Comparative study of vestibular projection pathway connectivity in cerebellar injury patients and healthy adults.

OBJECTIVE: Cerebellar injury can not only cause gait and postural instability, nystagmus, and vertigo but also affect the vestibular system. However, changes in connectivity regarding the vestibular projection pathway after cerebellar injury have not yet been reported. Therefore, in the current study, we investigated differences in the connectivity of the vestibular projection pathway after cerebellar injury using diffusion tensor imaging (DTI) tractography. METHODS: We recruited four stroke patients with cerebellar injury. Neural connectivity in the vestibular nucleus (VN) of the pons and medulla oblongata in patients with cerebellar injury was measured using DTI. Connectivity was defined as the incidence of connection between the VN on the pons and medulla oblongata and target brain regions such as the cerebellum, thalamus, parieto-insular vestibular cortex (PIVC), and parietal lobe. RESULTS: At thresholds of 10 and 30, there was lower connectivity in the ipsilateral hemisphere between the VN at the medullar level and thalamus in the patients than in healthy adults. At a threshold of 1 and 10, the patient group showed lower VN connectivity with the PIVC than healthy adults. At a threshold of 1, VN connectivity with the parietal lobe in the contralateral hemisphere was lower in the patients than in healthy adults. Additionally, at a threshold of 30, VN connectivity at the pons level with the cerebellum was lower in healthy adults than in the patients. CONCLUSION: Cerebellar injury seems to be associated with decreased vestibular projection pathway connectivity, especially in the ipsilateral thalamus, PIVC, and contralateral parietal lobe.

Breathing Exercise Called the Maximal Abdominal Contraction Maneuver.

Background and objectives: The maximal abdominal contraction maneuver (MACM) was designed as an effective and efficient breathing exercise to increase the stability of the spinal joint. However, it has not been determined whether MACM is more effective and efficient than the maximal expiration method. Thus, the present study was undertaken to investigate whole abdominal muscle thickness changes after MACM. Materials and Methods: Thirty healthy subjects (17 males and 13 females) participated in this study. An experimental comparison between MACM and the maximal expiration task was conducted by measuring the change of abdominal muscle thickness such as the transverse abdominis (TrA), internal oblique (IO), external oblique (EO) and rectus abdominis (RA) using ultrasound images. Results: The results indicated that MACM resulted in significantly greater muscle thickness increases of the TrA and RA than the maximal expiration exercise (p < 0.05). Conclusion: MACM provided better exercise than the maximal expiration exercise in terms of increasing spine stability, at least from a co-contraction perspective.

Lateral Medullary Syndrome Following Injury of Lateral Vestibulospinal Tract: Diffusion Tensor Imaging Study.

BACKGROUND: Unilateral lesions of vestibular nucleus can cause lateral medullary syndrome. Little is known about injury of medial and lateral vestibulospinal tract (VST) after dorsolateral medullary infarct. We investigated injury of the lateral VST in patients with typical central vestibular disorder using diffusion tensor tractography (DTT). METHODS: Seven patients with lateral medullary syndrome and ten control subjects were recruited. For the medial VST, we determined seed region of interest (ROI) as medial vestibular nuclei of pons and target ROI on posteromedial medulla. For the lateral VST, the seed ROI was placed on lateral vestibular nuclei of pons, and the target ROI on posterolateral medulla. Fractional anisotropy (FA), mean diffusivity (MD), and tract volume were measured. RESULT: Reconstructed lateral VST on both sides had significantly lower FA values in patients than controls (p<0.05). Tract volume of lateral VST in affected side was significantly lower than unaffected side and control group (p<0.05). However, no DTI parameters of the medial VST differed between patients and controls (p>0.05). CONCLUSION: Injury of the lateral VST was demonstrated in patients with lateral vestibular syndrome following dorsolateral medullary infarct. Analysis of the lateral VST using DTT would be helpful in evaluation of patients with lateral medullary syndrome.

Effects of injuries to descending motor pathways on restoration of gait in patients with pontine hemorrhage.

BACKGROUND AND PURPOSE: Gait disturbance due to injuries of the descending motor pathway, including corticospinal tract (CST), corticoreticular pathway (CRP), and medial and lateral vestibulospinal tracts (VSTs), are commonly encountered disabling sequelae of pontine hemorrhage. We investigated relations between changes in the CST, CRP, and medial and lateral VST and corresponding changes in gait function in patients with pontine hemorrhage. METHOD: Nine consecutive stroke patients with pontine hemorrhage, and 6 age-matched normal subjects were recruited. Four patients were allocated to group A (can't walk independently) and 5 to group B (can walk independently). Diffusion tensor imaging (DTI) data were acquired twice at acute to subacute stage and chronic stage after stroke onset. Diffusion tensor tractography (DTT) was used to reconstruct CST, CRP, medial and lateral VST. RESULT: The CRP shows a significantly different between groups A and B in both initial and follow up DTT (p > 0.05). In contrast, CST, medial VST and lateral VST did not show a significant difference (p > 0.05). Regarding DTI parameters of CRPs in group A, percentages of patients with fractional anisotropy (FA) and mean diffusivity (MD) values more than two standard deviation from normal were higher by follow up DTI than by initial DTI, however, the CRPs in group B only showed increased abnormal range of MD. CONCLUSIONS: The CST does not play an essential role in recovery of independent walking and vestibulospinal tracts may not crucially affect recovery of independent walking in patients with pontine hemorrhage. In contrast, and intact CRP or changes of the CRP integrity appear to be related to the recovery of gait function.

Validating attentive locomotion training using interactive treadmill: an fNIRS study.

BACKGROUND: Existing treadmill-based locomotion training, which has been used for gait function recovery, still has limitations, such as less attentive training. Interactive treadmills (ITMs) were developed to overcome these limitations, but it has not yet been verified that ITMs can make the user pay closer attention to walk training. METHODS: An experimental comparison between ITMs and conventional treadmills was conducted by measuring the level of the user's attention using functional near-infrared spectroscopy (fNIRS). To consider the effect of task complexity on the subject's attention, we provided two (slow and fast) speed conditions for walking on both treadmills. RESULTS: Both the cortical activity images and oxygenated hemoglobin (oxyHb) changes showed that the level of attention to walking induced by the ITM was significantly higher than that induced by the conventional treadmill. We found that the walking speed on the ITM also affected the level of attention. CONCLUSION: ITM-based locomotion training would be a promising solution to the limitations of existing treadmill-based locomotion training currently used to improve gait function recovery. TRIAL REGISTRATION: DGIST-HR-150309-03-02 . Registered 01 March 2015.

A robotic treadmill system to mimic overground walking training with body weight support.

Introduction: Body weight support overground walking training (BWSOWT) is widely used in gait rehabilitation. However, existing systems require large workspace, complex structure, and substantial installation cost for the actuator, which make those systems inappropriate for the clinical environment. For wide clinical use, the proposed system is based on a self-paced treadmill, and uses an optimized body weight support with frame-based two-wire mechanism. Method: The Interactive treadmill was used to mimic overground walking. We opted the conventional DC motors to partially unload the body weight and modified pelvic type harness to allow natural pelvic motion. The performance of the proposed system on the measurement of anterior/posterior position, force control, and pelvic motion was evaluated with 8 healthy subjects during walking training. Results: We verified that the proposed system was the cost/space-effective and showed the more accurate anterior/posterior position than motion sensor, comparable force control performance, and natural pelvic motion. Discussion: The proposed system is cost/space effective, and able to mimic overground walking training with body weight support. In future work, we will improve the force control performance and optimize the training protocol for wide clinical use.

Comparison of Abdominal Muscle Thickness between the Abdominal Draw-in Maneuver and Maximum Abdominal Contraction Maneuver.

All abdominal muscles, including the transverse abdominis (TrA), should be modulated to improve core stability. This study aimed to investigate easier and more effective core exercise methods by comparing thickness changes in the TrA, internal oblique (IO), external oblique (EO), and rectus abdominis (RA) muscles during the abdominal draw-in maneuver (ADIM) and maximum abdominal contraction maneuver (MACM). Thirty healthy subjects who participated in this study underwent ADIM and MACM three times in random order. We measured the abdominal muscle thickness during ADIM and MACM using ultrasonography and compared the changes in the thickness of TrA, IO, EO, and RA muscles using a paired t-test. Significant differences were observed in the thicknesses of all the abdominal muscles between the ADIM and MACM groups (p < 0.05). The MACM immediately increased the thickness of the TrA (p < 0.001, effect size (ES) = 0.931), IO (p = 0.001, ES = 0.761), EO (p = 0.008, ES = 0.415), and RA (p < 0.001, ES = 0.767) muscles. These results suggest that MACM is useful for immediately increasing the thickness of TrA, IO, EO, and RA muscles and may contribute to the clinical effect of simultaneous contractions on the changes in abdominal muscle thickness.

Associations Between Injury of the Parieto-Insular Vestibular Cortex and Changes in Motor Function According to the Recovery Process: Use of Diffusion Tensor Imaging.

Background and Purpose: Parieto-insular vestibular cortex (PIVC) injury can cause symptoms such as abnormal gait and affects the integration and processing of sensory inputs contributing to self-motion perception. Therefore, this study investigated the association of the vestibular pathway in the gait and motor function recovery process in patients with PIVC injury using diffusion tensor imaging (DTI). Methods: We recruited 28 patients with stroke with only PIVC injury and reconstructed the PIVC using a 1.5-T scanner for DTI. Fractional anisotropy (FA), mean diffusivity (MD), and tract volume were measured. The functional ambulatory category (FAC) test was conducted, and motricity index (MI) score was determined. These were conducted and determined at the start (phase 1), end of rehabilitation (phase 2), and during the follow-up 6 months after onset. Results: Although the tract volume of PIVC showed a decrease in subgroup A, all of DTI parameters were not different between two subgroups in affected side (p > 0.05). The results of MI and FAC were significantly different according to the recovery process (p < 0.05). In addition, FA of the PIVC showed a positive correlation with FAC in phase 2 of the recovery process on the affected side. On the unaffected side, FA of the PIVC showed a significant negative correlation with MI in all processes (p < 0.05). Conclusion: The degree of projection pathways to PIVC injury at onset time seems to be related to early restoration of gait function. Moreover, we believe that early detection of the projection pathway for PIVC injury using DTI would be helpful in the clinical evaluation and prediction of the prognosis of patients with PIVC injury.

Changes in Gait Performance in Stroke Patients after Taping with Scapular Setting Exercise.

The purpose of this study was to investigate the effects of combined taping with scapular setting exercise on the gait performance of stroke patients. Twenty stroke patients were randomly allocated to two groups: the taping with scapular setting exercise (TSSE) group (n = 10) and scapular setting exercise (SSE) group (n = 10). Intervention was performed for one week, and pre- and postintervention results for TSSE and SSE were compared. Outcomes were determined using the inertia measurement unit, which can measure spatiotemporal gait parameters, and using the timed up-and-go test. Two-way repeated analysis was used to compare pre- and postintervention results. In the TSSE group, intervention significantly improved cadence, gait speed, stride length, step length, gait cycle, swing phase duration, double support duration, and timed up-and-go test results more than in the SSE group. TSSE was found to improve all spatiotemporal gait parameters examined; thus, we recommend TSSE be considered as an intervention to improve gait parameters in stroke patients.

Effect of Plyometric versus Ankle Stability Exercises on Lower Limb Biomechanics in Taekwondo Demonstration Athletes with Functional Ankle Instability.

BACKGROUND: This study aimed to compare the effects of plyometric and ankle stability exercises on the dynamic balance and lower limb kinematic and kinetic parameters of Taekwondo demonstration athletes with functional ankle instability. METHODS: Fourteen subjects participated in this study and were randomly divided into two groups: a plyometric exercise group (n = 7) and an ankle stability exercise group (n = 7). Exercises were performed twice a week for 8 weeks. A Y-balance test was used to measure dynamic balance, and a motion analysis system and force plate were used to collect kinematic and kinetic parameters during single-leg drop landing. A paired t-test was used for intragroup comparisons, and an independent t-test was used for intergroup comparisons. RESULTS: In both groups, exercise increased dynamic balance and shock absorption and reduced postural sway on the anteroposterior displacement (p < 0.05). The plyometric exercise group decreased their ankle dorsiflexion and increased their knee and hip joint flexion at maximum knee flexion (p < 0.05). In contrast, the stability exercise increased their ankle plantar flexion at initial contact (p < 0.05). CONCLUSIONS: The plyometric exercise group altered their landing strategies using their knee and hip joints to control ankle instability at landing. This study suggests that the application of plyometric exercises in ankle rehabilitation would improve stability and shock absorption and help prevent injuries during Taekwondo demonstrations.

Immediate Effects of Tibialis Anterior and Calf Muscle Taping on Center of Pressure Excursion in Chronic Stroke Patients: A Cross-Over Study.

Stroke patients often have muscles spasticity, difficulty with posture control, and tend to fall. This study investigated the use of kinesiology tape for patients with spasticity of ankle muscles after stroke. This study had a randomized, repeated measures design, and evaluated the immediate effect of kinesiology tape on the center of pressure (COP) excursion when applied to the calf and tibialis anterior muscles in stroke survivors. We determined that the taping attachment direction affects the COP movement. Twenty subjects were randomly assigned to the tibialis anterior taping condition, calf taping condition, or nontaping condition. Condition excursion was assessed. The measured variables included the paretic side area, nonparetic side area, forward area, and backward area of COP. All evaluations were conducted immediately after taping. COP excursion for chronic stroke survivors improved after tibialis anterior and calf taping (p < 0.05). Calf taping conditions increased significantly in the forward area (p < 0.05), and tibialis anterior taping conditions increased significantly in the backward area (p < 0.05). Kinesiology tape immediately increased the forward and backward COP excursion for patients with stroke.

Role of diffusion tensor imaging in analyzing the neural connectivity of the parieto-insular vestibular cortex in pusher syndrome: As case report.

RATIONALE: Pusher syndrome is a disorder of postural control. It is associated with unilateral lesions on central vestibular system. In the current study, we attempted to identify and investigate neural connectivity of the parieto-insular vestibular cortex in a patient with pusher syndrome, using diffusion tensor imaging. PATIENT CONCERNS: A 60-year-old male patient had left hemiplegia due to an infarction on right premotor cortex, primary motor cortex, corona radiata and temporal and occipital lobe. The patient had severe motor weakness in left upper and lower limb, left side neglect and significant pusher syndrome. DIAGNOSIS: Patient was diagnosed with left hemiplegia due to an infarction in the right middle cerebral artery territory at the neurology department of a university hospital. INTERVENTIONS: One patient and 5 control subjects of similar age participated. Diffusion tensor imaging data were acquired at 4-month and 12-month after the initial injury. OUTCOMES: Fractional anisotropy, mean diffusivity, and tract volume (TV) were measured. TV values in both affected and unaffected hemispheres of the patient were significantly decreased at 4-month compared to those of control subjects. In the unaffected hemisphere of the patient, TV value showed significant increase at 12-month compared to that at 4-month. Although the TV value at 12-month of the affected hemisphere was out of reference range, TV was considerably increased compared to that at 4-month. Mean values for fractional anisotropy or mean diffusivity in 2 hemispheres did not show significant difference compared to those of control subjects regardless of month. LESSONS: Restoration of an injured projection pathway between the vestibular nuclei and parieto-insular vestibular cortex with recovery of pusher syndrome was found in a patient with stroke.

Changes in Gait Parameters and Gait Variability in Young Adults during a Cognitive Task while Slope and Flat Walking.

This study investigates the effects of a cognitive task while walking on a slope or a flat surface on gait parameters and gait variability in young adults. The participants consisted of thirty healthy young subjects. They were instructed to walk on a slope or on a flat surface while performing or not performing a cognitive task, which involved speaking a four-syllable word in reverse. A wearable inertia measurement unit (IMU) system was used to measure spatiotemporal parameters and gait variability. Flat gait (FG) while performing the cognitive task (FGC) and uphill gait (UG) while performing the cognitive task (UGC) significantly altered stride times, gait speeds, and cadence as compared with FG and UG, respectively. Downhill gait (DG) while performing the cognitive task (DGC) caused no significant difference as compared with DG. Gait variability comparisons showed no significant difference between UGC and UG or between FGC and FG, respectively. On the other hand, variabilities of stride times and gait speeds were significantly greater for DGC than DG. FGC and UGC induce natural changes in spatiotemporal gait parameters that enable the cognitive task to be performed safely. DGC should be regarded as high complexity tasks involving greater gait variability to reduce fall risk.

Toward Comparison of Cortical Activation with Different Motor Learning Methods Using Event-Related Design: EEG-fNIRS Study.

Recently, motor imagery brain-computer interface (MI-BCI) has been studied as a motor learning method and evaluated by comparing with conventional passive and active training. Most functional near-infrared spectroscopy (fNIRS) studies adopted block design for comparing those motor learning methods, including MI-BCI. Compared to the block design, event-related design would be more appropriate for estimating cortical activation in MI-BCI which provides feedback for each trial. This paper is a preliminary study to check the feasibility whether event-related design can be applicable for MI-BCI. To this end, three different motor learning methods involving MI-BCI were compared. In hemodynamic response, MI-BCI showed significantly stronger cortical activation than passive training (PT), and weaker than active training (AT), which conforms most existing studies. The results demonstrate that event-related design could be applied to investigate cortical effects of MI-BCI and comparing hemodynamic responses of different motor learning methods.

A two-wire body weight support system for interactive treadmill.

Body weight support (BWS) system is widely used for patients to help their gait training. However, that existing systems require large workspace and elastic component in actuation makes the systems inappropriate for wide clinical use. The interactive treadmill was reported to be cost/space effectively simulate overground walking, but there was no suitable BWS system for the treadmill. We proposed a new concept of body weight support system for interactive treadmill. For wide clinical use, we applied a two-wire driven mechanism with simple actuator and a custom pelvic-type harness. With three healthy subjects, the performance of the proposed BWS system on unloading force control was evaluated, and the result showed that the feasibility of the proposed BWS system.