OBJECTIVE: Afferent input is proposed to mediate its effect on motor functions by modulating the excitability of the motor cortex. We aimed to clarify - in a longitudinal study - how afferent input affects motor cortex excitability after stroke and how it is associated with recovery of hand function. METHODS: The motor cortex excitability was studied by measuring the reactivity of the motor cortex beta rhythm to somatosensory stimulation. We recorded the amplitude of the suppression and subsequent rebound of the beta oscillations during tactile finger stimulation with MEG in 23 first-ever stroke patients within one week and at 1 and 3 months after stroke, with concomitant evaluation of hand function. RESULTS: The strength of the beta rhythm rebound, suggested to reflect decreased motor cortex excitability, was weak in the affected hemisphere after stroke and it was subsequently increased during recovery. The rebound strength correlated with hand function tests in all recordings. CONCLUSION: Motor cortex excitability is modulated by afferent input after stroke. The motor cortex excitability is increased in the AH acutely after stroke and decreases in parallel with recovery of hand function. SIGNIFICANCE: The results implicate the importance of parallel recovery of both sensory and motor systems in functional recovery after stroke.
OBJECTIVE: Afferent input is proposed to mediate its effect on motor functions by modulating the excitability of the motor cortex. We aimed to clarify - in a longitudinal study - how afferent input affects motor cortex excitability after stroke and how it is associated with recovery of hand function. METHODS: The motor cortex excitability was studied by measuring the reactivity of the motor cortex beta rhythm to somatosensory stimulation. We recorded the amplitude of the suppression and subsequent rebound of the beta oscillations during tactile finger stimulation with MEG in 23 first-ever strokepatients within one week and at 1 and 3 months after stroke, with concomitant evaluation of hand function. RESULTS: The strength of the beta rhythm rebound, suggested to reflect decreased motor cortex excitability, was weak in the affected hemisphere after stroke and it was subsequently increased during recovery. The rebound strength correlated with hand function tests in all recordings. CONCLUSION: Motor cortex excitability is modulated by afferent input after stroke. The motor cortex excitability is increased in the AH acutely after stroke and decreases in parallel with recovery of hand function. SIGNIFICANCE: The results implicate the importance of parallel recovery of both sensory and motor systems in functional recovery after stroke.
Authors: Kwan L Ng; Ellen M Gibson; Robert Hubbard; Juemin Yang; Brian Caffo; Richard J O'Brien; John W Krakauer; Steven R Zeiler Journal: Stroke Date: 2015-08-20 Impact factor: 7.914
Authors: Lara A Boyd; Kathryn S Hayward; Nick S Ward; Cathy M Stinear; Charlotte Rosso; Rebecca J Fisher; Alexandre R Carter; Alex P Leff; David A Copland; Leeanne M Carey; Leonardo G Cohen; D Michele Basso; Jane M Maguire; Steven C Cramer Journal: Int J Stroke Date: 2017-07 Impact factor: 5.266
Authors: Elina Pihko; Päivi Nevalainen; Selja Vaalto; Kristina Laaksonen; Helena Mäenpää; Leena Valanne; Leena Lauronen Journal: Hum Brain Mapp Date: 2014-02-12 Impact factor: 5.038
Authors: Kristina Laaksonen; Liisa Helle; Lauri Parkkonen; Erika Kirveskari; Jyrki P Mäkelä; Satu Mustanoja; Turgut Tatlisumak; Markku Kaste; Nina Forss Journal: PLoS One Date: 2013-04-11 Impact factor: 3.240