Suradej Tretriluxana

Low frequency repetitive transcranial magnetic stimulation to the non-lesioned hemisphere improves paretic arm reach-to-grasp performance after chronic stroke

Purpose: To investigate the effect of inhibitory low frequency repetitive Transcranial Magnetic Stimulation (rTMS) applied to the non-lesioned hemisphere on kinematics and coordination of paretic arm reach-to-grasp (RTG) actions in individuals with stroke. Relevance: This study is designed as a phase I trial to determine the feasibility and efficacy of low frequency rTMS applied to the non-lesioned hemisphere for the recovery of reach-to-grasp actions in individuals with hemiparesis secondary to stroke. The results have important implications for the use of rTMS in parallel with complex paretic arm skill practice. Participants: Nine adults, anterior circulation unilateral stroke. Their average age was 59 years, the average time since stroke was 4.8 years. Method and analysis: Two TMS treatments were performed on two separate days: active rTMS and sham rTMS. Cortico-motor excitability (CE) of the non-lesioned hemisphere as well as RTG kinematics of the paretic hand as participants reached for a dowel of 1.2 cm in diameter was assessed before and after the rTMS treatments. In the active condition, rTMS was applied over the “hot spot” of the extensor digitorum communis muscle (EDC) in primary motor cortex (M1) of the non-lesioned hemisphere at 90% resting motor threshold. TMS pulses were delivered at 1 Hz for 20 min. In the sham condition, a sham coil was positioned similar to the active condition; TMS clicking noise was produced but no TMS pulse was delivered. Dependent measures: CE was measured as peak-to-peak amplitude of the motor evoked potential at 120% of resting motor threshold. RTG kinematics included movement time, peak transport velocity, peak aperture, time of peak transport velocity and time of peak aperture. RTG coordination was captured by cross correlation coefficient between transport velocity and grasp aperture size. Results: While 1 Hz rTMS applied over non-lesioned M1 significantly decreased the MEP amplitude of non-paretic EDC, sham TMS did not have a significant effect on MEP amplitude. Active rTMS significantly decreased total movement time and increased peak grasp aperture. There were no changes in peak transport velocity or the time of peak transport velocity or the time of peak aperture after application of active rTMS. Additionally, the participants completed RTG actions with a more coordinated pattern after undergoing active rTMS. Following sham TMS, there were no changes in CE, RTG kinematics or coordination. While there were no significant correlation between changes in cortico-motor excitability and RTG kinematics, the decrease in cortico-motor excitability of the non-lesioned hemisphere showed a strong correlation with an increase in cross-correlation coefficient. Conclusions and implications: The findings demonstrate the feasibility and efficacy of low frequency rTMS applied to the non-lesioned hemisphere for the recovery of reach-to-grasp actions in individuals with hemiparesis secondary to stroke. The inhibitory effect of low frequency rTMS resulted in improved paretic hand reach-to-grasp performance with faster movement time and more coordinated reach-to-grasp pattern. These results have important implications for the use of rTMS for stroke rehabilitation. Implications for Rehabilitation Low frequency repetitive transcranial magnetic stimulation (LF-rTMS) to the non-lesioned hemisphere improves paretic arm reach-to-grasp performance. The preliminary results have important implications for the use of LF-rTMS as conjunctive intervention for stroke rehabilitation.

Feasibility investigation of the Accelerated Skill Acquisition Program (ASAP): insights into reach-to-grasp coordination of individuals with postacute stroke.

Abstract Background: Skill acquisition, capacity building, and motivational enhancements are the basis of the Accelerated Skill Acquisition Program (ASAP) and form the foundation for effective incorporation of the paretic upper extremity into life activities. This is the first phase I trial to deliver ASAP during the postacute interval in mildly to moderately impaired stroke survivors and to include an assessment of paretic reach-to-grasp (RTG) coordination using RTG task and cross-correlation analyses. Methods: Two baseline and posttreatment evaluations consisted of RTG actions, the Wolf Motor Function Test (WMFT), and the Stroke Impact Scale (SIS). An individualized arm therapy program using ASAP principles was administered for a total of 30 hours, 2 hours per day, for 2 to 4 days per week over 5 weeks. Dependent measures were kinematics of RTG actions, RTG coordination, total time score of WMFT, and stroke recovery score of SIS. Results: All participants tolerated ASAP well, and none reported any adverse effects during or after the protocol. When the 2 baseline evaluations were compared, there were no changes in any RTG kinematics or RTG coordination. In contrast, after 30 hours of ASAP, total movement time and deceleration time of RTG actions markedly decreased, maximum reach (transport) velocity strikingly increased, and time of maximum aperture was accomplished later. Additionally, the maximal RTG correlation coefficient increased with a shorter associated time lag. A similar pattern was observed for the clinical outcome measures of WMFT and SIS. Conclusions: The findings demonstrate the feasibility of using an ASAP protocol for patients 1 to 3 months post stroke. Under ASAP, WMFT tasks and RTG actions were performed faster with higher peak transport velocity and a more coordinated RTG pattern. The next step is to determine whether the immediate gains in the skilled RTG actions persist 6 months alter.

Improvement in Paretic Arm Reach-to-Grasp following Low Frequency Repetitive Transcranial Magnetic Stimulation Depends on Object Size: A Pilot Study

Introduction. Low frequency repetitive transcranial magnetic stimulation (LF-rTMS) delivered to the nonlesioned hemisphere has been shown to improve limited function of the paretic upper extremity (UE) following stroke. The outcome measures have largely included clinical assessments with little investigation on changes in kinematics and coordination. To date, there is no study investigating how the effects of LF-rTMS are modulated by the sizes of an object to be grasped. Objective. To investigate the effect of LF-rTMS on kinematics and coordination of the paretic hand reach-to-grasp (RTG) for two object sizes in chronic stroke. Methods. Nine participants received two TMS conditions: real rTMS and sham rTMS conditions. Before and after the rTMS conditions, cortico-motor excitability (CE) of the nonlesioned hemisphere, RTG kinematics, and coordination was evaluated. Object sizes were 1.2 and 7.2 cm in diameter. Results. Compared to sham rTMS, real rTMS significantly reduced CE of the non-lesioned M1. While rTMS had no effect on RTG action for the larger object, real rTMS significantly improved movement time, aperture opening, and RTG coordination for the smaller object. Conclusions. LF-rTMS improves RTG action for only the smaller object in chronic stroke. The findings suggest a dissociation between effects of rTMS on M1 and task difficulty for this complex skill.

A development of real-time fetal movement detector

Fetal Movement (FM) is a marker for evaluating wellbeing of the unborn baby. Naturally, pregnant women can sense any movement in her abdomen. However, there are two groups of women who may have degraded this sensing ability. A primigravida, a first time pregnant woman, may not be able to recognize the fetus movement. A working pregnant woman may be too busy to aware of her fetus responses. In this paper, a development of real-time fetus movement detector is presented. An air pressurized bag is designed to be wrapped around the abdomen of pregnant woman. It is connected to a pressure sensor in order to detect the force exerted against the uterus wall in any direction. The signal is processed before uploaded into internet cloud services for real-time monitoring and remote access.