Yoshitaka Shiba

Sympathetic Nervous Activity and Myocardial Damage Immediately After Subarachnoid Hemorrhage in a Unique Animal Model

Background and Purpose— Obvious cardiac dysfunction, including ECG abnormalities and left ventricular asynergy, is known to develop after subarachnoid hemorrhage (SAH). To clarify the close relationship between myocardial damage and sympathetic nervous activity immediately after SAH, a novel experimental animal model was used. Methods— SAH was provoked by perforation of the basilar artery with the use of a microcatheter inserted through the femoral artery in 18 beagle dogs. Hemodynamic changes were recorded, and plasma concentrations of noradrenaline, adrenaline, and 3-methoxy-4-hydroxy-phenylethylene glycol (MHPG) and serum levels of creatine kinase–MB (CK-MB) and troponin T were measured at 0, 5, 15, 30, 60, 120, and 180 minutes after SAH. Results— Noradrenaline (pg/mL), adrenaline (pg/mL), and MHPG (ng/mL) increased abruptly from 120±70, 130±70, and 1.3±0.5 before SAH to 1700±1200, 5600±3500, and 3.2±1.2 at 5 minutes after SAH, respectively. Aortic pressure, left ventricular wall motion, and cardiac output increased by 60%, 40%, and 30%, respectively (P <0.001) at 5 minutes and then decreased by 50%, 55%, and 40%, respectively (P <0.001) >60 minutes after SAH compared with baseline values. The peak value of CK-MB correlated positively with the peak values of noradrenaline and adrenaline (r =0.730 and r =0.611, respectively). The peak value of troponin T also correlated positively with the peak values of noradrenaline and adrenaline (r =0.828 and r =0.792, respectively). Conclusions— These results suggest that the elevated activity of the sympathetic nervous system observed in the acute phase of SAH induced myocardial damage and contributed to the development of cardiac dysfunction.

The Feasibility of Measuring Joint Angular Velocity With a Gyro-Sensor

OBJECTIVESnTo determine the reliability of an assessment of joint angular velocity using a gyro-sensor and to examine the relationship between ankle angular velocity and physical functions.nnnDESIGNnCross-sectional.nnnSETTINGnKinesiology laboratory.nnnPARTICIPANTSnTwenty healthy young adults (mean age, 22.5 y) and 113 community-dwelling older adults (mean age, 75.1 y).nnnINTERVENTIONSnNot applicable.nnnMAIN OUTCOME MEASURESnMaximal ankle joint velocity was measured using a gyro-sensor during heel-rising and jumping with knee extended. The intraclass correlation coefficient (ICC) was used to determine the intertester and intratester reliability. The Pearson correlation coefficient was used to examine the relationships between maximal ankle joint velocity and isometric muscle strength and isokinetic muscle power in young adults and also to examine the relationships between maximal ankle joint velocity and functional performance measurements such as walking time in older adults.nnnRESULTSnHigh reliability was found for intertester (ICC=.96) and intratester reliability (ICC=.96). The data from the gyro-sensor highly correlated with muscle strength (r range, .62-.68; P<.01) and muscle power (r range, .45-.79; P range, .01-.05). In older subjects, mobility functions significantly correlated with the angular velocity of ankle plantarflexion.nnnCONCLUSIONSnMeasurement of ankle angular velocity using a gyro-sensor is both reliable and feasible, with the results representing a significant correlation to muscle power and performance measurements.

The validity of an assessment of maximum angular velocity of knee extension (KE) using a gyroscope.

Although it is more important to assess the muscular power of the lower extremities than the strength, no simplified method for doing so has been found. The aim of this study was to assess the validity of the assessment of the angular velocity of KE using a gyroscope. Participants included 105 community-dwelling older people (55 women, 50 men, age ± standard deviation (SD) 75±5.3). Pearson correlation coefficients and Spearman rank-correlation coefficients were used to examine the relationships between the angular velocity of KE and functional performance measurements, a self-efficacy scale and health-related quality of life (HRQOL). The data from the gyroscope were significantly correlated with some physical functions such as muscle strength (r=0.304, p<0.01), and walking velocity (r=0.543, p<0.001). In addition, the joint angular velocity was significantly correlated with self-efficacy (r=0.219-0.329, p<0.01-0.05) and HRQOL (r=0.207-0.359, p<0.01-0.05). The absolute value of the correlation coefficient of angular velocity tended to be greater than that of the muscle strength for mobility functions such as walking velocity and the timed-up-and-go (TUG) test. In conclusion, it was found that the assessment of the angular velocity of the knee joint using a gyroscope could be a feasible and meaningful measurement in the geriatrics field.

Construct validity of posture as a measure of physical function in elderly individuals: Use of a digitalized inclinometer to assess trunk inclination

The first aim of the present study was to determine the construct validity of evaluating posture as a measure of physical function in elderly individuals. The second aim was to determine reference values for sternum inclination in elderly individuals when measured using a digitalized inclinometer.

Motion correction for jPET-D4: improvement of measurement accuracy with a solid marker

We proposed a unique motion detection method that can be used for motion correction in brain PET imaging. This method uses a specially-designed solid marker that enables position and angle (direction) measurement with one optical movie camera. Therefore, it is applicable to a long, narrow patient port space in which a two-camera system cannot be installed. By refining machining accuracy of the solid marker, angle measurement accuracy was significantly improved. As a result, we obtained sufficient measurement accuracies in the angles as well as in the trans-axial positions. In addition, we have been developing a model to calculate axial positions from measured trans-axial positions and angles. As a result of a multivariate analysis of measured motion tracking data, we found that sufficient accuracy can be obtained under well-controlled experimental conditions. In order to realize head motion correction for jPET-D4, we are also considering marker attaching, camera calibration, device installation, and correction algorithms.

Head motion correction for jPET-D4

We propose a new method of head motion tracking for positron emission tomography (PET) brain imaging. This method uses one optical camera and one solid marker, differing from the conventional method, which uses two or more cameras and markers (e.g. the POLARIS system). We expect this to be useful for jPET-D4, whose patient port is long and small. We present the principle of the head motion measurement and show the results of preliminary experiments.

Reliability and validity of the Short Falls Efficacy Scale-International for Japanese older people

BackgroundThe Short Falls Efficacy Scale-International (Short FES-I) has been confirmed to be a good measure with reliability and validity in a UK sample; however, the reliability and validity of the Short FES-I for Japanese older people have not yet been established.AimThe aim of this study was to determine the reliability and validity of the Short FES-I for Japanese older people.MethodsThe study participants were 519 older people aged 65xa0years and over who were living independently in their community. The Short FES-I is composed of seven items rated on a four-point Likert scale. Lower scores indicate better fall-related efficacy. To investigate the validity of the Short FES-I, previous falls, physical function such as grip strength and scores on the Timed Up and Go (TUG) test, psychological factors such as self-rated health (SRH), cognitive function, and other confounding factors were collected. The association between the previous falls and the Short FES-I was analyzed using logistic regression analysis. Furthermore, factors related to the Short FES-I were investigated using multiple regression analysis.ResultsCronbach’s alpha for the Short FES-I was 0.87. Short FES-I scores were significantly higher in participants with a history of falls than in those without. In addition, Short FES-I scores were significantly and independently associated with falls in logistic regression analysis, and significantly associated with grip strength, TUG time, and SRH in multiple regression analysis.Conclusions and discussionThese results suggest that the Short FES-I is a reliable and valid fall-related measurement scale for Japanese older people.

Knee extensor strength assessed using a vertical squat and a simple geometric model to calculate joint torque: An evaluation of validity and clinical utility: Squat model for measuring knee strength

We propose a simple method to measure knee extensor muscle strength using a single‐legged vertical squat. The purpose of the present study was to assess the validity of this method in comparison with standard methods of measurement.

A novel clinical evaluation method using maximum angular velocity during knee extension to assess lower extremity muscle function of older adults

The purpose of this study is to examine the utilities of maximum angular velocity (AV) assessment during knee extension (KE) using a gyroscope for clinical evaluation of exercise program for older adults. Two hundred and 4 community-dwelling older adults underwent a 3-month exercise intervention program. Outcome measures included AV during KE and other physical functions (isometric strength (IS), walking abilities, and balance functions). A correlation coefficient was used to evaluate the relationships between AV and other physical functions at baseline. The differences of physical functions before and after intervention were evaluated and the effect size of each measurement was calculated after the program. The AV measurement was significantly correlated with IS during KE (r=0.303, P<0.01) and other physical functions. Most correlation coefficients of angular velocity were greater than that of IS. All of physical assessments were significantly improved. Also, effect size of AV was greater than that of IS (d=0.45 vs. 0.42). AV of the lower extremities is useful to evaluate the effects of exercise intervention in the elderly.

Is complex obstacle negotiation exercise more effective than other exercise interventions in fall prevention

three excellent methods to distinguish delirium superimposed on dementia from BPSD. These methods were derived from our prospective randomized controlled trial CADIS (Clinical Trials.Gov NCT01650896). The first method is to calculate the rate of decline in cognitive scores immediately before delirium (actual or imputed) to the actual scores on the day of delirium. For example, six-digit span forward (6-DSF) is a 5-s test for inattention. If 6-DSF was five out of six before possible delirium and fell to two out of six, the absolute change is three digits. The relative change is three out of the range of the test (6), which is 50%. The Delirium Index (DI) is a seven-item test useful in both dementia and delirium. Zero is the best score and 21 is the worst score. If DI was three out of 21 before possible delirium rising to 10 out of 21 with delirium, the absolute change is seven points. The relative change is seven out of 21 or 33%. In BPSD, behavior changes more than cognitive. The second method to distinguish delirium from BPSD is to calculate the magnitude and speed of recovery of key cognitive tests. Thus, in CADIS, six-digit span forward improved by an average of 25% during the first 2 days after admission for delirium. The overall rate of recovery was a mean of 1.4 days for five-digit span forward and 5.7 days for six-digit span and delirium index. The third method to distinguish delirium superimposed on dementia from BPSD is serial measurement of IADL. In CADIS, IADL fell by 57% during the 2 days before dementia, and rose to 75% of baseline by the time of discharge.