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1.
Cortex ; 178: 1-17, 2024 Jun 17.
Article in English | MEDLINE | ID: mdl-38954985

ABSTRACT

Recent advances in cognitive neurosciences suggest that intrinsic brain networks dynamics are associated with cognitive functioning. Despite this emerging perspective, limited research exists to validate this hypothesis. This Registered Report aimed to specifically test the relationship between intrinsic brain spatio-temporal dynamics and executive functions. Resting-state EEG microstates were used to assess brain spatio-temporal dynamics, while a comprehensive battery of nine cognitive function tasks was employed to evaluate executive functions in 140 participants. We hypothesized that microstates (class C and D) metrics would correlate with an executive functions composite score. Contrary to expectations, our hypotheses were not supported by the data. We however observed a small, non-significant trend with a negative correlation between microstate D occurrences and executive functions scores (r = -.18, 95% CI [-.33, -.01]) which however did not meet the adjusted threshold for significance. In light of the inconclusive or minor effect sizes observed, the assertion that intrinsic brain networks dynamics - as measured by resting-state EEG microstate metrics - are a reliable signature of executive functioning remains unsupported.

2.
J Rehabil Med ; 56: jrm18356, 2024 Mar 22.
Article in English | MEDLINE | ID: mdl-38528325

ABSTRACT

OBJECTIVE: To evaluate functional outcomes of surgery of spastic hip adductor muscles (obturator neurotomy with or without adductor longus tenotomy) in ambulatory and non-ambulatory patients, using preoperatively defined personalized goals. DESIGN: Retrospective observational descriptive study. PATIENTS: Twenty-three patients with adductor spasticity who underwent obturator neurotomy between May 2016 and May 2021 at the Clinique des Cèdres, Cornebarrieu, France, were included. METHODS: Postoperative functional results were evaluated in accordance with the Goal Attainment Scaling method. Patients were considered "responders" if their score was ≥ 0. Secondary outcomes included spasticity, strength, hip range of motion and change in ambulatory capacity. When data were available, a comparison of pre- and postoperative 3-dimensional instrumented gait analysis was also performed. RESULTS: Among the 23 patients only 3 were non-walkers. Seventeen/22 patients achieved their main goal and 14/23 patients achieved all their goals. Results were broadly similar for both walking goals (inter-knee contact, inter-feet contact, fluidity, walking perimeter, toe drag) and non-walking goals (intimacy, transfer, pain, posture, dressing). CONCLUSION: Surgery of spastic hip adductor muscles results in functional improvement in ambulation, hygiene, dressing and posture and can be offered to patients with troublesome adductor overactivity. The use of a motor nerve block is recommended to define relevant goals before the surgery.


Subject(s)
Cerebral Palsy , Muscle Spasticity , Adult , Humans , Cerebral Palsy/complications , Muscle Spasticity/surgery , Muscle, Skeletal , Pelvis , Retrospective Studies , Walking
3.
Disabil Rehabil ; 45(6): 1087-1096, 2023 03.
Article in English | MEDLINE | ID: mdl-35701095

ABSTRACT

PURPOSE: To test feasibility of a French translation and cross-cultural adaptation of the Upper-Limb Performance Assessment (ULPA) for task and ecologically based assessment of individualized passive function of upper-limb (UL) performance in adults treated with botulinum toxin-A. MATERIALS AND METHODS: A case series with seven adults with stroke (29-74 years) for spastic hypertonia management with passive use objectives (hygiene or positioning) established through Goal Attainment Scaling (GAS). Scores on ULPA Task Performance Mastery (TPM) were obtained through clinical and home-based performances before and after treatment. RESULTS: Time administration per task ranged from 5-10 min. Median (range) ULPA, Task Performance Mastery (ULPA-TPM) scores pre-intervention of 58 mastery (35-71) improved to 75 (58-88). Tau-U demonstrated significant large effect sizes (≥.65) for five participants. Complementary measures demonstrated improvement of passive performance for five participants and improvements in GAS for six participants. Testing indicates excellent intra-rater (ICC = 0.90) and moderate inter-rater (ICC = 0.64) reliability, with SDC of 10.16 and 18.23%, respectively. CONCLUSIONS: French use of ULPA is a promising standardized, objective and ecologically based assessment of passive performance in adults with stroke. Preliminary findings after TCCA support feasibility for measurement of individualized goals for UL passive use. Future studies may explore other tasks and environments. Implications for rehabilitationULPA is a performance-based, criterion-referenced and ecological measure of individualized goals based on task-analysis of upper-limb (UL) performance in real-life situations providing an interest for individualized assessment of activity and participation.The measure provides a standardized and quantitative approach, applicable to passive use of UL across environments, promoting ecological validity of assessment.Preliminary data will support clinical interpretation of change before and after botulinum injections of UL passive performance.Access to a transculturally validated French version of ULPA complements standardized assessment of UL impairment, perceived performance and goal attainment.


Subject(s)
Stroke Rehabilitation , Stroke , Humans , Adult , Pilot Projects , Feasibility Studies , Reproducibility of Results , Cross-Cultural Comparison , Upper Extremity , Treatment Outcome
4.
Neurology ; 99(7): 283-297, 2022 08 16.
Article in English | MEDLINE | ID: mdl-35750497

ABSTRACT

BACKGROUND: Cerebral palsy is a life-long condition that causes heterogeneous motor disorders. Motor rehabilitation interventions must be adapted to the topography of the symptoms, ambulatory capacity, and age of the individual. Current guidelines do not differentiate between the different profiles of individuals with cerebral palsy, which limits their implementation. OBJECTIVES: To develop evidence-based, implementable guidelines for motor rehabilitation interventions for individuals with cerebral palsy according to the age, topography of the cerebral palsy, and ambulatory capacity of the individual and to determine a level of priority for each intervention. METHODS: We used a mixed methods design that combined a systematic review of the literature on available motor rehabilitation interventions with expert opinions. Based on the French National Authority for Health methodology, recommendations were graded as strong, conditional, or weak. Interventions were then prioritized by the experts according to both the evidence and their own opinions on relevance and implementability to provide a guide for clinicians. All recommendations were approved by experts who were independent from the working group. RESULTS: Strong recommendations as first-line treatments were made for gait training, physical activities, and hand-arm bimanual intensive therapy for all children and adolescents with cerebral palsy. Moderate recommendations were made against passive joint mobilizations, muscle stretching, prolonged stretching with the limb fixed, and neurodevelopmental therapies for all children and adolescents with cerebral palsy. Strong recommendations as first-line treatments were made for gait training for all adults with cerebral palsy and moderate recommendations as moderate importance interventions for strengthening exercises and ankle-foot orthoses for motor impairment of the feet and the ankles. DISCUSSION: These guidelines, which combine research evidence and expert opinions, could help individuals with cerebral palsy and their families to codetermine rehabilitation goals with health professionals, according to their preferences.


Subject(s)
Cerebral Palsy , Gait Disorders, Neurologic , Adolescent , Cerebral Palsy/diagnosis , Child , Exercise Therapy/methods , Gait Disorders, Neurologic/etiology , Gait Disorders, Neurologic/rehabilitation , Humans , Muscles , Physical Therapy Modalities
5.
Sci Rep ; 12(1): 4618, 2022 03 17.
Article in English | MEDLINE | ID: mdl-35301388

ABSTRACT

Interest for neuromodulation, and transcranial random noise stimulation (tRNS) in particular, is growing. It concerns patients rehabilitation, but also healthy people who want or need to improve their cognitive and learning abilities. However, there is no consensus yet regarding the efficacy of tRNS on learning and performing a complex task. In particular, the most effective electrode montage is yet to be determined. Here, we examined the effect of two different tRNS montages on learning rate, short- and long-term performance in a video game (Space Fortress) that engages multiple cognitive abilities. Sixty-one participants were randomly assigned to one of three groups (sham vs. simple-definition tRNS vs. high-definition tRNS) in a double-blind protocol. Their performance on the Space Fortress task was monitored during a 15-day experiment with baseline (day 1), stimulation (day 2 to 4), short- (day 5) and long-term (day 15) evaluations. Our results show that the high-definition tRNS group improved more on the long term than simple-definition tRNS group, tended to learn faster and had better performance retention compared to both simple-definition tRNS and sham groups. This study is the first to report that high-definition tRNS is more effective than conventional simple-definition tRNS to enhance performance in a complex task.


Subject(s)
Transcranial Direct Current Stimulation , Cognition/physiology , Double-Blind Method , Humans , Intelligence , Learning/physiology , Transcranial Direct Current Stimulation/methods
6.
Ann Phys Rehabil Med ; 64(2): 101366, 2021 Mar.
Article in English | MEDLINE | ID: mdl-32156646

ABSTRACT

BACKGROUND: Kinematic analysis and clinical outcome measures with established responsiveness contribute to the quantified assessment of upper-limb function post-stroke, the selection of interventions and the differentiation of motor recovery patterns. OBJECTIVE: This systematic review and meta-analysis aimed to report trends in use and compare the responsiveness of kinematic and clinical measures in studies measuring the effectiveness of constraint-induced movement, trunk restraint and bilateral arm therapies for upper-limb function after stroke. METHODS: In this systematic review, randomised controlled trials implementing kinematic analysis and clinical outcome measures to evaluate the effects of therapies in post-stroke adults were eligible. We searched 8 electronic databases (MEDLINE, EMBASE, Web of Science, Scopus, CINAHL, CENTRAL, OTseeker and Pedro). Risk of bias was assessed according to the Cochrane Risk of Bias domains. A meta-analysis was conducted for repeated design measures of pre- and post-test data providing estimated standardised mean differences (SMDs). RESULTS: We included reports of 12 studies (191 participants) reporting kinematic smoothness, movement duration and efficiency, trunk and shoulder range of motion, control strategy and velocity variables in conjunction with assessment by Motor Activity Log, Fugl-Meyer Assessment and Wolf Motor Function Test. Responsiveness was higher (i.e., non-overlap of 95% confidence intervals [CIs]) for Motor Activity Log score (SMD for amount of use 1.0, 95% CI 0.75-1.25, P<0.001; SMD for quality of movement 0.96, 95% CI 0.72-1.20, P<0.001) than movement efficiency, trunk and shoulder range of motion, control strategy and peak velocity. CONCLUSION: These results are consistent with current literature supporting the use of combined kinematic and clinical measures for comprehensive and accurate evaluation of upper-limb function post-stroke. Future research should include other design trials and rehabilitation types to confirm these findings, focusing on subgroup analysis of type of rehabilitation intervention and functional levels.


Subject(s)
Stroke Rehabilitation , Stroke , Upper Extremity , Adult , Biomechanical Phenomena , Humans , Randomized Controlled Trials as Topic , Recovery of Function
7.
Front Neurogenom ; 2: 718176, 2021.
Article in English | MEDLINE | ID: mdl-38235214

ABSTRACT

Performance in complex tasks is essential for many high risk operators. The achievement of such tasks is supported by high-level cognitive functions arguably involving functional activity and connectivity in a large ensemble of brain areas that form the fronto-parietal network. Here we aimed at determining whether the functional connectivity at rest within this network could predict performance in a complex task: the Space Fortress video game. Functional Near Infrared Spectroscopy (fNIRS) data from 32 participants were recorded during a Resting-State period, the completion of a simple version of Space Fortress (monotask) and the original version (multitask). The intrinsic functional connectivity within the fronto-parietal network (i.e., during the Resting-State) was a significant predictor of performance at Space Fortress multitask but not at its monotask version. The same pattern was observed for the functional connectivity during the task. Our overall results suggest that Resting-State functional connectivity within the fronto-parietal network could be used as an intrinsic brain marker for performance prediction of a complex task achievement, but not for simple task performance.

9.
Ann Phys Rehabil Med ; 62(1): 35-42, 2019 Jan.
Article in English | MEDLINE | ID: mdl-29660413

ABSTRACT

BACKGROUND: Somatosensory impairment of the upper limb (UL) occurs in approximately 50% of adults post-stroke, associated with loss of hand motor function, activity and participation. Measurement of UL sensory impairment is a component of rehabilitation contributing to the selection of sensorimotor techniques optimizing recovery and providing a prognostic estimate of UL function. To date, no standardized official French version of a measure of somatosensory impairment has been established. OBJECTIVE: To develop and validate a French version of the Erasmus modified Nottingham Sensory Assessment somatosensory (EmNSA-SS) and stereognosis (EmNSA-ST) component for evaluating the UL among adults with stroke. METHODS: This study is a single-center observational cross-sectional study. A French version of the EmNSA for UL was developed by forward-backward translation and cross-cultural adaptation. Fifty stroke patients were recruited to establish concurrent-criterion-related validity, internal consistency, intra- and inter-rater reproducibility with intracorrelation coefficients (ICCs) for reliability and the minimal detectable change with 95% confidence interval (MDC95) for agreement, as well as ceiling and floor effects. Criterion validity was assessed against the Fugl-Meyer Assessment-Sensory (FMA-S) for the UL. RESULTS: The median (range) EmNSA-SS score was 41.5 (1-44). The Spearman rank correlation coefficient between EmNSA-SS and FMA-S total scores was moderate (rho=0.74, P<0.001). The EmNSA-SS/ST internal consistency was adequate across subscales; with Cronbach α ranging from 0.82-0.96. For the EmNSA-SS total score, intra- and inter-rater reliability was excellent (ICC=0.92 in both cases), with MDC95 of 12.3 and 14.6, respectively. EmNSA-SS/ST total scores demonstrated no ceiling or floor effects. CONCLUSIONS: The French EmNSA is a valid and reproducible scale that can be used for comprehensive and accurate assessment of somatosensory modalities in adults post-stroke. Taking less than 30min to administer, the instrument has clinical utility for use in patients with cognitive comorbidities and at various stages of recovery in multidisciplinary clinical practice and research settings.


Subject(s)
Hypesthesia/diagnosis , Neurologic Examination/standards , Stroke/complications , Adult , Aged , Cross-Sectional Studies , Female , Humans , Hypesthesia/etiology , Male , Middle Aged , Neurologic Examination/methods , Reproducibility of Results , Statistics, Nonparametric , Stereognosis/physiology , Stroke/physiopathology , Translations , Upper Extremity/physiopathology , Young Adult
10.
Ann Phys Rehabil Med ; 61(2): 78-84, 2018 Mar.
Article in English | MEDLINE | ID: mdl-29274471

ABSTRACT

BACKGROUND: Non-invasive brain stimulation has been studied as a therapeutic adjunct for upper-limb recovery in patients with stroke. One type of stimulation, paired associative stimulation (PAS), has effects on plasticity in both patients and healthy participants. Lasting several hours, these effects are reversible and topographically specific. OBJECTIVE: The goal was to investigate the presence of a lasting increase in motor cortex plasticity for extensor wrist muscles - extensor carpi radialis (ECR) - and an improvement in upper-limb function after 5 days of daily PAS in patients at the subacute post-stroke stage. METHODS: A total of 24 patients (mean [SD] age 50.1 [12.1] years, weeks since stroke 10.1 [5.3]) were included in a double-blind, placebo-controlled trial and randomly assigned to the PAS or sham group (n=13 and n=11). For the PAS group, patients underwent a 5-day course of electrical peripheral stimulation combined with magnetic cortical stimulation applied to the ECR muscle in a single daily session at 0.1Hz for 30min; patients with sham treatment received minimal cortical stimulation. Both patient groups underwent 2 hr of conventional physiotherapy. Variations in the motor evoked potential (MEP) surface area of the ECR muscle and Fugl-Meyer Assessment-Upper-Limb motor scores were analysed up to day 12. RESULTS: The 2 groups did not differ in electrophysiological or motor parameters. Repeated PAS sessions seemed to affect only patients with low initial cortical excitability. We found considerable variability in PAS effects between patients and across the sessions. CONCLUSION: We failed to induce a lasting effect with PAS in the present study. PAS does not seem to be the main method for post-stroke brain stimulation. Perhaps recruitment of patients could be more selective, possibly targeting those with a wide altered ipsilesional corticomotor pathway.


Subject(s)
Electric Stimulation Therapy/methods , Motor Cortex/physiopathology , Stroke Rehabilitation/methods , Stroke/physiopathology , Transcranial Magnetic Stimulation/methods , Adult , Double-Blind Method , Evoked Potentials, Motor/physiology , Female , Humans , Male , Middle Aged , Muscle, Skeletal/physiopathology , Treatment Outcome , Wrist/physiopathology
11.
Brain Imaging Behav ; 12(5): 1363-1378, 2018 Oct.
Article in English | MEDLINE | ID: mdl-29243119

ABSTRACT

Virtual reality (VR)-based paradigms use visual stimuli that can modulate visuo-motor networks leading to the stimulation of brain circuits. The aims of this study were to compare the changes in blood-oxygenation level dependent (BOLD) signal when watching and imitating moving real (RH) and virtual hands (VH) in 11 healthy participants (HP). No differences were found between the observation of RH or VH making this VR-based experiment a promising tool for rehabilitation protocols. VH-imitation involved more the ventral premotor cortex (vPMC) as part of the mirror neuron system (MNS) compared to execution and VH-observation conditions. The dorsal-anterior Precuneus (da-Pcu) as part of the Precuneus/posterior Cingulate Cortex (Pcu/pCC) complex, a key node of the Default Mode Network (DMN), was also less deactivated and therefore more involved. These results may reflect the dual visuo-motor roles for the vPMC and the implication of the da-Pcu in the reallocation of attentional and neural resources for bimodal task management. The ventral Pcu/pCC was deactivated regardless of the condition confirming its role in self-reference processes. Imitation of VH stimuli can then modulate the activation of specific areas including those belonging to the MNS and the DMN.


Subject(s)
Brain/physiology , Hand , Imitative Behavior/physiology , Motion Perception/physiology , Motor Activity/physiology , Virtual Reality , Adult , Brain/diagnostic imaging , Brain Mapping , Female , Humans , Magnetic Resonance Imaging , Male , Mirror Neurons/physiology , Neural Pathways/diagnostic imaging , Neural Pathways/physiology , Proof of Concept Study , Psychomotor Performance/physiology
12.
Neurourol Urodyn ; 36(3): 706-709, 2017 03.
Article in English | MEDLINE | ID: mdl-27028504

ABSTRACT

AIMS: Urinary disorders (UD) secondary to multiple sclerosis (MS) are common and can be responsible for complications. Since 2004, we organized in our region their management through a neuro-urological activity and a care network that established and distributed an algorithm for screening and first line care. The objective was to assess the effects of this organization on the management of UD and its impact for patients. METHODS: Between January 2004 and December 2009, 328 patients were seen in neuro-urological consultation. The data of a group of 168 patients consulting during the deployment of our organization (before January 2007: group 1) were compared to those of 160 patients taken when the organization was well established (from January 2007: group 2). In parallel, the modification of the prescription rate of the first-line examination patients was evaluated. RESULTS: The two groups were significantly different concerning age, duration of MS, EDSS score (Group 1 vs. Group 2 respectively 51.6 ± 12.6 vs. 48 ± 11.8 years, P = 0.008; 19 ± 9.7 vs. 13.8 ± 10.5 years, P < 0.0001; 5.8 ±2.0 vs. 5.1 ± 2.1, P = 0.008). The occurrence of urinary complications in group 1 was more frequent than in group 2 (66.3% vs. 40%, P < 0.0001). The rate of first-line examinations rose from 1/16 patient seen in January 2006 to 9/12 patients in January 2008. CONCLUSION: The multidisciplinary management of UD in MS led to patients being cared for sooner in the evolution of MS, with fewer complications and to an improvement in the rate of prescription of first-line examinations. Neurourol. Urodynam. 36:706-709, 2017. © 2016 Wiley Periodicals, Inc.


Subject(s)
Multiple Sclerosis/complications , Urination Disorders/therapy , Adult , Aged , Disease Management , Female , Humans , Male , Middle Aged , Program Evaluation , Retrospective Studies , Urination Disorders/etiology , Young Adult
13.
Behav Brain Res ; 297: 231-40, 2016 Jan 15.
Article in English | MEDLINE | ID: mdl-26477377

ABSTRACT

The event-related potential N270 component is known to be an electrophysiological marker of the supramodal conflict processing. However little is know about the factors that may modulate its amplitude. In particular, among all studies that have investigated the N270, little or no control of the conflict strength and of the load in working memory have been done leaving a lack in the understanding of this component. We designed a spatial audiovisual conflict task with simultaneous target and cross-modal distractor to evaluate the N270 sensitivity to the conflict strength (i.e., visual target with auditory distractor or auditory target with visual distractor) and the load in working memory (goal task maintenance with frequent change in the target modality). In a first session, participants had to focus on one modality for the target position to be considered (left-hand or right-hand) while the distractor could be at the same side (compatible) or at opposite side (incompatible). In a second session, we used the same set of stimuli as in the first session with an additional distinct auditory signal that clued the participants to frequently switch between the auditory and the visual targets. We found that (1) reaction times and N270 amplitudes for conflicting situations were larger within the auditory target condition compared to the visual one, (2) the increase in target maintenance effort led to equivalent increase of both reaction times and N270 amplitudes within all conditions and (3) the right dorsolateral prefrontal cortex current density was higher for both conflicting and active maintenance of the target situations. These results provide new evidence that the N270 component is an electrophysiological marker of the supramodal conflict processing that is sensitive to the conflict strength and that conflict processing and active maintenance of the task goal are two functions of a common executive attention system.


Subject(s)
Auditory Perception/physiology , Brain/physiology , Conflict, Psychological , Memory, Short-Term/physiology , Visual Perception/physiology , Acoustic Stimulation/methods , Brain Mapping , Cues , Electroencephalography , Evoked Potentials , Female , Humans , Male , Middle Aged , Neuropsychological Tests , Photic Stimulation/methods , Reaction Time , Software
14.
Cortex ; 65: 1-18, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25617826

ABSTRACT

This article describes the case of a patient who, following herpes simplex encephalitis (HSE), retained the ability to access rich conceptual semantic information for familiar people whom he was no longer able to name. Moreover, this patient presented the very rare combination of name production and name comprehension deficits for different categories of proper names (persons and acronyms). Indeed, besides his difficulty to retrieve proper names, SL presented a severe deficit in understanding and identifying them. However, he was still able to recognize proper names on familiarity decision, demonstrating that name forms themselves were intact. We interpret SL's deficit as a rare form of two-way lexico-semantic disconnection, in which intact lexical knowledge is disconnected from semantic knowledge and face units. We suggest that this disconnection reflects the role of the left anterior temporal lobe in binding together different types of knowledge and supports the classical convergence-zones framework (e.g., Damasio, 1989) rather than the amodal semantic hub theory (e.g., Patterson, Nestor, & Rogers, 2007).


Subject(s)
Anomia/pathology , Knowledge , Mental Recall/physiology , Temporal Lobe/pathology , Anomia/diagnosis , Face/physiology , Humans , Male , Middle Aged , Neuropsychological Tests , Recognition, Psychology/physiology , Semantics
15.
Neurourol Urodyn ; 34(1): 32-6, 2015 Jan.
Article in English | MEDLINE | ID: mdl-24115110

ABSTRACT

AIMS: Lower urinary tract dysfunctions (LUTD) are very common in Multiple Sclerosis (MS), have a significant social impact, while the organic impact is discussed. We studied urinary complications and their risk factors in our cohort of MS patients, in order to improve the management of LUTD in MS. METHODS: Between 2004 and 2009, all patients affected by MS and managed for LUTD were included in a retrospective study. We studied the epidemiological data (age, gender), the clinical data (duration of MS, EDSS score, progression of MS) and the paraclinical data (urinary creatinine clearance, urine culture, urinary tract ultrasonography and in some cases urodynamic assessment and cystography). We then identified the urinary complications and their risk factors. RESULTS: Three hundred twenty eight patients, mean age 49.9 ± 12.3 years, with a MS for 14.3 ± 10 years on average and with a median EDSS score equal to 6 (1-9), were managed for LUTD. One hundred seventy eight (54%) patients developed one or more urinary complications. We identified duration of MS greater than 8.5 years and an EDSS above 7 as risk factors. CONCLUSION: Urinary complications are common in symptomatic MS, these results imply screening and specialized care to limit the impact on the quality of life but also to prevent urinary complications.


Subject(s)
Lower Urinary Tract Symptoms/etiology , Multiple Sclerosis/complications , Adult , Age Factors , Cohort Studies , Disease Progression , Female , Humans , Male , Middle Aged , Quality of Life , Retrospective Studies , Risk Factors
16.
J Neurosci ; 33(16): 7091-8, 2013 Apr 17.
Article in English | MEDLINE | ID: mdl-23595766

ABSTRACT

The Salience Network (SN) consists of the dorsal anterior cingulate cortex (dACC) and bilateral insulae. The network responds to behaviorally salient events, and an important question is how its nodes interact. One theory is that the dACC provides the earliest cortical signal of behaviorally salient events, such as errors. Alternatively, the anterior right insula (aRI) has been proposed to provide an early cognitive control signal. As these regions frequently coactivate, it has been difficult to disentangle their roles using conventional methods. Here we use dynamic causal modeling and a Bayesian model evidence technique to investigate the causal relationships between nodes in the SN after errors. Thirty-five human subjects performed the Simon task. The task has two conditions (congruent and incongruent) producing two distinct error types. Neural activity associated with errors was investigated using fMRI. Subjects made a total of 1319 congruent and 1617 incongruent errors. Errors resulted in robust activation of the SN. Dynamic causal modeling analyses demonstrated that input into the SN was most likely via the aRI for both error types and that the aRI was the only region intrinsically connected to both other nodes. Only incongruent errors produced behavioral adaptation, and the strength of the connection between the dACC and the left insulae correlated with the extent of this behavioral change. We conclude that the aRI, not the dACC, drives the SN after errors on an attentionally demanding task, and that a change in the effective connectivity of the dACC is associated with behavioral adaptation after errors.


Subject(s)
Cognition/physiology , Gyrus Cinguli/physiology , Neural Pathways/physiology , Reaction Time/physiology , Adult , Analysis of Variance , Bayes Theorem , Cues , Female , Gyrus Cinguli/blood supply , Humans , Image Processing, Computer-Assisted , Magnetic Resonance Imaging , Male , Neural Pathways/blood supply , Oxygen/blood , Photic Stimulation , Space Perception/physiology , Young Adult
17.
Cereb Cortex ; 23(3): 703-13, 2013 Mar.
Article in English | MEDLINE | ID: mdl-22426336

ABSTRACT

Errors trigger changes in behavior that help individuals adapt to new situations. The dorsal anterior cingulate cortex (dACC) is thought to be central to this response, but more lateral frontal regions are also activated by errors and may make distinct contributions. We investigated error processing by studying 2 distinct error types: commission and timing. Thirty-five subjects performed a version of the Simon Task designed to produce large number of errors. Commission errors were internally recognized and were not accompanied by explicit feedback. In contrast, timing errors were difficult to monitor internally and were explicitly signaled. Both types of error triggered changes in behavior consistent with increased cognitive control. As expected, robust activation within the dACC and bilateral anterior insulae (the Salience Network) was seen for commission errors. In contrast, timing errors were not associated with activation of this network but did activate a bilateral network that included the right ventral attentional system. Common activation for both error types occurred within the pars operculari and angular gyri. These results show that the dACC does not respond to all behaviorally salient errors. Instead, the error-processing system is multifaceted, and control can be triggered independently of the dACC when feedback is unexpected.


Subject(s)
Attention/physiology , Brain Mapping , Cognition/physiology , Frontal Lobe/physiology , Adult , Female , Humans , Image Interpretation, Computer-Assisted , Magnetic Resonance Imaging , Male
18.
J Neurosci ; 31(38): 13442-51, 2011 Sep 21.
Article in English | MEDLINE | ID: mdl-21940437

ABSTRACT

Traumatic brain injury (TBI) frequently produces impairments of attention in humans. These can result in a failure to maintain consistent goal-directed behavior. A predominantly right-lateralized frontoparietal network is often engaged during attentionally demanding tasks. However, lapses of attention have also been associated with increases in activation within the default mode network (DMN). Here, we study TBI patients with sustained attention impairment, defined on the basis of the consistency of their behavioral performance over time. We show that sustained attention impairments in patients are associated with an increase in DMN activation, particularly within the precuneus and posterior cingulate cortex. Furthermore, the interaction of the precuneus with the rest of the DMN at the start of the task, i.e., its functional connectivity, predicts which patients go on to show impairments of attention. Importantly, this predictive information is present before any behavioral evidence of sustained attention impairment, and the relationship is also found in a subgroup of patients without focal brain damage. TBI often results in diffuse axonal injury, which produces cognitive impairment by disconnecting nodes in distributed brain networks. Using diffusion tensor imaging, we demonstrate that structural disconnection within the DMN also correlates with the level of sustained attention. These results show that abnormalities in DMN function are a sensitive marker of impairments of attention and suggest that changes in connectivity within the DMN are central to the development of attentional impairment after TBI.


Subject(s)
Attention Deficit Disorder with Hyperactivity/physiopathology , Brain Injuries/physiopathology , Gyrus Cinguli/physiopathology , Nerve Fibers, Myelinated/physiology , Parietal Lobe/physiopathology , Adolescent , Adult , Anisotropy , Attention Deficit Disorder with Hyperactivity/complications , Attention Deficit Disorder with Hyperactivity/pathology , Brain Injuries/complications , Brain Injuries/pathology , Brain Mapping/methods , Case-Control Studies , Choice Behavior/physiology , Diffusion Tensor Imaging/methods , Female , Gyrus Cinguli/pathology , Humans , Magnetic Resonance Imaging/methods , Male , Middle Aged , Nerve Fibers, Myelinated/pathology , Neural Pathways/pathology , Neural Pathways/physiopathology , Neuropsychological Tests , Parietal Lobe/pathology , Psychomotor Performance/physiology , Reaction Time/physiology
19.
Brain ; 134(Pt 8): 2233-47, 2011 Aug.
Article in English | MEDLINE | ID: mdl-21841202

ABSTRACT

Traumatic brain injury often results in cognitive impairments that limit recovery. The underlying pathophysiology of these impairments is uncertain, which restricts clinical assessment and management. Here, we use magnetic resonance imaging to test the hypotheses that: (i) traumatic brain injury results in abnormalities of functional connectivity within key cognitive networks; (ii) these changes are correlated with cognitive performance; and (iii) functional connectivity within these networks is influenced by underlying changes in structural connectivity produced by diffuse axonal injury. We studied 20 patients in the chronic phase after traumatic brain injury compared with age-matched controls. Network function was investigated in detail using functional magnetic resonance imaging to analyse both regional brain activation, and the interaction of brain regions within a network (functional connectivity). We studied patients during performance of a simple choice-reaction task and at 'rest'. Since functional connectivity reflects underlying structural connectivity, diffusion tensor imaging was used to quantify axonal injury, and test whether structural damage correlated with functional change. The patient group showed typical impairments in information processing and attention, when compared with age-matched controls. Patients were able to perform the task accurately, but showed slow and variable responses. Brain regions activated by the task were similar between the groups, but patients showed greater deactivation within the default mode network, in keeping with an increased cognitive load. A multivariate analysis of 'resting' state functional magnetic resonance imaging was then used to investigate whether changes in network function were present in the absence of explicit task performance. Overall, default mode network functional connectivity was increased in the patient group. Patients with the highest functional connectivity had the least cognitive impairment. In addition, functional connectivity at rest also predicted patterns of brain activation during later performance of the task. As expected, patients showed widespread white matter damage compared with controls. Lower default mode network functional connectivity was seen in those patients with more evidence of diffuse axonal injury within the adjacent corpus callosum. Taken together, our results demonstrate altered patterns of functional connectivity in cognitive networks following injury. The results support a direct relationship between white matter organization within the brain's structural core, functional connectivity within the default mode network and cognitive function following brain injury. They can be explained by two related changes: a compensatory increase in functional connectivity within the default mode network; and a variable degree of structural disconnection that modulates this change in network function.


Subject(s)
Brain Injuries/complications , Brain Injuries/pathology , Brain Mapping , Brain/pathology , Cognition Disorders/etiology , Models, Neurological , Adult , Anisotropy , Brain/blood supply , Choice Behavior/physiology , Cognition Disorders/diagnosis , Female , Humans , Male , Middle Aged , Neural Pathways/blood supply , Neural Pathways/pathology , Neuropsychological Tests , Reaction Time/physiology , Statistics as Topic , Tomography, X-Ray Computed/methods
20.
Neurourol Urodyn ; 30(8): 1503-6, 2011 Nov.
Article in English | MEDLINE | ID: mdl-21674595

ABSTRACT

OBJECTIVES: Neurogenic bladder dysfunction has a negative impact on the patient's quality of life (QoL). Cystectomy with ileal conduit urinary diversion is a treatment option in patients in failure after conservative management. The objective of this study was to evaluate the impact of ileal conduit urinary diversion on the QoL of patients with neurogenic bladder dysfunction. MATERIALS AND METHODS: From March 2004 to November 2010, 48 patients (36 women and 12 men with a mean age of 50.6 ± 11.8 years) treated by cystectomy with ileal conduit urinary diversion for neurogenic bladder dysfunction, prospectively completed, before and after surgery, two self-administered QoL questionnaires. Neurological diseases were multiple sclerosis in 38 cases, spinal cord injury in 7 cases, and other neurological disease in 3 cases. Cystectomy was performed by laparoscopy in all patients. QoL was measured by using two self-administered questionnaires, one questionnaire specific for urinary disorders validated in neurological patients, Qualiveen®, and the generic SF36-v2® questionnaire. Data were compared by Student's t test. RESULTS: Comparison of the Qualiveen® self-administered questionnaire scores and indices before and after surgery showed that, after surgery, patients presented a significant reduction of limitations (0.57 ± 0.64 vs. 1.55 ± 1.35, P < 0.001), constraints (2.12 ± 0.83 vs. 2.64 ± 1.12, P = 0.046) scores and the SIUP index (1.29 ± 0.65 vs. 1.79 ± 0.95, P = 0.015). No significant change in SF36-v2® scores was observed postoperatively. CONCLUSIONS: Ileal conduit urinary diversion improves the urinary QoL of patients with neurogenic bladder dysfunction by decreasing limitations and constraints induced by urinary disorders, but has no impact on general QoL.


Subject(s)
Cystectomy , Laparoscopy , Urinary Bladder, Neurogenic/surgery , Urinary Bladder/surgery , Urinary Diversion , Adult , Cystectomy/adverse effects , Female , France , Humans , Laparoscopy/adverse effects , Male , Middle Aged , Prospective Studies , Quality of Life , Surveys and Questionnaires , Time Factors , Treatment Outcome , Urinary Bladder/physiopathology , Urinary Bladder, Neurogenic/physiopathology , Urinary Bladder, Neurogenic/psychology , Urinary Diversion/adverse effects
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