Influence of gender on diaphragm thickness using a method for determining intima media thickness in healthy young adults.

BACKGROUND: To clarify the differences in diaphragm thickness between male and female participants in healthy young adults with ultrasonography using the mean intima media thickness (IMT) method and to investigate the relationship between diaphragm thickness and respiratory pressure. METHODS: Twenty-nine healthy individuals (16 females and 13 males) participated in the study. Diaphragm thickness was measured at total lung capacity (TLC) and at functional residual capacity (FRC) in each participant. We measured the diaphragm thickness using a method for mean intima media thickness. Moreover, change ratio of diaphragm thickness was calculated with the diaphragm thickness at TLC and FRC. RESULTS: Mean diaphragm thicknesses at FRC in males were significantly narrower than those in females (p < 0.001). The change ratio of diaphragm thickness was significantly augmented in males compared with that in females (p < 0.001). There was a positive correlation between the change ratio of diaphragm thickness and pulmonary function data and respiratory muscle strength in healthy young adults. CONCLUSIONS: The change ratio of diaphragm thickness using the IMT method can be accurately performed with a high degree of reproducibility by clinical laboratory technicians and may be a useful indicator for evaluating diaphragm muscle strength.

Change in fetal behavior in response to vibroacoustic stimulation.

Objective To assess fetal behavioral changes in response to vibroacoustic stimulation (VAS) in normal singleton pregnancies using four-dimensional (4D) ultrasound. Methods Ten types of fetal movements and facial expressions in 68 healthy pregnant women between 24 and 40 weeks were studied using 4D ultrasound for 3 min before and after 3-s VAS. The frequencies of mouthing, yawning, tongue expulsion, back arch, jerky arm movement, startle movement, smiling, scowling, hand-to-face movement, and blinking were evaluated. The fetuses were subdivided into four gestational age groups (24-27, 28-31, 32-35, and ≥36 weeks). Comparison of the frequencies of the fetal behaviors before and after the stimulation in each gestational age group was conducted to detect the response to stimulation with advancing gestation. Results There were no significant differences in the frequency of each fetal behavior before and after VAS at 24-27, 28-31, and 32-35 weeks of gestation. However, the frequencies of blinking and startle movements were significantly higher after VAS in the 36-40 gestational age group (P < 0.05). Conclusion The age of 36 weeks of gestation might represent an advanced stage of brain and central nervous system development and maturation as the response to stimuli is prominent at this age compared with earlier gestation.

[A New Method of Analyzing the Closing Volume (CV) Curve: "N2 First Derivative Wave Method"].

Evaluation of the lung function involves the measurement of many factors. The closing volume (CV) curve is clinically important as an index of uneven alveolar ventilation and airway closure. Although conventional methods for CV measurement are usually based on the pattern of the exhaled nitrogen (N2) concentration curve with respect to the lung volume, it is often difficult to measure the steep pattern of patients with chronic obstructive pulmonary disease (COPD). In this paper, we proposed a new method called the "N2 first derivative (fdN) wave method" for measuring CV. The N2 concentration of the CV curve was transformed to a derivative with respect to the lung volume, which revealed the existence of cardiogenic oscillations. Discrimination between phases III and IV was straightforward based on the difference in the slope or in the amplitude of oscillations of the fdN wave. Our new method was able to distinguish phase IV from phase III using the difference in amplitude of the oscillation of the fdN wave even in the presence of COPD with steep patterns of the CV curve. Close relationships were seen among normal subjects including COPD patients in both the slope of the alveolar plateau (ΔN2) and the CV values measured with the conventional and new methods. In conclusion, the new method we propose in this paper was able to provide measurements of CV for all subjects including those with COPD. [Original]

Phase Lag Analysis Scalp Electroencephalography May Predict Seizure Frequencies in Patients with Childhood Epilepsy with Centrotemporal Spikes.

Background: Childhood epilepsy with centrotemporal spikes (CECTS) is the most common epilepsy syndrome in school-aged children. However, predictors for seizure frequency are yet to be clarified using the phase lag index (PLI) analyses. We investigated PLI of scalp electroencephalography data at onset to identify potential predictive markers for seizure times. Methods: We compared the PLIs of 13 patients with CECTS and 13 age- and sex-matched healthy controls. For the PLI analysis, we used resting-state electroencephalography data (excluding paroxysmal discharges), and analyzed the mean PLIs among all electrodes and between interest electrodes (C3, C4, P3, P4, T3, and T4) and other electrodes. Furthermore, we compared PLIs between CECTS and control data and analyzed the associations between PLIs and total seizure times in CECTS patients. Results: No differences were detected in clinical profiles or visual electroencephalography examinations between patients with CECTS and control participants. In patients with CECTS, the mean PLIs among all electrodes and toward interest electrodes were higher at the theta and alpha bands and lower at the delta and gamma bands than those in control participants. Additionally, the mean PLIs toward interest electrodes in the beta frequency band were negatively associated with seizure times (P = 0.02). Conclusion: The resting-state delta, theta, alpha, and gamma band PLIs might reflect an aberrant brain network in patients with CECTS. The resting-state PLI among the selected electrodes of interest in the beta frequency band may be a predictive marker of seizure times in patients with CECTS.

Phase Lag Analyses on Ictal Scalp Electroencephalography May Predict Outcomes of Corpus Callosotomy for Epileptic Spasms.

Objective: We aimed to clarify the patterns of ictal power and phase lag among bilateral hemispheres on scalp electroencephalography (EEG) recorded pre-operatively during epileptic spasms (ESs) and the correlation with the outcomes following corpus callosotomy. Methods: We enrolled 17 patients who underwent corpus callosotomy for ESs before 20 years of age. After corpus callosotomy, seven patients did not experience further ESs (favorable outcome group), and the remaining 10 patients had ongoing ESs (unfavorable outcome group). We used pre-operative scalp EEG data from monopolar montages using the average reference. The relative power spectrum (PS), ictal power laterality (IPL) among the hemispheres, and phase lag, calculated by the cross-power spectrum (CPS) among symmetrical electrodes (i.e., F3 and F4), were analyzed in the EEG data of ESs from 143 pre-operative scalp video-EEG records. Analyses were conducted separately in each frequency band from the delta, theta, alpha, beta, and gamma range. We compared the means of those data in each patient between favorable and unfavorable outcome groups. Results: Among all frequency bands, no significant differences were seen in the individual mean relative PSs in the favorable and unfavorable outcome group. Although the mean IPLs in each patient tended to be high in the unfavorable outcome group, no significant differences were found. The mean CPSs in the delta, theta, and gamma frequency bands were significantly higher in the unfavorable than in the favorable outcome group. Using the Youden index, the optimal cutoff points of those mean CPS values for unfavorable outcomes were 64.00 in the delta band (sensitivity: 100%, specificity: 80%), 74.20 in the theta band (100, 80%), and 82.05 in the gamma band (100, 80%). Subanalyses indicated that those CPS differences originated from pairs of symmetrical electrodes in the bilateral frontal and temporal areas. Significance: Ictal power and laterality of the ictal power in each frequency band were not associated with the outcomes of CC; however, the phase lags seen in the delta, theta, and gamma frequency bands were larger in the unfavorable than in the favorable outcome group. The phase lags may predict outcomes of CC for ESs on pre-surgical scalp-ictal EEGs.