GABA levels are decreased after stroke and GABA changes during rehabilitation correlate with motor improvement.

TitleGABA levels are decreased after stroke and GABA changes during rehabilitation correlate with motor improvement.
Publication TypeJournal Article
Year of Publication2015
AuthorsBlicher JUdby, Near J, Næss-Schmidt E, Stagg CJ, Johansen-Berg H, Nielsen JFeldbæk, Østergaard L, Ho Y-CLynn
JournalNeurorehabil Neural Repair
Volume29
Issue3
Pagination278-86
Date Published2015 Mar-Apr
ISSN1552-6844
KeywordsAdult, Aged, Exercise Therapy, Female, gamma-Aminobutyric Acid, Humans, Magnetic Resonance Spectroscopy, Male, Middle Aged, Motor Activity, Motor Cortex, Recovery of Function, Stroke
Abstract

BACKGROUND AND OBJECTIVE: γ-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.

DOI10.1177/1545968314543652
Alternate JournalNeurorehabil Neural Repair
PubMed ID25055837
Grant List090955 / / Wellcome Trust / United Kingdom
/ / Wellcome Trust / United Kingdom

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  • Brain imaging centre