Article

Constraint-induced movement therapy. Gamma-Aminobutyric acid (GABA) is the dominant
inhibitory neurotransmitter in the brain and is important in motor learning. We
aimed to measure GABA content in primary motor cortex poststroke (using
GABA-edited magnetic resonance spectroscopy [MRS]) and in relation to motor
recovery during 2 weeks of constraint-induced movement therapy (CIMT). METHODS:
Twenty-one patients (3-12 months poststroke) and 20 healthy subjects were
recruited. Magnetic resonance imaging structural T1 and GABA-edited MRS were
performed at baseline and after CIMT, and once in healthy subjects. GABA:creatine
(GABA:Cr) ratio was measured by GABA-edited MRS. Motor function was measured
using Wolf Motor Function Test (WMFT). RESULTS: Baseline comparison between
stroke patients (n = 19) and healthy subjects showed a significantly lower
GABA:Cr ratio in stroke patients (P < .001) even after correcting for gray matter
content in the voxel (P < .01) and when expressing GABA relative to
N-acetylaspartic acid (NAA; P = .03). After 2 weeks of CIMT patients improved
significantly on WMFT, but no consistent change across the group was observed for
the GABA:Cr ratio (n = 17). However, the extent of improvement on WMFT correlated
significantly with the magnitude of GABA:Cr changes (P < .01), with decreases in
GABA:Cr ratio being associated with better improvements in motor function.
CONCLUSIONS: In patients 3 to 12 months poststroke, GABA levels are lower in the
primary motor cortex than in healthy subjects. The observed association between
GABA and recovery warrants further studies on the potential use of GABA MRS as a
biomarker in poststroke recovery.
CI - (c) The Author(s) 2014.

Langue : ANGLAIS