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

Tretriluxana J, Kantak S, Tretriluxana S, Wu AD, Fisher BE - Stroke Res Treat (2015)

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Physical Therapy, Mahidol University, Nakhon Pathom 73170, Thailand.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus

Kinematic parameters of the transport phase for the small object (left) and the large object (right) pre (—) and post (- - -) each TMS condition. (a) Effect on total movement time. (b) Effect on peak transport velocity. (c) Effect on time of peak transport velocity. ∗ indicates a significant interaction between the TMS condition and time. Error bar = SD.
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fig3: Kinematic parameters of the transport phase for the small object (left) and the large object (right) pre (—) and post (- - -) each TMS condition. (a) Effect on total movement time. (b) Effect on peak transport velocity. (c) Effect on time of peak transport velocity. ∗ indicates a significant interaction between the TMS condition and time. Error bar = SD.

Mentions: Figure 2 illustrates representative subject data for the effect of sham and real rTMS on transport velocity for small and large objects. Following real rTMS, but not sham TMS, reach-to-grasp movements were faster for both small and large objects. However, the effects of LF-rTMS on improvements in movement time were statistically significant only for the small object (Figure 3). There was a significant reduction in the total movement time for the small object following real rTMS, but not sham rTMS (Figure 3(a), left column, TMS condition (real, sham) × time (pre, post) interaction, F(1,16) = 12.701, p = 0.004). Although a similar trend was observed for the larger object (Figure 3(a), right column), the effect was not statistically significant. Compared to sham, real rTMS did not significantly affect peak transport velocity and time of peak transport velocity for either the small or the large object (Figures 3(b) and 3(c)).


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

Tretriluxana J, Kantak S, Tretriluxana S, Wu AD, Fisher BE - Stroke Res Treat (2015)

Kinematic parameters of the transport phase for the small object (left) and the large object (right) pre (—) and post (- - -) each TMS condition. (a) Effect on total movement time. (b) Effect on peak transport velocity. (c) Effect on time of peak transport velocity. ∗ indicates a significant interaction between the TMS condition and time. Error bar = SD.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4664821&req=5

fig3: Kinematic parameters of the transport phase for the small object (left) and the large object (right) pre (—) and post (- - -) each TMS condition. (a) Effect on total movement time. (b) Effect on peak transport velocity. (c) Effect on time of peak transport velocity. ∗ indicates a significant interaction between the TMS condition and time. Error bar = SD.
Mentions: Figure 2 illustrates representative subject data for the effect of sham and real rTMS on transport velocity for small and large objects. Following real rTMS, but not sham TMS, reach-to-grasp movements were faster for both small and large objects. However, the effects of LF-rTMS on improvements in movement time were statistically significant only for the small object (Figure 3). There was a significant reduction in the total movement time for the small object following real rTMS, but not sham rTMS (Figure 3(a), left column, TMS condition (real, sham) × time (pre, post) interaction, F(1,16) = 12.701, p = 0.004). Although a similar trend was observed for the larger object (Figure 3(a), right column), the effect was not statistically significant. Compared to sham, real rTMS did not significantly affect peak transport velocity and time of peak transport velocity for either the small or the large object (Figures 3(b) and 3(c)).

Bottom Line: 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.

View Article: PubMed Central - PubMed

Affiliation: Faculty of Physical Therapy, Mahidol University, Nakhon Pathom 73170, Thailand.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus