Henri Szliwowski

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.

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.

Regional Changes in Glucose Metabolism during Brain Development from the Age of 6 Years

Positron emission tomography (PET) with [18F]fluorodeoxyglucose (FDG) studies of 42 subjects ages 6 to 38 years were analyzed using statistical parametric mapping to identify age-related changes in regional distribution of glucose metabolism adjusted for global activity. Whereas adults were normal volunteers, children had idiopathic epilepsy. We studied polynomial expansions of age to identify nonlinear effects and found that adjusted glucose metabolism varied very significantly in the thalamus and the anterior cingulate cortex and to a lesser degree in the basal ganglia, the mesencephalon, and the insular, posterior cingulate, frontal, and postcentral cortices. Regression plots slowed that the best fit was not linear: adjusted glucose metabolism increased mainly before the age of 25 years and then remained relatively stable. Effects persisted when anti-epileptic drug intake and sleep during the FDG uptake were considered as confounding covariates. To determine if the metabolic changes observed were not due to the epileptic condition of the children, PET data obtained in adults with temporal lobe epilepsy were compared with those in our group of normal adult subjects, resulting in the absence of mapping in the age-related regions. This study suggests that brain maturation from the age of 6 years gives rise to a relative increase of synaptic activities in the thalamus, possibly as a consequence of improved corticothalamic connections. Increased metabolic activity in the anterior cingulate cortex is probably related to these thalamic changes and suggests that the limbic system is involved in the processes of brain maturation.

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.

Congenital Bilateral Perisylvian Syndrome in a Monozygotic Twin with Intra‐uterine Death ot the Co‐twin

Congenital bilateral perisylvian syndrome was diagnosed in a two‐year‐old boy with signs of pseudobulbar and diplegic cerebral palsy presenting on MRI a polymicrogyric appearance of the perisylvian regions. He was bom from a monochorionic bi‐amniotic twin pregnancy complicated by twin‐twin transfusion syndrome and death of the co‐twin between the 16th and 18th weeks of gestation. Ventricular enlargement and hepatic hyperechogenic lesions were seen during his sonographic intra‐uterine follow‐up. The authors suggest that ischaemic injury occurred in this patient as a consequence of acute haemodynamic changes induced by the death of his co‐twin.

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

SummaryIt 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.

Cerebral glucose metabolism and centrotemporal spikes

The pathophysiology of regional glucose hypometabolism often associated with refractory, lesion-related, epilepsy is not well understood. In particular, the role of interictal spiking is controversial since animal models of partial epilepsy have shown that interictal spiking increases glucose metabolism. We addressed this question by studying with positron emission tomography (PET) and 18F-fluorodeoxyglucose (FDG) the regional cerebral metabolism in children with focal spiking unrelated to a brain lesion. Patients (11 children with benign childhood epilepsy with centrotemporal spikes (BCECS) and two children without seizures) had on EEG centrotemporal spikes which were either strictly unilateral (ten cases) or strongly predominant on one side (three cases). We looked for an asymmetry in the distribution of cerebral glucose metabolism in our group of patients using statistical parametric mapping (SPM). After spatial normalization, a reversed copy of the 13 scans was obtained, resulting in 26 scans which were assigned to two groups: a group with left-sided centrotemporal spikes and a group with right-sided centrotemporal spikes. Regional glucose metabolism was not statistically different in the two groups. This suggests that metabolic changes associated with interictal spiking cannot be demonstrated by PET with FDG in BCECS, and that this technique could be helpful for the differentiation between idiopathic and symptomatic cases of partial epilepsy in children.

MRI of patients with cerebral palsy and normal CT scan

SummaryThree children with clinical evidence of cerebral palsy (CP) and normal cerebral computed tomography (CT) scans were evaluated by magnetic resonance imaging (MRI) to identify CT-undetectable white matter lesions in the watershed zones of arterial territories. The two patients with spastic diplegia showed bilateral lesions either in the subcortical regions or in the occipital periventricular regions. The patient with congenital hemiplegia exhibited unilateral lesions in the periventricular region. We conclude that MRI is more informative than CT for the evaluation of patients with CP.

Gray Matter Heterotopia and Acute Necrotizing Encephalopathy in Trichothiodystrophy

Trichothiodystrophy was diagnosed in a 3-year-old male presenting with speech delay, brittle hair, chronic neutropenia, and a history of febrile convulsions. Cranial magnetic resonance imaging revealed a focal subcortical and periventricular gray matter heterotopia. An acute encephalopathy with status epilepticus and coma occurred when he was 4 years of age during an upper respiratory tract infection. Magnetic resonance imaging revealed multifocal T2-weighted hypersignal lesions involving mainly the thalami, hippocampi, midbrain, and pons. Analysis of cerebrospinal fluid revealed hyperproteinorachia without pleocytosis. Results of an extensive metabolic evaluation of this acute brain injury, resembling the syndrome of acute necrotizing encephalopathy of childhood described in Japan, were negative. Focal neuronal migration disorder and acute encephalopathy with symmetric thalamic involvement are newly described neurologic manifestations of syndromes with trichothiodystrophy, which suggests that these conditions may have a common genetic background.

Ultrastructural aspects of muscle and nerve in Werdnig-Hoffmann disease.

SummaryThe authors describe in biopsies from 6 cases of Werdnig-Hoffmann disease, including 2 of the more benign type, the ultrastructural typical aspects of denervation. They compare their findings with those of other workers. The striking points are the great variation in the diameter of the muscle fibres and the myofibrils, the disorganisation of the myofibrils, the sarcomeres and the filaments, with persistance of the relations between thick and thin filaments at various levels, the modifications of the Z-band and the triads in chains. The folds and the basement membrane are examined. Centrioles are present in a muscle fibre and in a satellite. Glycogen is very abundant. The nerves seem normal but some Schwann cells contain π granules which are not observed usually at the age of the patient. The end plates and a muscle spindle are normal.