A Case of Spinal Cavernous Hemangioma with Rapidly Worsening Neurological Symptoms after COVID-19 Infection.

Background: : COVID-19 can cause respiratory symptoms, as well as various complications and sequelae. This report describes a patient with worsening neurological symptoms caused by a spinal cavernous hemangioma after infection with COVID-19. Cavernous hemangioma usually occurs in the upper part of the brain (70%-90%) and rarely occurs in the spinal cord (5%-7%). Approximately 65% of cases of intramedullary spinal cavernous hemangioma present with neurological symptoms, and more than half of these cases show a slow worsening of symptoms. This is a rare case of intramedullary spinal cavernous hemangioma with cysto-rectal involvement in which neurological symptoms rapidly worsened following COVID-19 infection. Case: : A woman in her 30s was admitted to the hospital because of the sudden onset of muscle weakness in both lower limbs and cysto-rectal disturbances after COVID-19 infection. She was diagnosed with a hemorrhage from a spinal cord tumor and underwent emergency resection. The pathological diagnosis was a spinal cavernous hemangioma. At first, she had a spinal cord injury (third thoracic vertebrae; American Spinal Injury Association Impairment Scale, C; Frankel classification, B; with cysto-rectal impairment), but 2 months later, she started walking with knee-ankle-foot orthoses and parallel bars. After 3 months, she could move independently around the ward using a wheelchair. Upon discharge, the patient could walk with ankle-foot orthoses and Lofstrand crutches. Discussion: : COVID-19 is associated with various extrapulmonary manifestations and may increase the risk of hemorrhage in cases of intramedullary spinal cavernous hemangioma.

Case Report: Virtual reality training for phantom limb pain after amputation.

Several reports have demonstrated the effectiveness of neurorehabilitation, such as mirror therapy or virtual reality, in treating phantom limb pain (PLP). This case study describes the effect of virtual reality training (VRT) on severe, long-term PLP and upper limb activity on the amputated side in a patient who underwent digit amputation 9 years prior. A woman in her 40 s underwent amputation of 2-5 fingers 9 years prior due to a workplace accident. She experienced persistent pain in the palms of her hand near the amputation sites. A single case design (ABA'B') was applied. Periods A and A' were set as periods without VRT intervention, and Periods B and B' were set as periods with VRT intervention. Periods A, B, A', and B' lasted 4, 10, 8, and 10 weeks, respectively. VRT was a task during which visual stimulation and upper limb movements were linked. The task consisted of catching a rolling ball in the display with a virtual hand, operated with both hands using a controller. VRT was performed once every 2-4 weeks for 30 min. Pain intensity was assessed using the short-form McGill Pain Questionnaire-2. Bilateral upper limb activity was measured continuously for 24 h using a triaxial accelerometer attached to the right and left wrist joints. The pain intensity was 147/220 points during Period A, 128 points during Period B, 93 points during Period A', and 100 points during Period B', showing a gradual decrease. Upper limb activity occurred mainly on the intact side during Periods A and B, whereas the activity on the amputated side increased 2-fold after Period A', and both upper extremities were used equally. Virtual reality training resulted in reduced pain intensity and increased activity in the upper limb. VRT may have induced reintegration of the sensory-motor loop, leading to a decrease in the PLP intensity. The upper limb activity on the amputated side may have also increased with the pain reduction. These results suggest that VRT may be valuable in reducing severe, long-term PLP.

The impact of diabetic polyneuropathy on toe grip strength in patients with type 2 diabetes mellitus: a cross-sectional study.

Purpose: Type 2 diabetes mellitus (T2DM) and concomitant diabetic polyneuropathy (DPN) induce muscle weakness. Muscle weakness in the foot is associated with foot deformities and falls. However, factors affecting toe grip strength (TGS) are not well known. Therefore, the present study investigated factors related to TGS in patients with T2DM. Methods: This was a cross-sectional study involving 100 patients with T2DM who were hospitalized for the treatment of T2DM and 50 healthy adults. The subjects were divided into three groups: a group of healthy subjects, a group of T2DM patients without DPN, and a group of T2DM patients with DPN. Hierarchical multiple regression analysis was performed with TGS and the TGS-to-weight ratio (TGS/Wt%) as dependent variables and with age, the presence of T2DM, and DPN as independent variables, and sex and BMI as confounders. Results: There were no significant differences in age or sex among the three groups. In the final regression analysis, age and presence of T2DM and DPN were associated in both models with TGS and TGS/Wt% as dependent variables. Conclusion: DPN, T2DM, and age were found to be related to TGS. The findings of this study could contribute to healthcare providers developing foot care and rehabilitation programs for diabetic patients. Trial registration: This study was registered with UMIN-CTR (UMIN000034320) on 1 November 2018.

The association between sarcopenia and functional outcomes in patients undergoing convalescent rehabilitation.

Sarcopenia is widely believed to be linked to poorer outcomes in inpatient rehabilitation. This study aimed to assess the impact of sarcopenia on functional outcomes and dietary intake during hospitalization in adults undergoing convalescent rehabilitation. We conducted a retrospective cohort analysis at a single rehabilitation institution. The Asian Working Group Consensus Criteria for Sarcopenia was used to diagnose. The Functional Independence Measure (FIM) score was used at hospital discharge to measure the primary functional outcome. Energy and protein intakes during hospitalization were calculated as part of the nutritional assessment. There were 126 patients in the research (median age, 73 yr;54% women). Stroke (n = 73;53.4% sarcopenia) and musculoskeletal disorders (n = 53;56.6% sarcopenia) were among the admission diagnoses. Multiple linear regression analysis revealed that the FIM total score at discharge was modestly associated with sarcopenia only in stroke patients (? = 0.1872, P = 0.09), as well as significantly and independently associated with protein intake during admission only in stroke patients (? = 0.3217, P < 0.05). In hospitalized stroke patients undergoing convalescent therapy, sarcopenia is related to lower functional results. Early identification of sarcopenia and treatment with rehabilitation nutrition should be implemented in this population. J. Med. Invest. 70 : 457-463, August, 2023.

Effect of cranioplasty on FIM in patients with severe cerebral infarction after cerebral decompression.

Arai N, Abe Y, Metani H, Hiraoka T, Hanayama K. Effect of cranioplasty on FIM in patients with severe cerebral infarction after cerebral decompression. Jpn J Compr Rehabil Sci 2023; 14: 33-38. Objective: The functional effects of cranioplasty were measured in patients with severe cerebral infarction who had undergone cerebral decompression by comparing the functional independence measure (FIM) during convalescent rehabilitation before and after cranioplasty. Methods: The study design was a single-center retrospective cohort study. Results: Fifty-five patients underwent cerebral decompression after cerebral infarction at our hospital, six of whom were included in this study. Two patients who exhibited cranial depression had no changes in FIM one month prior to cranioplasty. However, the FIM increased one month postoperatively. These patients showed a large increase in the scores for movement and transfer. Discussion: Cranioplasty may play a role in improving ability during convalescent rehabilitation in patients with severe cerebral infarction who undergo cerebral decompression, especially in movement and transfer items.

Shoulder function after neck dissection with level IIb preservation: a prospective observational study.

BACKGROUND: Shoulder syndrome can be reduced by preserving the spinal accessory nerve (SAN). However, it is unclear whether performing level IIb preservation will decrease the risk of SAN injury and shoulder syndrome. AIMS/OBJECTIVES: We investigated whether neck dissection with level IIb preservation can reduce shoulder dysfunction and postoperative quality of life (QOL) in head and neck cancer patients. MATERIAL AND METHODS: This prospective observational study enrolled patients who underwent neck dissection from 2011 to 2014. Patients were divided into three groups (level IIb preservation group [group 1], IIb dissection group [group 2], and IIb and V dissection group [group 3]). Postoperative shoulder function and QOL were evaluated among the three groups. RESULTS: There were a total of 35 neck sides in three groups, with nine neck sides in group 1, 16 neck sides in group 2, and 10 neck sides in group 3. Although the results showed less shoulder dysfunction in group 1 at early postoperative period. The QOL in group 1 was preserved in the early postoperative period. CONCLUSIONS AND SIGNIFICANCE: Neck dissection with level IIb preservation may help reduce shoulder syndrome and maintain QOL in the early postoperative period.

Relationship between Clinical Severity and Cross-sectional Area of Ultrasonographic Examinations in Ulnar Neuropathy at the Elbow.

Objectives: This study explored the relationship between clinical severity of ulnar neuropathy at the elbow (UNE) and ulnar nerve cross-sectional area (CSA) by ultrasound examination to identify appropriate measurement sites for UNE diagnosis and evaluation. Methods: In this retrospective analysis, we examined the arms of 37 patients diagnosed with UNE and those of 34 individuals as controls. The ulnar nerve CSAs were measured at 2 cm distal to the tip of the medial epicondyle (dME), the tip of the medial epicondyle (ME), 2 cm proximal to the tip of the medial epicondyle (pME), and any site showing the maximum CSA between the dME and pME (largest dpME). The modified McGowan classification (grades I, IIA, IIB, and III) was used to rate the clinical severity of UNE. Results: For all sites, the CSAs were significantly correlated with clinical severity. The sites showing the maximum CSA were inconsistent between controls and grade IIA patients. Grade IIB patients showed the largest CSA at the ME in the majority of patients. In grade III patients, maximum CSA occurred only at the ME. Conclusions: Serial assessment to detect nerve enlargement at multiple sites was beneficial for mild UNE patients with weakness of the ulnar distal muscles with Medical Research Council (MRC) score of 4 or higher (grade IIA). For severe UNE patients with weakness of the ulnar distal muscles classified as MRC3 or less (grades IIB, III), the most efficient method for detecting enlarged nerves was to initially measure the CSA at the ME.

Efficacy of soft palatal augmentation prosthesis for oral functional rehabilitation in patients with dysarthria and dysphagia: a protocol for a randomised controlled trial.

INTRODUCTION: Palatal augmentation prosthesis (PAP) is used in patients with articulation and swallowing disorders caused by postoperative loss of tongue tissue due to tongue cancer, cerebrovascular disease sequelae and age-related hypofunction. We have previously reported a newly designed soft PAP fabricated using an thermoplastic material that is particularly appropriate for early intervention. However, the effect of soft PAP on oral function improvement remains to be elucidated. The aim of this study is to investigate whether soft PAP can improve dysarthria and dysphagia occurring as cerebrovascular disease sequelae. METHODS AND ANALYSIS: This prospective, randomised, controlled trial will compare the immediate and training effects of rehabilitation using soft PAP with those of rehabilitation without using it. Primary outcomes are the single-word intelligibility test score and pharyngeal transit time (PTT). Secondary outcomes are tongue function (evaluated based on maximum tongue pressure, repetitions of tongue pressure and endurance of tongue pressure), articulation function (evaluated based on speech intelligibility, oral diadochokinesis, Voice-Related Quality of Life (V-RQOL)) and swallowing function (evaluated using Eating Assessment Tool-10). The study results will help determine the efficacy of Soft PAP in improving functional outcomes of word intelligibility and PTT. We hypothesised that early rehabilitation using Soft PAP would more effectively improve articulation and swallowing function compared with conventional rehabilitation without using soft PAP. ETHICS AND DISSEMINATION: Ethical approval was obtained from the Okayama University Certified Review Board. The study findings will be published in an open access, peer-reviewed journal and presented at relevant conferences and research meetings. TRIAL REGISTRATION NUMBER: jRCTs062200054.

Correlation between kinesthetic motor imagery of an amputated limb and phantom limb pain.

BACKGROUND: Phantom limb pain (PLP) is a frequent painful sensation in amputees, and motor imagery (MI) is a useful approach for the treatment of this type of pain. However, it is not clear regarding the best MI modality for PLP. OBJECTIVES: The purpose of this study was to investigate the relationship between the PLP and MI modality in upper limb amputees. STUDY DESIGN: Observational study. METHODS: Eleven patients who underwent unilateral upper limb amputation participated in this study. The MI modality (kinesthetic and visual) and PLP intensity were evaluated using the Kinesthetic and Visual Imagery Questionnaire (KVIQ)-20 and a visual analog scale. MI ability was also assessed during the hand mental rotation task. We examined the correlation between MI modalities, ability, and pain intensity. RESULTS: The total KVIQ kinesthetic score was negatively correlated with pain intensity (r = -0.71, P < 0.01): the more vivid the kinesthetic imagery, the weaker the pain. In particular, the reduction in pain intensity was associated with strong kinesthetic imagery of opposing movements of the deficient thumb (r = -0.81, P < 0.01). The KVIQ visual score and MI ability were not associated with pain intensity. CONCLUSIONS: Our data showed that the reduction of PLP could be associated with the kinesthetic modality of MI but not with visual modality or MI ability. In other words, it was suggested that the more vivid the sensation of moving muscles and joints in the defect area, the lower the PLP intensity. To reduce PLP, clinicians may prefer interventions using the kinesthetic modality.

Characteristics of Patients with Trephine Syndrome: A Retrospective Study.

Objectives: This study retrospectively investigated the prevalence and clinical features of trephine syndrome, which is a late complication of craniectom, in patients who underwent craniectomy decompression. Methods: Trephine syndrome was defined as an increase of ≥2 points in the functional independent measure (FIM) score at 7 days after cranioplasty compared with that 3 days before cranioplasty. Patients who underwent craniectomy at Kawasaki Medical School Hospital between January 1, 2010, and March 15, 2020, were included in the study. Results: During the observation period, 102 patients underwent craniectomy decompression; 71 of them later underwent cranioplasty. In total, 12 and 59 patients were assigned to the trephine and non-trephine syndrome groups, respectively. The patients in the trephine syndrome group were significantly younger than those in the non-trephine syndrome group (P<0.05). The mean durations±standard deviations (in days) from craniectomy decompression to cranioplasty were 57.1±38.9 and 83.6±69.3 for the trephine and non-trephine syndrome groups, respectively (P<0.05). Improvements in the FIM motor scores were greater than the improvements in the cognitive scores for all but one case (P<0.05). The frequency with which patients experienced exacerbation (worsened consciousness and sudden anisocoria) after hospitalization was significantly higher in the trephine syndrome group than in the non-trephine syndrome group (P<0.05). Conclusions: Performing cranioplasty as early as possible in young patients may lead to functional improvement. In the trephine syndrome group, the improvement in motor FIM score was greater than that of the cognitive score. Moreover, post-hospitalization exacerbation was more frequent in the trephine syndrome group.

Foundational Study on the Simple Detection of Impairment Resulting in Dangerous Driving in Patients with Higher Brain Dysfunction.

OBJECTIVES: We performed a survey of medical records to reveal the cognitive deficits behind dangerous driving in patients with higher brain dysfunction. METHODS: Thirty-four patients with higher brain dysfunction were included in this study. Patients' basic characteristics, neuropsychological test results, scores on two types of driving aptitude tests, and accident/near miss data from a driving simulator were extracted from medical records. We conducted χ2 tests for independence between comprehensive driving aptitude scores and "traffic accidents" / "being prohibited from driving as defined by the number of traffic accidents and near misses." Backward logistic regression analysis was carried out to assess correlations of "traffic accidents" and "being prohibited from driving as defined by the number of traffic accidents and near misses" with neuropsychological test scores. RESULTS: No significant correlation was observed between the comprehensive driving aptitude score and "traffic accidents" / "being prohibited from driving as defined by the number of traffic accidents and near misses." The score on the Raven's Colored Progressive Matrices test was the only factor identified as a significant predictor of "being prohibited from driving as defined by the number of traffic accidents and near misses." CONCLUSIONS: The results of this study suggest that it is important to focus on the decline in problem-solving ability as a predictor of "being prohibited from driving as defined by the number of traffic accidents and near misses."

Effectiveness of simple body image evaluation and manipulation for chronic pain: a case report.

Arai N, Yoshimura M, Yamamoto S, Abe H, Hanayama K. Effectiveness of simple body image evaluation and manipulation for chronic pain: A case report. Jpn J Compr Rehabil Sci 2021; 12: 15-18. Introduction: We report a case in which chronic pain was successfully relieved using a new simple body image evaluation and body image manipulation based on the evaluation results. Case: The patient, a man in his 60s, accidentally sustained a left ulnar trunk fracture and left hand degloving injury at work. Occupational therapy for approximately 2 years could not completely relieve pain in the ring finger (allodynia), causing difficulty in changing clothes and driving a car. Images of the left and right ring fingers were compared and manipulated using bandages to make the two images similar. Allodynia was reduced (visual analog scale 10 cm → 3.6 cm), and the ability to change clothes and drive a car improved. Discussion: The bandage presumably changed the tactile and visual information inputs of size, weight, length, thickness, and thickness and reconstructed the perceptual-motor loop.

Effects of Tongue-Strengthening Self-Exercises in Healthy Older Adults: A Non-Randomized Controlled Trial.

Tongue-strengthening exercises (TSE) using a device have been proposed as an intervention for improving tongue strength and endurance. However, devices for TSE have been expensive and difficult to manipulate and are not commonly used in home or clinical settings. This study therefore aimed to investigate whether tongue-strengthening self-exercises (TSsE) using a tongue-strengthening self-exercise tool at home can improve tongue strength in healthy older adults. This study included 27 participants (exercise group, η = 16, 7 men, 9 women, median age 84.5 years; control group, n = 11, 2 men, 9 women, median age 79.0 years). Exercises in the exercise group consisted of pushing the anterior tongue against the hard palate 30 times, 3 times a day, 5 days a week, for 8 weeks using a tongue-strengthening self-exercise tool. This tool is available in five levels of hardness. The most suitable hardness of the tool for each participant was calculated based on 60% of maximum tongue pressure (MTP) during the first 2 weeks of the training period and 80% of MTP for the remainder of the training period, as assessed using a tongue pressure-measuring device. The exercise group showed a significant improvement of 4.1 kPa in MTP (an 11.53% increase) and 4.53 s in endurance of tongue pressure (ETP) (a 99.86% increase). Furthermore, adherence in the exercise group was 99.2%. In conclusion, performing TSsE for 8 weeks was effective for increasing MTP and ETP in healthy older adults. This indicates that TSsE may be useful in older individuals at home to prevent age-related tongue muscle weakness.

Effectiveness of impedance parameters for muscle quality evaluation in healthy men.

We investigated the relationship between impedance parameters and skeletal muscle function in the lower extremities, as well as the effectiveness of impedance parameters in evaluating muscle quality. Lower extremity impedance of 19 healthy men (aged 23-31 years) measured using the direct segmental multi-frequency bioelectrical impedance analysis were arc-optimized using the Cole-Cole model, following which phase angle (PA), [Formula: see text], and ß were estimated. Skeletal muscle function was assessed by muscle thickness, muscle intensity, and isometric knee extension force (IKEF). IKEF was positively correlated with PA (r = 0.58, p < 0.01) and ß (r = 0.34, p < 0.05) was negatively correlated with [Formula: see text] (r = - 0.43, p < 0.01). Stepwise multiple regression analysis results revealed that PA, ß, and [Formula: see text] were correlated with IKEF independently of muscle thickness. This study suggests that arc-optimized impedance parameters are effective for evaluating muscle quality and prediction of muscle strength.

Enhancement of Facilitation Training for Aphasia by Transcranial Direct Current Stimulation.

We aimed to enhance the performance of naming and sentence production in chronic post-stroke aphasia by tablet-based language training combined with transcranial direct current stimulation (tDCS) conducted on non-consecutive days. We applied a deblocking method involved in stimulation-facilitation therapy to six participants with chronic aphasia who performed naming and sentence production tasks for impaired modalities, immediately after a spoken-word picture-matching task for an intact modality. The participants took part in two conditional sessions: a tDCS condition in which they performed a spoken word-picture matching task while we delivered an anodal tDCS over the left inferior frontal cortex; and a sham condition in which sham stimulation was delivered. We hypothesized that, compared with the sham stimulation, the application of anodal tDCS over the left inferior frontal cortex during the performance of tasks requiring access to semantic representations would enhance the deblocking effect, thereby improving the performances for subsequent naming and sentence production. Our results showed greater improvements 2 weeks after training with tDCS than those after training with sham stimulation. The accuracy rate of naming was significantly higher in the tDCS condition than in the sham condition, regardless of whether the words were trained or not. Also, we found a significant improvement in the production of related words and sentences for the untrained words in the tDCS condition, compared with that found pre-training, while in the sham condition we found no significant improvement compared with that found pre-training. These results support our hypothesis and suggest the effectiveness of the use of tDCS during language training on non-consecutive days.

Preventive Effects of Repetitive Peripheral Magnetic Stimulation on Muscle Atrophy in the Paretic Lower Limb of Acute Stroke Patients: A Pilot Study.

OBJECTIVE: The aim of this study was to investigate the effect of repetitive peripheral magnetic stimulation (rPMS) on muscle atrophy prevention in the rectus femoris muscle (RF) of the paretic limb in acute stroke patients. METHODS: Twelve acute stroke patients with a National Institute of Health Stroke Scale score >5 and a motor score of the paretic lower limb >2 at admission were divided into an intervention group (rPMS: mean age, 75±6.4 years) and a conventional care group (non-rPMS: mean age, 62±11.8 years). Baseline measurements were performed within 4 days of stroke onset. In the rPMS group, treatment was applied to the paretic thigh only for 2 weeks, 5 days a week, in addition to conventional care. The cross-sectional area (CSA) of the RF was assessed in both limbs using ultrasound at baseline and 2 weeks later. Data on patient characteristics were collected from the clinical records to assess correlations with the CSA rate of change. RESULTS: Patients in the rPMS group were significantly older. Although the CSA of the RF did not change significantly on either side in the rPMS group, there was a significant decrease in the CSA on the paretic side in the non-rPMS group. However, no significant difference was observed in the CSA rate of change in the rPMS and non-rPMS groups. The CSA rate of change on the paretic side correlated negatively with age in the rPMS group. CONCLUSIONS: Our results suggest that rPMS prevents muscle atrophy more effectively in patients in their 60s than in patients more than 70 years old.

Virtual reality-based action observation facilitates the acquisition of body-powered prosthetic control skills.

BACKGROUND: Regular body-powered (BP) prosthesis training facilitates the acquisition of skills through repeated practice but requires adequate time and motivation. Therefore, auxiliary tools such as indirect training may improve the training experience and speed of skill acquisition. In this study, we examined the effects of action observation (AO) using virtual reality (VR) as an auxiliary tool. We used two modalities during AO: three-dimensional (3D) VR and two-dimensional (2D) computer tablet devices (Tablet). Each modality was tested from first- and third-person perspectives. METHODS: We studied 40 healthy right-handed participants wearing a BP prosthesis simulator on their non-dominant hands. The participants were divided into five groups based on combinations of the different modalities and perspectives: first-person perspective on VR (VR1), third-person perspective on VR (VR3), first-person perspective on a tablet (Tablet1), third-person perspective on a tablet (Tablet3), and a control group (Control). The intervention groups observed and imitated the video image of prosthesis operation for 10 min in each of two sessions. We evaluated the level of immersion during AO using the visual analogue scale. Prosthetic control skills were evaluated using the Box and Block Test (BBT) and a bowknot task (BKT). RESULTS: In the BBT, there were no significant differences in the amount of change in the skills between the five groups. In contrast, the relative changes in the BKT prosthetic control skills in VR1 (p < 0.001, d = 3.09) and VR3 (p < 0.001, d = 2.16) were significantly higher than those in the control group. Additionally, the immersion scores of VR1 (p < 0.05, d = 1.45) and VR3 (p < 0.05, d = 1.18) were higher than those of Tablet3. There was a significant negative correlation between the immersion scores and the relative change in the BKT scores (Spearman's rs = - 0.47, p < 0.01). CONCLUSIONS: Using the BKT of bilateral manual dexterity, VR-based AO significantly improved short-term prosthetic control acquisition. Additionally, it appeared that the higher the immersion score was, the shorter the execution time of the BKT task. Our findings suggest that VR-based AO training may be effective in acquiring bilateral BP prosthetic control, which requires more 3D-based operation.

Diagnosis and treatments for oropharyngeal dysphagia: effects of capsaicin evaluated by newly developed ultrasonographic method.

Oropharyngeal dysphagia (OD) is a common symptom in the older people, and may cause fatal complications such as aspiration pneumonia. However, there is no established treatment for OD. The relationship between the transient receptor potential vanilloid 1 (TRPV1) and substance P released by activated TRPV1 was recently demonstrated. Further, there are several reports showing that capsaicin, a specific agonist of TRPV1, can improve OD. Currently, the evaluation of swallowing is mainly performed by videofluoroscopic examination. However, there are no reports on the clinical application of ultrasonography using tissue Doppler imaging. In this review, we describe the pathophysiology and treatments for OD, introduce our novel US method to evaluate cervical esophageal motility, and then outline our clinical study examining the effects of capsaicin, a specific TRPV1 agonist, in older patients with OD.

Motor activation is modulated by visual experience during cyclic gait observation: A transcranial magnetic stimulation study.

Transcranial magnetic stimulation (TMS) has been widely utilized to noninvasively explore the motor system during the observation of human movement. However, few studies have characterized motor cortex activity during periodic gait observation. Thus, this study examined the effects of an observer's visual experience and/or intention to imitate on corticospinal excitability during the observation of another's gait. Twenty-six healthy volunteers were included in this study and allocated to two different groups. Participants in the visual experience group had formal experience with gait observation (physical therapist training), while those in the control group did not. Motor-evoked potentials induced by TMS in the tibialis anterior and soleus muscles were measured as surrogates of corticospinal excitability. Participants were seated and, while resting, they observed a demonstrator's gait or observed it with the intention to subsequently reproduce it. Compared with the resting state, cyclic gait observation led to significant corticospinal facilitation in the tibialis anterior and soleus muscles. However, this pattern of corticospinal facilitation in the measured muscles was not coupled to the pattern of crural muscle activity during actual gait and was independent of the step cycle. This motor cortex facilitation effect during gait observation was enhanced by the observer's visual experience in a manner that was not step cycle-dependent, while the observer's intent to imitate did not affect corticospinal excitatory input to either muscle. In addition, visual experience did not modulate corticospinal excitability in gait-related crural muscles. Our findings indicate that motor cortex activity during gait observation is not in line with the timing of muscle activity during gait execution and is modulated by an individual's gait observation experience. These results suggest that visual experience acquired from repetitive gait observation may facilitate the motor system's control on bipedal walking, but may not promote the learning of muscle activity patterns.

Effects of Tongue-Strengthening Exercise on the Geniohyoid Muscle in Young Healthy Adults.

The activities of the suprahyoid muscles have been reported to be induced by tongue muscle contraction. The purpose of this research was to investigate whether tongue-strengthening exercises using a device cause hypertrophy of the geniohyoid muscle in healthy adults. Seven healthy young adults (3 men and 4 women, 21.0 ± 1.3 years old) received 8-week tongue muscle training with the JMS Tongue Pressure Measuring Device. The participants were instructed to press the anterior tongue against the hard palate 30 times in each session, three sessions a day, and 3 days a week. The exercise intensity was set to 60% of maximum tongue pressure in the first week, and to 80% of maximum tongue pressure for the remaining period. The training effect was evaluated by measuring (1) maximum tongue pressure value with the JMS Tongue Pressure Measuring Device, and (2) the area at rest, shortening amount, and contraction ratio of the geniohyoid muscle using ultrasonic imaging. After the 8-week training program, the maximum tongue pressure increased significantly from 44.9 to 61.6 kPa. The area of the geniohyoid muscle at rest also increased significantly from 2.3 to 2.6 cm2 after the program. There were no significant differences in the shortening amounts and the contraction ratios of the geniohyoid muscle between the values before and after the program. The tongue-strengthening exercise was useful to increase the muscle power of the geniohyoid, as well as the tongue muscles, in healthy young adults.