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Effects of brain polarization on reaction times and pinch force in chronic stroke.

Hummel FC, Voller B, Celnik P, Floel A, Giraux P, Gerloff C, Cohen LG - BMC Neurosci (2006)

Bottom Line: Previous studies showed that anodal transcranial DC stimulation (tDCS) applied to the primary motor cortex of the affected hemisphere (M1affected hemisphere) after subcortical stroke transiently improves performance of complex tasks that mimic activities of daily living (ADL).It is not known if relatively simpler motor tasks are similarly affected.Anodal tDCS shortened reaction times and improved pinch force in the paretic hand relative to Sham stimulation, an effect present in patients with higher impairment. tDCS of M1affected hemisphere can modulate performance of motor tasks simpler than those previously studied, a finding that could potentially benefit patients with relatively higher impairment levels.

View Article: PubMed Central - HTML - PubMed

Affiliation: Human Cortical Physiology Section and Stroke Neurorehabilitation Clinic, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA. f.hummel@uke.uni-hamburg.de <f.hummel@uke.uni-hamburg.de>

ABSTRACT

Background: Previous studies showed that anodal transcranial DC stimulation (tDCS) applied to the primary motor cortex of the affected hemisphere (M1affected hemisphere) after subcortical stroke transiently improves performance of complex tasks that mimic activities of daily living (ADL). It is not known if relatively simpler motor tasks are similarly affected. Here we tested the effects of tDCS on pinch force (PF) and simple reaction time (RT) tasks in patients with chronic stroke in a double-blind cross-over Sham-controlled experimental design.

Results: Anodal tDCS shortened reaction times and improved pinch force in the paretic hand relative to Sham stimulation, an effect present in patients with higher impairment.

Conclusion: tDCS of M1affected hemisphere can modulate performance of motor tasks simpler than those previously studied, a finding that could potentially benefit patients with relatively higher impairment levels.

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Related in: MedlinePlus

(A) Effects of Sham stimulation on RT compared to No stimulation. Reaction times were comparable during Sham stimulation and No stimulation with slight slowing of reaction times during POST compared to BASE. (B) Effects of Sham stimulation on PF compared to No stimulation Forces were comparable during Sham stimulation and No stimulation with slight decrease of pinch force during POST compared to BASE.
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Figure 4: (A) Effects of Sham stimulation on RT compared to No stimulation. Reaction times were comparable during Sham stimulation and No stimulation with slight slowing of reaction times during POST compared to BASE. (B) Effects of Sham stimulation on PF compared to No stimulation Forces were comparable during Sham stimulation and No stimulation with slight decrease of pinch force during POST compared to BASE.

Mentions: To determine if relatively slower RT and mild decrement in PF during Sham were a consequence of the 30 sec application of tDCS, we compared effects of Sham (30 sec tDCS, see Methods) with no stimulation (n = 4). Both Sham and no stimulation elicited comparable trends towards slightly longer RT and weaker PF (Fig. 4; RT: BaseNo Stimulation = 240.9 ± 16.0 N, PostNo Stimulation = 272.6 ± 31.3 N and BaseSham = 257.2 ± 19.5 N, PostSham = 281.3 ± 24.0 N; PF: BaseNo Stimulation = 75.8 ± 22.6 N, PostNo Stimulation = 76.16 ± 25.1 N and BaseSham = 74.8 ± 25.0 N, PostSham = 73.9 ± 23.9 N) consistent with the independence of these effects from the 30 sec tDCS application during Sham.


Effects of brain polarization on reaction times and pinch force in chronic stroke.

Hummel FC, Voller B, Celnik P, Floel A, Giraux P, Gerloff C, Cohen LG - BMC Neurosci (2006)

(A) Effects of Sham stimulation on RT compared to No stimulation. Reaction times were comparable during Sham stimulation and No stimulation with slight slowing of reaction times during POST compared to BASE. (B) Effects of Sham stimulation on PF compared to No stimulation Forces were comparable during Sham stimulation and No stimulation with slight decrease of pinch force during POST compared to BASE.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC1636653&req=5

Figure 4: (A) Effects of Sham stimulation on RT compared to No stimulation. Reaction times were comparable during Sham stimulation and No stimulation with slight slowing of reaction times during POST compared to BASE. (B) Effects of Sham stimulation on PF compared to No stimulation Forces were comparable during Sham stimulation and No stimulation with slight decrease of pinch force during POST compared to BASE.
Mentions: To determine if relatively slower RT and mild decrement in PF during Sham were a consequence of the 30 sec application of tDCS, we compared effects of Sham (30 sec tDCS, see Methods) with no stimulation (n = 4). Both Sham and no stimulation elicited comparable trends towards slightly longer RT and weaker PF (Fig. 4; RT: BaseNo Stimulation = 240.9 ± 16.0 N, PostNo Stimulation = 272.6 ± 31.3 N and BaseSham = 257.2 ± 19.5 N, PostSham = 281.3 ± 24.0 N; PF: BaseNo Stimulation = 75.8 ± 22.6 N, PostNo Stimulation = 76.16 ± 25.1 N and BaseSham = 74.8 ± 25.0 N, PostSham = 73.9 ± 23.9 N) consistent with the independence of these effects from the 30 sec tDCS application during Sham.

Bottom Line: Previous studies showed that anodal transcranial DC stimulation (tDCS) applied to the primary motor cortex of the affected hemisphere (M1affected hemisphere) after subcortical stroke transiently improves performance of complex tasks that mimic activities of daily living (ADL).It is not known if relatively simpler motor tasks are similarly affected.Anodal tDCS shortened reaction times and improved pinch force in the paretic hand relative to Sham stimulation, an effect present in patients with higher impairment. tDCS of M1affected hemisphere can modulate performance of motor tasks simpler than those previously studied, a finding that could potentially benefit patients with relatively higher impairment levels.

View Article: PubMed Central - HTML - PubMed

Affiliation: Human Cortical Physiology Section and Stroke Neurorehabilitation Clinic, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892, USA. f.hummel@uke.uni-hamburg.de <f.hummel@uke.uni-hamburg.de>

ABSTRACT

Background: Previous studies showed that anodal transcranial DC stimulation (tDCS) applied to the primary motor cortex of the affected hemisphere (M1affected hemisphere) after subcortical stroke transiently improves performance of complex tasks that mimic activities of daily living (ADL). It is not known if relatively simpler motor tasks are similarly affected. Here we tested the effects of tDCS on pinch force (PF) and simple reaction time (RT) tasks in patients with chronic stroke in a double-blind cross-over Sham-controlled experimental design.

Results: Anodal tDCS shortened reaction times and improved pinch force in the paretic hand relative to Sham stimulation, an effect present in patients with higher impairment.

Conclusion: tDCS of M1affected hemisphere can modulate performance of motor tasks simpler than those previously studied, a finding that could potentially benefit patients with relatively higher impairment levels.

Show MeSH
Related in: MedlinePlus