[Show abstract][Hide abstract] ABSTRACT: In Motor Neglect (MN) syndrome, a specific impairment in non-congruent bimanual movements has been described. In the present case-control study, we investigated the neuro-functional correlates of this behavioral deficit. Two right-brain-damaged (RBD) patients, one with (MN+) and one without (MN−) MN, were evaluated by means of functional Magnetic Resonance Imaging (fMRI) in a bimanual Circles-Lines (CL) paradigm. Patients were requested to perform right-hand movements (lines-drawing) and, simultaneously, congruent (lines-drawing) or non-congruent (circles-drawing) left-hand movements. In the behavioral task, MN− patient showed a bimanual-coupling-effect, while MN+ patient did not. The fMRI study showed that in MN−, a fronto-parietal network, mainly involving the pre-supplementary motor area (pre-SMA) and the posterior parietal cortex (PPC), was significantly more active in non-congruent than in congruent conditions, as previously shown in healthy subjects. On the contrary, MN+ patient showed an opposite pattern of activation both in pre-SMA and in PPC. Within this fronto-parietal network, the pre-SMA is supposed to exert an inhibitory influence on the default coupling of homologous muscles, thus allowing the execution of non-congruent movements. In MN syndrome, the described abnormal pre-SMA activity supports the hypothesis that a failure to inhibit ipsilesional motor programs might determine a specific impairment of non-congruent movements.
Frontiers in Human Neuroscience 11/2015; 9. DOI:10.3389/fnhum.2015.00541 · 3.63 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Objectives:
Previous findings suggest that, in anosognosic patients, their illusory motor experience is based on a "normal" motor intention and planning for the paralyzed limbs. However, these studies involved proximal muscles (shoulder) that can be mediated by the ipsilateral (intact) cortex more than distal muscles (fingers). In the present study, we asked whether, in anosognosic patients, the spared motor intention for the paralyzed limb can go as far as to influence kinematic parameters of distal movements.
Six hemiplegic patients (1 with and 5 without anosognosia) were required to reach and grasp with both hands targets of the same or different size, attached to a plinth. Maximum grip aperture of the right (intact) hand was recorded using an infrared motion capture system. All patients were evaluated with a specific battery for anosognosia and different neurpsychological test.
In the patient affected by anosognosia for hemiplegia, the grip aperture of the healthy hand was influenced by the intended (but not executed) movement of the plegic hand when the patient was trying to reach to grasp targets of different size, F(2, 14) = 11.87, p < .001. Patients affected by hemiplegia (without anosognosia) didn't show any interference effect between the plegic and healthy hand even when they were asked to reach to grasp targets of different size.
Our results confirm the hypothesis that a spared intention-programming system within the contralateral (damaged) cortex can go as far as to influence distal kinematic parameters of the healthy hand of patients affected by anosognosia for hemiplegia. (PsycINFO Database Record
[Show abstract][Hide abstract] ABSTRACT: Background
Advances in technology are allowing for the production of several viable wearable robotic devices to assist with activities of daily living and with rehabilitation. One of the most pressing limitations to user satisfaction is the lack of consistency in motion between the user and the robotic device. The displacement between the robot and the body segment may not correspond because of differences in skin and tissue compliance, mechanical backlash, and/or incorrect fit.
This report presents the results of an analysis of relative displacement between the user’s hand and a wearable exoskeleton, the HX. HX has been designed to maximize comfort, wearability and user safety, exploiting chains with multiple degrees-of-freedom with a modular architecture. These appealing features may introduce several uncertainties in the kinematic performances, especially when considering the anthropometry, morphology and degree of mobility of the human hand. The small relative displacements between the hand and the exoskeleton were measured with a video-based motion capture system, while the user executed several different grips in different exoskeleton modes.
The analysis furnished quantitative results about the device performance, differentiated among device modules and test conditions. In general, the global relative displacement for the distal part of the device was in the range 0.5–1.5 mm, while within 3 mm (worse but still acceptable) for displacements nearest to the hand dorsum. Conclusions over the HX design principles have been drawn, as well as guidelines for future developments.
Journal of NeuroEngineering and Rehabilitation 10/2014; 11(1):147. DOI:10.1186/1743-0003-11-147 · 2.74 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Gait Analysis (GA) was demonstrated to change pre--surgical planning and improve gait outcomes in children with Cerebral Palsy. GA is often used also to assess walking capability of post--stroke subjects, although its influence in the clinical management of these patients has not yet been established.
European journal of physical and rehabilitation medicine 09/2014; 51(2). · 1.90 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The aim of the present study was to assess postural stabilization skill in adult subjects affected by Charcot-Marie-Tooth disease (CMT) type 1A. For this purpose Ground Reaction Force (GRF) was measured by means of a piezoelectric force platform during the Sit-To-Stand (STS) movement, until a steady state erect posture was achieved. Specific indexes to quantify Center of Mass acceleration, both during postural stabilization and during quiet standing, were computed using a mathematical model. Forty-seven CMT1A subjects were recruited for the study, and the control group was formed by forty-one age- and sex-matched healthy subjects.
The results show that CMT1A subjects are less stable than controls during the quiet stance. Greater difficulty (high values of Yinf, the final instability rate) to maintain erect posture appears to be mainly associated with plantar-flexor muscle weakness, rather than to damage of the proprioceptive system. The worst performances shown by CMT1A subjects in the stabilization phase (high values of I, the global index of postural stabilization performance) seem to be associated with reduced muscle strength and the loss of large sensory nerve fibres.
Distal muscle weakness appears to affect both postural stabilization and quiet erect posture. The presented protocol and the analysis of postural stabilization parameters provide useful information on CMT1A balance disorders.
[Show abstract][Hide abstract] ABSTRACT: Advanced rehabilitation strategies of the upper limb in stroke patients focus on the recovery of the most important daily activities. In this study we analyzed quantitatively and qualitatively the motor strategies employed by stroke patients when reaching and drinking from a glass. We enrolled 6 hemiparetic poststroke patients and 6 healthy subjects. Motion analysis of the task proposed (reaching for the glass, bringing it to the mouth, and putting it back on the table) with the affected limb was performed. Clinical assessment using the Fugl-Meyer Assessment for Upper Extremity was also included. During the reaching for the glass the patients showed a reduced arm elongation and trunk axial rotation due to motor deficit. For this reason, as observed, they carried out compensatory strategies which included trunk forward displacement and head movements. These preliminary data should be considered to address rehabilitation treatment. Moreover, the kinematic analysis protocol developed might represent an outcome measure of upper limb rehabilitation processes.
BioMed Research International 04/2014; 2014(12):636123. DOI:10.1155/2014/636123 · 1.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The ability to walk independently is a primary goal for rehabilitation after stroke. Gait analysis provides a great amount of valuable information, while functional magnetic resonance imaging (fMRI) offers a powerful approach to define networks involved in motor control. The present study reports a new methodology based on both fMRI and gait analysis outcomes in order to investigate the ability of fMRI to reflect the phases of motor learning before/after electromyographic biofeedback treatment: the preliminary fMRI results of a post stroke subject's brain activation, during passive and active ankle dorsal/plantarflexion, before and after biofeedback (BFB) rehabilitation are reported and their correlation with gait analysis data investigated.
A control subject and a post-stroke patient with chronic hemiparesis were studied. Functional magnetic resonance images were acquired during a block-design protocol on both subjects while performing passive and active ankle dorsal/plantarflexion. fMRI and gait analysis were assessed on the patient before and after electromyographic biofeedback rehabilitation treatment during gait activities. Lower limb three-dimensional kinematics, kinetics and surface electromyography were evaluated. Correlation between fMRI and gait analysis categorical variables was assessed: agreement/disagreement was assigned to each variable if the value was in/outside the normative range (gait analysis), or for presence of normal/diffuse/no activation of motor area (fMRI).
Altered fMRI activity was found on the post-stroke patient before biofeedback rehabilitation with respect to the control one. Meanwhile the patient showed a diffuse, but more limited brain activation after treatment (less voxels). The post-stroke gait data showed a trend towards the normal range: speed, stride length, ankle power, and ankle positive work increased. Preliminary correlation analysis revealed that consistent changes were observed both for the fMRI data, and the gait analysis data after treatment (R > 0.89): this could be related to the possible effects BFB might have on the central as well as on the peripheral nervous system.
Our findings showed that this methodology allows evaluation of the relationship between alterations in gait and brain activation of a post-stroke patient. Such methodology, if applied on a larger sample subjects, could provide information about the specific motor area involved in a rehabilitation treatment.
Journal of NeuroEngineering and Rehabilitation 04/2014; 11(1):53. DOI:10.1186/1743-0003-11-53 · 2.74 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Purpose:
In accordance with the Task Oriented Approach, clinicians need assessment procedures providing information on the execution of multiple tasks. Instrumented task assessment can add information regarding sensory-motor strategies, difficult to assess purely by clinical observation. It has been shown that People with Multiple Sclerosis (PwMS) have difficulties in maintaining upright balance, but little is known about their ability to achieve a stable posture after the execution of tasks related to activities of daily living. The aim of the present study was to assess postural stabilization in a population of PwMS.
Twenty Healthy Subjects (HS) and twenty PwMS were assessed in three tasks leading to a quiet erect posture: sit-to-stand, taking a step forward, bending forward. Antero-posterior ground reaction force was measured by a force platform and interpolated by a model providing information on the initial instability after task execution (Transitional_Sway), the time required to dissipate this initial instability (Stabilization_Time), and their stability in quiet upright posture (Static_Sway).
PwMS had statistically significant altered performance in comparison to HS: their instability after task execution (Transitional_Sway) was higher in bending and sit-to-stand (p < 0.05), their stabilization time (Stabilization_Time) was longer in bending and step forward (p < 0.05). Static_Sway was higher in all tasks (p < 0.05) indicating imbalance also in quiet upright posture.
Disability and Rehabilitation 03/2014; 36(26). DOI:10.3109/09638288.2014.904933 · 1.99 Impact Factor