Near-infrared Spectroscopy–mediated Neurofeedback Enhances Efficacy of Motor Imagery–based Training in Poststroke Victims

Abstract

Background and Purpose-Despite the findings that motor imagery and execution are supposed to share common neural networks, previous studies using imagery-based rehabilitation have revealed inconsistent results. In the present study, we investigated whether feedback of cortical activities (neurofeedback) using near-infrared spectroscopy could enhance the efficacy of imagery-based rehabilitation in stroke patients. Methods-Twenty hemiplegic patients with subcortical stroke received 6 sessions of mental practice with motor imagery of the distal upper limb in addition to standard rehabilitation. Subjects were randomly allocated to REAL and SHAM groups. In the REAL group, cortical hemoglobin signals detected by near-infrared spectroscopy were fed back during imagery. In the SHAM group, irrelevant randomized signals were fed back. Upper limb function was assessed using the finger and arm subscales of the

Brain‐computer interfaces for post‐stroke motor rehabilitation: a meta‐analysis

“…The mean age of the participants ranged from 49.3 ± 12.5 to 67.1 ± 5.51 years. Six studies targeted chronic patients,39, 41, 59, 60, 61, 62 whereas the remaining three studies targeted,42, 63, 64 patients in the subacute phase, with a mean time from stroke approximately ranging from 2 to 4.5 months. In eight out of the nine studies, the BCI relied on the detection of ERD of SMR related to motor imagery.…”

“…In eight out of the nine studies, the BCI relied on the detection of ERD of SMR related to motor imagery. The other study used near‐infrared spectroscopy (NIRS) to measure task‐related changes in levels of oxygenated and deoxygenated hemoglobin from the sensory‐motor cortices 63. The motor intent detection signals were then used to trigger a sensory feedback provided by external devices (orthosis, robot, NMES system or visual display).…”

“…The duration of therapies ranged from two to eight weeks. The nature of the control group differed across studies: sham‐feedback triggered orthosis movement at random instances in four studies,39, 59, 60, 63 one study used conventional therapy,62 one study used robot‐assisted training,41 one study used NMES,64 and one study used motor imagery 42. Ang et al61 reported results of two different control groups: robot only and conventional therapy only.…”

“…Most published clinical trials using BCI systems for upper limb rehabilitation hint at such subclinical effects. Mihara et al.,63 for instance, reported increased motor imagery‐related BOLD activity in the premotor area in a group trained with a BCI compared to a group receiving placebo‐BCI training. Similarly, Pichiorri et al.…”

The self-regulating brain and neurofeedback: Experimental science and clinical promise

“…Four studies reported that fNIRS-nf increased activity in a variety of motor areas (Kanoh, Susila, & Miyamoto, 2011;Kober et al, 2014;Mihara et al, 2012Mihara et al, , 2013. However, simply moving a limb or covertly tensing a muscle can also modulate motor cortex activity and researchers rarely measure electromyography (EMG) to detect such covert muscle tensing.…”