression. The aim of this study was to specify diabetes and pain-related fears. METHODS: This questionnaire-based cross-sectional study included 154 patients with PDN (mean age 65.7 ± 6.6 years). Correlation analyses corrected for age, gender, pain intensity, pain duration and insulin treatment were performed to assess the associations of fear of hypoglycaemia (Hypoglycaemia Fear Survey, HFS), kinesiophobia (Tampa Scale of Kinesiophobia, TSK), fear of pain (Pain Anxiety Symptom Scale, PASS-20), fear of falling (Falls Efficacy Scale-I, FES-I), fear of fatigue (Tampa Scale of Fatigue, TSF) and fear of negative evaluation (Brief Fear of Negative Evaluation Scale, BFNE), with quality of life (QoL) (Norfolk Quality of Life Questionnaire, Diabetic Neuropathy Version, QOL-DN) and disability (Pain Disability Index, PDI), respectively. RESULTS: In univariate analyses, all fears were independently associated with QOL-DN and PDI (p < 0.001 for all variables). Linear regression models including all fears and confounders, showed that pain intensity, pain duration and FES-I were significantly associated with QOL-DN (R2  = 0.603). Pain intensity, male gender and FES-I were significantly associated with PDI (R2  = 0.526). CONCLUSIONS: After controlling for confounders, levels of pain intensity, duration of pain and fear of falling were negatively associated with QoL in patients with PDN. Pain intensity, male gender and fear of falling were positively associated with disability. Specifying fears enables us to identify potential targets for behavioural interventions that aim to improve psychosocial well-being in patients with PDN. SIGNIFICANCE: This study shows that patients with PDN suffer from various fears, which should enable us to design a treatment strategy that directly targets these fears, hereby improving physical and psychosocial well-being in these patients.

A cognitive-behavioral program for parents of children with chronic musculoskeletal pain; A feasibility study.

BACKGROUND: The purpose of the study is to evaluate the feasibility of a newly developed parent program for parents of children with non-specific chronic musculoskeletal pain. This program is part of the child's interdisciplinary outpatient pain rehabilitation treatment. The goal of the parent program is to change parent's thoughts/behaviour regarding pain with the ultimate intention to further improve their child's functioning. There were two main objectives in the study: First, to evaluate the feasibility of the parent program. Second, to evaluate changing in parental behavioral factors pre- and posttreatment. METHODS: Participants were parents of adolescents, who underwent a interdisciplinary outpatient pain program for non-specific chronic musculoskeletal pain. Parents participated in a parent program as part of their child's treatment. Adolescents reported their level of disability, pain intensity, fear of pain and pain catastrophizing by filling out questionnaires. Parents reported catastrophic thinking about their child's pain, fear of pain and disabilities of their child. In addition, they evaluated the parent program. RESULTS: Sixty five parents (36 mothers and 29 fathers) of 44 adolescents filled in the baseline questionnaires. Result showed significant and clinically relevant improvements for both parents as well for adolescents. Parents were positive about the content of the parent program, they evaluated the program as supportive and informative. CONCLUSION: Adding a parent program to a interdisciplinary outpatient pain program for adolescent with chronic musculoskeletal pain, seems to be feasible in daily life of the parents and results in positive behavioural changes for both parents and adolescents. SIGNIFICANCE: A parent program, designed to change cognition and behaviour of parents of children with chronic musculoskeletal pain is feasible.

Dealing with a life changing event: The influence of spirituality and coping style on quality of life after survival of a cardiac arrest or myocardial infarction.

BACKGROUND: Survivors of a cardiac arrest often have cognitive and emotional problems. As a cardiac arrest is also an obvious life-threatening event, other psychological sequelae associated with surviving such as spirituality may also affect quality of life. OBJECTIVES: To determine the relationship between spirituality, coping and quality of life in cardiac patients both with and without a cardiac arrest. METHODS: In this retrospective cohort study, participants received a questionnaire by post. The primary outcome measure was quality of life (LiSat-9). Secondary outcome measures were spiritual well-being (FACIT-Sp12), coping style (UPCC), emotional well-being (HADS, IES), fatigue (FSS) and daily activities (FAI). Statistical analyses included multiple regression analyses. RESULTS: Data were available from 72 (60% response rate) cardiac arrest survivors and 98 (47%) patients with a myocardial infarction. Against our hypothesis, there were no differences in spirituality or other variables between the groups, with the exception of more depressive symptoms in patients with myocardial infarction without arrest. Analysis of the total data set (170 participants) found that a better quality of life was associated with higher levels of meaning and peace in life, higher levels of social and leisure activities, and lower levels of fatigue. CONCLUSIONS: Quality of life after a cardiac arrest and after a myocardial infarction without arrest are not different; fatigue, a sense of meaning and peace, and level of extended daily activities are factors related to higher life satisfaction.

Systematic review: risk factors for musculoskeletal disorders in musicians.

BACKGROUND: Although many musicians suffer from musculoskeletal disorders, aetiological factors are unclear. AIMS: To systematically search for and synthesize the best available evidence on risk factors for musculoskeletal disorders in musicians. METHODS: A database search was performed in PubMed, EMBASE, CINAHL, Pedro, OTseeker and Psychinfo. A manual search was conducted in the journals Medical Problems of Performing Artists and Psychology of Music. Studies with an objective to investigate determinants associated with playing-related musculoskeletal disorders were included. Papers were selected based on adequacy of statistical methods for the purpose of the study. Search, first screening and selection were performed by one author. Two reviewers independently performed the final selection using full-text reports. Methodological quality assessment was performed by two reviewers independently. RESULTS: One case-control and 14 cross-sectional studies were included. Methodological quality was in general low. Large heterogeneity existed in study design, population, measurement of determinant and outcome and analysis techniques. Data were presented descriptively. Consistent results were found indicating that previous musculoskeletal injury, music performance anxiety, high levels of stress and being a female playing a stringed instrument seemed to be associated with more musculoskeletal disorders. Influence over or support at work, orchestra category/status, exercise behaviour and cigarette smoking seemed to be unrelated with musculoskeletal disorders. No conclusions could be made on causality, as the current data only represent cross-sectional associations. CONCLUSIONS: Because of lack of prospective studies, no causal relations could be identified in the aetiology of (playing-related) musculoskeletal disorders in instrumental musicians.

Social functioning in adulthood: Understanding long-term outcomes of adolescents with chronic pain/fatigue treated at inpatient rehabilitation programs.

BACKGROUND: Chronic pain and fatigue are both common complaints in childhood and adolescence and often persist over time. The aim of the study was to investigate whether chronic pain/fatigue persists during adulthood and how former patients function and participate in society as adults. METHODS: This historical cohort study used questionnaires to gather the data. Predictors for social participation in adulthood were also identified. Differences in functioning and health care use between young adults with current pain/fatigue complaints and those without were also discussed. RESULTS: Ninety-four young adults responded; their mean age was 26.6 years and 91.5% were women. The average time since treatment was 10.2 years. 63.4% reported ongoing or new pain/fatigue complaints. 72.0% had a paid job; of those who worked, 22.1% reported taking sick leave in the past month. 78.7% of them reported having one or more chronic diseases. A higher level of pain/fatigue measured pre-treatment was identified as a predictor for more impaired social participation in adulthood. Young adults with current pain/fatigue complaints reported more healthcare utilization, lower levels of physical functioning and limitations in daily activities due to physical problems. CONCLUSIONS: A considerable number of these young adults still have pain/fatigue complaints in adulthood. More pain/fatigue pre-treatment during adolescence predict impaired functioning in the work-educational domain in young adulthood. WHAT DOES THIS STUDY ADD?: This study examines the social participation of young adults who suffered from severe chronic pain/fatigue during adolescence. Predictors for social participation are reported, as are the differences between young adults with and without persistent pain/fatigue complaints.

Measuring outcome after cardiac arrest: construct validity of Cerebral Performance Category.

INTRODUCTION: Approximately half of the survivors of cardiac arrest have cognitive impairments due to hypoxic brain injury. To describe the outcome after a cardiac arrest, the Cerebral Performance Category (CPC) is frequently used. Although widely used, its validity is still debatable. OBJECTIVE: To investigate the construct validity of the Cerebral Performance Category in survivors of a cardiac arrest. Participants were 18 years and older that survived a cardiac arrest more than six months. METHODS: Cross-sectional design. A method to administer the CPC in a structured and reproducible manner was developed. This 'Structured CPC' was administered by a structured interview. Construct variables were Cognitive Failure Questionnaire (CFQ), Barthel Index (BI), Frenchay Activity Index (FAI), Community Integration Questionnaire (CIQ) and Quality of Life after Brain Injury (Qolibri). Associations were tested based on Spearman correlation coefficients. RESULTS: A total of 62 participants responded. In 58 (94%) patients the CPC was determined, resulting in CPC 1 (48%), CPC 2 (23%) and CPC 3 (23%). The CPC-scoring correlated significantly with the CFQ (r=-0.40); BI (r=-0.57); FAI (r=-0.65), CIQ (r=-0.53) and Qolibri (r=-0.67). DISCUSSION AND CONCLUSIONS: In this study we developed the 'Structured CPC' to improve the transparency and reproducibility of the original CPC. A moderate correlation between the 'Structured CPC' and the constructs 'activities', 'participation' and 'quality of life' confirmed the validity of the 'Structured CPC'. CLINICAL MESSAGE: The 'Structured CPC' can be used as an instrument to measure the level of functioning after cardiac arrest.

Future goals of adolescents and young adults with chronic musculoskeletal pain.

BACKGROUND: Chronic non-specific musculoskeletal pain is a common problem among adolescents. This study investigates the importance of future goals and goal frustration for adolescents and young adults with chronic musculoskeletal pain compared to healthy adolescents. It also explores the impact that pain intensity, pain catastrophizing and depressive symptoms have on goal frustration for adolescents with chronic pain. METHODS: Using a cross-sectional design, we compared the importance and frustration of future goals for 42 adolescents and young adults with chronic musculoskeletal pain (41 women, 1 man) to those of 42 adolescents without pain (35 women, 7 men). For the adolescents with chronic pain, we also examined levels of pain intensity, pain catastrophizing and depressive symptoms to assess their ability to explain goal frustration levels. Statistics included t-tests, Mann-Whitney test and multivariate regression analysis. RESULTS: We found no differences in the importance of future goals, except for goals related to health, which were more important for adolescents with chronic pain (p = 0.03). Furthermore, adolescents with chronic pain perceived higher levels of goal frustration in all domains, except that related to school (p = 0.16). Depression explained goal frustration related to personal values (p = 0.02), social acceptance (p < 0.01), self-acceptance (p < 0.01) and health (p < 0.01). CONCLUSIONS: Dealing with chronic pain in adolescence and early adulthood does not seem to change future goals, but is associated with perceiving barriers to achieving them. The level of depressive symptoms seems to influence this relationship. Some caution is required in generalizing the results due to the relatively low number of male participants.

The psychometric characteristics of an assessment instrument for perceived harmfulness in adolescents with musculoskeletal pain (PHODA-youth).

BACKGROUND: Cognitive-behavioural models of chronic pain predict that dysfunctional assumptions about harmfulness of activities may maintain pain-related fear and disability. To assess perceived harmfulness in adolescents, the Photograph Series of Daily Activities for youth (PHODA-youth) was developed. Information concerning its methodological quality is currently lacking. OBJECTIVE: To investigate psychometric characteristics (factor structure, test-retest reliability, construct validity) and feasibility of the PHODA-youth in adolescents with chronic musculoskeletal pain. STUDY DESIGN: Test-retest design. STUDY POPULATION: Adolescents aged 13-21 years with chronic nonspecific musculoskeletal pain. METHODS: Participants filled in an electronic version of the PHODA-youth including 89 items twice with a 4-week interval. The instrument's factor structure was determined by a factor analysis. Construct validity was studied with criterion variables: catastrophizing (Pain Catastrophizing Scale for Children), pain intensity (visual analogue scale), depression (Children's Depression Inventory) and pain-related disability (Functional Disability Inventory) using regression analysis. Test-retest reliability was evaluated based on the Pearson correlation coefficient. Feasibility was studied with self-constructed questions. RESULTS: Seventy-one adolescents participated. Results show a three-factor structure for the PHODA-youth including 51 items with subscales labelled as: 'activities of daily life', 'intensive physical activities' and 'social activities'. Total and subscale scores showed a high internal consistency. Its test-retest reliability was good (r = 0.94) and its construct validity is supported by the finding that both catastrophizing (ß = 0.25; p = 0.02) and disability (ß = 0.71; p < 0.001) were uniquely related to the PHODA-youth. In addition, feasibility appeared adequate. CONCLUSION: The findings support the PHODA-youth as a valid and reliable measure of the perceived harmfulness of activities in adolescents with musculoskeletal pain.

Responsiveness of the Child Health Questionnaire-Parent Form in adolescents with non-specific chronic pain or fatigue.

BACKGROUND: The Child Health Questionnaire (CHQ) is a widely used instrument for measuring health-related quality of life covering both the physical and psychosocial domain. This study examined the responsiveness of the Dutch CHQ 50-item Parent Form (PF50) in a sample of adolescents with chronic non-specific pain and/or fatigue. METHOD: Five different methods were used to calculate the responsiveness for the physical (PhS) and psychosocial (PsS) subscale of the CHQ-50: standardized response mean (SRM), pooled effect sizes (ESs), standard error of measurement of agreement (SEMagreement ), minimal detectable change (MDC) and the area under the receiver operating characteristics (ROC) curve. For data analysis, the population was divided into two groups based on the parent's global perceived effect of treatment: a changed group (A) and an unchanged group (B). RESULTS: The responsiveness analyses were performed including 92 adolescents (88.0% girls; mean age 16.4 years). The SRMs are 2.89 and 1.01 for the PhS and PsS, respectively. Large ESs are found for group A (PhS = 3.30; PsS = 1.16). The method used for calculating SEMagreement results in a score of PhS = 18.92 and PsS = 11.39. The MDCs of PhS and PsS are 52.45 and 31.57, respectively. The area under the ROC curve (AUC) for PhS = 0.79 and for PsS = 0.64, and the corresponding optimal cut-off points are 21.1 and 7.0. CONCLUSION: Using the methods SRM, ES and AUC, the responsiveness of the CHQ-PF50 in adolescents with non-specific chronic pain or fatigue treated in a rehabilitation clinic is adequate for the physical scale and moderate for the psychosocial scale.

Children with generalised joint hypermobility and musculoskeletal complaints: state of the art on diagnostics, clinical characteristics, and treatment.

INTRODUCTION: To provide a state of the art on diagnostics, clinical characteristics, and treatment of paediatric generalised joint hypermobility (GJH) and joint hypermobility syndrome (JHS). METHOD: A narrative review was performed regarding diagnostics and clinical characteristics. Effectiveness of treatment was evaluated by systematic review. Searches of Medline and Central were performed and included nonsymptomatic and symptomatic forms of GJH (JHS, collagen diseases). RESULTS: In the last decade, scientific research has accumulated on all domains of the ICF. GJH/JHS can be considered as a clinical entity, which can have serious effects during all stages of life. However research regarding the pathological mechanism has resulted in new potential opportunities for treatment. When regarding the effectiveness of current treatments, the search identified 1318 studies, from which three were included (JHS: n = 2, Osteogenesis Imperfecta: n = 1). According to the best evidence synthesis, there was strong evidence that enhancing physical fitness is an effective treatment for children with JHS. However this was based on only two studies. CONCLUSION: Based on the sparsely available knowledge on intervention studies, future longitudinal studies should focus on the effect of physical activity, fitness, and joint stabilisation. In JHS and chronic pain, the effectiveness of a multidisciplinary approach should be investigated.

Pain-related fear: a critical review of the related measures.

OBJECTIVES: In regards to pain-related fear, this study aimed to: (1) identify existing measures and review their measurement properties, and (2) identify the optimum measure for specific constructs of fear-avoidance, pain-related fear, fear of movement, and kinesiophobia. DESIGN: Systematic literature search for instruments designed to measure fear of pain in patients with persistent musculoskeletal pain. Psychometric properties were evaluated by adjusted Wind criteria. RESULTS: Five questionnaires (Fear-Avoidance Beliefs Questionnaire (FABQ), Fear-Avoidance of Pain Scale (FAPS), Fear of Pain Questionnaire (FPQ), Pain and Anxiety Symptoms Scale (PASS), and the Tampa Scale for Kinesiophobia (TSK)) were included in the review. The main findings were that for most questionnaires, there was no underlying conceptual model to support the questionnaire's construct. Psychometric properties were evaluated by diverse methods, which complicated comparisons of different versions of the same questionnaires. Construct validity and responsiveness was generally not supported and/or untested. CONCLUSION: The weak construct validity implies that no measure can currently identify who is fearful. The lack of evidence for responsiveness restricts the current use of the instruments to identify clinically relevant change from treatment. Finally, more theoretically driven research is needed to support the construct and thus the measurement of pain-related fear.

Life after survival: long-term daily functioning and quality of life after an out-of-hospital cardiac arrest.

BACKGROUND: Information about long-term consequences of cardiac arrest is sparse. Because the survival rate is expected to increase, better knowledge of long-term functioning and quality of survival is essential. OBJECTIVES: To determine the level of functioning of out-of-hospital cardiac arrest survivors 1-6 years later, and to evaluate the predictive value of medical variables on long-term functioning. METHODS: A retrospective cohort study including 63 survivors of an out-of-hospital cardiac arrest, admitted to a Dutch University hospital between 2001 and 2006. Participants received a questionnaire by post. Primary outcome measures were: participation in society (Community Integration Questionnaire) and quality of life (SF-36). Secondary outcome measures were: physical, cognitive and emotional impairment, daily functioning and caregiver strain. Statistical analyses included multiple regression analyses. RESULTS: On average 3 years post-cardiac arrest, 74% of the patients experienced a low participation level in society compared with the general population. Over 50% reported severe fatigue, 38% feelings of anxiety and/or depression and 24% a decreased quality of life. Caregivers reported stress related responses, feelings of anxiety and lower quality of life. Seventeen percent of the caregivers reported high caregiver strain, which was associated with the patient's level of functioning. Gender, age, percutaneous coronary intervention (PCI) and therapeutic hypothermia contributed to outcome on at least one domain of long-term functioning. CONCLUSIONS: After surviving an out-of-hospital cardiac arrest, many patients and partners encounter extensive impairments in their level of functioning and quality of life. Gender, age, PCI and therapeutic hypothermia are associated with differences in long-term functioning of patients.

Graph theoretical analysis of magnetoencephalographic functional connectivity in Alzheimer's disease.

In this study we examined changes in the large-scale structure of resting-state brain networks in patients with Alzheimer's disease compared with non-demented controls, using concepts from graph theory. Magneto-encephalograms (MEG) were recorded in 18 Alzheimer's disease patients and 18 non-demented control subjects in a no-task, eyes-closed condition. For the main frequency bands, synchronization between all pairs of MEG channels was assessed using a phase lag index (PLI, a synchronization measure insensitive to volume conduction). PLI-weighted connectivity networks were calculated, and characterized by a mean clustering coefficient and path length. Alzheimer's disease patients showed a decrease of mean PLI in the lower alpha and beta band. In the lower alpha band, the clustering coefficient and path length were both decreased in Alzheimer's disease patients. Network changes in the lower alpha band were better explained by a 'Targeted Attack' model than by a 'Random Failure' model. Thus, Alzheimer's disease patients display a loss of resting-state functional connectivity in lower alpha and beta bands even when a measure insensitive to volume conduction effects is used. Moreover, the large-scale structure of lower alpha band functional networks in Alzheimer's disease is more random. The modelling results suggest that highly connected neural network 'hubs' may be especially at risk in Alzheimer's disease.

Resting state oscillatory brain dynamics in Parkinson's disease: an MEG study.

OBJECTIVE: The pathophysiological mechanisms of cognitive dysfunction and dementia in Parkinson's disease (PD) are still poorly understood. Altered resting state oscillatory brain activity may reflect underlying neuropathological changes. The present study using magneto encephalography (MEG) was set up to study differences in the pattern of resting state oscillatory brain activity in groups of demented and non-demented PD patients and healthy, elderly controls. METHODS: The pattern of MEG background oscillatory activity was studied in 13 demented PD patients, 13 non-demented PD patients and 13 healthy controls. Whole head MEG recordings were obtained in the morning in an eyes closed and an eyes open, resting state condition. Relative spectral power was calculated using Fast Fourier Transformation in delta, theta, alpha, beta and gamma frequency bands. RESULTS: In the non-demented PD patients, relative theta power was diffusely increased and beta power concomitantly decreased relative to controls. gamma Power was decreased in central and parietal channels. In the demented PD patients, a diffuse increase in relative delta and to lesser extent theta power and a decrease in relative alpha, beta and to lesser extent gamma power were found in comparison to the non-demented PD group. In addition, reactivity to eye opening was much reduced in the demented PD group. CONCLUSIONS: Parkinson's disease is characterized by a slowing of resting state brain activity involving theta, beta and gamma frequency bands. Dementia in PD is associated with a further slowing of resting state brain activity, additionally involving delta and alpha bands, as well as a reduction in reactivity to eye-opening. SIGNIFICANCE: The differential patterns of slowing of resting state brain activity in demented and non-demented PD patients suggests that, in conjunction with a progression of the pathological changes already present in non-demented patients, additional mechanisms are involved in the development of dementia in PD.

Magnetoencephalographic evaluation of resting-state functional connectivity in Alzheimer's disease.

Statistical interdependencies between magnetoencephalographic signals recorded over different brain regions may reflect the functional connectivity of the resting-state networks. We investigated topographic characteristics of disturbed resting-state networks in Alzheimer's disease patients in different frequency bands. Whole-head 151-channel MEG was recorded in 18 Alzheimer patients (mean age 72.1 years, SD 5.6; 11 males) and 18 healthy controls (mean age 69.1 years, SD 6.8; 7 males) during a no-task eyes-closed resting state. Pair-wise interdependencies of MEG signals were computed in six frequency bands (delta, theta, alpha1, alpha2, beta and gamma) with the synchronization likelihood (a nonlinear measure) and coherence and grouped into long distance (intra- and interhemispheric) and short distance interactions. In the alpha1 and beta band, Alzheimer patients showed a loss of long distance intrahemispheric interactions, with a focus on left fronto-temporal/parietal connections. Functional connectivity was increased in Alzheimer patients locally in the theta band (centro-parietal regions) and the beta and gamma band (occipito-parietal regions). In the Alzheimer group, positive correlations were found between alpha1, alpha2 and beta band synchronization likelihood and MMSE score. Resting-state functional connectivity in Alzheimer's disease is characterized by specific changes of long and short distance interactions in the theta, alpha1, beta and gamma bands. These changes may reflect loss of anatomical connections and/or reduced central cholinergic activity and could underlie part of the cognitive impairment.

MEG-compatible force sensor.

By use of an insulating material we constructed a strain gauge based sensor to measure isometric forces in parallel with magneto-encephalographic recordings (i.e. without interference). The sensor can be used in different geometries to measure force production in different dimensions. Furthermore, it can easily be adapted or modified for specific experimental applications. Finally, on-line processing of the recorded forces, e.g., for the purpose of feedback, can be realized using standard MEG equipment.

Temporal and spatial congruence of components of motion-onset evoked responses investigated by whole-head magneto-electroencephalography.

Motion-onset related components in averaged whole head co-recorded MEG and EEG responses of 24 adults to a low-contrast checkerboard pattern were studied. The aims were to identify these components, to characterize quantitatively their maps and to localize the underlying sources by equivalent-current-dipole (ECD) analyses with a spherical head model.After a weak P1, a large start-elicited negativity arises, comprising the novel N2a (occipital positive and parieto-central negative, peak-latency 141 ms) and the N2 like N2b (bilateral parieto-temporal, 175 ms) component. It is followed by a large positive stop-related component, P2 (156 ms after motion-offset). The corresponding MEG components N2am and N2bm showed bilateral dipole fields with considerable overlap. P1m has a single dipole field around the midline. N2a(m) and N2b(m) can be modelled with two bilateral ECDs with significant different locations. The study shows that accurate mapping and ECD analyses can distinguish two neighbouring areas of the visual cortex, 21+/-4 (SE) mm separated, which activities are reflected in both spatio-temporally closely related N2(m) components. N2a(m) and N2b(m) originate in the extrastriate cortex, possibly close to or in V3/V3A and MT/V5 respectively. Motion-evoked activity in (near) V3/V3A is novel on the basis of EEG data.

A whole head MEG study of the amplitude-modulation-following response: phase coherence, group delay and dipole source analysis.

OBJECTIVE: The amplitude-modulation-following response (AMFR) is the frequency component detectable in the electroencephalogram (EEG) or magnetoencephalography (MEG) corresponding to the modulation frequency of an amplitude modulated tone used as a continuous acoustic stimulus. Various properties of the AMFR depend on modulation frequency, suggesting that different generators along the auditory pathway are involved. The present study addresses these issues on the basis of a whole head MEG experiment. METHODS: AM tones with modulators in the 40 Hz and 80 Hz range were presented unilaterally to 10 normal hearing subjects. Biomagnetic responses were recorded with a 151 channel MEG system. The data analysis concentrated on the phase coherence of the responses, group delays and the estimated location of underlying equivalent dipole sources. RESULTS: MEG AMFR is more reliably detected in the 40 Hz than in the 80 Hz range. Both response amplitude and phase coherence indicate clear bilateral activation over the parietal/temporal region. Dipole source analysis confirms that sources are located in or near the auditory cortex. Group delays at 80 Hz are shorter than at 40 Hz. CONCLUSIONS: In both modulation frequency ranges MEG responses are dominated by activity in the auditory cortex, in apparent contrast with EEG data in the literature, pointing to dominant contributions of thalamic sources to the 80 Hz AMFR.