PubMed Health⌕ Search

Biomedical subjects

H Szliwowski

Publications and source records attributed to H Szliwowski.

15 recordsLinked to original sources

Influence of ambient temperature on sleep characteristics and autonomic nervous control in healthy infants.

OBJECTIVE: To evaluate the influence of ambient temperature on infant's sleep and cardiorespiratory parameters during sleep. PATIENTS AND METHOD: 20 healthy infants with a median age of 11.5 weeks (range 7 to 18 weeks) were recorded polygraphically for one night. They were exposed to 3 different ambient temperatures (20 degrees C-25 degrees C-30 degrees C). Ambient and core temperatures were measured throughout the procedure. RESULTS: Influence of ambient temperature was seen in: RESPIRATORY PARAMETERS: The frequency of central apneas increased significantly with increasing temperatures in REM sleep, but not in NREM sleep. HEART RATE (HR) PARAMETERS AND HR SPECTRAL ANALYSIS: Elevation of temperature was characterized by significantly higher basal HR, shorter RR intervals, and lower parasympathetic activity in REM and NREM sleep. SATURATION IN OXYGEN: During total sleep time, rise in temperature induced a decrease in basal oxygen saturation. During REM sleep, a greater frequency of oxygen saturation drops was associated with central apneas. CORE TEMPERATURE: With increasing ambient temperature, the rise of rectal temperature was mild. Despite this lack of significant increase, similar results were found when sleep and cardiorespiratory parameters were evaluated according to rectal temperatures. CONCLUSION: Changes in ambient temperatures associated with mild increases in body temperature significantly modified cardiorespiratory parameters and autonomic controls in healthy infants. The changes associated with increases in temperature were mainly seen during REM sleep.

Apnea↗

Influence of maternal smoking on autonomic nervous system in healthy infants.

To determine the influence of maternal smoking on autonomic nervous system in healthy infants, 36 infants were recorded polygraphically for one night. Their mothers were defined, according to their smoking frequency during pregnancy, as "nonsmokers" (no cigarettes smoked during pregnancy) or "smokers" (10 or more cigarettes per day). The infants had a median postnatal age of 10.5 wk (range 6 to 16 wk); 18 were born to nonsmokers, and 18 to smokers. During the whole night, spectral analyses of heart rate (HR) were evaluated as a function of sleep stages. Two major peaks were recognizable: a low-frequency component (LF) related to sympathetic and parasympathetic activities and a high-frequency component (HF) reflecting parasympathetic tonus. The ratio of LF/HF powers was calculated as an index of sympathovagal interaction. In REM sleep, "smokers" infants were characterized by significantly lower HF powers and normalized HF powers, and higher LF/HF ratios than "nonsmokers." The finding did not reach statistical significance in NREM sleep. In conclusion, maternal smoking induced changes in autonomic control and maturation in infants. These effects of cigarette smoke exposure can be added to those already reported and offer additional evidence for counseling mothers to stop smoking.

Adult↗

Decreased autonomic responses to obstructive sleep events in future victims of sudden infant death syndrome.

To evaluate changes in autonomic nervous system controls in response to obstructive events in future victims of sudden infant death syndrome (SIDS), we studied the polysomnographic sleep recordings of 18 future SIDS infants and those of 36 matched control infants. A heart rate autoregressive power spectral analysis was performed preceding and after the obstructive apneas. The low-frequency to high-frequency power ratio was computed to evaluate sympathovagal balance. Future SIDS victims had significantly more obstructive apneas (p = 0.001) and mixed apneas (p = 0.005) than control infants. Obstructive events occurred mainly during rapid eye movement sleep in the two populations (84.5% in future SIDS victims and 95.8% in control infants; p = NS). Comparing heart rate power spectral analysis before and after obstructive apneas in rapid eye movement sleep, high-frequency power values were significantly lower and low-frequency to high-frequency power ratios higher in future SIDS victims than in control infants. Compared with preapnea values, low-frequency to high-frequency power ratios significantly decreased after obstructive apneas in control infants (p < 0.001) but not in the future SIDS victims. When the obstructive apneas were divided according to duration, the findings were seen mainly for long apneas. In conclusion, future SIDS victims were characterized by different autonomic status and responses to obstructive apneas during sleep. These findings could be relevant to mechanisms implicated in some cases of SIDS.

Apnea↗

Polysomnographic study of the autonomic nervous system in potential victims of sudden infant death syndrome.

To determine the influence of sleep stages and night-time distribution on cardiac autonomic activity, the polysomnographic recordings of 18 victims of sudden infant death syndrome (SIDS) and of 36 control infants were studied. Autoregressive spectral analyses of heart rate (HR), using both short-term and whole-night methods, were evaluated as a function of sleep stages. The two main peaks of normalized LF and HF were computed during the night and the sympathovagal balance (LF/HF) was determined. In both NREM and REM sleep, SIDS infants were characterized by significantly lower normalized HF powers and higher LF/HF ratios. This finding was observed in both short-term and whole-night HR spectral analyses. In addition, SIDS victims were characterized by the presence of a high desynchronized peak of sympathetic tonus in the late hours of the night, a finding not seen in the control subjects. This report adds further indirect evidence for a possible sleep-related impairment of autonomic controls in some infants who died of SIDS.

Autonomic Nervous System↗

On an autosomal dominant form of retinal-cerebellar degeneration: an autopsy study of five patients in one family.

We describe a family with an autosomal dominant form of retinal-cerebellar atrophy. There is an extreme variability in age of onset and severity of the clinical symptoms: some patients remain nearly asymptomatic throughout their entire life; others develop severe retinal and cerebellar symptoms after the age of 35 years; others suffer from a severe disorder with onset in adolescence and death during the third decade of life; in others the onset is in early childhood with prevalence of cerebellar symptoms. There is neither dementia nor epilepsy in any of the patients. Four out of five autopsies showed a severe retinal atrophy, and all five autopsies were also characterized by (1) a cerebellar atrophy affecting the spinocerebellar and olivocerebellar tracts, the cerebellar cortex and the efferent cerebellar pathways, (2) an involvement of the pyramidal pathways and of the motor neurons of brain stem and spinal cord, and (3) an atrophy of the subthalamic nucleus and to a much lesser extent of the pallidum, with also some damage to the substantia nigra. The posterior columns are much less affected except in one patient. In this family, we have excluded linkage with the two loci for spinocerebellar ataxia, i.e., SCA1 on chromosome 6p and SCA2 on chromosome 12q as well as with the locus for Machado-Joseph disease (MJD) on chromosome 14q. A genome-wide search is currently being performed to detect the disease locus responsible.

Adolescent↗

[Prematurity: developments during the last decade at Erasmus Hospital. II. Long-term follow-up].

Morbidity and mortality of these preterm infants weighing < 1000 g at birth was reported in another paper. The mortality and neuro-developmental prognosis improved clearly in the last 3 years. A particular attention is given for protecting these babies against brain lesions. These ELBW have a high risk of neurodevelopmental disturbances. Therefore, a multidisciplinary team follows the neurological evolution to assess the quality of neonatal care and detect and treat developmental abnormalities as early as possible. We present the weight and height evolutions, the neurological, social and familial outcome of our 15 survivors. Economical and ethical discussions are open.

Child Development↗

[Prematurity: development during the last decade at Erasme Hospital, neonatal evaluation].

Our institution admitted 39 ELBW (less than 1 kg) between November 1978 and December 1990. In our center, mortality has decreased from 61% to 33% within a decade. Improvements in neonatal intensive care have lowered the limit for these possible survival to 26 weeks of gestational age and 700g of birthweight. Morbidity is still very high. The mean hospital stay is 96 days. Perinatal asphyxia is frequent (3/4) as well as infections, nutritional problems and renal failure. Sixty-six % of this population suffer from respiratory distress syndrome which is the main cause of death. Morbidity and mortality are explained and compared to the recent literature.

Belgium↗

Mapping of normal brain maturation in infants on phase-sensitive inversion--recovery MR images.

It is illustrated that phase-sensitive inversion-recovery MR images are particularly well suited for the monitoring of brain maturation and myelination in the neonate and young infant. Provided appropriate timings are applied with the inversion-recovery MR pulse sequence, the myelinated areas show up as bright spots in the phase-sensitive images. The chronology of the appearance, and the location of these hyperintense zones correlate well with the chronology of brain maturation, as assessed by other means. In particular, the progressive functional capabilities of the infant correlate well with the progress of myelination, as exhibited by the MR images.

Brain↗

Mucocutaneous lymph node syndrome with necrotic pharyngitis.

We report a case of Kawasaki disease in which some unusual symptoms, including petechiae, an urticaria-like eruption, and necrotic pharyngitis, made the diagnosis difficult. No complications were detected during a follow-up period of 15 months.

Biopsy↗

Changes in motor innervation and histochemical pattern of muscle fibers in some congenital myopathies.

Changes in motor innervation were compared with histologic and histochemical pattern of muscle fibers in three biopsies of central core disease, four biopsies of nemaline myopathy, one biopsy of myotubular myopathy, and three biopsies of mitochondrial myopathy. Evidence of collateral reinnervation was obtained only in one biopsy from central core disease. In other biopsies, no structural or ultrastructural abnormality of axis cylinders, myelin, or myoneural junction suggesting denervation were observed. The only relevant change found in centronuclear myopathy and to a lesser extent in nemaline myopathy was an unusual smallness and simplication of motor endings, suggesting delayed or impaired maturation. Muscle fibers strongly reactive for both adenosinetriphosphatase and nicotinamide-adenine dinucleotide diaphorase, observed in central core disease and mitochondrial myopathy, were not associated with increased terminal innervation ratio.

Adolescent↗