Introduction: Clarification of the relationship between external stimuli and brain response has been an important topic in neuroscience and brain rehabilitation. In the current study, using functional near infrared spectroscopy (fNIRS), we attempted to investigate cortical activation patterns generated during execution of a rehabilitation robotic hand. Methods: Ten normal subjects were recruited for this study. Passive movements of the right fingers were performed using a rehabilitation robotic hand at a frequency of 0.5 Hz. We measured values of oxy-hemoglobin(HbO), deoxy-hemoglobin(HbR) and total-hemoglobin(HbT) in five regions of interest: the primary sensory-motor cortex (SM1), hand somatotopy of the contralateral SM1, supplementary motor area (SMA), premotor cortex (PMC), and prefrontal cortex (PFC). Results: HbO and HbT values indicated significant activation in the left SM1, left SMA, left PMC, and left PFC during execution of the rehabilitation robotic hand(uncorrected, pConclusions: Our results appear to indicate that execution of the rehabilitation robotic hand could induce cortical activation.

Little is known about injury of the corticospinal tract (CST) in patients with mild traumatic brain injury (TBI). This study reports on patients with mild TBI who showed traumatic axonal injury of the CST in the sub-cortical white matter, as demonstrated by diffusion tensor tractography (DTT). Four patients with mild TBI who complained of motor weakness and had DTT parameters within the normal range, including fractional anisotropy, apparent diffusion coefficient and fibre number of the CST, and 10 normal control subjects were recruited for this study. All four patients showed partial tearing of the CSTs in a portion of the sub-cortical white matter in both hemispheres on DTT. However, three patients showed low amplitude on motor evoked potential obtained from both hand muscles by transcranial magnetic stimulation and two patients revealed abnormality of hand motor function in terms of grip strength or Purdue Pegboard score. This study demonstrated traumatic axonal injury of the CST using configurational evaluation of DTT in patients with mild TBI. It is believed that configurational evaluation using DTT would be a useful technique for detection of localized traumatic axonal injury in patients with mild TBI.

Background: There are known limitations of conventional computed tomography and magnetic resonance imaging in detecting neural injury in patients with mild traumatic brain injury (TBI). Diffusion tensor imaging (DTI) provides a method to further assess cerebral injury in this patient population. We report 2 patients with mild TBI who showed injury of the optic radiation (OR) as demonstrated by DTI. Method: Two patients who complained of visual field loss after mild TBI and 9 age-matched normal control subjects were recruited for this study. Peripheral field defects were detected with automated perimetry in both patients. Results: Regarding the configuration of OR, the total volume of OR was decreased in the right OR of both patients compared with controls; in contrast, the left ORs were divided into 2 parts in both patients. The voxel numbers of both ORs in both patients were more than 2 standard deviations lower than that of normal control subjects. The apparent diffusion coefficient value of the right OR in patient 2 was more than 2 standard deviations higher than that of normal controls. Conclusions: We demonstrated injury of the OR using DTI in 2 patients who showed visual field defects after mild TBI.

We attempted to determine whether shoulder subluxation at the early stage of stroke can predict motor outcome in relation to the corticospinal tract (CST) state on diffusion tensor tractography. Fifty-nine stroke patients with severe hemiparesis were recruited. The patients were classified according to the distance of shoulder subluxation (group A: ≥2 cm, group B: <2 cm) and the affected CST on diffusion tensor tractography at the first evaluation (CST type A—the CST was discontinued at the stroke lesion; CST type B—the integrity of the CST was preserved). Motor function of the patients was evaluated twice (first: beginning of rehabilitation—24.1 ± 16.6 days; second: discharge after first rehabilitation—58.5 ± 24.1 days) using the Medical Research Council score, Motricity Index, and Modified Brunnstrom Classification. Regarding the improvement of the Medical Research Council for the finger extensor and upper Motricity Index, the order in terms of better recovery was as follows: group B–type B, group A–type B, group B–type A, and group A–type A (P < 0.05). The distance of shoulder subluxation showed significant correlation with improvement of the finger extensor (moderate negative correlation, r = −0.37) and improvement of the Modified Brunnstrom Classification (weak negative correlation, r = −0.29) (P < 0.05). The presence of shoulder subluxation at the early stage of stroke can be a predictor of motor outcome of the affected upper extremity and the degree of shoulder subluxation can be a predictor of the motor function of the affected hand. Therefore, our results suggest that shoulder subluxation in relation to the affected CST state at the early stage of stroke can be a prognostic factor for motor outcome.