Time course of sensorimotor cortex reorganization during upper extremity task accompanying motor recovery early after stroke: An fNIRS study

Abstract

Background: The acute phase of stroke is accompanied by functional changes and interplay of both hemispheres. However, our understanding of how the time course of upper limb functional motor recovery is related to the progression of brain reorganization in the sensorimotor areas remains limited. This study aimed to assess the time course of hemodynamic patterns of cortical sensorimotor areas using functional near infrared spectroscopy (fNIRS) and motor recovery within three months after a stroke. Method: Eight right-handed first ischemic/hemorrhagic stroke patients (60±8 years, 3 women) with mild to severe hemiparesis were examined with repetitive fNIRS measurements and motor recovery tests (Fugl-Meyer score) during two months. Hemodynamic changes over the ipsilesional and contralesional sensorimotor areas were collected from a multi-channel fNIRS system during intermittent isometric muscle contractions at self-selected submaximal force levels for each arm. Lateralization index was computed to evaluate the changes in the interhemispheric balance between the cortical sensorimotor areas. Results: Lateralization index values during non-paretic arm movements showed no significant changes over time in patients and were comparable to those observed in eight healthy controls. Paretic-arm movements were associated early with a bilateral cortical activity before shifting to ipsilesional patterns ( p < 0.01). Progressive lateralization observed over the two months ( p < 0.05) evolved concomitantly with an increase in the Fugl-Meyer score ( p < 0.001). Conclusions: Cortical reorganization monitoring using fNIRS during the first weeks after stroke may be applied for assessing progressive brain plasticity in addition to clinical measures of performance.

Recovering arm function in chronic stroke patients using combined anodal HD-tDCS and virtual reality therapy (ReArm): a study protocol for a randomized controlled trial

“…EEG measures functional brain activity by detecting the variations of electrical fields created by neuronal activation, while fNIRS allows indirect measurement of neuronal activity by monitoring local changes in the oxygenated (O 2 Hb) and deoxygenated (HHb) haemoglobin concentrations in the cerebral microcirculation based on neurovascular coupling mechanism [ 2 , 59 ]. These two imaging methods have previously been independently used to evaluate changes in motor cortical region activation during functional movements following stroke rehabilitation programs [ 7 , 18 ], and fNIRS has already been tested and validated during various UL tasks by our team (reaching task in [ 6 ]; force task in [ 18 ] and in [ 20 ]).…”

“…In addition, a laterality index (LI) will be calculated for each task and trial [ 20 ] to determine whether sensorimotor cortex activation, based on O 2 Hb concentration, during the task is mainly contralesional or ipsilesional. The LI will be calculated from the ratio of ipsilesional and contralesional O 2 Hb concentration, which varies between − 1 (purely contralesional activation) and + 1 (purely ipsilesional activation [ 18 ]).…”

Recovering arm function in chronic stroke patients using combined anodal HD-tDCS and virtual reality therapy (ReArm): a study protocol for a randomised controlled trial

“…These two imaging methods have previously been independently used to evaluate changes in motor cortical region activation during functional movements following stroke rehabilitation programs (Bartur et al, 2019;Delorme et al, 2019); and fNIRS has already been tested and validated during various UL tasks by our team (reaching task in Bakhti et al, 2016; force task in Delorme et al, 2019 andin Derosière et al, 2014).…”

“…In addition, a laterality index (LI) will be calculated for each task and trial (Derosière et al, 2014) to determine whether sensorimotor cortex activation, based on O 2 Hb concentration, during the task is mainly contralesional or ipsilesional. The LI will be calculated from the ratio of ipsilesional and contralesional O 2 Hb concentration, which varies between − 1 (purely contralesional activation) and + 1 (purely ipsilesional activation; Delorme et al, 2019).…”

Functional near-infrared spectroscopy combined with unilateral task-oriented training with and without an orthosis in subacute stroke: A pilot study

“…A three-dimensional (3D)-digitizer was used to record the exact locations of each fNIRS probe for a standard brain before converting these coordinates into the locations of the forty-eight channels in an estimated Montreal Neurological Institute (MNI) space using the MATLAB toolbox NIRS-SPM (26). The positioning of the 48 channels on a reconstructed 3D brain is shown in Fig.2A (20). Based on the mean MNI coordinates and Brodmann's area (BA) correspondences, the 6 ROIs were covered by the following channels for the left and the right hemispheres: the left SMC was covered by channels 4, 5, 6, 8, and 9 (both sides of C3); the right SMC was covered by channels 25, 29, 32, 36, and 39 (both sides of C4); the left PMC was covered by channels 11, 12, 13, 15, and 16; the right PMC was covered by channels 26, 30, 33, 37, and 40; the left PFC was covered by channels 18, 19, 20, 22, and 23; and the right PFC was covered by channels 27, 31, 34, 38, and 41(Fig.…”