Fumihiro Tajima

Muscle Sympathetic Nerve Activity During Cold Pressor Test in Patients With Cerebrovascular Accidents

BACKGROUND AND PURPOSE Autonomic dysfunction is frequently present in patients with cerebrovascular accidents (CVA). However, the pathophysiological mechanisms of these disorders are not clear. The purpose of the study was to assess the effects of CVA on the autonomic nervous system. METHODS In eight male patients with a history of CVA with damage of the cortical or subcortical structures, we measured the cold pressor response during recording of muscle sympathetic nerve activity (MSNA) from the peroneal nerve on the hemiplegic side. We also studied 10 age-matched male control subjects. Tests were performed before, during, and after immersion of the nonhemiplegic hand in ice water for a period of 3 minutes in each phase. We also recorded changes in heart rate (HR), arterial blood pressure, skin temperature of the middle finger, and perception of pain using the Borgs score. RESULTS During the control period, the mean burst count of MSNA in CVA (57.2 +/- 3.9 beats/100 HR) was higher than in control subjects (36.3 +/- 3.2 beats/100 HR) (P<.05). Total MSNA (the mean burst amplitude per minute times burst rate) increased significantly in CVA and control during the immersion period by 79.9 +/- 18.4% and 133.1 +/- 25.6%, respectively. The percent change in total MSNA in CVA was attenuated during immersion compared with control subjects. The HR and skin temperature responses as well as the Borgs score were similar in both groups during control, hand immersion, and recovery periods. CONCLUSIONS The present results suggest that increased MSNA in CVA may be due to damage of cortical or subcortical structures or stroke-related changes in other areas or nonspecific changes that cause continuous increase in basal MSNA.

Low-echoic lesions underneath the skin in subjects with spinal-cord injury

Study design:Criterion standard and survey cases.Objectives:To assess the utility of ultrasonography for detecting deep tissue injury or incipient pressure ulcers and to determine the patterns of development of pressure ulcers in subjects with chronic spinal-cord injury (SCI).Setting:Ambulatory setting at public hospital.Methods:The subjects were 43 men with SCI between C5 and L1 (age: 42.6±11.6 years, mean±s.d.). A total of 129 areas (sacral region and bilateral ischial regions in each subject) were examined by inspection, palpation and ultrasonography.Results:Of the 129 areas, 112 were normal by inspection, palpation and ultrasound imaging. Nine areas were abnormal on ultrasonography alone and six were lesion positive by palpation and ultrasonography. Only two areas were abnormal by all three methods. Ultrasonography always detected a heterogeneous pattern and low-echoic areas directly adjacent to the bone.Conclusions:Our results indicated that low-echoic lesions, signaling deep tissue injuries or early pressure ulcers, originated in areas near the bone and extended toward the epidermis. The results suggest that ultrasonography is a useful tool for the early detection of deep tissue injuries or pressure ulcers.

Plasma IL-6 levels during arm exercise in persons with spinal cord injury.

Study design:Non-randomized study.Objectives:Previous studies indicated that at least 2-h leg exercise at more than 60% maximum oxygen consumption (VO2max) increased plasma interleukin (IL)-6 in able-bodied (AB) subjects. The purpose of the present study was to compare IL-6 response to arm exercise in AB subjects and persons with spinal cord injury (SCI).Setting:Wakayama Medical University in Japan.Methods:Six subjects with SCI between T6 and T10 and seven AB subjects performed 2-h arm crank ergometer exercise at 60%VO2max. Plasma catecholamines, IL-6, tumor necrosis factor (TNF)-α and high-sensitivity C-reactive protein (hsCRP) were measured before exercise, 60-min exercise, immediately and 2 h after the completion of exercise.Results:Arm exercise increased myoglobin and plasma IL-6 levels in SCI and AB (P<0.01), but there were no differences in them between the two groups throughout the study. Plasma levels creatine kinase, lactate dehydrogenase, TNF-α and hsCRP did not change throughout the study in both groups.Conclusion:These findings suggest neither significant muscle damage nor inflammatory response during exercise. The increase in plasma IL-6 in SCI was not unexpected, confirming that moderate intensity and relatively long-arm exercise is safe and beneficial for SCI subjects with regard to IL-6 excretion, as in AB subjects.

Age-related sex differences in erector spinae muscle endurance using surface electromyographic power spectral analysis in healthy humans.

BACKGROUND CONTEXT Previous studies reported that the erector spinae muscle is more resistant to fatigue in healthy adult women than in men. However, no study has reported changes in back muscle fatigue with aging in healthy men and women. PURPOSE The aim of this study was to evaluate age-related changes in muscle fatigue of erector spinae muscle in men and women. STUDY DESIGN/SETTING This cross-sectional study was conducted in a laboratory. PATIENT SAMPLE Fifty-three healthy subjects (11 elderly men, 11 elderly women, 17 young men, and 14 young women) without low back pain history. OUTCOME MEASURES The median frequency (MF) and mean power frequency (MPF) during trunk holding test were derived from the raw electromyographic (EMG) signal using Fast Fourier Transform spectrum analysis program. The rates of changes in MF and MPF were calculated. METHODS Subjects performed the unsupported trunk holding test until exhaustion. The results of power spectral analysis of the EMG activity of the left erector spinae muscle were compared in both age groups and sexes. RESULTS The endurance time in young men was significantly shorter than in young women. The slopes of MF and MPF in young men were significantly higher than in young women. There were no significant differences in MF and MPF slopes of elderly men and elderly women. Furthermore, the MF and MPF slopes were significantly lower in elderly men than young men but similar in the two women groups. CONCLUSIONS Age-related changes in the slopes of MF and MPF of erector spinae muscle occur in healthy men but not in healthy women.

A dysphagia study in patients with sporadic inclusion body myositis (s-IBM)

The nature of the swallowing impairment in patients with sporadic inclusion body myositis (s-IBM) has not been well characterized. In this study, we examined ten consecutive s-IBM patients using videofluoroscopy (VF) and computed pharyngoesophageal manometry (CPM). The patients were divided into two groups: patients with complaint and without complaint of dysphagia. VF results indicated pharyngeal muscle propulsion (PP) at the hypopharyngeal and upper esophagus sphincter (UES) in all s-IBM patients. Patients without complaint of dysphagia showed a mild degree of PP, whereas a severe form of PP was observed in patients with complaint of dysphagia. CPM revealed that negative pressure during UES opening was not observed in the s-IBM patients with complaint of dysphagia. Incomplete opening and PP at the UES were observed in all s-IBM patients. These results indicate that the dysphagic processes occur subclinically in s-IBM patients who may not report swallowing impairments.

Anthropometric features of wheelchair marathon race competitors with spinal cord injuries

The anthropometric data of the health check programme in the Oita Wheelchair Marathon Race were analysed. In the past 10 years, a total of 2677 competitors participated in this programme. Age, height, body weight, body fat, lung vital capacity, girth of chest, girth of upper arm, grasping force and power of upper arm were compared between 710 fine competitors and 99 poor competitors. Power of the upper arms and lung vital capacity played a major part in the result of the races. It was suggested that these two factors had major influences on the achievement of this type of sports activity.

Longitudinal Changes in Physical Capacity Over 20 Years in Athletes With Spinal Cord Injury

OBJECTIVE To investigate the longitudinal changes in physical capacity over 20 years in athletes with spinal cord injury (SCI). DESIGN Longitudinal study (20-y follow-up). SETTING Laboratory setting. PARTICIPANTS Persons with SCI (N=7). INTERVENTIONS Not applicable. MAIN OUTCOME MEASURES Maximum oxygen consumption Vo(2)max) measured in 1986-1988 and in 2006. RESULTS Subjects with SCI maintained stable Vo(2)max in 2006. Six of the 7 continued various wheelchair sports activities, while 1 person quit sports activities 1 year after the baseline study. The latter person showed reduced Vo(2)max by 53%, while 2 persons who continued strenuous wheelchair sports activities showed increased Vo(2)max by 43% and 45% after 20 years. CONCLUSION The results indicated that physical capacity reflected the level of sports activity in subjects with SCI who maintained sports activities.

Balloon Dilation in sporadic Inclusion Body Myositis patients with Dysphagia

Here, we describe balloon catheter dilation at the upper esophageal sphincter (UES) in three sporadic inclusion body myositis (s-IBM) patients with dysphagia. Initially, we performed IVIg therapy, and, three months later, switched to balloon dilation therapy. A 12-Fr balloon catheter was inserted from the mouth under fluoroscopy and the balloon inflated at the UES. The catheter was pulled back and re-inserted several times. We examined videofluoroscopy (VF) and pressure at the oropharynx, hypopharynx and UES using computed pharyngoesophageal manometry (CPM). Before both therapies, the VF study revealed a very small amount of barium paste passing through the UES. After balloon dilation therapy, as well as IVIg, subjective complaints of dysphagia disappeared and the VF study revealed an increased amount of barium paste passing through the UES. We conclude that balloon dilation therapy is a complementary method for conventional dysphagia therapies in s-IBM patients with dysphagia.

Impaired immune response to voluntary arm-crank ergometer exercise in patients with cervical spinal cord injury

Study design:Non-randomized study.Objective:The mechanism underlying exercise-induced argumentation of natural killer cell cytotoxic activity (NKCA) in humans remains unclear. To address this, NKCA responses were studied during and after exercise in persons with cervical spinal cord injury (CSCI) and dysfunctional sympathetic nervous system.Setting:Kibikogen Rehabilitation Center for Employment Injuries.Methods:We examined the NKCA responses to 20-min arm-crank ergometer exercise at 60% of maximum oxygen consumption in eight persons with CSCI (between C6 and C7) and six able-bodied subjects. NKCA, adrenaline, and cortisol were measured before, immediately after exercise, 1 h after exercise, and 2 h after exercise.Results:In able-bodied subjects, NKCA increased immediately after exercise (P<0.01) and then decreased to below the pre-exercise level 1 h after exercise, before recovering to the baseline level at 2 h after exercise. Plasma adrenaline concentrations increased significantly immediately after exercise (P<0.01) and returned to the baseline level 1 h after exercise. The plasma cortisol level did not change throughout the study. In contrast, NKCA, plasma concentrations of adrenaline, and cortisol did not change throughout the study in subjects with CSCI.Conclusion:In subjects with CSCI, the lack of response in NKCA throughout the experiment is probably mainly due to a dysfunctional sympathetic nervous system.

Improvements in impaired GABA and GAD65/67 production in the spinal dorsal horn contribute to exercise-induced hypoalgesia in a mouse model of neuropathic pain

Background Physical exercise effectively attenuates neuropathic pain, and multiple events including the inhibition of activated glial cells in the spinal dorsal horn, activation of the descending pain inhibitory system, and reductions in pro-inflammatory cytokines in injured peripheral nerves may contribute to exercise-induced hypoalgesia. Since fewer GABAergic hypoalgesic interneurons exist in the dorsal horn in neuropathic pain model animals, the recovery of impaired GABAergic inhibition in the dorsal horn may improve pain behavior. We herein determined whether the production of gamma-aminobutyric acid (GABA) and glutamic acid decarboxylase (GAD) in the dorsal horn is restored by treadmill running and contributes to exercise-induced hypoalgesia in neuropathic pain model mice. C57BL/6 J mice underwent partial sciatic nerve ligation (PSL). PSL-Runner mice ran on a treadmill at 7 m/min for 60 min/day, 5 days/week, from two days after PSL. Results Mechanical allodynia and heat hyperalgesia developed in PSL-Sedentary mice but were significantly attenuated in PSL-Runner mice. PSL markedly decreased GABA and GAD65/67 levels in neuropils in the ipsilateral dorsal horn, while treadmill running inhibited these reductions. GABA+ neuronal nuclei+ interneuron numbers in the ipsilateral dorsal horn were significantly decreased in PSL-Sedentary mice but not in PSL-Runner mice. Pain behavior thresholds positively correlated with GABA and GAD65/67 levels and GABAergic interneuron numbers in the ipsilateral dorsal horns of PSL-Sedentary and -Runner mice. Conclusions Treadmill running prevented PSL-induced reductions in GAD65/67 production, and, thus, GABA levels may be retained in interneurons and neuropils in the superficial dorsal horn. Therefore, improvements in impaired GABAergic inhibition may be involved in exercise-induced hypoalgesia.