Movement observation activates motor cortex in fibromyalgia patients: a fNIRS study

Abstract

Scientific evidence points to a shared neural representation between performing and observing an action. The action observation notoriously determines a modulation of the observer’s sensorimotor system, a phenomenon called Motor Resonance (MR). Fibromyalgia (FM) patients suffer from a condition characterized by generalized musculoskeletal pain in which even simple movement can exacerbate their symptoms. Maladaptive functioning of the primary motor cortex is a common finding in patients with chronic pain. Activation of the motor cortex is known to induce an analgesic effect in patients with chronic pain. In this exploratory study, we intend to verify if the mere observation of a movement could elicit activation of the motor cortical areas in patients with FM. Therefore, the purpose of this study was to examine the presence of MR in patients affected by fibromyalgia. We adopted a behavioral paradigm known for detecting the presence of MR and a neurophysiological experiment. Participants watched videos showing gripping movements towards a graspable or an ungraspable object, respectively, and were asked to press a button the instant the agent touched the object (Time-to-contact detection session). In a different experimental session, participants were only requested to observe and pay attention to the videos (Observation-only session). During each experimental session, the participants’ cerebral hemodynamic activity was recorded using the functional Near-Infrared Spectroscopy method. The behavioral task analysis revealed the presence of MR in both FM patients and healthy controls. Moreover, neurophysiological findings suggested that the observation of movement during the Observation-only session provoked activation and modulation of the cortical motor networks of FM patients. These results could represent evidence of the possible beneficial effects of movement observation in restarting motor activation, notoriously reduced, in FM patients.

Effect of Single Session of Anodal M1 Transcranial Direct Current Stimulation—TDCS—On Cortical Hemodynamic Activity: A Pilot Study in Fibromyalgia

“…In FM patients, who before TDCS expressed reduced cortical metabolism during active hand movement on both hemispheres, in accordance with previous studies [ 14 , 15 ], the anodal stimulation of M1 could compensate for this functional gap, restoring the activity at least on the stimulated hemisphere. On the opposite side, slight differences persisted between patients and controls, for a reduced effect in patients and the already explained phenomenon of increased oxyhemoglobin levels in controls.…”

“…According to previous reports [ 14 ], FM patients had slower movement as compared to controls. The low motor efficiency, corresponded to a reduced metabolic activation of the cortical motor network, as also previously shown [ 14 , 15 ]. The motor impairment could be a tract of FM, due to an inhibitory effect on the motor cortex caused by chronic pain [ 32 ], or to a primary cortical motor network dysfunction, with a low efficient modulatory effect on noxious information processing.…”

“…Khan et al [ 12 ] analyzed changed hemodynamic examples in the sensorimotor cortex because of bi-hemispheric TDCS polarities and their relationship to muscle movement and motor task execution. In our previous studies, FM patients showed an impairment in movement speed during finger-tapping tasks, corresponding to a reduced metabolism of motor cortical networks, detected by means of fNIRS [ 14 , 15 ]. In this pilot study, we investigated metabolic activity in FM patients compared to controls during a finger tapping task in basal condition, sham condition, and under anodal TDCS on M1, in order to understand if a single stimulation session can recover the reduced metabolism expected in FM patients.…”

A single session of action observation therapy versus observing a natural landscape in adults with chronic neck pain – a randomized controlled trial

“…Potentially, this might be due to the unfamiliarity of participants with the exercises. A previous study has suggested that observing a familiar action activates the sensorimotor maps relative to the person’s experience, but if the viewer observes unfamiliar movements, the motor system could in turn be inhibited [ 52 ]. These might suggest that the choice of movement for mental practice might have an impact on the results.…”

Sensorimotor Adaptation in Spatial Orientation Task: A fNIRS Study

“…SPM-1 within subject analysis was performed to estimate the degree of activation in each channel with respect to the baseline 31 . For group analysis of the brain activity in accordance with the statistical analysis, SPM-2 between subject analysis was used (p<0.05, corrected for multiple comparisons) 32 .…”