Contralesional hemisphere control of the proximal paretic upper limb following stroke

Bradnam, LV; Stinear, CM; Barber, PA; Byblow, WD

Contralesional hemisphere control of the proximal paretic upper limb following stroke

Bradnam, LV

Stinear, CM Barber, PA Byblow, WD

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Publication Type:: Journal Article
Citation:: Cerebral Cortex, 2012, 22 (11), pp. 2662 - 2671
Issue Date:: 2012-11-01

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Field	Value	Language
dc.contributor.author	Bradnam, LV https://orcid.org/0000-0002-3067-0326	en_US
dc.contributor.author	Stinear, CM	en_US
dc.contributor.author	Barber, PA	en_US
dc.contributor.author	Byblow, WD	en_US
dc.date.issued	2012-11-01	en_US
dc.identifier.citation	Cerebral Cortex, 2012, 22 (11), pp. 2662 - 2671	en_US
dc.identifier.issn	1047-3211	en_US
dc.identifier.uri	http://hdl.handle.net/10453/114310
dc.description.abstract	Cathodal transcranial direct current stimulation (c-tDCS) can reduce excitability of neurons in primary motor cortex (M1) and may facilitate motor recovery after stroke. However, little is known about the neurophysiological effects of tDCS on proximal upper limb function. We hypothesized that suppression of contralesional M1 (cM1) excitability would produce neurophysiological effects that depended on the severity of upper limb impairment. Twelve patients with varying upper limb impairment after subcortical stroke were assessed on clinical scales of upper limb spasticity, impairment, and function. Magnetic resonance imaging was used to determine lesion size and fractional anisotropy (FA) within the posterior limbs of the internal capsules indicative of corticospinal tract integrity. Excitability within paretic M1 biceps brachii representation was determined from motor-evoked potentials during selective isometric tasks, after cM1 sham stimulation and after c-tDCS. These neurophysiological data indicate that c-tDCS improved selective proximal upper limb control for mildly impaired patients and worsened it for moderate to severely impaired patients. The direction of the neurophysiological after effects of c-tDCS was strongly related to upper limb spasticity, impairment, function, and FA asymmetry between the posterior limbs of the internal capsules. These results indicate systematic variation of cM1 for proximal upper limb control after stroke and that suppression of cM1 excitability is not a one size fits all approach. © 2012 The Author.	en_US
dc.relation.ispartof	Cerebral Cortex	en_US
dc.relation.isbasedon	10.1093/cercor/bhr344	en_US
dc.subject.classification	Experimental Psychology	en_US
dc.subject.mesh	Upper Extremity	en_US
dc.subject.mesh	Muscle, Skeletal	en_US
dc.subject.mesh	Motor Cortex	en_US
dc.subject.mesh	Humans	en_US
dc.subject.mesh	Muscle Spasticity	en_US
dc.subject.mesh	Paresis	en_US
dc.subject.mesh	Magnetic Resonance Imaging	en_US
dc.subject.mesh	Diffusion Magnetic Resonance Imaging	en_US
dc.subject.mesh	Electromyography	en_US
dc.subject.mesh	Regression Analysis	en_US
dc.subject.mesh	Cross-Over Studies	en_US
dc.subject.mesh	Electric Stimulation	en_US
dc.subject.mesh	Psychomotor Performance	en_US
dc.subject.mesh	Evoked Potentials, Motor	en_US
dc.subject.mesh	Image Processing, Computer-Assisted	en_US
dc.subject.mesh	Adult	en_US
dc.subject.mesh	Aged	en_US
dc.subject.mesh	Aged, 80 and over	en_US
dc.subject.mesh	Middle Aged	en_US
dc.subject.mesh	Female	en_US
dc.subject.mesh	Male	en_US
dc.subject.mesh	Transcranial Magnetic Stimulation	en_US
dc.subject.mesh	Functional Laterality	en_US
dc.subject.mesh	Stroke	en_US
dc.title	Contralesional hemisphere control of the proximal paretic upper limb following stroke	en_US
dc.type	Journal Article
utslib.citation.volume	11	en_US
utslib.citation.volume	22	en_US
utslib.for	1109 Neurosciences	en_US
utslib.for	1103 Clinical Sciences	en_US
utslib.for	1702 Cognitive Sciences	en_US
utslib.for	1701 Psychology	en_US
pubs.embargo.period	Not known	en_US
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Graduate School of Health
pubs.organisational-group	/University of Technology Sydney/Strength - CHT - Health Technologies
utslib.copyright.status	closed_access
pubs.issue	11	en_US
pubs.publication-status	Published	en_US
pubs.volume	22	en_US

Abstract:

Cathodal transcranial direct current stimulation (c-tDCS) can reduce excitability of neurons in primary motor cortex (M1) and may facilitate motor recovery after stroke. However, little is known about the neurophysiological effects of tDCS on proximal upper limb function. We hypothesized that suppression of contralesional M1 (cM1) excitability would produce neurophysiological effects that depended on the severity of upper limb impairment. Twelve patients with varying upper limb impairment after subcortical stroke were assessed on clinical scales of upper limb spasticity, impairment, and function. Magnetic resonance imaging was used to determine lesion size and fractional anisotropy (FA) within the posterior limbs of the internal capsules indicative of corticospinal tract integrity. Excitability within paretic M1 biceps brachii representation was determined from motor-evoked potentials during selective isometric tasks, after cM1 sham stimulation and after c-tDCS. These neurophysiological data indicate that c-tDCS improved selective proximal upper limb control for mildly impaired patients and worsened it for moderate to severely impaired patients. The direction of the neurophysiological after effects of c-tDCS was strongly related to upper limb spasticity, impairment, function, and FA asymmetry between the posterior limbs of the internal capsules. These results indicate systematic variation of cM1 for proximal upper limb control after stroke and that suppression of cM1 excitability is not a one size fits all approach. © 2012 The Author.

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http://hdl.handle.net/10453/114310