Ruud W. Selles

Motor Recovery and Cortical Reorganization After Mirror Therapy in Chronic Stroke Patients A Phase II Randomized Controlled Trial

Objective. To evaluate for any clinical effects of home-based mirror therapy and subsequent cortical reorganization in patients with chronic stroke with moderate upper extremity paresis. Methods. A total of 40 chronic stroke patients (mean time post .onset, 3.9 years) were randomly assigned to the mirror group (n = 20) or the control group (n = 20) and then joined a 6-week training program. Both groups trained once a week under supervision of a physiotherapist at the rehabilitation center and practiced at home 1 hour daily, 5 times a week. The primary outcome measure was the Fugl-Meyer motor assessment (FMA). The grip force, spasticity, pain, dexterity, hand-use in daily life, and quality of life at baseline—posttreatment and at 6 months—were all measured by a blinded assessor. Changes in neural activation patterns were assessed with functional magnetic resonance imaging (fMRI) at baseline and posttreatment in an available subgroup (mirror, 12; control, 9). Results. Posttreatment, the FMA improved more in the mirror than in the control group (3.6 ± 1.5, P < .05), but this improvement did not persist at follow-up. No changes were found on the other outcome measures (all Ps >.05). fMRI results showed a shift in activation balance within the primary motor cortex toward the affected hemisphere in the mirror group only (weighted laterality index difference 0.40 ± 0.39, P < .05). Conclusion. This phase II trial showed some effectiveness for mirror therapy in chronic stroke patients and is the first to associate mirror therapy with cortical reorganization. Future research has to determine the optimum practice intensity and duration for improvements to persist and generalize to other functional domains.

Disorders in trunk rotation during walking in patients with low back pain: a dynamical systems approach

OBJECTIVE (1) To introduce an evaluation tool for the assessment of walking disorders in low back pain patients. (2) To investigate whether walking patterns in low back pain patients are different from those of control subjects. DESIGN Relative phase measures of movement coordination are applied in the assessment of trunk function in a small group of patients with non-specific low back pain and in control subjects. BACKGROUND Normal subjects change the coordination of pelvic and thoracic rotations from an in-phase to an out-of-phase pattern with increasing walking speed. Low back pain patients may have a reduced ability to counter rotate pelvis and thorax at higher walking speeds (from 1.0 m/s onwards) as a result of hyperstable coordination patterns. METHODS Six patients with non-specific low back pain and six healthy control subjects walked on a treadmill at comfortable walking speeds and during a systematic variation of the treadmill velocity. Coordination of arm and leg movements as well as of pelvic and thoracic rotations was analyzed using a relative phase algorithm. RESULTS AND CONCLUSIONS The comfortable walking speed was reduced in the patient group. In contrast to the control subjects, four of the six patients were not able to establish an out-of-phase coordination pattern between thorax and pelvis at higher walking speeds. This coincided with an increased stability of movement coordination, indicating guarded behavior. In addition, an increased asymmetry between the phase-relations of left and right side of the body was found in some of the patients.

Development and validation of ultrasound speckle tracking to quantify tendon displacement

Ultrasound can be used to study tendon movement. However, measurement of tendon movement is mostly based on manual tracking of anatomical landmarks such as the musculo-tendinous junction, limiting the applicability to a small number of muscle-tendon units. The aim of this study was to quantify tendon displacement without anatomical landmarks using a speckle tracking algorithm optimized for tendons in long B-mode image sequences. A dedicated two-dimensional multi-kernel block-matching scheme with subpixel motion estimation was devised to handle large displacements over long sequences. The accuracy of the tracking on porcine tendons was evaluated during different displacements and velocities. Subsequently, the accuracy of tracking the flexor digitorum superficialis (FDS) of a human cadaver hand was evaluated. Finally, the in-vivo accuracy of the tendon tracking was determined by measuring the movement of the FDS at the wrist level. For the porcine experiment and the human cadaver arm experiment tracking errors were, on average, 0.08 and 0.05mm, respectively (1.3% and 1.0%). For the in-vivo experiment the tracking error was, on average, 0.3mm (1.6%). This study demonstrated that our dedicated speckle tracking can quantify tendon displacement at different physiological velocities without anatomical landmarks with high accuracy. The technique allows tracking over large displacements and in a wider range of tendons than by using anatomical landmarks.

Automated estimation of initial and terminal contact timing using accelerometers; development and validation in transtibial amputees and controls

The aim of this study was to develop and validate an automated accelerometry-based system for estimating initial contact (IC) and terminal contact (TC) timing information from walking patterns of healthy control subjects and transtibial amputees that can be used in daily life with minimal interference of researchers. Subjects were instrumented with two uniaxial accelerometers just below the knee while synchronized ground reaction force (GRF) recordings were used as reference measurements. An automated multiphase algorithm was developed to estimate the time of IC and TC in the acceleration signals of five healthy subjects and two transtibial amputees walking at different walking speeds. The accuracy of the detection algorithm in ten control subjects and eight transtibial amputees indicated mean errors ranging between 0.013 and 0.034 s for the TC and IC timing, with 95% confidence interval of the individual step errors ranging between -0.062 and 0.115 s. Correlation coefficients between the estimated stance phase duration and GRF data were 0.98 and 0.97 for controls and amputees, respectively. We concluded that IC and TC can be accurately and easily measured using this system in both healthy subjects and transtibial amputees walking at different walking speeds. The system can be used in clinical situations or gait labs as well as during daily life.

Mirror-Induced Visual Illusion of Hand Movements: A Functional Magnetic Resonance Imaging Study

OBJECTIVE To identify neural networks associated with the use of a mirror to superimpose movement of 1 hand on top of a nonmoving contralateral hand (often referred to as mirror therapy or mirror-induced visual illusion). DESIGN A functional magnetic resonance imaging (fMRI) study of mirror-induced visual illusion of hand movements using a blocked design in a 1.5T magnetic resonance imaging scanner. Neural activation was compared in a no-mirror experiment and a mirror experiment. Both experiments consisted of blocks of finger tapping of the right hand versus rest. In the mirror experiment, movement of the left hand was simulated by mirror reflection of right hand movement. SETTING University medical center. PARTICIPANTS Eighteen healthy subjects. INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Differences in fMRI activation between the 2 experiments. RESULTS In the mirror experiment, we found supplementary activation compared with the no-mirror experiment in 2 visual areas: the right superior temporal gyrus (STG) and the right superior occipital gyrus. CONCLUSIONS In this study, we found 2 areas uniquely associated with the mirror-induced visual illusion of hand movements: the right STG and the right superior occipital gyrus. The STG is a higher-order visual region involved in the analysis of biological stimuli and is activated by observation of biological motion. The right superior occipital gyrus is located in the secondary visual cortex within the dorsal visual stream. In the literature, the STG has been linked with the mirror neuron system. However, we did not find activation within the frontoparietal mirror neuron system to support further a link with the mirror neuron system. Future studies are needed to explore the mechanism of mirror induced visual illusions in patient populations in more detail.

The neuronal correlates of mirror therapy: an fMRI study on mirror induced visual illusions in patients with stroke

Aim To investigate the neuronal basis for the effects of mirror therapy in patients with stroke. Methods 22 patients with stroke participated in this study. The authors used functional MRI to investigate neuronal activation patterns in two experiments. In the unimanual experiment, patients moved their unaffected hand, either while observing it directly (no-mirror condition) or while observing its mirror reflection (mirror condition). In the bimanual experiment, patients moved both hands, either while observing the affected hand directly (no-mirror condition) or while observing the mirror reflection of the unaffected hand in place of the affected hand (mirror condition). A two-factorial analysis with movement (activity vs rest) and mirror (mirror vs no mirror) as main factors was performed to assess neuronal activity resultant of the mirror illusion. Results Data on 18 participants were suitable for analysis. Results showed a significant interaction effect of movement×mirror during the bimanual experiment. Activated regions were the precuneus and the posterior cingulate cortex (p<0.05 false discovery rate). Conclusion In this first study on the neuronal correlates of the mirror illusion in patients with stroke, the authors showed that during bimanual movement, the mirror illusion increases activity in the precuneus and the posterior cingulate cortex, areas associated with awareness of the self and spatial attention. By increasing awareness of the affected limb, the mirror illusion might reduce learnt non-use. The fact that the authors did not observe mirror-related activity in areas of the motor or mirror neuron system questions popular theories that attribute the clinical effects of mirror therapy to these systems.

Economic impact of hand and wrist injuries: Health-care costs and productivity costs in a population-based study

BACKGROUND Injuries to the hand and wrist account for approximately 20% of patient visits to emergency departments and may impose a large economic burden. The purpose of this study was to estimate the total health-care costs and productivity costs of injuries to the hand and wrist and to compare them with other important injury groups in a nationwide study. METHODS Data were retrieved from the Dutch Injury Surveillance System, from the National Hospital Discharge Registry, and from a patient follow-up survey conducted between 2007 and 2008. Injury incidence, health-care costs, and productivity costs (due to absenteeism) were calculated by age group, sex, and different subgroups of injuries. An incidence-based cost model was used to estimate the health-care costs of injuries. Follow-up data on return to work rates were incorporated into the absenteeism model for estimating the productivity costs. RESULTS Hand and wrist injuries annually account for

Extensive percutaneous aponeurotomy and lipografting: A new treatment for dupuytren disease

740 million (in U.S. dollars) and rank first in the order of most expensive injury types, before knee and lower limb fractures (

Age-specific reliability of two grip-strength dynamometers when used by children.

562 million), hip fractures (

Trends in Wrist Fractures in Children and Adolescents, 1997–2009

532 million), and skull-brain injury (