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.

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.

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.

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.

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.

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.

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.

Perisylvian dysgenesis. Clinical, EEG, MRI and glucose metabolism features in 10 patients.

We studied 10 patients who had neurological disorders with a MRI-based diagnosis of perisylvian dysgenesis based on the fact that the parasagittal and centrifugal extremity of the sylvian fissure was abnormally mesial. This abnormality was bilateral in seven cases; in the other three patients, the contralateral sylvian fissure appeared either normal (two cases) or enlarged (open operculum). The perisylvian cortex had a polymicrogyric appearance in most patients. Potential aetiopathogenic factors were determined in four patients. In two of them, ischaemia at mid-gestation was ascribed to death of a co-twin in a context of monozygotic twinning. In the other two patients, who were siblings, genetic factors were suspected. Pseudobulbar palsy was found in eight patients and epilepsy in five patients. We used PET with [18F]fluorodeoxyglucose to test the hypothesis that, despite this clinical and MRI heterogeneity, regional cerebral glucose distribution could have common features in these patients. The analysis of PET data was performed by visual inspection in two cases and by using statistical parametric mapping (SPM) in eight patients compared with a control group. Segmented grey matter MRIs of seven out these patients were also analysed using SPM. We found that the abnormal perisylvian cortex had normal grey matter activity in eight patients and in the other two there was a heterogeneous pattern with areas of preserved metabolism and of decreased metabolism. Metabolic changes were also detected outside the polymicrogyric-like cortex; three patients had hypometabolic areas in cortical regions where the MRI appeared normal and had a normal intensity. When polymicrogyria extended into the white matter, this ectopic dysgenetic cortex was associated with a grey matter pattern within the white matter territory, and was detected by SPM as areas of PET hypermetabolism and MRI hyperintensity. In order to detect possible metabolic changes undetected by the individual analyses, the group of patients was compared with the control group. This comparison revealed bilateral hypometabolism in the frontal opercular cortex. We propose that these PET data be considered in light of the presumed cyto-architectonic pattern of perisylvian dysgenesis, i.e. polymicrogyria. In this malformation, two dense cell layers are separated by a necrotic sparse cell layer. We speculate that the amount of synaptic activity preserved in these dense cell layers depends on the importance and timing of the necrotic process; this hypothesis accounts for the large range of metabolic patterns found, from profoundly decreased glucose metabolism to nearly normal activity.

Post-embolisation flow disturbances at the basilar tip triggering the development of an arterial aneurysm. A case report.

SUMMARY: We present the case of an ll-year-old boy with a large intracerebral and intraventricular haemorrhage due to rupture of a left temporal arteriovenous malformation. The child initially presented with severe headaches and meningism, right VIth nerve palsy, right hemianopsia, and expressive aphasia. After stabilization of his neurological status, the patient was embolised in two sessions with acrylic glue (Histoacryl(*)), obliterating nearly 90% of the nidus, the residual to be considered for gamma-knife radiosurgery. The first session of embolisation had been complicated, during retrieval of the microcatheter, by an erratic embolus of glue in the basilar artery. The child was kept for 24 hours under heparin anticoagulation in order to avoid any thrombosis, followed by aspirin. His neurological examination remained stable without worsening of his clinical condition. Further angiographic controls demonstrated the patency of the basilar artery itself with remodelling changes at the basilar tip, with preservation of the perforators in this region. Secondary dilatation of the basilar tip with development of an arterial aneurysm was noted three years after the accident, pointing to the importance of flow turbulence and vascular wall weakness in the development of an arterial aneurysm. The clinical follow-up of this patient is 3.5 years; his neurological status is stable with hemianopsia, mild dysphasia and memory difficulties. Further follow-up will be needed in order to determine the therapeutic requirement for the arterial aneurysm.

Cranial disjunction and visual failure in a slit ventricle syndrome with patent shunt.

A 6.5-year-old child who received a shunt at 3 weeks of age for triventricular hydrocephalus related to his congenital toxoplasmosis developed symptoms of intracranial hypertension and papilloedema. Computed tomographic scan demonstrated slit ventricles. The shunt device was shown to be patent on isotope transit study. Spontaneously the cranial sutures widened and headaches disappeared, but loss of vision occurred and did not reverse despite optic nerve sheath fenestration. We suspect that a rapid drop in intracranial pressure played a role in the pathogenesis of our patient's blindness. This possible complication should be taken into account when calvarial expansion is planned in a patient with an intracranial hypertension syndrome with papilloedema in the presence of slit ventricles and a patent shunt.

Congenital bilateral perisylvian syndrome in a monozygotic twin with intra-uterine death of 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 born 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.

EEG findings in acetazolamide-responsive hereditary paroxysmal ataxia.

EEG studies were performed in six family members affected by acetazolamide-responsive paroxysmal ataxia. Intermittent rhythmic delta activity was found at rest in five of them; low amplitude spikes were associated with delta waves in two cases, resulting in irregular spike and wave patterns. Slowing of background activity was present in three patients. EEG abnormalities were activated by hyperventilation and modified neither by intermittent photic stimulation, nor by acetazolamide therapy. Our results suggest that EEG may be helpful to recognize this rare, but well defined, treatable disorder.

Mid-portion agenesis of corpus callosum in a presumed Baller-Gerold syndrome.

We report an association of trigonocephaly and thumb hypoplasia in a 6.5-year-old boy, diagnosed as Baller-Gerold syndrome. In addition to craniosynostosis and radial limb defect, which are constant in this syndrome, our patient presents two unusual features: the first is an epidermal nevus and the second is an agenesis of the middle portion of corpus callosum. This unique type of callosal agenesis in the context of a polymalformative disorder supports the hypothesis that partial agenesis of corpus callosum may be due to an event occurring before the 12th week gestation with continued development of the midline structures.

Total recuperation in a case of sudden total paraplegia due to an aneurysmal bone cyst of the thoracic spine.

A 3-year-old girl developed sudden complete paraplegia because of an aneurysmal bone cyst of the fourth thoracic vertebra. We performed a two-step surgical procedure resulting in complete neurological recuperation and no cyst recurrence within 2.5-year follow-up. Although the literature shows the prognosis of such a condition to be poor, this case reveals the positive effect of rapid surgical decompression and of postponing assessment by magnetic resonance imaging until before the second surgical stage. Furthermore, this case is an example of cure with neither interbody fusion nor postoperative radiotherapy, despite the total involvement of the vertebrae by the lesion.

[Cerebral lesions following convulsive partial status epilepticus. Clinical, neuroradiologic and PET study of a case]. / Lésions cérébrales séquellaires d'un etat de mal épileptique partiel convulsivant. Etude clinique, neuroradiologique et par TEP d'un cas.

An 11-year-old girl developed signs of intracranial hypertension after status epilepticus with convulsive movements of her right upper limb. Computerized tomography revealed left hemispheric hypodensity with mass effect, attributed to vasogenic edema. Intracranial hypertension was controlled under intracranial pressure monitoring and clinical status slowly improved. The patient was aphasic and right hemiplegic when she recovered consciousness but she remarkably recovered from her neurological deficits during the following two years despite neuroradiological evolution demonstrating extensive destruction of the left cortex and white matter. Two positron emission tomography (PET) scans were performed respectively six weeks and eight months after status epilepticus, and both demonstrated profound left hemispheric hypometabolism except in the lenticular nucleus and a restricted area of motor/premotor cortex. On the other hand, glucose metabolism in the right hemisphere was heterogeneously increased on the second PET when compared with the first PET. We concluded that, in this case, clinical recovery might have implicated functional reorganization arising from the intact hemisphere.

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.

MRI of acute disseminated encephalomyelitis after coxsackie B infection.

Acute disseminated encephalomyelitis (ADEM) is a rare demyelinating condition of the central nervous system, usually developing after a viral infection or vaccination. We report a case of ADEM predominantly affecting the spinal cord in an 8-year old boy evaluated by MRI. The radiographic picture consisted of multiple focal lesions of the spinal cord, a left posterior thalamic lesion and a subcortical right posterior parietal lesion. These lesions regressed several weeks after corticosteroid treatment. The clinical presentation, the laboratory results and the radiological findings suggest the diagnosis of ADEM secondary to viral infection by Coxsackie B.

Reversible striatal hypermetabolism in a case of Sydenham's chorea.

We studied a 10-year-old girl with Sydenham's chorea (SC) using positron emission tomography (PET) with fluorodeoxyglucose (FDG). Choreic movements involved the head and the left side of her body. PET showed increased glucose metabolism in the right caudate nucleus and putamen. Three months after complete recovery, striatal glucose metabolism had returned to normal in the caudate nucleus. In the right putamen, glucose metabolism had decreased compared to that in the first study but remained elevated compared to that of normal young adults. We propose that the transient striatal hypermetabolism may have been due to increased afferent inputs to the striatum as a consequence of striatal or subthalamic nucleus dysfunction.

[Unilateral congenital glaucoma and glioma of the optic nerve in the framework of neurofibromatosis 1]. / Glaucome congénital unilatéral et gliome des nerfs optiques dans le cadre d'une neurofibromatose type I.

A three and a half year-old boy with neurofibromatosis-1 was shown to have an unilateral glaucoma without other associated characteristics (homolateral facial hypertrophy, homolateral eyelid plexiform neuroma). This presentation is rare. Moreover, cerebral MRI disclosed a bilateral intraneural optic nerve glioma. The MRI of optic nerve glioma is discussed.

Lipomyeloschisis associated with thoracic syringomyelia and Chiari I malformation.

Co-existence of Chiari I malformation and myelomeningocele is uncommon. Syringomyelia, when associated with a Chiari I malformation, classically involves the cervical spinal cord. Intramedullary extension of lipoma is unusual in lipomyeloschisis. A patient with lumbar lipomyelomeningocele with tethered cord, lower thoracic syringomyelia and Chiari I malformation, shown by MRI is reported.