Near-Infrared Spectroscopic Topography as a Tool to Monitor Motor Reorganization After Hemiparetic Stroke

Abstract

Background and Purpose-Motor functional recovery from stroke can occur, but the mechanisms underlying this restorative process remain to be elucidated. We used near-infrared spectroscopic (NIRS) topography in comparison with functional MRI (fMRI) to evaluate the compensatory motor activation of cortical regions in patients who recovered from hemiparesis after cortical cerebral infarction. Methods-We examined 6 right-handed patients who suffered cerebral infarction of the middle cerebral artery territory with minimal or mild residual contralateral hemiparesis (4 men and 2 women, 59 to 79 years old, all had left hemiparesis). Both fMRI and NIRS were studied during a hand movement task at chronic stages. Five right-handed, normal subjects (3 men and 2 women, 44 to 81 years old) served as controls. Results-fMRI and NIRS detected very similar cerebral cortical activation, although NIRS detected only superficial activation. The spatial resolution of NIRS was less than that of fMRI, but NIRS provided a dynamic profile of activation. Normal subjects activated predominantly the contralateral primary sensorimotor cortex and supplementary motor areas during each hand movement. All the stroke patients exhibited the normal activation pattern during normal hand movement. On affected hand movement, the stroke patients showed extended activation not only in the contralateral motor cortex but also in the ipsilateral motor cortex (primary motor cortex and supplementary motor areas). Conclusions-Both fMRI and NIRS studies provided evidence for the contribution of ipsilateral motor cortical compensation or reorganization to the recovery from poststroke hemiparesis. The result demonstrated that NIRS was a unique tool to monitor poststroke alterations in cortical motor functions.

Sensorimotor Cortex Activation during Mirror Therapy in Healthy Right-Handed Subjects: A Study with Near-Infrared Spectroscopy

“…During right hand grasping without mirror viewing (condition A), the LI showed a contralateral SMC predominant activation pattern. This activation pattern was the same as that observed in previous NIRS studies 11,12,16) . However, the same subjects exhibited LI that was close to zero during left hand grasping without mirror viewing (condition C).…”

“…An advantage of NIRS is the unnecessity of restraint because of resistance to motion artifacts when the NIRS probes are mounted securely 12) . Therefore, the subjects could perform the hand grasping task with mirror viewing during NIRS measurement with a natural posture without any constraint.…”

Changes in Task-associated Cerebral Blood Induced by Role Lettering: Measurement by Multichannel Near-infrared Spectroscopy

“…Unfamiliar strategies, such as the retrograde writing task before Role lettering practice, may therefore become familiar [25]. Persistent practice may enhance skill in performing the task as the result of familiarity [23,26]. Role lettering should act with other therapeutic techniques used in combination [1,2].…”

Activation of Brain Sensorimotor Network by Somatosensory Input in Patients with Hemiparetic Stroke: A Functional MRI Study

“…The fMRI studies were performed using a 1.5 T Siemens Magnetom Symphony MRI scanner as described previously (Kato et al, 2002). Briefly, blood oxygenation level-dependent (BOLD) images were obtained continuously in a transverse orientation using a gradientecho, single shot echo planar imaging pulse sequence.…”