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.

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.

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.

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.

Acetazolamide-responsive hereditary paroxysmal ataxia: report of a new family.

Five family members were examined because of occurrence since childhood of recurrent episodes characterized by vertigo, dysarthria and gait ataxia. Analysis of the pedigree was consistent with an autosomal dominant mode of inheritance. Though asymptomatic between attacks, all the patients presented on examination a gaze-evoked and rebound nystagmus associated with a saccadic pursuit, a deficient optokinetic response and an inability to suppress the horizontal oculo-vestibular reflex by fixation; hypermetric saccades and truncal ataxia were also present in most of them. A sixth family member, aged 6 years, was found to present a gaze-evoked nystagmus but was completely asymptomatic. Response of the attacks to acetazolamide therapy (250 mg twice a day) was assessed in two patients and was either partial or complete. A positron emission tomography (PET) study was realized between ataxic spells in one patient and demonstrated a decrease of glucose metabolism in the whole cerebellum, the inferior part of the temporal lobes and the thalami. These PET data as well as the detailed neuro-ophthalmological findings bring new informations about acetazolamide-responsive hereditary paroxysmal ataxia, a rare but probably often misdiagnosed and treatable disorder.

MRI of patients with cerebral palsy and normal CT scan.

Three 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.

[Etiological evaluation of deafness in children]. / Bilan étiologique de la surdité de l'enfant.

In relation to cochlear implants, the authors review the various etiologies of deafness in infancy and childhood, either genetic or acquired in order to determine the criteria for advising implantation. They put forward the necessity of complete evaluation of all the auditory pathways involved to determine if a premature who has sustained hypoxicischemic encephalopathy and a full term baby have the same chance to benefit from cochlear implants after meningitis. Defined criteria are urgent needs for patients and parents.

Periodic hypokalemic paralysis transmitted by an unaffected male with negative family history: a delayed mutation?

A pedigree is described that includes three cases of periodic hypokalemic paralysis. Apparently, the disease has arisen by de novo mutation in a father of two affected daughters, who, however, is not affected himself. This is unexpected, since in males the disorder is generally inherited as a fully dominant trait. Therefore we propose that these findings result from an early somatic or a half-chromatid mutation.

Oculocraniosomatic neuromuscular disease with hypoparathyroidism.

During a six-year period, an adolescent girl developed a polyglandular disease characterized by hypoparathyroidism, chemical diabetes, growth failure and pubertal delay, hypercholesterolemia, and hypomagnesemia. A slowly progressive neurological disorder occurred simultaneously, consisting of progressive external ophthalmoplegia, mitochondrial myopathy, ataxia, neural deafness, mental subnormality, atypical retinitis, corneal dystrophy, cataract, and increased protein level in the cerebrospinal fluid. An intracardiac conduction defect was also found. This disorder, the cause of which is uncertain, is termed oculocraniosomatic disease. Our patient is apparently unique in that there was an associated hypoparathyroidism.

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

The 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 pi granules which are not observed usually at the age of the patient. The end plates and a muscle spindle are normal.