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The spatiotemporal dynamics of cortical oscillations across human brain regions remain poorly understood because of a lack of adequately validated methods for reconstructing such activity from noninvasive electrophysiological data. In this paper, we present a novel adaptive spatial filtering algorithm optimized for robust source time–frequency reconstruction from magnetoencephalography (MEG) and electroencephalography (EEG) data. The efficacy of the method is demonstrated with simulated sources and is also applied to real MEG data from a self-paced finger movement task. The algorithm reliably reveals modulations both in the beta band (12–30 Hz) and high gamma band (65–90 Hz) in sensorimotor cortex. The performance is validated by both across-subjects statistical comparisons and by intracranial electrocorticography (ECoG) data from two epilepsy patients. Interestingly, we also reliably observed high frequency activity (30–300 Hz) in the cerebellum, although with variable locations and frequencies across subjects. The proposed algorithm is highly parallelizable and runs efficiently on modern high-performance computing clusters. This method enables the ultimate promise of MEG and EEG for five-dimensional imaging of space, time, and frequency activity in the brain and renders it applicable for widespread studies of human cortical dynamics during cognition.

Low dose ketamine can be used as analgesic in acute pain management in the emergency department (ED). Efficacy of IN ketamine in acute pain management in the ED. This is a double blind randomized clinical trial on patients older than 15 years who needed digital nerve block (DNB). Participants randomly received IN Ketamine (1 ml = 50 mg) or placebo (normal saline, 1 ml) 5 min before DNB. In both groups, patients' pain score was recorded by visual analogue score (VAS) at baseline, after DNB and 45 min after completion of DNB. Adverse effects of ketamine and changes in vital signs were also recorded and compared with placebo group. A total number of 100 patients were enrolled in the study with the median (IQR) age of 36.5 (26) years, including 65 men and 35 women. IN ketamine resulted in less pain compared to placebo after performing DNB and 45 min after the procedure. Median (IQR) basic VAS score was 50 (15) in ketamine group, and 49 (27) in control group. Median (IQR) block pain VAS score was 28.5 (19) in ketamine group and 47.5 (31) in control group. Median (IQR) procedural pain VAS score was 21.5 (16) in ketamine group and 43.5 (29) in control group. Only 7 patients had adverse effects in either group. The findings of this study suggest that IN ketamine can be effective in reducing pain in patients with acute pain, without adding significant side effects.

Lateral epicondylitis is a common condition for which botulinum toxin has been reported to have a therapeutic role in uncontrolled studies. To determine if an injection of botulinum toxin is more effective than placebo for reducing pain in adults with lateral epicondylitis. Randomized, double-blind, placebo-controlled trial conducted from September 2002 to December 2004. Outpatient clinics at a university hospital and a district hospital in Hong Kong. 60 patients with lateral epicondylitis. The primary outcome was change in subjective pain as measured by a 100-mm visual analogue scale (VAS) ranging from 0 (no pain) to 10 (worst pain ever) at 4 weeks and 12 weeks. All patients completed post-treatment follow-up. A single injection of 60 units of botulinum toxin type A or normal saline placebo. Mean VAS scores for the botulinum group at baseline and at 4 weeks were 65.5 mm and 25.3 mm, respectively; respective scores for the placebo group were 66.2 mm and 50.5 mm (between-group difference of changes, 24.4 mm [95% CI, 13.0 to 35.8 mm]; P < 0.001). At week 12, mean VAS scores were 23.5 mm for the botulinum group and 43.5 mm for the placebo group (between-group difference of changes, 19.3 mm [CI, 5.6 to 32.9 mm]; P = 0.006). Grip strength was not statistically significantly different between groups at any time. Mild paresis of the fingers occurred in 4 patients in the botulinum group at 4 weeks. One patient's symptoms persisted until week 12, whereas none of the patients receiving placebo had the same complaint. At 4 weeks, 10 patients in the botulinum group and 6 patients in the placebo group experienced weak finger extension on the same side as the injection site. The trial was small, and most participants were women. The blinding protocol may have been ineffective because the 4 participants who experienced paresis of the fingers could have correctly assumed that they received an active treatment. Botulinum toxin injection may improve pain over a 3-month period in some patients with lateral epicondylitis, but injections may be associated with digit paresis and weakness of finger extension.

The literature reports that anticipatory postural adjustments (APAs) are programmed according to movement velocity. However, the linkage between APAs and velocity has been highlighted within single subjects who were asked to voluntarily change movement velocity; therefore, till now, it has been impossible to discern whether the key factor determining APA latency was the intended movement velocity or the actual one. Aim of this study was to distinguish between these two factors. We analyzed the APA chain that stabilizes the arm during a brisk index finger flexion in two groups of subjects: (1) 29 who composed our database from previous experiments and were asked to “go-as-fast-as-possible” ( go - fast ), but actually performed the movement with different speeds (238–1,180°/s), and (2) ten new subjects who performed the go - fast movement at more than 500°/s and were then asked to go - slow at about 50 % of their initial velocity, thus moving at 300–800°/s. No correlation between APA latency and actual movement speed was observed when all subjects had to go - fast ( p  > 0.50), while delayed APAs were found in the ten new subjects when they had to go - slow ( p  < 0.001). Moreover, in the speed range between 300 and 800°/s, the APA latency depended only on movement instruction: subjects going fast showed earlier APAs than those going slow ( p  < 0.001). These data suggest a stronger role of the intended movement velocity versus the actual one in modifying the timing of postural muscles recruitment with respect to the prime mover. These results also strengthen the idea of a shared postural and voluntary command within the same motor act.

•In this trial, eight healthy adult volunteers were randomly divided into placebo stage and venlafaxine stage.•The behavioral assessment, TST and conventional TMS examination for each hand were recorded in each stage.•The performance of index finger tapping in the venlafaxine stage was significantly increased.•The TST amplitude and area ratios in the venlafaxine stage were increased with significant differences.•Venlafaxine positively regulates central motor conduction in healthy adults. Using the triple stimulation technique (TST) and conventional transcranial magnetic stimulation (TMS), this study was designed to investigate the effect of venlafaxine on central motor conduction in healthy adults. In this crossover, self-controlled trial, eight healthy adult volunteers were randomly divided into groups A and B. In group A, the volunteers were administered 1 venlafaxine capsule once daily for 7 consecutive days, followed by a 3-day break. Next, volunteers in this group received 1 placebo capsule once daily for 7 consecutive days. Group B received the treatments in the opposite order. The index finger tapping test, grip strength test, TST and conventional TMS examination for each hand were recorded before and one week after the administration of venlafaxine or placebo. Compared to the placebo stage, in the venlafaxine stage, the number of index finger taps was significantly increased for both hands, and the TST amplitude and area ratios were significantly increased. The improvement in the TST amplitude ratio was significantly and positively correlated with the improvements in performance on the index finger tapping test. Venlafaxine positively regulates central motor conduction in healthy adults.

Changes in fine motor control that eventually compromise dexterity accompany advanced age; however there is evidence that age-related decline in motor control may not be uniform across effectors. Particularly, the role of central mechanisms in effector-specific decline has not been examined but is relevant for placing age-related motor declines into the growing literature of age-related changes in brain function. We examined sub-maximal force control across three different effectors (fingers, lips, and tongue) in 18 young and 14 older adults. In parallel with the force variability measures we examined changes in white matter structural integrity in effector-specific pathways in the brain with diffusion tensor imaging (DTI). Motor pathways for each effector were identified by using an fMRI localizer task followed by tractography to identify the fiber tracts propagating to the midbrain. Increases in force control variability were found with age in all three effectors but the effectors showed different degrees of age-related variability. Motor control changes were accompanied by a decline in white matter structural integrity with age shown by measures of fractional anisotropy and radial diffusivity. The DTI metrics appear to mediate some of the age-related declines in motor control. Our findings indicate that the structural integrity of descending motor systems may play a significant role in age-related increases in motor performance variability, but that differential age-related declines in oral and manual effectors are not likely due to structural integrity of descending motor pathways in the brain. •Oral and manual fine-motor performance of young and old adults were compared•Obtained DTI neural integrity measures specific to oral and manual effectors•Effector-specific age related declines in motor control were observed•Age-related motor control declines were correlated to changes in neuronal structure•White matter integrity did not predict differential decline among the effectors

The deposition of alpha-synuclein in the brain, the neuropathological hallmark of Parkinson’s disease (PD), follows a distinct anatomical and temporal sequence. This study aimed to characterize alpha-synuclein deposition in cutaneous nerves from patients with PD. We further strived to explore whether peripheral nerve involvement is intrinsic to PD and reflective of known features of brain pathology, which could render it a useful tool for pathogenetic studies and pre-mortem histological diagnosis of PD. We obtained skin biopsies from the distal and proximal leg, back and finger of 31 PD patients and 35 controls and quantified the colocalization of phosphorylated alpha-synuclein in somatosensory and autonomic nerve fibers and the pattern of loss of different subtypes of dermal fibers. Deposits of phosphorylated alpha-synuclein were identified in 16/31 PD patients but in 0/35 controls ( p  < 0.0001). Quantification of nerve fibers revealed two types of peripheral neurodegeneration in PD: (1) a length-dependent reduction of intraepidermal small nerve fibers ( p  < 0.05) and (2) a severe non-length-dependent reduction of substance P-immunoreactive intraepidermal nerve fibers ( p  < 0.0001). The latter coincided with a more pronounced proximal manifestation of alpha-synuclein pathology in the skin. The histological changes did not correlate with markers of levodopa toxicity such as vitamin B12 deficiency. Our findings suggest that loss of peripheral nerve fibers is an intrinsic feature of PD and that peripheral nerve changes may reflect the two types of central alpha-synuclein-related PD pathology, namely neuronal death and axonal degeneration. Detection of phosphorylated alpha-synuclein in dermal nerve fibers might be a useful diagnostic test for PD with high specificity but low sensitivity.

This tutorial focuses on the sense of touch within the context of a fully active human observer. It is intended for graduate students and researchers outside the discipline who seek an introduction to the rapidly evolving field of human haptics. The tutorial begins with a review of peripheral sensory receptors in skin, muscles, tendons, and joints. We then describe an extensive body of research on “what” and “where” channels, the former dealing with haptic perception of objects, surfaces, and their properties, and the latter with perception of spatial layout on the skin and in external space relative to the perceiver. We conclude with a brief discussion of other significant issues in the field, including vision-touch interactions, affective touch, neural plasticity, and applications.

Synergism of rehabilitative interventions could maximize recovery following stroke. We examined whether the combination of peripherally initiated electrical stimulation of finger extensors and centrally operating finger tracking training could accentuate brain reorganization and its relationship to recovery, beyond the effects of either treatment alone. Twenty subjects with stroke were randomly assigned to an electrical stimulation (ES), tracking training (TR) or combination (CM) group. Each group was trained for ten 1-h sessions over 2-3 weeks. Pretest and posttest measurements consisted of the Box and Block and Jebsen Taylor tests of manual dexterity and a finger tracking test that was performed during functional magnetic resonance imaging (fMRI). fMRI variables included laterality index and BOLD signal intensity of primary motor (M1), primary sensory (S1), sensorimotor (SMC) and premotor (PMC) cortices as well as, supplementary motor area (SMA). ES and CM groups improved on dexterity, whereas the TR group did not. Improvement in the CM group was not greater than the other two groups. Subjects who had an intact M1 showed greater functional improvement than those who had direct involvement of M1. fMRI analysis did not yield significant changes from pretest to posttest. In the CM group only, functional improvement was positively correlated with laterality index change in M1, S1, SMC and PMC, indicating greater ipsilesional control and was negatively correlated with BOLD Signal Intensity change in ipsilesional S1 and SMA, indicating neurophysiological trimming of irrelevant neurons. The correlational results suggest that the combined intervention may be more influential on brain reorganization than either treatment alone but a larger sample size, longer duration of training, or a restricted inclusion of stroke location and volume may be needed to demonstrate a difference in efficacy for producing behavioral changes.

When a standing person applies a light finger touch to an external stable object, postural sway is reduced. We tested a hypothesis that two factors related to touch can induce this effect, the presence of a stable reference point and the modulation of contact forces leading to tissue deformation. Force platform signals were analyzed while subjects stood quietly with or without additional light touch to an external object (contact forces under 1 N). The point of touch on the body was manipulated. We also investigated the effects of active touch vs fixation of a finger at a point in external space. The results show that touch to the head or neck can be more effective in reducing body sway than a finger touch. A larger reduction in sway was observed when the finger was fixed in a clip (the net forces between the clip and the point of its fixation to the stand were under 1 N) as compared to a free light touch to a pad. The subjects showed a reduction in postural sway while holding a load suspended using a pulley system; in this situation, contact with the load via the pulley provided modulation of contact forces but not a fixed reference point. This finding emphasizes the importance of such factors as stability of the contact point and modulation of contact forces, as compared to active touch or to an implicit task of stabilizing the kinematic chain. The system of postural stabilization can reduce postural sway, making use of either of two sources of sensory information associated with touch, one related to providing a fixed reference point in space, and the other related to transient force changes at the point of contact related to the sway.