Accuracy of spinal curvature assessed by a computer-assisted device and anthropometric indicators in discriminating vertebral fractures among individuals with back pain.

UNLABELLED: This study examined the accuracy of thoracic and lumbar kyphotic angles as well as anthropometric indicators for discriminating patients with vertebral fracture among Japanese women >50 years old with back pain. Along with region-specific kyphotic angles and anthropometric indicators, the combination of thoracic and lumbar kyphotic angles offered the highest accuracy. INTRODUCTION: Vertebral fractures have been associated with thoracic kyphosis. However, reports on lumbar kyphotic changes in association with vertebral fracture are scarce. This study investigated the accuracy of thoracic kyphotic angle (TKA) and lumbar kyphotic angle (LKA) measurements as well as anthropometric indicators (wall-occiput distance (WOD) and rib-pelvis distance (RPD)) in discriminating patients with vertebral fracture. METHODS: Lateral radiographs of the spine were obtained in 70 postmenopausal Japanese women who visited an orthopedic clinic with low back pain (mean age, 76.2 ± 9.0 years). Radiographic vertebral fracture was diagnosed using quantitative measurement according to Japanese criteria. Osteoarthritis (OA) was defined as Kellgren-Lawrence (KL) grade 3 or higher. TKA and LKA were measured using SpinalMouse®. WOD and RPD were also measured. RESULTS: At least one vertebral fracture was present in 49 subjects (70 %). Women with vertebral fractures showed significant increases in LKA, TKA + LKA, and WOD and decreases in RPD. Logistic regression analysis showed significant association between TKA + LKA and vertebral fracture independent of the presence of OA. Receiver operating characteristic analysis revealed that TKA was useful for discriminating thoracic fractures (area under the curve (AUC), 0.730) and LKA was useful for lumbar fractures (AUC, 0.691). The combination of TKA + LKA offered the highest accuracy for detecting thoracic, lumbar, and any vertebral fractures, with AUCs of 0.779, 0.728, and 0.783, respectively. WOD and RPD showed low-to-moderate accuracies for thoracic, lumbar, and any vertebral fractures. CONCLUSIONS: Assessment of spinal kyphosis by SpinalMouse® as well as anthropometric indicators proved useful in discriminating subjects with vertebral fractures. These convenient and radiation-free methods could contribute to early diagnosis of vertebral fractures and subsequent appropriate treatment, thus preventing additional osteoporotic fractures.

The influence of strenuous muscle stimulation on the menarche.

Nowadays, the average age at which menarche begins is lowering by three to four years every century, that is, four months every decade, according to both Japanese, and European and American annual changes of the average age. It emerged that the menarche shows a tendency to occur later in female gymnasts, because of the influence of strenuous muscle stimulation, and the fact that a higher level of technic is required in gymnastic games each year. These conclusions have been drawn from replies submitted to a questionnaire distributed among a relatively small number of gymnasts who participated in the competitions including the Inter High School Championship and the World Cup Championship. For example, at the age of 14, the percentage of women who had menstruated is almost 100% among women in general, but only 24% among World Cup Championship gymnasts, the average age at menarche of the latter being later than that of the former by as many as 3 years. At the age of 16, the percentage of women who had menstruated is 100% among women in general, but on the other hand, it is only 60% among World Cup Championship gymnasts, in other words, only a low percentage of women, of the latter group, had menstruated. Finally in our study, we established that the age at menarche of gymnasts is three or five years later than that of women in general. From our study, we concluded that the excessive burden imposed on muscles might cause an abnormal menstrual cycle, and the influence on menstruation would be considerable.

A new pattern discriminant method for evoked potentials.

A statistical approach to evaluate evoked potentials (EPs), consisting of three stages in procedure, was proposed with an application to study on postictal changes of visually evoked potentials (VEPs). At the first step, time series data of EPs were reduced by the means of using an autoregressive (AR) model. In this way, EPs were described in terms of AR coefficient vectors. Then statistical distances which are well known as the Mahalanobis' distances were determined as a scale for dissimilarity between patterns of EPs. At the third stage, a retrospective classification through a numerical taxonomy based on similarity of patterns was demonstrated. This procedure will tell us some standards for future experiments as well as an integrative insight of results from present experiment. By the above method, it was suggested that there may be two different processes in postictal recovery of kindled cats.

On some EEG patterns in children and adults.

The EEGs of 76 children (6--9 years of age) were classified into five types for the occipital regions (O1 and O2) and into seven types for the central regions (C3 and C4) by the method of EEG pattern discrimination (Sato, Ono et al., 1977). The five types of EEG patterns observed in the occipital regions were: (1) low frequency alpha wave of about 8--9 Hz, (2) Hz alpha wave, (3) low frequency alpha and theta wave, (4) 10 Hz alpha wave and theta wave and (5) irregular wave patterns, while two more types, (6) the low pass and (7) theta wave types, were observed in the central regions. These same types were also observed in the EEGs of 41 adults (20--25 years of age). The amount of difference between the above five and seven types in children and adults were obtained by the generalized (Mahalanobis') distances. In the occipital regions, the percentage frequency of the alpha wave type was the highest followed by that of the alpha and theta wave type, while the frequency of the alpha and theta waves type was the highest in the central regions, followed, next and third in order by the low pass type and the alpha type, respectively.

On some methods for EEG pattern discrimination.

Two methods of statistical inference for EEG pattern discrimination are described with examples of their application. One concerns whether an arbitrary EEG pattern belongs to a standard EEG group or not, and the other concerns whether a group of EEG belongs to the standard EEG group.

Component activities in the autoregressive activity of physiological systems.

The higher-order autoregressive (AR) activity of a physiological system (Sato 1975a,b; Sato et al., 1977) was decomposed into first- and second-order activities. The former time-pattern displays a fast rise and an exponential decay, while the latter exhibits a damped sine wave. Application of this component analysis to EEG showed the first-order activity to coincide with the nonoscillatory delta component. The frequency distribution of the natural, damped and resonance frequencies of the second-order activities was found to show one, two or three modes in each frequency range of the delta, theta and beta rhythms in ninety normal adult EEGs. Hence, the second-order activities agree with the oscillatory delta, theta, alpha and beta rhythms. Some changes were induced not only in the frequency of theta and beta rhythms but also in that of alpha rhythm by over-breathing for about three minutes.