Evaluation of the brain activation induced by functional electrical stimulation and voluntary contraction using functional magnetic resonance imaging

Abstract

BackgroundTo observe brain activation induced by functional electrical stimulation, voluntary contraction, and the combination of both using functional magnetic resonance imaging (fMRI).MethodsNineteen healthy young men were enrolled in the study. We employed a typical block design that consisted of three sessions: voluntary contraction only, functional electrical stimulation (FES)-induced wrist extension, and finally simultaneous voluntary and FES-induced movement. MRI acquisition was performed on a 3.0 T MR system. To investigate activation in each session, one-sample t-tests were performed after correcting for false discovery rate (FDR; p < 0.05). To compare FES-induced movement and combined contraction, a two-sample t-test was performed using a contrast map (p < 0.01).ResultsIn the voluntary contraction alone condition, brain activation was observed in the contralateral primary motor cortex (MI), thalamus, bilateral supplementary motor area (SMA), primary sensory cortex (SI), secondary somatosensory motor cortex (SII), caudate, and cerebellum (mainly ipsilateral). During FES-induced wrist movement, brain activation was observed in the contralateral MI, SI, SMA, thalamus, ipsilateral SII, and cerebellum. During FES-induced movement combined with voluntary contraction, brain activation was found in the contralateral MI, anterior cingulate cortex (ACC), SMA, ipsilateral cerebellum, bilateral SII, and SI.The activated brain regions (number of voxels) of the MI, SI, cerebellum, and SMA were largest during voluntary contraction alone and smallest during FES alone. SII-activated brain regions were largest during voluntary contraction combined with FES and smallest during FES contraction alone. The brain activation extent (maximum t score) of the MI, SI, and SII was largest during voluntary contraction alone and smallest during FES alone. The brain activation extent of the cerebellum and SMA during voluntary contraction alone was similar during FES combined with voluntary contraction; however, cerebellum and SMA activation during FES movement alone was smaller than that of voluntary contraction alone or voluntary contraction combined with FES. Between FES movement alone and combined contraction, activated regions and extent due to combined contraction was significantly higher than that of FES movement alone in the ipsilateral cerebellum and the contralateral MI and SI.ConclusionsVoluntary contraction combined with FES may be more effective for brain activation than FES-only movements for rehabilitation therapy. In addition, voluntary effort is the most important factor in the therapeutic process.

Functional near‐infrared spectroscopy to probe sensorimotor region activation during electrical stimulation‐evoked movement

“…Neuroimaging studies using fMRI have reported that NMES‐evoked wrist extension movements activate a bilateral region of subcortical and cortical sensorimotor regions (Blickenstorfer et al ., ; Iftime‐Nielsen et al ., ; Joa et al ., ). In the present and previous (Muthalib et al ., ) fNIRS studies, the O 2 Hb‐ and HHb‐derived bilateral cortical sensorimotor activation profile induced by unilateral NMES of the wrist extensors is in agreement with these previous fMRI findings.…”

“…NMES induces CNS effects by enhancing voluntary motor control (Knutson et al ., ). Increased proprioceptive and cutaneous afferent signals (from the NMES electric field directly activating peripheral sensory nerves and from NMES‐evoked movements) send signals to subcortical and cortical bilateral sensorimotor regions, particularly the contralateral sensorimotor region (Blickenstorfer et al ., ; Iftime‐Nielsen et al ., ; Joa et al ., ; Muthalib et al ., ), which was confirmed by the present study. Furthermore, the ipsilateral sensorimotor region activation elicited by unilateral NMES‐evoked wrist extension movements indicated that there were transcallosal interactions between the two hemispheres (Iwamura, ; Maffiuletti et al ., ; Muthalib et al ., ).…”

“…VOL and NMES‐evoked wrist extension movements at moderate intensity (50%MTI; 13–25 mA) primarily activated a contralateral (LH) sensorimotor region of interest (ROI), including the primary sensorimotor cortex, premotor cortex and supplementary motor area, with smaller activation of the corresponding ipsilateral sensorimotor region. This greater contralateral than ipsilateral sensorimotor region activation pattern has also been characterized by fMRI studies (Han et al ., ; Blickenstorfer et al ., ; Iftime‐Nielsen et al ., ; Joa et al ., ). Although NMES at 100%MTI levels activated a similar bilateral sensorimotor region as the 50%MTI condition, there was an additional activation of a prefrontal region.…”

Effects of Increasing Neuromuscular Electrical Stimulation Current Intensity on Cortical Sensorimotor Network Activation: A Time Domain fNIRS Study

“…Cortical correlates of NMES-evoked movements have been demonstrated in a few functional magnetic resonance imaging (fMRI) studies [ 10 – 14 ]. For instance, Blickenstorfer et al (2009) observed a cortical activation pattern including the contralateral primary motor (M1) and sensory (S1) cortex (i.e., sensorimotor cortex-SMC) and bilateral secondary somatosensory area (S2), supplementary motor area (SMA), premotor cortex (PMC), and regions of the prefrontal cortex (PFC) during NMES-evoked wrist extension/flexion movements at current intensities just above the individual motor threshold (9–23mA) but minimising pain discomfort.…”

Artificial motor control for electrically stimulated upper limbs of plegic or paretic people

“…On the other hand, individuals with SCI that preserve small motor responses might be benefited from the use of FES. This can be explained by the fact that when the individual has the ability to perform concurrent voluntary contraction to the FES, the final motor response can be more effective and coordinate than when only FES application occurs (Joa et al, 2012).…”