Upper-limb Dexterity Research Articles

Effects of Cerebellar Non-Invasive Stimulation on Neurorehabilitation in Stroke Patients: An Updated Systematic Review.

The cerebellum is emerging as a promising target for noninvasive brain stimulation (NIBS). A systematic review was conducted to evaluate the effects of cerebellar NIBS on both motor and other symptoms in stroke rehabilitation, its impact on functional ability, and potential side effects (PROSPERO number: CRD42022365697). A systematic electronic database search was performed by using PubMed Central (PMC), EMBASE, and Web of Science, with a cutoff date of November 2023. Data extracted included study details, NIBS methodology, outcome measures, and results. The risk of bias in eligible studies was also assessed. Twenty-two clinical studies involving 1016 participants were finally included, with a focus on outcomes related to post-stroke motor recovery (gait and balance, muscle spasticity, and upper limb dexterity) and other functions (dysphagia and aphasia). Positive effects were observed, especially on motor functions like gait and balance. Some efficiency was also observed in dysphagia rehabilitation. However, findings on language recovery were preliminary and inconsistent. A slight improvement in functional ability was noted, with no serious adverse effects reported. Further studies are needed to explore the effects of cerebellar NIBS on post-stroke non-motor deficits and to understand how cerebellar engagement can facilitate more precise treatment strategies for stroke rehabilitation.

Kinematic Assessment of Fine Motor Skills in Children: Comparison of a Kinematic Approach and a Standardized Test.

Deficits in fine motor skills have been reported in some children with neurodevelopmental disorders such as amblyopia or strabismus. Therefore, monitoring the development of motor skills and any potential improvement due to therapy is an important clinical goal. The aim of this study was to test the feasibility of performing a kinematic assessment within an optometric setting using inexpensive, portable, off-the-shelf equipment. The study also assessed whether kinematic data could enhance the information provided by a routine motor function screening test (the Movement Assessment Battery for Children, MABC). Using the MABC-2, upper limb dexterity was measured in a cohort of 47 typically developing children (7-15 years old), and the Leap motion capture system was used to record hand kinematics while children performed a bead-threading task. Two children with a history of amblyopia were also tested to explore the utility of a kinematic assessment in a clinical population. For the typically developing children, visual acuity and stereoacuity were within the normal range; however, the average standardized MABC-2 scores were lower than published norms. Comparing MABC-2 and kinematic measures in the two children with amblyopia revealed that both assessments provide convergent results and revealed deficits in fine motor control. In conclusion, kinematic assessment can augment standardized tests of fine motor skills in an optometric setting and may be useful for measuring visuomotor function and monitoring treatment outcomes in children with binocular vision anomalies.

Reversed Mirror Therapy (REMIT) after Stroke—A Proof-of-Concept Study

In mirror training (MIT), stroke patients strive to move their hands while looking at the reflected image of the unaffected one. The recruitment of the mirror neurons and visual-proprioceptive conflict are expected to facilitate the paretic voluntary movement. Here, a reversed MIT (REMIT) is presented, which requires moving hands while looking at the reflected image of the paretic one, giving the illusion of being unable to move the unimpaired hand. This study compares MIT and REMIT on post-stroke upper-limb recovery to gain clues on the mechanism of action of mirror therapies. Eight chronic stroke patients underwent two weeks of MIT and REMIT (five sessions each) in a crossover design. Upper-limb Fugl-Meyer, Box and Block and handgrip strength tests were administered at baseline and treatments end. The strength of the mirror illusion was evaluated after each session. MIT induced a larger illusory effect. The Fugl-Meyer score improved to the same extent after both treatments. No changes occurred in the Box and Block and the handgrip tests. REMIT and MIT were equally effective on upper-limb dexterity, challenging the exclusive role of mirror neurons. Contrasting learned nonuse through an intersensory conflict might provide the rationale for both forms of mirror-based rehabilitation after stroke.

Exercise Therapy in Early Multiple Sclerosis Improves Physical Function But Not Cognition: Secondary Analyses From a Randomized Controlled Trial

Background Exercise positively affects multiple sclerosis (MS) symptoms, physiological systems, and potentially cognition. However, an uninvestigated “window of opportunity” exists for exercise therapy early in the disease. Objective This study presents secondary analyses from the Early Multiple Sclerosis Exercise Study, and aims to investigate the efficacy of exercise on physical function, cognition, and patient-reported measures of disease and fatigue impact early in the disease course of MS. Methods This randomized controlled trial (n = 84, time since diagnosis <2 years) included 48 weeks of aerobic exercise or an active control condition (health education) and between-group changes are based on repeated measurement mixed regression models. Physical function tests included measures of aerobic fitness, walking (6-minute walk, Timed 25-foot walk, Six-spot step test), and upper-limb dexterity. Tests of processing speed and memory evaluated cognition. The questionnaires Multiple Sclerosis Impact Scale and Modified Fatigue Impact Scale assessed perception of disease and fatigue impact. Results Following early exercise aerobic fitness showed superior between-group physiological adaptations (4.0 [1.7; 6.3] ml O2/min/kg; large effect size [ES = 0.90]). No other outcomes showed significant between-group differences, yet all measures of walking and upper-limb function showed small-to-medium effect sizes in favor of exercise (ES = 0.19−0.58). Overall disability status as well as cognition were unaffected by exercise, whereas perception of disease and fatigue impact were reduced in both groups. Conclusion In early MS, 48 weeks of supervised aerobic exercise seem to positively modify physical function, but not cognitive function. Perception of disease and fatigue impact may be modifiable by exercise in early MS. Trial registration: Clinicaltrials.gov (identifier: NCT03322761).

Chronic muscle recordings reveal recovery of forelimb function in spinal injured female rats after cortical epidural stimulation combined with rehabilitation and chondroitinase ABC.

Cervical level spinal cord injury (SCI) can severely impact upper limb muscle function, which is typically assessed in the clinic using electromyography (EMG). Here, we established novel preclinical methodology for EMG assessments of muscle function after SCI in awake freely moving animals. Adult female rats were implanted with EMG recording electrodes in bicep muscles and received bilateral cervical (C7) contusion injuries. Forelimb muscle activity was assessed by recording maximum voluntary contractions during a grip strength task and cortical motor evoked potentials in the biceps. We demonstrate that longitudinal recordings of muscle activity in the same animal are feasible over a chronic post‐injury time course and provide a sensitive method for revealing post‐injury changes in muscle activity. This methodology was utilized to investigate recovery of muscle function after a novel combination therapy. Cervical contused animals received intraspinal injections of a neuroplasticity‐promoting agent (lentiviral‐chondroitinase ABC) plus 11 weeks of cortical epidural electrical stimulation (3 h daily, 5 days/week) and behavioral rehabilitation (15 min daily, 5 days/week). Longitudinal monitoring of voluntary and evoked muscle activity revealed significantly increased muscle activity and upper limb dexterity with the combination treatment, compared to a single treatment or no treatment. Retrograde mapping of motor neurons innervating the biceps showed a predominant distribution across spinal segments C5–C8, indicating that treatment effects were likely due to neuroplastic changes in a mixture of intact and injured motor neurons. Thus, longitudinal assessments of muscle function after SCI correlate with skilled reach and grasp performance and reveal functional benefits of a novel combination therapy.

Validation Study for the Brazilian Population of the Nine Hole Peg Test Visumotor Evaluation Instrument

The present study aimed to verify the validity and reliability of the Nine Pins Visuomotor Integration (NHPT) assessment instrument for the Brazilian population, with the objective of measuring upper limb dexterity (arm and hand) of individuals between 04 and 14 years of age. Participated in the present study, 2765 individuals of both sexes, aged between 04 and 14 years. To perform the test, a square board with nine holes and 9 pins was used and the dominant and non-dominant hands were tested. The test was timed and the result measured by the time required for the individual to complete the activity, considering a maximum time of 300 seconds. In the quantitative validation stage, a statistical analysis was performed to obtain objective evidence regarding its functionality and effectiveness. Our results confirm the validity (accuracy) in the application of the NHPT test. In order to verify the reliability (trustworthiness) of the instrument proposed in this study, 3 steps were followed. The results showed high reliability (precision) in the scores for the non-preferred hand for children aged 4 to 14 years. Regarding the preferred hand, the values ​​show high reliability for children aged 04 to 8 years and 10 to 14 years and for children aged 9 years old, it showed good reliability, satisfying the rates recommended by the literature.: Through the results presented in this study, it was possible to , to conclude by the reliability of the test for which it proposes to evaluate, that is, the evidence is very safe in favor of the hypothesis that the results are correlated not only in the analyzed sample, but also for other experiments that may be carried out, to compare such domains by others.

Evaluation of the Psychometric Properties of Jebsen Taylor Hand Function Test (JTHFT) in Italian Individuals With Multiple Sclerosis.

IntroductionThe Jebsen Taylor Hand Function Test (JTHFT) is a non-diagnostic assessment scale for hand and upper limb dexterity that is commonly used in various countries around the world for diseases, such as muscular dystrophy, stroke, spinal cord injury, Parkinson, carpal tunnel syndrome, and rheumatoid arthritis. This study aimed to evaluate the psychometric properties of the JTHFT in Italian adults with Multiple Sclerosis (MS).Materials and MethodsThe test's internal consistency was evaluated with Cronbach's alpha, whereas its concurrent validity was evaluated by comparing the JTHFT with the Health Assessment Questionnaire (HAQ) and by calculating Pearson's correlation coefficient.ResultsThe JTHFT was administered to 29 Italians with MS. The Cronbach's alpha showed that the nondominant hand has a value of 0.76 and 0.91 for the dominant hand. Pearson's correlation coefficient showed significant correlations between JTHFT and HAQ.DiscussionThe JTHFT is a reliable tool to evaluate the functionality of the upper limb and hand in patients with MS. This tool is useful for testing the effectiveness of a treatment in various diseases. The results obtained in this study are coherent with previous studies that are conducted in populations with different diseases. In particular, the correlation between JTHFT and HAQ showed that a disability related to the upper limbs can often have repercussions, not only on activities of daily living, but also on walking. Based on this correlation, the motor deficits that emerged may be linked to a brain marrow disease rather than a spinal disease, even if an essential deepening can confirm this hypothesis.

POSA292 MSCopilot® as a Digital Tool to Collect Patients’ Insights in Health Economics Research in Multiple Sclerosis

MSCopilot® is a CE-marked software medical device used by multiple sclerosis (MS) patients for the remote monitoring of their disease in four dimensions: walking, upper-limb dexterity, cognition and low-contrast vision. This research explored the relevancy of the usage of MSCopilot® as a digital tool in PETALS study estimating the total societal impact of MS in France.

Ladder Use in Older People: Type, Frequency, Tasks and Predictors of Risk Behaviours.

Ladder fall and injury risk increases with age. People who present to a hospital after an injurious ladder fall have been surveyed, but little is known about ladder use in the community. The purpose of this study was to: (1) document salient factors related to ladder safety, and (2) determine physical, executive function, psychological and frequency-of-use factors associated with unsafe ladder use in older people. One hundred and two older people (aged 65+ years) were recruited. Participants completed questionnaires on demographics, health, and ladder use (type, frequency, task, behaviours) and underwent assessments of physical and executive function ability. Results showed both older men and women commonly use step ladders (61% monthly, 96% yearly), mostly inside the home for tasks such as changing a lightbulb (70%) and decorating (43%). Older men also commonly use straight ladders (27% monthly, 75% yearly), mostly outside the home for tasks such as clearing gutters (74%) and pruning trees (40%). Unsafe ladder use was more common in males and individuals with greater ladder use frequency, greater quadriceps strength, better upper limb dexterity, better balance, better stepping ability, greater self-reported everyday risk-taking, a lower fear of falling, and fewer health problems compared to their counterparts (all p < 0.05). These findings document ladder use by older people and provide insight into unsafe ladder behaviours that may be amenable to interventions to reduce ladder falls and associated injuries.

Longer length of post-acute care stay causes greater functional improvements in poststroke patients.

Post-acute care (PAC) is a type of transitional care for poststroke patients after the acute medical stage; it offers a relatively intensive rehabilitative program. Under Taiwan's National Health Insurance guidelines, the only patients who can transfer to PAC institutions are those who have had an acute stroke in the previous month, are in a relatively stable medical condition, and have the potential for improvement after aggressive rehabilitation. Poststroke patients receive physical, occupational, and speech therapy in PAC facility. However, few studies have evaluated the effects of PAC in poststroke patients since PAC's initiation in Taiwan. Thus, this study aims to investigate whether the length of stay in a PAC institution correlates with patients’ improvements.This retrospective and single-center study in Taiwan enrolled 193 poststroke patients who had received acute care at Chi-Mei Medical Center, Taiwan, at any period between 2014 and 2017. Data on their length of stay in the PAC institution were collected. Poststroke patients’ functional ability—such as activities of daily living (ADL) function and swallowing ability—as well as their corresponding scales were assessed on the first and last day of PAC stay. Statistical analysis was conducted by SPSS version 21.0.The average duration of PAC stay was 35.01 ± 16.373 days. Duration of PAC stay was significantly positively correlated with the Barthel index (P < .001), Berg balance test score (P < .001), gait speed (P = .002), and upper sensory function and upper motor function within the Fugl–Meyer Assessment (both P < .001).Poststroke patients with longer stay in a PAC institution had superior ADL function, balance and coordination, walking speed, and upper-limb dexterity and sensory function.

Objectively characterizing Huntington\u2019s disease using a novel upper limb dexterity test

BackgroundThe Clinch Token Transfer Test (C3t) is a bi-manual coin transfer task that incorporates cognitive tasks to add complexity. This study explored the concurrent and convergent validity of the C3t as a simple, objective assessment of impairment that is reflective of disease severity in Huntington’s, that is not reliant on clinical expertise for administration.MethodsOne-hundred-and-five participants presenting with pre-manifest (n = 16) or manifest (TFC-Stage-1 n = 39; TFC-Stage-2 n = 43; TFC-Stage-3 n = 7) Huntington’s disease completed the Unified Huntington’s Disease Rating Scale and the C3t at baseline. Of these, thirty-three were followed up after 12 months. Regression was used to estimate baseline individual and composite clinical scores (including cognitive, motor, and functional ability) using baseline C3t scores. Correlations between C3t and clinical scores were assessed using Spearman’s R and visually inspected in relation to disease severity using scatterplots. Effect size over 12 months provided an indication of longitudinal behaviour of the C3t in relation to clinical measures.ResultsBaseline C3t scores predicted baseline clinical scores to within 9–13% accuracy, being associated with individual and composite clinical scores. Changes in C3t scores over 12 months were small (Omega ≤ 0.15) and mirrored the change in clinical scores.ConclusionThe C3t demonstrates promise as a simple, easy to administer, objective outcome measure capable of predicting impairment that is reflective of Huntington’s disease severity and offers a viable solution to support remote clinical monitoring. It may also offer utility as a screening tool for recruitment to clinical trials given preliminary indications of association with the prognostic index normed for Huntington’s disease.

Effects of virtual reality associated with serious games for upper limb rehabilitation in patients with multiple sclerosis: randomized controlled trial

BackgroundDexterity and activities of daily living limitations on the upper limb (UL) represent one of the most common problems in patients with multiple sclerosis (MS). The aim of this study was to evaluate the effectiveness of the specially developed Serious Games that make use of the Leap Motion Controller (LMC) as main user interface for improving UL grip muscle strength, dexterity, fatigue, quality of life, satisfaction and compliance.MethodsA single-blinded randomized controlled trial was conducted. The sample was randomized into two groups: an experimental group who received treatment based on serious games designed by the research team using the developed LMC based Serious Games for the UL plus conventional rehabilitation, and a control group who received the same conventional rehabilitation for the UL. Both groups received two 60 min sessions per week over a ten-week period. Grip muscle strength, coordination, speed of movements, fine and gross UL dexterity, fatigue, quality of life, satisfaction and compliance were assessed in both groups pre-treatment, post-treatment and in a follow-up period of 1 month without receiving any treatment.ResultsIn the experimental group compared to the control group, significant improvements were observed in the post-treatment assessment for coordination, speed of movements, fine and gross UL dexterity. Also, significant results were found in the follow-up in coordination, speed of movements, fine and gross for the more affected side.ConclusionsAn experimental protocol using an LMC based Serious Games designed for UL rehabilitation showed improvements for unilateral gross manual dexterity, fine manual dexterity, and coordination in MS patients with high satisfaction and excellent compliance.Trial registrationThis randomized controlled trial has been registered at ClinicalTrials.gov Identifier: NCT04171908, Nov 2019.

Upper Limb Dexterity in Patients with Multiple Sclerosis: An Important and Underrated Morbidity.

Scales to assess disability in multiple sclerosis (MS) rarely provide reliable data on actual global impairment. Upper limb dysfunction is usually overlooked, which has a negative effect on patient well-being. We sought to analyze associations among upper limb dexterity, lower limb speed, and Expanded Disability Status Scale (EDSS) score; the difference in upper limb dexterity between patients with EDSS scores less than 5 and 5 or greater; and the associations that upper limb dexterity, lower limb speed, and EDSS score have with health-related quality of life measurements and depression. A total of 140 adults with MS were evaluated using the Nine-Hole Peg Test, Timed 25-Foot Walk test, EDSS, Multiple Sclerosis International Quality of Life (MusiQoL) questionnaire, and Beck Depression Inventory. Thorough descriptive-analytical research was conducted using the Spearman correlation, multiple linear regression, and structural equation modeling. Upper limb dexterity was more closely related to EDSS score than lower limb speed (r = 0.43 vs 0.29, R 2 = 0.38) and was greatest in patients with EDSS scores less than 5 (P < .01). Moreover, upper limb dexterity was negatively associated with EDSS score and the MusiQoL questionnaire (rS = -0.557 to -0.321, P < .05). The correlation that depression has with upper limb dexterity loss was higher than the one it has with lower limb speed (0.098 vs 0.066, t > 1.96). Upper limb dexterity is associated with global disability, depression, and health-related quality of life. We advocate for the assessment of upper limb dexterity in patients with MS to adopt a better approach to their functional impairment.

Psychophysical Health Factors and Its Correlations in Elderly Wheelchair Users Who Live in Nursing Homes.

Background: The aging is a multi-faceted process comprising both—the physical and mental alterations. Thus, the aim of the study was to evaluate the variables affecting the psychophysical state of the elderly people using wheelchairs and living in nursing homes (NH). Methods: 165 older wheelchair users were included in the study after meeting the inclusion criteria and expressing written consent. The assessment involved cognitive functioning, depression, body balance and flexibility, lung capacity and upper limbs dexterity, strenght and endurance. The results showed negative correlation between depression and balance, upper limb dexterity and endurance and shoulder flexion. A positive correlation between cognitive functioning and balance, upper limb dexterity, strenght and endurance, lung capacity and joint mobility was determined. Also, the study proved positive correlation between daily functioning and functional fitness, muscle strength and endurance, body flexibility, joint mobility. The regression analysis showed that better scores in balance test and joint mobility implied with higher scores in cognitive functioning. The most important determinants of functional fitness were balance, hand grip strenght and joint mobility. Conclusion: The future study should be focused on developing interventions aimed at senior wheelchair users living in NHs to prevent the deterioration of their mental and physical fitness.

Leap motion controlled video game-based therapy for upper limb rehabilitation in patients with Parkinson\u2019s disease: a feasibility study

BackgroundNon-immersive video games are currently being used as technological rehabilitation tools for individuals with Parkinson’s disease (PD). The aim of this feasibility study was to evaluate the effectiveness of the Leap Motion Controller® (LMC) system used with serious games designed for the upper limb (UL), as well as the levels of satisfaction and compliance among patients in mild-to-moderate stages of the disease.MethodsA non-probabilistic sampling of non-consecutive cases was performed. 23 PD patients, in stages II-IV of the Hoehn & Yahr scale, were randomized into two groups: an experimental group (n = 12) who received treatment based on serious games designed by the research team using the LMC system for the UL, and a control group (n = 11) who received a specific intervention for the UL. Grip muscle strength, coordination, speed of movements, fine and gross UL dexterity, as well as satisfaction and compliance, were assessed in both groups pre-treatment and post-treatment.ResultsWithin the experimental group, significant improvements were observed in all post-treatment assessments, except for Box and Blocks test for the less affected side. Clinical improvements were observed for all assessments in the control group. Statistical intergroup analysis showed significant improvements in coordination, speed of movements and fine motor dexterity scores on the more affected side of patients in the experimental group.ConclusionsThe LMC system and the serious games designed may be a feasible rehabilitation tool for the improvement of coordination, speed of movements and fine UL dexterity in PD patients. Further studies are needed to confirm these preliminary findings.

Cerebellar transcranial direct current stimulation in spinocerebellar ataxia type 3 (SCA3-tDCS): rationale and protocol of a randomized, double-blind, sham-controlled study

BackgroundSpinocerebellar ataxia type 3 (SCA3) is the most common subtype among the autosomal dominant cerebellar ataxias, a group of neurodegenerative disorders for which currently no disease-specific therapy is available. Evidence-based options for symptomatic treatment of ataxia are also limited. Recent investigations in a heterogeneous group of hereditary and acquired ataxias showed promising, prolonged effects of a two-week course with daily sessions of cerebellar anodal transcranial direct current stimulation (tDCS) on ataxia severity, gait speed, and upper limb dexterity. The aim of the SCA3-tDCS study is to further examine whether tDCS improves ataxia severity and various (cerebellar) non-motor symptoms in a homogeneous cohort of SCA3 patients and to explore the time course of these effects.Methods/designAn investigator-initiated, double-blind, randomized, sham-controlled, single-center trial will be conducted. Twenty mildly to moderately affected SCA3 patients (Scale for the Assessment and Rating of Ataxia score between 3 and 20) will be included and randomly assigned in a 1:1 ratio to either cerebellar anodal tDCS or sham cerebellar tDCS. Patients, investigators, and outcome assessors are unaware of treatment allocation. Cerebellar tDCS (20 min, 2 mA, ramp-up and down periods of 30 s each) will be delivered over ten sessions, distributed in two groups of five consecutive days with a two-day break in between. Outcomes are assessed after a single session of tDCS, after the tenth stimulation (T1), and after three, six, and twelve months. The primary outcome measure is the absolute change of the SARA score between baseline and T1. In addition, effects on a variety of other motor and neuropsychological functions in which the cerebellum is known to be involved will be evaluated using quantitative motor tests, static posturography, neurophysiological measurements, cognitive assessment, and questionnaires.DiscussionThe results of this study will inform us whether repeated sessions of cerebellar anodal tDCS benefit SCA3 patients and whether this form of non-invasive stimulation might be a novel therapeutic approach to consider in a neurorehabilitation setting. Combined with two earlier controlled trials, a positive effect of the SCA3-tDCS study will encourage implementation of this intervention and stimulate further research in other SCAs and heredodegenerative ataxias.Trial registrationNL7321, registered October 8, 2018.

Multidomain Geriatric Screen and Physical Fitness Assessment Identify Prefrailty/Frailty and Potentially Modifiable Risk Factors in Community-Dwelling Older Adults

Frailty begins in middle life and manifests as a decline in functional fitness. We described a model for community frailty screening and factors associated with prefrailty and frailty and fitness measures to distinguish prefrail/frail from robust older adults. We also compared the Fatigue, Resistance, Ambulation, Illnesses and Loss of weight (FRAIL) scale against Fried frailty phenotype and Frailty Index (FI). Community-dwelling adults ≥55 years old were designated robust, prefrail or frail using FRAIL. The multidomain geriatric screen included social profiling and cognitive, psychological and nutritional assessments. Physical fitness assessments included flexibility, grip strength, upper limb dexterity, lower body strength and power, tandem and dynamic balance and cardiorespiratory endurance. In 135 subjects, 99 (73.3%) were robust, 34 (25.2%) were prefrail and 2 (1.5%) were frail. After adjusting for age and sex, depression (odds ratio [OR], 2.90; 95% confidence interval [CI], 1.05-7.90; P = 0.040) and malnutrition (OR, 6.07; 95% CI, 2.52-14.64; P <0.001) were independently associated with prefrailty/frailty. Prefrail/frail participants had significantly poorer performance in upper limb dexterity (P = 0.030), lower limb power (P = 0.003), tandem and dynamic balance (P = 0.031) and endurance (P = 0.006). Except for balance and flexibility, all fitness measures differentiated prefrail/frail from robust women. In men, only lower body strength was significantly associated with frailty. Area under receiver operating characteristic curves for FRAIL against FI and Fried were 0.808 (0.688-0.927, P <0.001) and 0.645 (0.546-0.744, P = 0.005), respectively. Mood and nutrition are targets in frailty prevention. Physical fitness declines early in frailty and manifests differentially in both genders.

Clinical spectrum and importance of evaluation systems in degenerative cervical myeloradiculopathy

Degenerative cervical myelopathy includes facet joint arthropathy and/or intervertebral disc prolapse, as well as aberration (hypertrophy, calcification, or ossification) in the ligamentum flavum, and/or posterior longitudinal ligament. Cervical spondylotic myelopathy and ossification of posterior longitudinal ligament are two major conditions under this spectrum. Patients with degenerative changes of the cervical spine can present with wide spectrum of symptoms and signs ranging from axial neck pain, radiculopathy or myelopathy. A combination of history, physical examination, and provocative tests such as Spurling's sign, shoulder abduction test, neck distraction test, Valsalva maneuver, Elvey's upper limb tension/brachial plexus tension test increase the likelihood of diagnosis of cervical radiculopathy. Myelopathy can manifest in the early stage as subtle changes in the upper limb dexterity or mild walking difficulty and in late stage with severe spasticity and flexor spasms. Clinicians are increasingly using quantitative or semi-quantitative scales of neurological impairment. However, there is no gold standard evaluation systems that can reliably assess disease severity.

Effect of Subthalamic Deep Brain Stimulation on Upper Limb Dexterity in Patients with Parkinson Disease

The efficacy of deep brain stimulation (DBS) of the subthalamic nucleus (STN) on dexterity remains controversial despite its recognition as an effective strategy for Parkinson disease. The present study investigated the efficacy of STN-DBS for ameliorating bradykinesia and dexterity compared with dopaminergic medications. Part III of the Unified Parkinson's Disease Rating Scale was used for the evaluation of bradykinesia, whereas the Purdue Pegboard Test and the Box and Block test were selected for dexterity. Our findings indicate that bradykinesia is significantly improved with both DBS and dopaminergic medication, whereas dexterity is improved only with DBS. Dopaminergic medication did not show a satisfactory efficacy on dexterity, and there was little synergistic effect of dopaminergic medication and STN-DBS for improving dexterity associated with Parkinson disease. Our results suggest that DBS is potentially more effective than dopaminergic medications for improving dexterity. The disparities in efficacy for bradykinesia and dexterity between DBS and dopaminergic medication hint at the potential mechanisms of STN-DBS. We speculate that DBS follows at least 2 different mechanisms for improving parkinsonian symptoms: 1) the dopaminergic system, primarily for the improvement of bradykinesia and 2) the nondopaminergic system, for the improvement of dexterity. This hypothesis requires further verification and investigation.

Taxonomy based analysis of force exchanges during object grasping and manipulation.

The flexibility of the human hand in object manipulation is essential for daily life activities, but remains relatively little explored with quantitative methods. On the one hand, recent taxonomies describe qualitatively the classes of hand postures for object grasping and manipulation. On the other hand, the quantitative analysis of hand function has been generally restricted to precision grip (with thumb and index opposition) during lifting tasks. The aim of the present study is to fill the gap between these two kinds of descriptions, by investigating quantitatively the forces exerted by the hand on an instrumented object in a set of representative manipulation tasks. The object was a parallelepiped object able to measure the force exerted on the six faces and its acceleration. The grasping force was estimated from the lateral force and the unloading force from the bottom force. The protocol included eleven tasks with complementary constraints inspired by recent taxonomies: four tasks corresponding to lifting and holding the object with different grasp configurations, and seven to manipulating the object (rotation around each of its axis and translation). The grasping and unloading forces and object rotations were measured during the five phases of the actions: unloading, lifting, holding or manipulation, preparation to deposit, and deposit. The results confirm the tight regulation between grasping and unloading forces during lifting, and extend this to the deposit phase. In addition, they provide a precise description of the regulation of force exchanges during various manipulation tasks spanning representative actions of daily life. The timing of manipulation showed both sequential and overlapping organization of the different sub-actions, and micro-errors could be detected. This phenomenological study confirms the feasibility of using an instrumented object to investigate complex manipulative behavior in humans. This protocol will be used in the future to investigate upper-limb dexterity in patients with sensory-motor impairments.