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Biomedical subjects

C Christophe

Publications and source records attributed to C Christophe.

At least 19 recordsLinked to original sources

[Acute myocardial infarction and MRI: a comparison of infarct size by MRI and peak creatine kinase after a first episode].

AIM: To compare the assessment of infarct size using MRI and peak CK value. POPULATION AND METHODS: 16 patients presenting with a first MI and seriall measurement of CK underwent gadolinium-enhanced MRI. RESULTS: A significant correlation was observed between both estimates of infarct size (r=0.56, p=0.0025). In addition, an inverse correlation was found between residual viability and peak CK (r=-0.51; p=0.043). CONCLUSION: After a first episode of MI, infarct size estimate by MRI correlates with that determined by peak CK measurement.

Aged↗

[Imaging in paediatric epilepsy].

Epilepsy is a chronic disease, often with an onset during childhood and characterized by spontaneous and recurrent seizures. It concerns 0.5-1% of children under 16 years of age. A classification proposed by the International League Against Epilepsy (ILEA) in 2001 takes into account recent genetic factors involved in epilepsy and attenuates the sharp demarcation between generalized and partial seizures. This classification tends to define whether imaging is indicated or not. Imaging is useless in simple cases of fits associated with hyperthermia and in benign idiopathic epilepsy. It is debated if it is a first episode of epilepsy without a particular context and no neurological signs. In all other cases of epilepsy in children, imaging is indicated. In descending order of frequency the possible causes include malformations (as abnormal gyral development and phakomatoses), hypoxic-ischemic lesions, non-accidental injuries, infections, metabolic diseases and tumors. Being much more sensitive than computed tomography (CT), magnetic resonance imaging (MRI) is the technique of choice to identify an underlying cause in symptomatic epilepsy. Clinical data are mandatory in order to direct a proper MRI investigation. The recently developed diffusion-weighted sequence is particularly useful in the acute phase of certain events such as hypoxia-ischemia, trauma and metabolic disease. CT scan is used in emergency situations and also as a complement to MRI for example to identify calcified lesions. In this way, imaging contributes to establish the nature and define the extension of epileptogenic lesions, thereby guiding therapeutic management. MRI also allows follow-up of the consequences of repeated seizures (such as mesial temporal sclerosis and selective neuronal necrosis) on the cerebral parenchyma and plays a role in the establishment of a prognosis.

Adolescent↗

Apparent diffusion coefficient (ADC) and magnetization transfer ratio (MTR) in pediatric hypoxic-ischemic brain injury.

BACKGROUND AND PURPOSE: a review of the literature reveals the increasing interest in using Diffusion magnetic resonance imaging, with diffusion weighted images (DWI) and ADC (Apparent Diffusion Coefficient) quantitation, in pediatric hypoxic-ischemic brain injury. However, ADC and MTR (Magnetization Transfer Ratio) as quantitative tools have not been investigated together in these pathological conditions in young pediatric patients. The aim of this study was to apply a quantitative method by using ADC and MTR calculation in order to propose a reproducible quantitation of brain parenchymal lesions. METHODS: we conducted a prospective study including all children presenting with suspected cerebral hypoxic-ischemic injury. 15 children were included, among them 10 males and 5 females aged from 36 weeks of gestation to 17 months with a median age of 10,5 months. All MR examinations were performed at 1.5 Tesla unit including conventional MR (T1, T2 and Inversion-recovery sequences) and DWI with ADC map. ADC and MTR ROI (region of interest) measurements were made, in the frontal subcortical and periventricular white matter (WM) as well as in the gray matter (GM=basal ganglia), and in focal lesions. RESULTS: ADC and MTR values were abnormal in focal lesions and in diffuse injury with no evidence of lesion on conventional MRI and DWI. We observed a strong inverse correlation between these ADC and MTR (R=0,66 in WM; R=0,61 in GM). CONCLUSION: ADC and MTR calculation may be helpful as a reproductive method to quantify the lesions and detect diffuse lesions in hypoxic-ischemic pediatric brain injury.

Diffusion Magnetic Resonance Imaging↗

Meningitis following basal skull fracture in two in-line skaters.

INTRODUCTION: In-line skating has been reported to cause severe head injury. Basilar skull fracture (BSF) is associated with a high risk of complication. CASE REPORT: We report two children who had bacterial meningitis following seemingly trivial in-line skating injuries. In both, anterior BSF was diagnosed retrospectively following occurrence of Streptococcus pneumoniae meningitis. DISCUSSION: The clinical signs indicating BSF depend on the fracture location. Plain skull radiography and computed tomography (CT) are not sensitive enough to detect thin fractures in the anterior cranial fossa. We argue that high resolution multiple-plane CT and coronal T2-weighted magnetic resonance imaging are indicated to diagnose BSF.

Child↗

[Headache in childhood: which diagnostic imaging strategies?].

There are various causes of headaches in children. The majority of cases are considered as primary and include migraine and tension headaches. Headaches secondary to an underlying pathology are much less frequent. The aim of imaging will be to depict lesions that can benefit from specific therapy and hence improve life quality and expectancy of the affected child. In case of secondary headaches, imaging will have to precise the diagnosis, which is based mainly upon history of the disease and clinical findings. These findings are important to the radiologist as they will help to choose the more adequate technique between CT scan and MRI. This choice is based upon the presumed diagnoses, degree of emergency and availability of the technique. Knowledge of the differential diagnoses influences the way to perform the examination itself (choice of slice thickness, plane of imaging, MR sequences, need for an MR angiogram or injection of contrast medium...). In our opinion, dedicated MR imaging is the technique of choice to investigate secondary headaches in children given its superior sensitivity in depicting certain tumors (glioma of the pons, posterior fossa tumors...), intracranial hypotension, Chiari I malformation, lesions of the hypothalamo-hypophyseal axis etc...

Adolescent↗

[Chronic subdural hematoma and extramedullary erythropoiesis in an infant].

We report the case of a six-month old child with bilateral chronic subdural hematoma of unknown origin containing erythroblasts, metamyelocytes and blast-like cells. No such cells were found in venous blood. No primary neoplastic disorder was found. Throughout a 19-month follow-up period, general and neurodevelopmental examination remained normal with complete resolution of the subdural haematoma in the presence of macrocephaly. We discuss the origin and role of these cells.

Brain↗

[Importance of echocardiography and MRI in periventricular leukomalacia].

Periventricular leukomalacia (PVL) consists of focal coagulation necrosis and of more diffuse and mild white matter involvement as gliosis and lesions of immature oligodendrocytes. PVL affects essentially the premature newborn and has become the dominant form of perinatal neurological insults. Its diagnosis remains difficult to assess as neurological examination is poorly contributive. Diagnostic imaging plays an important role as it completes clinical, biological and electrophysiological data in depicting the cerebral lesions. Cerebral ultrasound remains the first imaging modality to perform in order to investigate and follow ill neonates. However ultrasound has a low sensitivity and specificity in depicting non cavitated PVL. Magnetic resonance imaging (MRI), in the acute stage, provides additional information about the extension and the depiction of hemorrhagic component of the lesions. Furthermore, diffusion-weighted MRI appears useful for the early identification of the diffuse component of PVL. MRI in the chronic stage is the only imaging method to study the progress of myelination and precise the extension of sequellar lesions.

Echocardiography↗

Crossed cerebellar diaschisis secondary to refractory frontal seizures in childhood.

We report a girl with refractory partial seizures since 7 years of age, secondary to right frontal cortical dysplasia, who developed MRI and SPECT abnormalities in the contralateral hemicerebellar cortex. These became more marked, leading to left hemicerebellar atrophy. Crossed cerebellar diaschisis has been described mostly in hemispheric stroke and supratentorial tumours, but less often in epilepsy. It is usually a transient phenomenon. This report shows that crossed cerebellar diaschisis can develop within two years of seizure onset and evolve over time.

Atrophy↗

[Postinfectious hemicerebellitis].

The clinical signs of cerebellitis are usually bilateral and symmetrical. We report the case of a 9-year-old girl who presented with acute hemiataxia and flaccid hemiparesis associated with a lesion in the ipsilateral cerebellar cortex two weeks after a viral upper respiratory tract infection. The clinical outcome was good without treatment. Imaging follow-up showed hemiatrophy of the cerebellar cortex.

Cerebellar Diseases↗

[Gastric pneumatosis as a sign of duodenal stenosis in a child with Down syndrome].

A case of gastric pneumatosis is described in a 6 month old girl with Down syndrome. Plain abdominal radiographs showed a radiolucent rim within the gastric wall and a dilated stomach. Ultrasonography showed diffuse echoic streaks of air in the gastric wall, pneumobilia and gastroduodenal dilatation. Upper GI series showed duodenal stenosis. Gastric pneumatosis (air within the gastric wall), is an unusual radiographic finding. It may be of mechanical or inflammatory origin or, in some rare cases, remain unexplained.

Constriction, Pathologic↗

Connatal Pelizaeus-Merzbacher disease in two girls.

We report the clinical, radiological and electrophysiological signs in two unrelated girls with the connatal form of Pelizaeus-Merzbacher disease (PMD). MRI plays an important role in the diagnosis, demonstrating the virtual absence of myelination. PMD is classically described as an X-linked leukodystrophy. Our two cases reinforce the hypothesis of a possible autosomal recessive transmission of the connatal form of PMD in some families, as recently presented.

Diagnosis, Differential↗

Peri-optic nerve infiltration during leukaemic relapse: MRI diagnosis.

BACKGROUND: A 10-year-old boy with a history of acute lymphoblastic leukaemia (ALL), but without previous evidence of central nervous system involvement, presented with seizures 3 years after complete remission. MATERIALS AND METHODS: MRI showed bilateral enlargement of the optic nerves despite normal ophthalmological examination. RESULTS: Only the third cerebrospinal fluid examination showed 2 % blasts without concomitant bone-marrow infiltration. Enlargement of the optic nerves was consistent with bilateral leukaemic peri-optic nerve infiltration. The appearances returned to normal after chemotherapy. CONCLUSION: The optic nerves are a potential site of relapse in patients with systemic and meningeal ALL, even in the absence of ophthalmological signs.

Child↗

MRI spectrum of cortical malformations in tuberous sclerosis complex.

The diagnostic and prognostic value of magnetic resonance imaging in the tuberous sclerosis complex has increasingly been recognized. In this paper, we review the presumed pathogenesis of the cerebral dysgenesis seen in this condition in the light of magnetic resonance imaging features of selected patients. In addition to typical findings related to tubers, we show and discuss varied cortical malformations (from simple localized cortical dysplasia to transmantle dysplasia and schizencephaly) similar to those seen in sporadic cerebral dysgenesis. These cases support the hypothesis that the tuberous sclerosis complex focally affects the radial glial-neuronal complex as a basic unit for brain development. Abnormal stem cells would create dysplastic glia and neurons that fail to differentiate, proliferate, migrate and form a normally organized cortex.

Cell Differentiation↗

Transcranial magnetic stimulation and other evoked potentials in pediatric multiple sclerosis.

In children, multiple sclerosis is rare and has some clinical and paraclinical differences compared with adults. The assessment of corticospinal motor tracts is expected to be relevant because of their frequent early involvement in this disease. Reported are the results of transcranial magnetic stimulation in two children who presented at 12 and 9 years of age with clinically probable and definite multiple sclerosis, respectively. In Patient 1 the excitatory cortical threshold for the upper limbs was abnormally raised. In Patient 2 the latency of the motor-evoked potentials was considerably increased for the right tibialis anterior muscle, with a slowing of the central conduction time. Although these abnormalities may be consistent with central conduction impairment, they may alternatively suggest early axonal damage because irreversible axonal lesions occurring at the onset of the disease have recently been reported. Testing of central motor tracts, in addition to visual, auditory, and somatosensory pathways, therefore appears appropriate in the multimodal assessment of pediatric patients with suspected multiple sclerosis.

Axons↗