Shaping Early Reorganization of Neural Networks Promotes Motor Function after Stroke

• Published in: Cerebral cortex (New York, N.Y. 1991) N.Y. 1991), 2016-06, Vol.26 (6), p.2882-2894
• Main Authors: Volz, L J, Rehme, A K, Michely, J, Nettekoven, C, Eickhoff, S B, Fink, G R, Grefkes, C
• Format: Article
• Language: English
• Subjects: Aged; Aged, 80 and over; Arm - physiopathology; Female; Hand Strength - physiology; Humans; Inpatients; Magnetic Resonance Imaging; Male; Motor Cortex - diagnostic imaging; Motor Cortex - physiopathology; Movement Disorders - diagnostic imaging; Movement Disorders - etiology; Movement Disorders - physiopathology; Movement Disorders - therapy; Neural Pathways - diagnostic imaging; Neural Pathways - physiopathology; Neuronal Plasticity - physiology; Physical Therapy Modalities; Recovery of Function - physiology; Rest; Single-Blind Method; Stroke - complications; Stroke - diagnostic imaging; Stroke - physiopathology; Stroke - therapy; Transcranial Magnetic Stimulation - methods; Treatment Outcome
• ISSN: 1047-3211; 1460-2199
• DOI: 10.1093/cercor/bhw034

Neural plasticity is a major factor driving cortical reorganization after stroke. We here tested whether repetitively enhancing motor cortex plasticity by means of intermittent theta-burst stimulation (iTBS) prior to physiotherapy might promote recovery of function early after stroke. Functional magnetic resonance imaging (fMRI) was used to elucidate underlying neural mechanisms. Twenty-six hospitalized, first-ever stroke patients (time since stroke: 1-16 days) with hand motor deficits were enrolled in a sham-controlled design and pseudo-randomized into 2 groups. iTBS was administered prior to physiotherapy on 5 consecutive days either over ipsilesional primary motor cortex (M1-stimulation group) or parieto-occipital vertex (control-stimulation group). Hand motor function, cortical excitability, and resting-state fMRI were assessed 1 day prior to the first stimulation and 1 day after the last stimulation. Recovery of grip strength was significantly stronger in the M1-stimulation compared to the control-stimulation group. Higher levels of motor network connectivity were associated with better motor outcome. Consistently, control-stimulated patients featured a decrease in intra- and interhemispheric connectivity of the motor network, which was absent in the M1-stimulation group. Hence, adding iTBS to prime physiotherapy in recovering stroke patients seems to interfere with motor network degradation, possibly reflecting alleviation of post-stroke diaschisis.