Optimizing Epoch Length and Activity Count Threshold Parameters in Accelerometry: Enhancing Upper Extremity Use Quantification in Cerebral Palsy.

Various accelerometry protocols have been used to quantify upper extremity (UE) activity, encompassing diverse epoch lengths and thresholding methods. However, there is no consensus on the most effective approach. The aim of this study was to delineate the optimal parameters for analyzing accelerometry data to quantify UE use in individuals with unilateral cerebral palsy (CP). METHODS: A group of adults with CP (n = 15) participated in six activities of daily living, while a group of children with CP (n = 14) underwent the Assisting Hand Assessment. Both groups performed the activities while wearing ActiGraph GT9X-BT devices on each wrist, with concurrent video recording. Use ratio (UR) derived from accelerometry and video analysis and accelerometer data were compared for different epoch lengths (1, 1.5, and 2 s) and activity count (AC) thresholds (between 2 and 150). RESULTS: In adults, results are comparable across epoch lengths, with the best AC thresholds being ≥ 100. In children, results are similar across epoch lengths of 1 and 1.5 (optimal AC threshold = 50), while the optimal threshold is higher with an epoch length of 2 (AC = 75). CONCLUSIONS: The combination of epoch length and AC thresholds should be chosen carefully as both influence the validity of the quantification of UE use.

Visuotactile integration in individuals with fibromyalgia.

Our brain constantly integrates afferent information, such as visual and tactile information, to perceive the world around us. According to the maximum-likelihood estimation (MLE) model, imprecise information will be weighted less than precise, making the multisensory percept as precise as possible. Individuals with fibromyalgia (FM), a chronic pain syndrome, show alterations in the integration of tactile information. This could lead to a decrease in their weight in a multisensory percept or a general disruption of multisensory integration, making it less beneficial. To assess multisensory integration, 15 participants with FM and 18 pain-free controls performed a temporal-order judgment task in which they received pairs of sequential visual, tactile (unisensory conditions), or visuotactile (multisensory condition) stimulations on the index and the thumb of the non-dominant hand and had to determine which finger was stimulated first. The task enabled us to measure the precision and accuracy of the percept in each condition. Results indicate an increase in precision in the visuotactile condition compared to the unimodal conditions in controls only, although we found no intergroup differences. The observed visuotactile precision was correlated to the precision predicted by the MLE model in both groups, suggesting an optimal integration. Finally, the weights of the sensory information were not different between the groups; however, in the group with FM, higher pain intensity was associated with smaller tactile weight. This study shows no alterations of the visuotactile integration in individuals with FM, though pain may influence tactile weight in these participants.

Preserved tactile distance estimation despite body representation distortions in individuals with fibromyalgia.

Our mental representation of our body depends on integrating various sensory modalities, such as tactile information. In tactile distance estimation (TDE) tasks, participants must estimate the distance between two tactile tips applied to their skin. This measure of tactile perception has been linked to body representation assessments. Studies in individuals with fibromyalgia (FM), a chronic widespread pain syndrome, suggest the presence of body representation distortions and tactile alterations, but TDE has never been examined in this population. Twenty participants with FM and 24 pain-free controls performed a TDE task on three Body regions (upper limb, trunk, lower limb), in which they manually estimated the interstimuli distance on a tablet. TDE error, the absolute difference between the estimation and the interstimuli distance, was not different between the Groups, on any Body region. Drawings of their body as they felt it revealed clear and frequent distortions of body representation in the group with FM, compared to negligible perturbations in controls. This contrast between distorted body drawings and unaltered TDE suggests a preserved integration of tactile information but an altered integration of this information with other sensory modalities to generate a precise and accurate body representation. Future research should investigate the relative contribution of each sensory information and prior knowledge about the body in body representation in individuals with FM to shed light on the observed distortions.

Relationship between somatosensory and visuo-perceptual impairments and motor functions in adults with hemiparetic cerebral palsy.

Introduction: Children with cerebral palsy (CP) exhibit a variety of sensory impairments that can interfere with motor performance, but how these impairments persist into adulthood needs further investigation. The objective of this study was to describe the sensory impairments in adults having CP and how they relate to motor impairments. Methods: Nineteen adults having CP performed a set of robotic and clinical assessments. These assessments were targeting different sensory functions and motor functions (bilateral and unilateral tasks). Frequency of each type of impairments was determined by comparing individual results to normative data. Association between the sensory and motor impairments was assessed with Spearman correlation coefficient. Results: Impairment in stereognosis was the most frequent, affecting 57.9% of participants. Although less frequently impaired (26.3%), tactile discrimination was associated with all the motor tasks (unilateral and bilateral, either robotic or clinical). Performance in robotic motor assessments was more frequently associated with sensory impairments than with clinical assessments. Finally, sensory impairments were not more closely associated with bilateral tasks than with unilateral tasks. Discussion: Somatosensory and visuo-perceptual impairments are frequent among adults with CP, with 84.2% showing impairments in at least one sensory function. These sensory impairments show a moderate association with motor impairments.

Conditioned pain modulation, kinesiophobia, and pain catastrophizing as prognostic factors for chronicity in a population with acute low back pain: An exploratory prospective study.

BACKGROUND: Psychosocial factors and alteration of the somatosensory functions have been associated with persistent low back pain (LBP). A decreased capacity of the central nervous system to modulate pain has been suggested as a potential contributor to the persistence of pain. OBJECTIVE: To investigate whether conditioned pain modulation (CPM), initial symptoms/disability, kinesiophobia, and pain catastrophizing is associated with the transition from acute to chronic LBP. DESIGN: Prospective cohort study. METHOD: Fifty participants presenting with acute LBP (<6 weeks) took part in three evaluation sessions (baseline, 3 and 6 months). At baseline and 3-month evaluations, all participants completed self-administered questionnaires (Oswestry Disability Index [ODI], Short Form of Brief Pain Inventory [BPI-SF], Tampa Scale of Kinesiophobia [TSK] and Pain Catastrophizing Scale [PCS]) and CPM was assessed. At the 6-month evaluation, questionnaires were readministered, and participants were dichotomized according to their status (Non-chronic LBP [NCLBP] or chronic LBP [CLBP]). Univariate tests were used to compare baseline variables between NCLBP and CLBP. RESULTS: No significant baseline difference was found for TSK (p = 0.48), PCS (p = 0.78), CPM (p = 0.82), ODI (p = 0.78), BPI-SF severity (p = 0.50), and interference subscales (p = 0.54) between those categorized as NCLBP or CLBP at 6 months. CONCLUSIONS: This exploratory study failed to support the hypothesis that inefficient CPM mechanisms and the presence of psychological factors could be factors associated with the transition to chronic pain in individuals with acute LBP.

The effect of a task-specific training on upper limb performance and kinematics while performing a reaching task in a fatigued state.

BACKGROUND: Fatigue impacts motor performance and upper limb kinematics. It is of interest to study whether it is possible to minimize the potentially detrimental effects of fatigue with prevention programs. OBJECTIVE: To determine the effect of task-specific training on upper limb kinematics and motor performance when reaching in a fatigued state. METHODS: Thirty healthy participants were recruited (Training group n = 15; Control group n = 15). Both groups took part in two evaluation sessions (Day 1 and Day 5) during which they performed a reaching task (as quickly and accurately as possible) in two conditions (rested and fatigued). During the reaching task, joint kinematics and motor performance (accuracy and speed) were evaluated. The Training group participated in three task-specific training sessions between Day 1 and Day 5; they trained once a day, for three days. The Control group did not perform any training. A three-way non-parametric ANOVA for repeated measures (Nonparametric Analysis of Longitudinal Data; NparLD) was used to assess the impact of the training (Condition [within subject]: rested, fatigued; Day [within subject]: Day 1 vs. Day 5 and Group [between subjects]: Training vs. Control). RESULTS: After the training period, the Training group significantly improved their reaching speed compared to the Control group (Day x Group p < .01; Time effect: Training group = p < .01, Control group p = .20). No between-group difference was observed with respect to accuracy. The Training group showed a reduction in contralateral trunk rotation and lateral trunk flexion in Day 2 under the fatigue condition (Group x Day p < .04; Time effect: Training group = p < .01, Control group = p < .59). CONCLUSION: After the 3-day training, participants demonstrated improved speed and reduced reliance on trunk compensations to complete the task under fatigue conditions. Task-specific training could help minimizing some effects of fatigue.

Corticomotor Control of Lumbar Erector Spinae in Postural and Voluntary Tasks: The Influence of Transcranial Magnetic Stimulation Current Direction.

Lumbar erector spinae (LES) contribute to spine postural and voluntary control. Transcranial magnetic stimulation (TMS) preferentially depolarizes different neural circuits depending on the direction of electrical currents evoked in the brain. Posteroanterior current (PA-TMS) and anteroposterior (AP-TMS) current would, respectively, depolarize neurons in the primary motor cortex (M1) and the premotor cortex. These regions may contribute differently to LES control. This study examined whether responses evoked by PA- and AP-TMS are different during the preparation and execution of LES voluntary and postural tasks. Participants performed a reaction time task. A Warning signal indicated to prepare to flex shoulders (postural; n = 15) or to tilt the pelvis (voluntary; n = 13) at the Go signal. Single- and paired-pulse TMS (short-interval intracortical inhibition-SICI) were applied using PA- and AP-TMS before the Warning signal (baseline), between the Warning and Go signals (preparation), or 30 ms before the LES onset (execution). Changes from baseline during preparation and execution were calculated in AP/PA-TMS. In the postural task, MEP amplitude was higher during the execution than that during preparation independently of the current direction (p = 0.0002). In the voluntary task, AP-MEP amplitude was higher during execution than that during preparation (p = 0.016). More PA inhibition (SICI) was observed in execution than that in preparation (p = 0.028). Different neural circuits are preferentially involved in the two motor tasks assessed, as suggested by different patterns of change in execution of the voluntary task (AP-TMS, increase; PA-TMS, no change). Considering that PA-TMS preferentially depolarize neurons in M1, it questions their importance in LES voluntary control.

A cross-sectional observational study comparing individuals with a symptomatic full-thickness rotator cuff tear with age-matched controls.

Background: A full-thickness rotator cuff tear (FTRCT) is defined as a complete tear of one of the four rotator cuff muscle tendons (supraspinatus, infraspinatus, subscapularis or teres minor). This condition can lead to pain and reduced function. However, not all FTRCT are symptomatic. A better understanding of the characteristics that lead some individuals with FTRCT to experience pain is fundamental to improve strategies used to manage this condition. This level II descriptive study aimed to explore potential sociodemographic, anatomical, psychosocial, pain sensitivity, biomechanical and neuromuscular variables that may differ between individuals with symptomatic FTRCT and age-matched individuals with asymptomatic shoulders. Methods: In this cross-sectional observational study, adults aged 50 to 80 years of age, either with symptomatic FTRCT or no shoulder pain, were recruited via convenience sampling. Participants filled out questionnaires on sociodemographic and psychosocial variables. Then, various tests were performed, including pain pressure threshold, shoulder range of motion, shoulder muscle strength, shoulder ultrasound and radiologic examination, and sensorimotor functions testing. Each variable was compared between groups using univariate analyses (independent t-tests, Mann-Whitney U tests, exact probability Fisher tests). Significance was set at 0.05. Results: FTRCT (n = 30) and Control (n = 30) groups were comparable in terms of sex, age, and number of comorbidities. The symptomatic FTRCT group showed a higher proportion of smokers (P = .026) and more participants indicated consuming alcohol or drugs more than they meant to (P = .010). The FTRCT group had a significantly higher prevalence of glenohumeral osteophytes (48% vs. 17%; P = .012). Participants in the FTRCT group were significantly more stressed (P = .04), anxious (P = .003) and depressed (P = .002). The FTRCT group also showed significantly higher levels of pain catastrophisation (P < .001) and sleep disturbance (P < .001). The FTRCT group showed significantly lower range of motion for flexion (P < .001), and external rotation at 0° (P < .001) and 90° (P < .001) of abduction. Isometric strength in both abduction and external rotation were weaker (P = .005) for the FTRCT group. Conclusion: Sociodemographic, anatomical, psychosocial and biomechanical variables showed statistically significant differences between the FTRCT and Control groups.

Relationship between COVID-19 pandemic-related experienced stress and lifestyle habits among university students from Québec, Canada.

Whether COVID-19-related experienced stress influenced lifestyle habits remains to be thoroughly evaluated among university students. This study examined the relationship between COVID-19-related experienced stress and subsequent lifestyle habits among undergraduate students. This cross-sectional study included 708 undergraduate students from Université Laval (Québec, Canada) participating in the Expériences Pandémiques (ExPan) cohort. Data on COVID-19-related experienced stress and lifestyle were self-reported using a questionnaire completed between February and April of 2022. A stress index (SI) was computed by summing scores associated with 31 situational statements related to the pandemic (e.g., not being able to see friends, dealing with job loss). A healthy lifestyle score (HLS) ranging from zero to seven was calculated based on seven lifestyle habits: moderate-to-vigorous physical activity, sleep quality, fruit and vegetable intake, tobacco and electronic cigarette use, alcohol consumption, cannabis use, and hard or sedative-hypnotic drugs use. In multivariable-adjusted models, a negative association between the SI and the HLS was found (ß10% increment SI = -0.23, 95% CI = -0.30, -0.16 HLS point; P < 0.0001). The SI was also negatively associated with sleep quality, and fruit and vegetable consumption, while being positively associated with at-risk alcohol consumption, cannabis use, and hard or sedative-hypnotic drug use. Subgroup analyses suggested a negative relationship between the SI and HLS among participants who did not receive academic accommodations (e.g., additional time for evaluations, personal notetaker), but not those who received such accommodations. This study suggests that COVID-19-related experienced stress was negatively associated with healthy lifestyle habits in this cohort of undergraduate students.

Beyond numbers: integrating qualitative analysis into quantitative sensory testing for neuropathic pain.

This article investigates the benefits of adopting qualitative and quantitative sensory testing (QQST) in sensory assessment, with a focus on understanding neuropathic pain. The innovative QQST method combines participant qualitative experiences with quantitative psychophysical measurements, offering a more varied interpretation of sensory abnormalities and normal sensory function. This article also explores the steps for the optimization of the method by identifying qualitative signs of sensory abnormalities and standardizing data collection. By leveraging the inherent subjectivity in the test design and participant responses, the QQST method contributes to a more holistic exploration of both normal and abnormal sensory experiences. This article positions the QQST approach as a foundational element within the Sensory Evaluation Network, uniting international experts to harmonize qualitative and quantitative sensory evaluation methods.

Clinical Characteristics, Developmental Trajectory, and Caregiver Burden of Patients With Creatine Transporter Deficiency (SLC6A8).

BACKGROUND AND OBJECTIVES: Creatine transporter deficiency (CTD) is a rare X-linked genetic disorder characterized by intellectual disability (ID). We evaluated the clinical characteristics and trajectory of patients with CTD and the impact of the disease on caregivers to identify relevant endpoints for future therapeutic trials. METHODS: As part of a French National Research Program, patients with CTD were included based on (1) a pathogenic SLC6A8 variant and (2) ID and/or autism spectrum disorder. Families and patients were referred by the physician who ordered the genetic analysis through Reference Centers of ID from rare causes and inherited metabolic diseases. After we informed the patients and their parents/guardians about the study, all of them gave written consent and were included. A control group of age-matched and sex-matched patients with Fragile X syndrome was also included. Physical examination, neuropsychological assessments, and caregiver impact were assessed. All data were analyzed using R software. RESULTS: Thirty-one patients (27 male, 4 female) were included (25/31 aged 18 years or younger). Most of the patients (71%) had symptoms at <24 months of age. The mean age at diagnosis was 6.5 years. Epilepsy occurred in 45% (mean age at onset: 8 years). Early-onset behavioral disorder occurred in 82%. Developmental trajectory was consistently delayed (fine and gross motor skills, language, and communication/sociability). Half of the patients with CTD had axial hypotonia during the first year of life. All patients were able to walk without help, but 7/31 had ataxia and only 14/31 could walk tandem gait. Most of them had abnormal fine motor skills (27/31), and most of them had language impairment (30/31), but 12/23 male patients (52.2%) completed the Peabody Picture Vocabulary Test. Approximately half (14/31) had slender build. Most of them needed nursing care (20/31), generally 1-4 h/d. Adaptive assessment (Vineland) confirmed that male patients with CTD had moderate-to-severe ID. Most caregivers (79%) were at risk of burnout, as shown by Caregiver Burden Inventory (CBI) > 36 (significantly higher than for patients with Fragile X syndrome) with a high burden of time dependence. DISCUSSION: In addition to clinical endpoints, such as the assessment of epilepsy and the developmental trajectory of the patient, the Vineland scale, PPVT5, and CBI are of particular interest as outcome measures for future trials. TRIAL REGISTRATION INFORMATION: ANSM Registration Number 2010-A00327-32.

Phosphatidylserine enriched with polyunsaturated n-3 fatty acid supplementation for attention-deficit hyperactivity disorder in children and adolescents with epilepsy: A randomized placebo-controlled trial.

BACKGROUND: Attention-deficit hyperactivity disorder (ADHD) is a frequent comorbidity in children with epilepsy, which management mostly relies on the usual treatments of ADHD, especially methylphenidate. Supplementation with polyunsaturated n-3 Fatty Acid (PUFA) has been proposed as an alternative therapeutic approach in ADHD without epilepsy but has never been evaluated in epilepsy-associated ADHD. METHODS: A multicenter double blind randomized placebo-controlled trial evaluating supplementation with PUFA, in eicosapentaenoic- and docosahexaenoic-acid form, conjugated to a phospholipid vector (PS-Omega3) in children aged >6 and <16-years old, and suffering from any type of epilepsy and ADHD (inattentive or combined type) according to DSM-V. After a 4-week baseline period, patients were allocated (1:1) either to placebo group or to PS-Omega 3 group and entered a 12 week-double-blind treatment period which was followed by a 12 week-open-label treatment period. The primary outcome was the reduction of the ADHD-rating scale IV attention-deficit subscore after 12 weeks of treatment. RESULTS: The study was stopped early because of lack of eligible participants and the expected sample size was not reached. Seventy-four patients were randomized, 44 in PS-Omega3, and 30 in the placebo group. The reduction after 12 weeks of treatment in the inattention subscore of the ADHD-IV scale was -1.57 in the PS-Omega3 group, and -2.90 in the placebo group (p = 0.33, α = 5%). Results were similar after 24 weeks of treatment and for all other ADHD-related secondary outcomes, with no difference between placebo and PS-Omega3. CONCLUSION: Our study remaining underpowered, no formal conclusion about the effect of Ps-Omega3 could be drawn. However, our data strongly suggested that the PS-Omega 3 formulation used in the current study did not improve ADHD symptoms in children with epilepsy. PLAIN LANGUAGE SUMMARY: Supplementation with polyunsaturated n-3 Fatty Acid (PUFA) has been proposed in ADHD but has never been evaluated in patients with both epilepsy and ADHD. To address this issue, we conducted a multicenter double blind randomized placebo-controlled trial evaluating supplementation with PUFA in children with epilepsy and ADHD. The study was stopped early because of lack of eligible participants, hampering formal conclusion. However, the evolution of the ADHD symptoms at 12 and 24 weeks did not differ between placebo and PUFA supplementation, strongly suggesting that PUFA did not improve ADHD symptoms in children with epilepsy.