Context-dependent reduction in corticomuscular coupling for balance control in chronic stroke survivors.

Balance control is an important indicator of mobility and independence in activities of daily living. How the functional coupling between the cortex and the muscle for balance control is affected following stroke remains to be known. We investigated the changes in coupling between the cortex and leg muscles during a challenging balance task over multiple frequency bands in chronic stroke survivors. Fourteen participants with stroke and ten healthy controls performed a challenging balance task. They stood on a computerized support surface that was either fixed (low difficulty condition) or sway-referenced with varying gain (medium and high difficulty conditions). We computed corticomuscular coherence between electrodes placed over the sensorimotor area (electroencephalography) and leg muscles (electromyography) and assessed balance performance using clinical and laboratory-based tests. We found significantly lower delta frequency band coherence in stroke participants when compared with healthy controls under medium difficulty condition, but not during low and high difficulty conditions. These differences were found for most of the distal but not for proximal leg muscle groups. No differences were found at other frequency bands. Participants with stroke showed poor balance clinical scores when compared with healthy controls, but no differences were found for laboratory-based tests. The observation of effects at distal but not at proximal muscle groups suggests differences in the (re)organization of the descending connections across two muscle groups for balance control. We argue that the observed group difference in delta band coherence indicates balance context-dependent alteration in mechanisms for the detection of somatosensory modulation resulting from sway-referencing of the support surface for balance maintenance following stroke.

The Bead Maze Hand Function Test for Children.

IMPORTANCE: There is a need for a pediatric hand function test that can be used to objectively assess movement quality. We have developed a toy-based test, the Bead Maze Hand Function (BMHF) test, to quantify how well a child performs an activity. This is achieved by assessing the control of forces applied while drawing a bead over wires of different complexity. OBJECTIVE: To study the psychometric properties of the BMHF test and understand the influence of age and task complexity on test measures. DESIGN: A cross-sectional, observational study performed in a single visit. SETTING: Clinical research laboratory. PARTICIPANTS: Twenty-three participants (ages 4-15 yr) were recruited locally. They were typically developing children with no illness or conditions that affected their movement. Interventions/Assessments: Participants performed the BMHF test and the Box and Block test with both hands. OUTCOMES AND MEASURES: Total force and completion time were examined according to age and task complexity using a linear mixed-effects model. We calculated intraclass correlation coefficients to measure interrater reliability of the method and estimated concurrent validity using the Box and Block test. RESULTS: Total force and completion time decreased with age and depended on task complexity. The total force was more sensitive to task complexity. The Box and Block score was associated with BMHF completion time but not with total force. We found excellent interrater reliability. CONCLUSIONS AND RELEVANCE: A familiar toy equipped with hidden sensors provides a sensitive tool to assess a child's typical hand function. Plain-Language Summary: We developed the Bead Maze Hand Function (BMHF) test to determine how well a child performs an activity with their hands. The BMHF test is a toy equipped with hidden sensors. Twenty-three typically developing children with no illnesses or conditions that affected their hand movement participated in the study. We asked the children to perform the BMHF test with both hands. Our study found that occupational therapists can reliably use the BMHF test to assess a child's hand function.

Outcomes of a single dose of injection polidocanol application in aneurysmal bone cyst.

Background: Aneurysmal bone cysts are common osteolytic tumours that have ability to expand and produce pathological fractures. Recurrence is a major issue in such tumours posing a treatment dilemma to clinicians. Injection polidocanol has shown promising results, but the number of injections still remains a topic of debate. Methodology: A prospective interventional study done on 13 patients of biopsy-proven aneurysmal bone cysts. Patient related outcome measures(PROM's) seen using VAS score, SF-12 score and ROM of the involved extremity. Radiologically volume of tumour and cortico-medullary ratio were calculated. All patients received single dose of injection polidocanol and were followed up to 6 months. Results: The mean age of patients was 9.5 years, with slight female predominance. Most cases had Campana grade 1. Mean VAS score improved from 9/10 to 1/10, ROM of the proximal and distal joints of the involved bone improved from 60 % (± 20 %) to 100 %. Mean SF12 score increased from 41 (±7): 47 (±3) to 54 (±2): 58 (±2) at the end of 6 months(p < 0.05).Mean volume of the lesion decreased from 6.30 cc (± 1.30) to 2.86 cc (±1.34) (p < 0.0005) with a reduction of MCR from 4.8 (±0.6) to 3.6 (±0.5) on a similar time span (p < 0.0005) at end of 6 months. 2 patients showed recurrence with none of the patients showing any complication. Conclusion: Single dose of Injection Polidocanol for Aneurysmal Bone Cysts is a unique study, not described in literature before. The smaller lesion in initial staging can be treated effectively with single dose of polidocanol reducing morbidity and treatment cost to the patient. It is as good as giving multiple doses of Polidocanol as per as functionality of the limb is concerned.Also, we propose a new parameter "Medullary-cortical ratio", which is an effective way to assess the improvement and resolution of ABC after administration of Polidocanol.

Increased medial talar tilt may incite ankle pain and predispose ankle osteoarthritis after correction of severity of knee varus deformity among patients undergoing bilateral total knee arthroplasty: a prospective observation.

PURPOSE: Patients with varus knee osteoarthritis usually compensate at the ankle and typically walk with hindfoot valgus alignment. As the neutral weight-bearing axis of the lower limbs is restored with Total Knee Arthroplasty (TKA), ankle and hindfoot biomechanics also acutely change. This study aims to investigate whether any ankle clinical-radiographical changes occur as a result of bilateral mechanical TKA in patients with bilateral Osteoarthritis knee at a minimum follow-up of 6 months. METHODS: The prospective observational study included 61 patients (122 knees) undergoing simultaneous bilateral TKA (mechanical alignment). Tibio-talar angle(TTA), tibial Anterior Surface angle (TAS), lateral distal tibial angle (LDTA), talar-tilt angle (TT), anatomical talocrural angle (aTC), ground surface and distal tibial plafond angle (GP), ground surface and an upper surface of talus angle (GT)and tibial plateau and tibial plafond angle (PP) were measured on long-film radiographs to look for changes in the ankle, whereas functional assessment was done using American Foot and Ankle Society (AOFAS), Foot and Ankle Disability Index (FADI), and Forgotten Joint (FJS-12) scores. Patients were sub-grouped based on the Hip-Knee-Ankle (HKA) axis, and the effect of the severity of knee varus on the ankles after TKA was also analyzed. The minimum follow-up was 6 months. RESULTS: A significant decrease in the tibial plateau-tibial plafond (PP), ground-tibial plafond (GP), and ground-talar dome (GT) angles was noted after TKA (p-value < 0.05). Postoperative functional parameters were comparable to the preoperative status except for FADI, which significantly improved (p-value-0.03). Sub-group analysis based on the severity of knee varus (HKA) revealed GT to be most significantly reduced (p-value-0.036), while the talar tilt (TT) increased (p-value-0.044). Functional outcomes of the ankles clinically improved with the correction of severe knee varus after TKA. At a mean follow-up of 13.2 months post-TKA, 7 out of 61 (11.4%) patients complained of post-TKA ipsilateral ankle pain. CONCLUSION: Mechanically aligned bilateral TKA in severe varus deformity of the knee significantly decreases the GT angle but increases the varus tilt of the talus with lateral talar incongruency and under-coverage. Although the acute correction of severe knee varus deformity aligns the tibia more neutrally, resulting in an overall clinically evident improvement in ankle functional outcome, the increased varus talar tilt remains a deep concern. LEVEL OF EVIDENCE: Prospective, observational, comparative study Level II.

One-Pot Formation of Pairing Proto-RNA Nucleotides and Their Supramolecular Assemblies.

Most contemporary theories for the chemical origins of life include the prebiotic synthesis of informational polymers, including strong interpretations of the RNA World hypothesis. Existing challenges to the prebiotic emergence of RNA have encouraged exploration of the possibility that RNA was preceded by an ancestral informational polymer, or proto-RNA, that formed more easily on the early Earth. We have proposed that the proto-nucleobases of proto-RNA would have readily formed glycosides with ribose and that these proto-nucleosides would have formed base pairs as monomers in aqueous solution, two properties not exhibited by the extant nucleosides or nucleotides. Here we demonstrate that putative proto-nucleotides of the model proto-nucleobases barbituric acid and melamine can be formed in the same one-pot reaction with ribose-5-phosphate. Additionally, the proto-nucleotides formed in these reactions spontaneously form assemblies that are consistent with the presence of Watson-Crick-like base pairs. Together, these results provide further support for the possibility that heterocycles closely related to the extant bases of RNA facilitated the prebiotic emergence of RNA-like molecules, which were eventually replaced by RNA over the course of chemical and biological evolution.

Task-dependent Alteration in Delta Band Corticomuscular Coherence during Standing in Chronic Stroke Survivors.

Balance control is an important indicator of mobility and independence in activities of daily living. How the changes in functional integrity of corticospinal tract due to stroke affects the maintenance of upright stance remains to be known. We investigated the changes in functional coupling between the cortex and lower limb muscles during a challenging balance task over multiple frequency bands in chronic stroke survivors. Eleven stroke patients and nine healthy controls performed a challenging balance task. They stood on a computerized platform with/without somatosensory input distortion created by sway-referencing the support surface, thereby varying the difficulty levels of the task. We computed corticomuscular coherence between Cz (electroencephalography) and leg muscles and assessed balance performance using Berg Balance scale (BBS), Timed-up and go (TUG) and center of pressure (COP) measures. We found lower delta frequency band coherence in stroke patients when compared with healthy controls under medium difficulty condition for distal but not proximal leg muscles. For both groups, we found similar coherence at other frequency bands. On BBS and TUG, stroke patients showed poor balance. However, similar group differences were not consistently observed across COP measures. The presence of distal versus proximal effect suggests differences in the (re)organization of the corticospinal connections across the two muscles groups for balance control. We argue that the observed group difference in the delta coherence might be due to altered mechanisms for the detection of somatosensory modulation resulting from sway-referencing of the support platform for balance control.

Effects of simulated hypo-gravity on lower limb kinematic and electromyographic variables during anti-gravitational treadmill walking.

Introduction: This study investigated kinematic and EMG changes in gait across simulated gravitational unloading levels between 100% and 20% of normal body weight. This study sought to identify if each level of unloading elicited consistent changes-particular to that percentage of normal body weight-or if the changes seen with unloading could be influenced by the previous level(s) of unloading. Methods: 15 healthy adult participants (26.3 ± 2.5 years; 53% female) walked in an Alter-G anti-gravity treadmill unloading system (mean speed: 1.49 ±0.37 mph) for 1 min each at 100%, 80%, 60%, 40% and 20% of normal body weight, before loading back to 100% in reverse order. Lower-body kinematic data were captured by inertial measurement units, and EMG data were collected from the rectus femoris, biceps femoris, medial gastrocnemius, and anterior tibialis. Data were compared across like levels of load using repeated measures ANOVA and statistical parametric mapping. Difference waveforms for adjacent levels were created to examine the rate of change between different unloading levels. Results: This study found hip, knee, and ankle kinematics as well as activity in the rectus femoris, and medial gastrocnemius were significantly different at the same level of unloading, having arrived from a higher, or lower level of unloading. There were no significant changes in the kinematic difference waveforms, however the waveform representing the change in EMG between 100% and 80% load was significantly different from all other levels. Discussion: This study found that body weight unloading from 100% to 20% elicited distinct responses in the medial gastrocnemius, as well as partly in the rectus femoris. Hip, knee, and ankle kinematics were also affected differentially by loading and unloading, especially at 40% of normal body weight. These findings suggest the previous level of gravitational load is an important factor to consider in determining kinematic and EMG responses to the current level during loading and unloading below standard g. Similarly, the rate of change in kinematics from 100% to 20% appears to be linear, while the rate of change in EMG was non-linear. This is of particular interest, as it suggests that kinematic and EMG measures decouple with unloading and may react to unloading uniquely.

Lateralized Neural Entropy modulates with Grip Force during Precision Grasping.

When holding a coffee mug filled to the brim, we strive to avoid spilling the coffee. This ability relies on the neural processes underlying the control of finger forces on a moment-to-moment basis. The brain activity lateralized to the contralateral hemisphere averaged over a trial and across the trials is known to be associated with the magnitude of grip force applied on an object. However, the mechanistic involvement of the variability in neural signals during grip force control remains unclear. In this study, we examined the dependence of neural variability over the frontal, central, and parietal regions assessed using noninvasive electroencephalography (EEG) on grip force magnitude during an isometric force control task. We hypothesized laterally specific modulation in EEG variability with higher magnitude of the grip force exerted during grip force control. We utilized an existing EEG dataset (64 channel) comprised of healthy young adults, who performed an isometric force control task while receiving visual feedback of the force applied. The force magnitude to be exerted on the instrumented object was cued to participants during the task, and varied pseudorandomly among 5, 10, and 15% of their maximum voluntary contraction (MVC) across the trials. We quantified neural variability via sample entropy (sequence-dependent measure) and standard deviation (sequence-independent measure) of the temporal EEG signal over the frontal, central, and parietal electrodes. The EEG sample entropy over the central electrodes showed lateralized, nonlinear, localized, modulation with force magnitude. Similar modulation was not observed over frontal or parietal EEG activity, nor for standard deviation in the EEG activity. Our findings highlight specificity in neural control of grip forces by demonstrating the modulation in sequence-dependent but not sequence-independent component of EEG variability. This modulation appeared to be lateralized, spatially constrained, and functionally dependent on the grip force magnitude. We discuss the relevance of these findings in scenarios where a finer precision is essential to enable grasp application, such as prosthesis and associated neural signal integration, and propose directions for future studies investigating the mechanistic role of neural entropy in grip force control.

Amalgamation of solid dispersion and melt adsorption techniques for augmentation of oral bioavailability of novel anticoagulant rivaroxaban.

The objective of the present study was to evaluate the potential of solid dispersion adsorbate (SDA) to improve the solubility and bioavailability of rivaroxaban (RXN). SDA of RXN was developed by fusion method using PEG 4000 as carrier and Neusilin as adsorbent. A 32 full factorial design was utilized to formulate various SDAs. The selected independent variables were the amount of carrier (X1) and amount of adsorbent (X2). The responses measured were the time required for 85% drug release (Y1) and saturated solubility (Y2). MTT assay was employed for cytotoxicity studies on Caco-2 cells. In vivo pharmacokinetics and pharmacodynamic evaluations were carried out to assess the prepared SDA. Pre-compression evaluation of SDA suggests the prepared batches (B1-B9) possess adequate flow properties and could be used for compression of tablets. Differential scanning calorimetry and X-ray diffraction data signified the conversion of the crystalline form of drug to amorphous form, a key parameter accountable for improvement in drug dissolution. Optimization data suggests that the amount of carrier and amount of adsorbent significantly (P < 0.05) influence both dependent variables. Post-compression data signifies that the compressibility behavior of prepared tablets was within the official standard limits. A significant increase (P < 0.0001) in the in vitro dissolution characteristics of RXN was noticed in optimized SDA (> 85% in 10 min) as compared to the pure drug, marketed product, and directly compressible tablet. Cytotoxicity studies confirmed the nontoxicity of prepared RXN SDA tablets. RXN SDA tablets exhibited 2.79- and 1.85-fold higher AUC in comparison to RXN suspension and Xarelto tablets respectively indicating improved oral bioavailability. Higher bleeding time and percentage of platelet aggregation noticed with RXN SDA tablets in comparison to RXN suspension further substantiate the efficacy of the prepared formulation. In summary, the results showed the potential of RXN SDA tablets to enhance the bioavailability of RXN and hence can be an alternate approach of solid dosage form for its development for commercial application.

Assessment of Biomechanical Predictors of Occurrence of Low-Amplitude N1 Potentials Evoked by Naturally Occurring Postural Instabilities.

Naturally occurring postural instabilities that occur while standing and walking elicit specific cortical responses in the fronto-central regions (N1 potentials) followed by corrective balance responses to prevent falling. However, no framework could simultaneously track different biomechanical parameters preceding N1s, predict N1s, and assess their predictive power. Here, we propose a framework and show its utility by examining cortical activity (through electroencephalography [EEG]), ground reaction forces, and head acceleration in the anterior-posterior (AP) direction. Ten healthy young adults carried out a balance task of standing on a support surface with or without sway referencing in the AP direction, amplifying, or dampening natural body sway. Using independent components from the fronto-central cortical region obtained from subject-specific head models, we first robustly validated a prior approach on identifying low-amplitude N1 potentials before early signs of balance corrections. Then, a machine learning algorithm was used to evaluate different biomechanical parameters obtained before N1 potentials, to predict the occurrence of N1s. When different biomechanical parameters were directly compared, the time to boundary (TTB) was found to be the best predictor of the occurrence of upcoming low-amplitude N1 potentials during a balance task. Based on these findings, we confirm that the spatio-temporal characteristics of the center of pressure (COP) might serve as an essential parameter that can facilitate the early detection of postural instability in a balance task. Extending our framework to identify such biomarkers in dynamic situations like walking might improve the implementation of corrective balance responses through brain-machine-interfaces to reduce falls in the elderly.

Effects of aging on conditional visuomotor learning for grasping and lifting eccentrically weighted objects.

Explicit knowledge of object center of mass or CM location fails to guide anticipatory scaling of digit forces necessary for dexterous manipulation. We previously showed that allowing young adults to choose where to grasp the object entailed an ability to use arbitrary color cues about object CM location to gradually minimize object tilt across several trials. This conditional learning was achieved through accurate anticipatory modulation of digit position using the color cues. However, it remains unknown how aging affects the ability to use explicit color cues about object CM location to modulate digit placement for dexterous manipulation. We instructed healthy older and young adults to learn a manipulation task using arbitrary color cues about object CM location. Subjects were required to exert clockwise, counterclockwise, or no torque on the object according to the color cue and lift the object while minimizing its tilt. Older adults produced larger torque error during conditional learning trials, resulting in a slower rate of learning than young adults. Importantly, older adults showed impaired anticipatory modulation of digit position when information of the CM location was available via explicit color cues. The older adults also did not modulate their digit forces to compensate for this impairment. Interestingly, however, anticipatory modulation of digit position was intact in the same individuals when information of object CM location was implicitly conveyed from trial-to-trial. We discuss our findings in relation to age-dependent changes in processes and neural network essential for learning dexterous manipulation using arbitrary color cue about object property.NEW & NOTEWORTHY We studied whether older adults are able to predictively modulate digit position using arbitrary color cues indicating object center of mass location for dexterous manipulation. Older adults showed an impaired ability to modulate digit position using the color cues when compared with young adults. Interestingly, similar impairments were not found when same older individuals learned the task using implicit knowledge. Our findings suggest an age-related impairment specifically in the conditional learning mechanisms for dexterous manipulation.

DFT Analysis of Organotin Catalytic Mechanisms in Dehydration Esterification Reactions for Terephthalic Acid and 2,2,4,4-Tetramethyl-1,3-cyclobutanediol.

Polyesters synthesized from 2,2,4,4-tetramethyl-1,3-cyclobutanediol (TMCD) and terephthalic acid (TPA) are improved alternatives to toxic polycarbonates based on bisphenol A. In this work, we use ωB97X-D/LANL2DZdp calculations, in the presence of a benzaldehyde polarizable continuum model solvent, to show that esterification of TMCD and TPA will reduce and subsequently dehydrate a dimethyl tin oxide catalyst, becoming ligands on the now four-coordinate complex. This reaction then proceeds most plausibly by an intramolecular acyl-transfer mechanism from the tin complex, aided by a coordinated proton donor such as hydronium. These findings are a key first step in understanding polyester synthesis and avoiding undesirable side reactions during production.

Enhanced Oral Bioavailability of Etodolac by the Liquisolid Compact Technique: Optimisation, In-Vitro and In-Vivo Evaluation.

BACKGROUND: Poor dissolution of Etodolac is one of the major challenges in achieving the desired therapeutic effect in oral therapy. OBJECTIVE: This study aimed to assess the potential of the liquisolid compact technique in increasing the rate of dissolution of Etodolac and thus its bioavailability. METHODS: Liquisolid compacts were prepared using PEG 400, Avicel PH-200 and Aerosil 200 as non-volatile liquid, carrier and coating material, respectively. The optimisation was carried out by applying a 32 full factorial design using Design expert software 11.0.3.0 to examine the effects of independent variables (load factor and carrier: coating ratio) on dependent variables (angle of repose and % cumulative drug release at 30 min [Q _{30 min]). Assessment of bioavailability was based on a pharmacokinetic study on rabbits and pharmacodynamics evaluation on rats, respectively. RESULTS: The formulation M3 was identified as the optimised formulation based on the better flow (lower angle of repose) and a higher rate of dissolution (Q 30 min >95%). The higher dissolution rate could be due to conversion of Etodolac into an amorphous molecularly dispersed state, availability of larger surface area, enhancement of aqueous solubility and enhanced wetting of drug particles. Studies with DSC, XRD, and SEM verified the transformation of Etodolac from crystalline to amorphous state, a key factor responsible for improving the dissolution rate. The pharmacokinetic profile of M3 was prominent, demonstrating higher absorption of Etodolac in comparison to oral suspension and immediate-release conventional tablets in rabbits. Liquisolid formulation exhibited a 27% increment in paw thickness as compared to 57% and 46% increments for oral suspension and immediate-release conventional tablets, respectively, after 7 hrs in the carrageenan-induced paw model in rats. CONCLUSION: The results indicated the liquisolid compact technique to be a promising strategy to enhance the bioavailability of Etodolac.}

The Posterior Parietal Cortex Is Involved in Gait Adaptation: A Bilateral Transcranial Direct Current Stimulation Study.

Gait is one of the fundamental behaviors we use to interact with the world. The functionality of the locomotor system is thus related to enriching interactions with our environment. The posterior parietal cortex (PPC) has been found to contribute to motor adaptation during both visuomotor and postural adaptation tasks. Additionally, structural or functional deficits of the PPC lead to impairments in gaits such as shortened steps and increased step width. Based on the aforementioned roles of the PPC, and the importance of gait adaptability, the current investigation sought to identify the role of the PPC in gait adaptation. To achieve this, we performed transcranial direct current stimulation (tDCS) over the bilateral PPC before performing a split-belt treadmill gait adaptation paradigm. We used three stimulation conditions in a within-subject design. tDCS was administered in a randomized and double-blinded order. Following each stimulation session, subjects first performed baseline walking with both belts running at the same speed. Then, subjects walked for 15 min on an uncoupled treadmill, with the belts being driven at a 3:1 speed ratio. Last, they returned to normal (i.e., tied-belt) walking for 5 min. Results from 15 young and healthy subjects identified that subjects required more steps to adapt to split-belt walking following the suppression of the left hemisphere PPC, contralateral to the fast belt. Furthermore, while suppression of the left hemisphere PPC did not increase the number of steps required to re-adapt to tied-belt walking, this condition did lead to increased magnitude of after-effects. Together, these findings indicate that the PPC is involved in locomotor adaptation. These results support previous literature regarding the upper body or postural adaptation and extend these findings to the realm of gait. Results highlight the PPC as a potential target for neurorehabilitation designed to improve gait adaptability.

Non-invasive Brain Stimulation of the Posterior Parietal Cortex Alters Postural Adaptation.

Effective central sensory integration of visual, vestibular, and proprioceptive information is required to promote adaptability in response to changes in the environment during postural control. Patients with a lesion in the posterior parietal cortex (PPC) have an impaired ability to form an internal representation of body position, an important factor for postural control and adaptation. Suppression of PPC excitability has also been shown to decrease postural stability in some contexts. As of yet, it is unknown whether stimulation of the PPC may influence postural adaptation. This investigation aimed to identify whether transcranial direct current stimulation (tDCS) of the bilateral PPC could modulate postural adaptation in response to a bipedal incline postural adaptation task. Using young, healthy subjects, we delivered tDCS over bilateral PPC followed by bouts of inclined stance (incline-interventions). Analysis of postural after-effects identified differences between stimulation conditions for maximum lean after-effect (LAE; p = 0.005) as well as a significant interaction between condition and measurement period for the average position (p = 0.03). We identified impaired postural adaptability following both active stimulation conditions. Results reinforce the notion that the PPC is involved in motor adaptation and extend this line of research to the realm of standing posture. The results further highlight the role of the bilateral PPC in utilizing sensory feedback to update one's internal representation of verticality and demonstrates the diffuse regions of the brain that are involved in postural control and adaptation. This information improves our understanding of the role of the cortex in postural control, highlighting the potential for the PPC as a target for sensorimotor rehabilitation.

Pain profile of premature infants during routine procedures in neonatal intensive care: An observational study.

BACKGROUND: Premature neonates receive a large number of painful procedures during their stay in the neonatal intensive care unit (NICU). However, there are many other processes that happen in the NICU, which may not be considered painful but can cause discomfort and/or stress to the neonate. METHOD: Pain profile during routine procedures in NICU was assessed using the premature infant pain profile (PIPP) score. Neonates of gestational age >26 weeks, less than 7 days old and admitted for less than 7 days in the NICU were included. RESULTS: A total of 662 procedures were observed in 132 (78 M, 54 F) neonates. The mean (SD) age of the neonates was 2.4 (1.8) days and the mean (SD) birth weight was 2.3 (0.6) kg. 63 (54.5%) were of low birth weight (LBW), 85 (64.39%) were full term. High PIPP score was noted in blood sampling, heel prick, suction, and weight measurement. Significant differences were observed in the PIPP score during blood sampling and suction across gender. Some ordinary and non-stressful procedures also scored very high on the PIPP scale. CONCLUSIONS: The validity of PIPP needs to be reexamined. Our understanding of pain during routine procedures may need to be revisited.

Time-course of pain threshold after continuous theta burst stimulation of primary somatosensory cortex in pain-free subjects.

Primary somatosensory cortex (S1) is involved in pain processing and thus its suppression using neuromodulatory techniques such as continuous theta burst stimulation (cTBS) might be a potential pain management strategy in patients with neuropathic pain. cTBS over S1 is known to elevate pain threshold in young adults. However, the time course of this after-effect is unknown. Furthermore, the effect of cTBS over S1 on pain threshold might be confounded by changes in the excitability of primary motor cortex (M1), an area known to be involved in pain processing, due to spread of current. Therefore, whether S1 plays a role in pain processing independent of M1 also remains unknown. The corticospinal excitability (CSE) can provide a measure of M1 excitability because cTBS over M1 is known to reduce CSE. Here, we studied the time-course of the effects of MRI-guided cTBS over S1 on electrical pain threshold (EPT) and CSE. Ten healthy young adults received cTBS over S1 and sham stimulation in counterbalanced sessions at least 5 days apart. EPT and CSE were recorded before and following cTBS over S1. We assessed each measure once before stimulation and then every 10 min starting immediately after stimulation until 40 min. cTBS over S1 elevated EPT compared to sham stimulation with the after-effect lasting for 40 min. We observed no change in CSE following cTBS and sham stimulation. Our findings suggest that cTBS over S1 can elevate EPT for 40 min without altering M1 excitability.

Dexterous Object Manipulation Requires Context-Dependent Sensorimotor Cortical Interactions in Humans.

Dexterous object manipulation is a hallmark of human evolution and a critical skill for everyday activities. A previous work has used a grasping context that predominantly elicits memory-based control of digit forces by constraining where the object should be grasped. For this "constrained" grasping context, the primary motor cortex (M1) is involved in storage and retrieval of digit forces used in previous manipulations. In contrast, when choice of digit contact points is allowed ("unconstrained" grasping), behavioral studies revealed that forces are adjusted, on a trial-to-trial basis, as a function of digit position. This suggests a role of online feedback of digit position for force control. However, despite the ubiquitous nature of unconstrained hand-object interactions in activities of daily living, the underlying neural mechanisms are unknown. Using noninvasive brain stimulation, we found the role of primary motor cortex (M1) and somatosensory cortex (S1) to be sensitive to grasping context. In constrained grasping, M1 but not S1 is involved in storing and retrieving learned digit forces and position. In contrast, in unconstrained grasping, M1 and S1 are involved in modulating digit forces to position. Our findings suggest that the relative contribution of memory and online feedback modulates sensorimotor cortical interactions for dexterous manipulation.

Report of Caridina babaulti Bouvier, 1918 (Crustacea: Decapoda: Caridea: Atyidae) and description of a new species Caridina kutchi sp. nov. from Gujarat, India.

This study aims to report the freshwater shrimps of the genus Caridina H. Milne Edwards, 1837, from the Indian state of Gujarat, which has a unique landscape and climatic conditions that form a significant environment for biological studies. Caridina babaulti Bouvier, 1918, is re-described with type specimens and fresh collections from Shetrunji River, Saurashtra Peninsula. Caridina kutchi sp. nov., is described from Khari River, Kutch Peninsula.