85 research outputs found

    Bra.Di.P.O. and P.I.G.R.O.: Innovative Devices for Motor Learning Programs

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    Two mechatronics prototypes, useful for robotic neurotreatments and new clinical trainings, are here presented. P.I.G.R.O. (pneumatic interactive gait rehabilitation orthosis) is an active exoskeleton with an electropneumatic control. It imposes movements on lower limbs in order to produce in the patient’s brain proper motor cortex activation. Bra.Di.P.O. (brain discovery pneumatic orthosis) is an MR-compatible device, designed to improve fMRI (functional magnetic resonance imaging) analysis. The two devices are presented together because both are involved in the study of new robotic treatments of patients affected by ictus or brain stroke or in some motor learning experimental investigations carried out on healthy subjects

    Brain Areas Associated with Force Steadiness and Intensity During Isometric Ankle Dorsiflexion in Men and Women

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    Although maintenance of steady contractions is required for many daily tasks, there is little understanding of brain areas that modulate lower limb force accuracy. Functional magnetic resonance imaging was used to determine brain areas associated with steadiness and force during static (isometric) lower limb target-matching contractions at low and high intensities. Fourteen young adults (6 men and 8 women; 27.1 ± 9.1 years) performed three sets of 16-s isometric contractions with the ankle dorsiflexor muscles at 10, 30, 50, and 70 % of maximal voluntary contraction (MVC). Percent signal changes (PSCs, %) of the blood oxygenation level-dependent response were extracted for each contraction using region of interest analysis. Mean PSC increased with contraction intensity in the contralateral primary motor area (M1), supplementary motor area, putamen, pallidum cingulate cortex, and ipsilateral cerebellum (p \u3c 0.05). The amplitude of force fluctuations (standard deviation, SD) increased from 10 to 70 % MVC but relative to the mean force (coefficient of variation, CV %) was greatest at 10 % MVC. The CV of force was associated with PSC in the ipsilateral parietal lobule (r = −0.28), putamen (r = −0.29), insula (r = −0.33), and contralateral superior frontal gyrus (r = −0.33, p \u3c 0.05). There were minimal sex differences in brain activation across the isometric motor tasks indicating men and women were similarly motivated and able to activate cortical motor centers during static tasks. Control of steady lower limb contractions involves cortical and subcortical motor areas in both men and women and provides insight into key areas for potential cortical plasticity with impaired or enhanced leg function

    Simultaneous measurements of kinematics and fMRI: compatibility assessment and case report on recovery evaluation of one stroke patient

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    <p>Abstract</p> <p>Background</p> <p>Correlating the features of the actual executed movement with the associated cortical activations can enhance the reliability of the functional Magnetic Resonance Imaging (fMRI) data interpretation. This is crucial for longitudinal evaluation of motor recovery in neurological patients and for investigating detailed mutual interactions between activation maps and movement parameters.</p> <p>Therefore, we have explored a new set-up combining fMRI with an optoelectronic motion capture system, which provides a multi-parameter quantification of the performed motor task.</p> <p>Methods</p> <p>The cameras of the motion system were mounted inside the MR room and passive markers were placed on the subject skin, without any risk or encumbrance. The versatile set-up allows 3-dimensional multi-segment acquisitions including recording of possible mirror movements, and it guarantees a high inter-sessions repeatability.</p> <p>We demonstrated the integrated set-up reliability through compatibility tests. Then, an fMRI block-design protocol combined with kinematic recordings was tested on a healthy volunteer performing finger tapping and ankle dorsal- plantar-flexion. A preliminary assessment of clinical applicability and perspectives was carried out by pre- and post rehabilitation acquisitions on a hemiparetic patient performing ankle dorsal- plantar-flexion. For all sessions, the proposed method integrating kinematic data into the model design was compared with the standard analysis.</p> <p>Results</p> <p>Phantom acquisitions demonstrated the not-compromised image quality. Healthy subject sessions showed the protocols feasibility and the model reliability with the kinematic regressor. The patient results showed that brain activation maps were more consistent when the images analysis included in the regression model, besides the stimuli, the kinematic regressor quantifying the actual executed movement (movement timing and amplitude), proving a significant model improvement. Moreover, concerning motor recovery evaluation, after one rehabilitation month, a greater cortical area was activated during exercise, in contrast to the usual focalization associated with functional recovery. Indeed, the availability of kinematics data allows to correlate this wider area with a higher frequency and a larger amplitude of movement.</p> <p>Conclusions</p> <p>The kinematic acquisitions resulted to be reliable and versatile to enrich the fMRI images information and therefore the evaluation of motor recovery in neurological patients where large differences between required and performed motion can be expected.</p

    The Neural Correlates of Long-Term Carryover following Functional Electrical Stimulation for Stroke

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    Concurrent impact of bilateral multiple joint functional electrical stimulation and treadmill walking on gait and spasticity in post-stroke survivors: a pilot study

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    Background: Stroke causes multi-joint gait deficits, so a major objective of post-stroke rehabilitation is to regain normal gait function. Design and Setting: A case series completed at a neuroscience institute. Aim: The aim of the study was to determine the concurrent impact of functional electrical stimulation (FES) during treadmill walking on gait speed, knee extensors spasticity and ankle plantar flexors spasticity in post-stroke survivors. Participants: Six post-stroke survivors with altered gait patterns and ankle plantar flexors spasticity (4=male; age 56.8 ± 4.8 years; Body Mass Index (BMI) 26.2 ±4.3; since onset of stroke: 30.8 ±10.4 months; side of hemiplegia [L/R]: 3:3) were recruited. Intervention: Nine treatment sessions using FES bilaterally while walking on a treadmill. Main Outcome Measures: Primary outcome measures included the Modified Modified Ashworth Scale (MMAS), Timed Up and Go test (TUG), 10-m walking test, gait speed, and Functional ambulation category (FAC). Secondary outcome measures included the Step Length Test (SLT), and active range of motion (ROM) of the affected ankle and the knee. Measurements were taken at baseline (T0), at the end of last treatment (T1), and one month after the final treatment session (T2). Results: The TUG, 10-m walking test, gait speed, FAC, active ROM, and SLT all significantly improved following treatment (

    Optimization of proprioceptive stimulation for echo-planar and inverse magnetic resonance imaging

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    In echo-planar imaging (EPI), the optimal passive movement parameters (rate and duration) for studying proprioceptive brain responses are unknown. The aim of this thesis was to test the effect of stimulus rate on brain responses evoked by proprioceptive stimulation in EPI. In addition, we attempted to develop a measurement protocol for experiments focused on proprioception in ultrafast inverse magnetic resonance imaging (InI) and investigate the amplitude of blood oxygen level-dependent (BOLD) signal at varying stimulus duration. This experimental setup was supposed to be applied in future connectivity studies of the proprioceptive brain network. We found that the optimum rate for right index finger proprioceptive stimulation in EPI varies from 3 to 6 Hz. While we managed to sample the BOLD responses every 100 ms (a 20-fold increase in temporal resolution compared to EPI), the experimental design in InI is challenging due to methodological constraints. Thus, the appropriate stimulation parameters for InI still remain a topic for further research
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