Kazuya Goto

Cardio-respiratory control in an infant with Ondine's curse: a multivariate autoregressive modelling approach

We applied spectral analysis through multivariant autoregressive model fitting [1] to RR interval (RRI) and respiratory (RES) oscillation obtained during quiet sleep in an infant with congenital central hypoventilation syndrome (Ondines curse), a child with obstructive sleep apnea, and two healthy children. Power spectra, impulse response and noise contribution ratio between RRI and RES oscillation were calculated by using a minicomputer PFU-1200 (FACOM) to determine the structure of the feedback system between RRI and RES within the central nervous system. We found that the respiratory noise contribution ratio to RRI was significantly smaller in Ondines curse (37 +/- 7.7%, at 0.23 Hz) than in obstructive sleep apnea (90 +/- 6.7%, at 0.39 Hz) and healthy subjects. We postulate that the result shows disturbance of the central autonomic control of breathing and heart rate in Ondines curse.

Sequential changes in electroencephalogram continuity in very premature infants

This study was conducted to quantify sequential changes in electroencephalogram (EEG) continuity for 24 h in very premature infants. For a total of 122 days, continuous 2-channel EEG recording was conducted for 28 premature infants from 26 to 33 weeks of conceptional age (CA). None of the infants showed evidence of neurological impairment during hospitalization. Normal neurological outcome was noted at a minimum 12 months of age. By classifying each 5.5 min epoch according to EEG continuity, the number of contiguous epochs of each series of discontinuous type (DTs) and the number of epochs between two series of discontinuous type (IDTIs) were counted at each CA. The duration of DT decreased with increasing CA. The mean duration remained at 13-16 min after 29 weeks CA. The mean duration of each IDTI increased with CA, up to about 1 h at 33 weeks. A constant period of DTs was noted at longer intervals with increasing CA. These changes appear related to the development of sleep state organization with CA.

CARDIAC RHABDOMYOMA ASSOCIATED WITH TUBEROUS SCLEROSIS

An autopsy case of cardiac rhabdomyoma associated with tuberous sclerosis in a 27‐day‐old infant is presented. He was born with severe cyanosis. Echocardiogram revealed the presence of multiple mass lesions, some of which protruded into the left ventricle at the level of subaortic valve. From the age of 4 days, cardiac arrhythmia developed and lasted until his death. The arrythmia started as WPW syndrome and atrial extrasystoles and then additional paroxysmal supraventricular tachycardia, ventricular fibrillation, sinus arrest, and S‐A block occurred. Computed tomographic scanning of the brain revealed the presence of symmetric high‐density spots around the central part of lateral ventricle. Before his death paroxysmal supraventricular tachycardia occurred frequently which changed to ventricular fibrillation and he collapsed without urination and then died. Autopsy examination revealed the presence of generalized congestion, multiple nodules of cardiac rhabdomyoma, some of which causing subaortic stenosis, and tuberous sclerosis in the brain. From the clinical and autopsy findings, the direct cause of death was attributable to the cardiac rhabdomyoma.

Development of ultradian rhythm of EEG activities in premature babies

Ultradian rhythms in electroencephalogram (EEG) activity in premature neonates were studied. The values of square roots of total power (SQP) of EEG showed a normal Gaussian distribution. We analyzed the smoothed time series of SQP by autoregressive analysis and component analysis. Ultradian rhythm was divided into four groups by period length (group I: 5-30 min, group II: 30-60 min, group III: 60-100 min, group IV: longer than 100 min). Group IV rhythms were not detected before 32 weeks of gestation. Changes in the characteristic values of ultradian components in group II showed that there were critical periods in the development of central nervous activity at 29 and 33 weeks of gestation. This method allowed detection of ultradian rhythms, even at very early gestation, directly from the neonatal central nervous system. This method may be applicable to ill infants.