A Prospective Study of Arterial Spin Labelling in Paediatric Posterior Fossa Tumour Survivors: A Correlation with Neurocognitive Impairment.

AIMS: Posterior fossa tumours (PFTs), which account for two-thirds of paediatric brain tumours, are successfully treated in about 70% of patients, but most survivors experience long-term cognitive impairment. We evaluated arterial spin labelling (ASL), a common, non-invasive magnetic resonance imaging (MRI) technique, as a biomarker of cognitive impairment in a paediatric PFT survivor population. MATERIALS AND METHODS: Sixty participants were prospectively analysed. PFT survivors were at least 5 years post-treatment and had been treated as appropriate for their age and type of tumour. Group 1 had received radiotherapy and Group 2 had not. Group 3 were healthy controls matched to Group 1 for age, sex and handedness. All participants underwent cognitive assessment and multimodal MRI, including an ASL perfusion sequence. We used semi-quantitative ASL methods to assess differences in mean perfusion in the thalamus, caudate, putamen and hippocampus. RESULTS: Statistically, no significant associations between cognitive data and radiation doses were identified. Compared with healthy controls, Group 1 patients had significantly lower overall mean perfusion values (20-30% lower, depending on the cerebral structure) and Group 2 had slightly lower mean perfusion values (5-10% lower). Perfusion values did not correlate with total prescribed irradiation doses nor with doses received by different cerebral structures. Episodic and semantic memory test scores were significantly lower in Group 1 and correlated with lower mean absolute perfusion values in the hippocampus (P < 0.04). CONCLUSIONS: These preliminary results indicate that radiotherapy affects the perfusion of specific cerebral structures and identify perfusion as a potential biomarker of hippocampus-dependent memory deficit.

[Fragile X syndrome and white matter abnormalities: Case study of two brothers]. / Syndrome de l'X fragile et anomalies de la substance blanche : à propos d'une fratrie.

Fragile X syndrome is the most usual cause of hereditary intellectual deficiency. Typical symptoms combine intellectual deficiency, social anxiety, intense emotional vigilance, and a characteristic facial dysmorphy. This is subsequent to a complete mutation of the FMR1 gene, considering a semidominant transmission linked to the unstable X. The expansion of the CGG triplet greater than 200 units combined with a high methylation pattern lead to a transcriptional silence of the FMR1 gene, and the protein product, the FMRP, is not synthesized. This protein is involved in synaptic plasticity. Brain MRI can show an increased volume of the caudate nucleus and hippocampus, combined with hypoplasia of the cerebellar vermis. Fragile X Associated Tremor Ataxia Syndrome (FXTAS) syndrome is a neurodegenerative disorder occurring in carriers of the premutation in FMR1. Brain MRI shows an increased T2 signal in the middle cerebellar peduncles. This syndrome is linked to a premutation in the FMR1 gene. We report here the case of two brothers presenting a typical fragile X symptomatology. Brain MRI showed hyperintensities of the middle cerebellar peduncles. Such MRI findings support the assumption of a genetic mosaicism.

[Reversible cerebral vasoconstriction syndrome: A rare pediatric cause of thunderclap headaches]. / Syndrome de vasoconstriction cérébrale réversible : une cause de céphalée en coup de tonnerre peu connue chez l'enfant.

Reversible cerebral vasoconstriction syndrome (RCVS) is characterized by thunderclap headaches with diffuse segmental constriction of cerebral arteries that resolves spontaneously within 3 months. We report on a case of a 13-year-old boy presenting with acute severe headaches, triggered by physical exertion. His past medical history was uneventful. Moderate headache persisted between exacerbations for 4 weeks. He secondarily presented with signs of intracranial hypertension. Brain magnetic resonance angiography (MRA) revealed multifocal narrowing of the cerebral arteries. A glucocorticoid treatment was started based on the hypothesis of primary angiitis of the CNS. The symptoms rapidly improved, and repeat angiography at 3 months showed no vasoconstriction. Although pediatric cases are rare, RCVS should be considered in a child complaining of severe headache, especially after the use of vasoactive drugs or after Valsalva manoeuvres. RCVS is attributed to a transient, reversible dysregulation of cerebral vascular tone, which leads to multifocal arterial constriction and dilation. Physical examination, laboratory values, and initial cranial computed tomography are unremarkable, except when RCVS is associated with complications. Thunderclap headaches tend to resolve and then recur over a 1- to 4-week period, often with a milder baseline headache persisting between acute exacerbations. Angiography shows segmental narrowing and dilatation of one or more arteries, like a string of beads. Despite the absence of a proven treatment, important steps should be taken during the acute phase: removal of precipitants such as vasoactive substances, giving the patient rest, lowering blood pressure, and controlling seizures. Drugs targeted at vasospasms, such as calcium channel inhibitors, can be considered when cerebral vasoconstriction has been assessed. In most patients, the RCVS symptoms resolve spontaneously within days or weeks. Ischemic and hemorrhagic stroke are the major complications of the syndrome. A diagnosis of RCVS can only be confirmed when the reversibility of the vasoconstriction is assessed.

[Respiratory syncytial virus brainstem encephalitis in a 7-year-old boy]. / Rhombencéphalite liée au virus respiratoire syncytial chez un garçon de 7 ans.

The literature reports that neurological complications of childhood respiratory diseases due to respiratory syncytial virus (RSV) fluctuate between 1 and 40% of cases. They mostly involve central apnea - often the first symptom of infection - anoxia, and ischemic brain damage due to severe sudden weakness in infants, and seizures and consciousness disorders more or less associated with focalized neurological deficiency proving an encephalitis lesion. We report the case of brainstem encephalitis in a 7-year-old boy with RSV A nasopharyngitis, with meningitis, positive polymerase chain reaction in cerebrospinal fluid and magnetic resonance imaging (MRI) abnormalities, which was explained by viral replication encephalitis. Based on a literature review, we discuss the main aspects of epidemiology and physiopathology of the main neurological complication of RSV. Most of them have not been fully investigated and only a few articles report encephalitis. As far as central apnea is concerned, an animal experimental hypothesis surprisingly suggests a peripheral mechanism.

[Asymptomatic neonatal neurocutaneous melanosis]. / Mélanose neurocutanée néonatale asymptomatique.

Giant congenital nevi in 1% of cases are associated with anomalies of the central nervous system, which are characteristic of neurocutaneous melanosis. When neurocutaneous melanosis becomes symptomatic, it is associated with a poor prognosis. With recommended neonatal screening, asymptomatic neonatal cases are being discovered more frequently. On the basis of this observation, we consider various aspects of this association.

[The outcome of children presenting with a prenatally diagnosed arachnoid cyst]. / Devenir des enfants présentant un kyste arachnoïdien de diagnostic anténatal.

AIM: Evaluate the outcome of children with prenatally diagnosed arachnoid cysts. MATERIAL AND METHODS: Retrospective study of seventeen cases of children who were diagnosed with an arachnoid cyst during prenatal MRI between July 1994 and January 2007 and followed up for a mean 6 years and 6 months. Follow-up was based on evaluation of clinical files and contacts with the physicians who were following the children. The children were divided into three groups: group 1 normal development, group 2: minor clinical signs, normal schooling, group 3: major clinical symptoms, schooling disturbed. RESULTS: Eight of the 17 patients included in this study underwent derivation surgery for the cyst. Eight of the 17 children were in group 1, and 3 in group 2. Four of the 6 children in group 3 had associated symptoms. Two of the children in group 3 present with a supratentorial cyst, and 4 with a cyst of the posterior fossa. CONCLUSION: The prenatal diagnosis of a arachnoid cyst should be accompanied by a search for associated lesions. The risk of hydroencephalitis should be explained to the parents.

Desmoplastic infantile astrocytoma with benign histological phenotype and multiple intracranial localizations at presentation.

Desmoplastic infantile astrocytoma (DIA) and desmoplastic infantile ganglioglioma (DIG) are rare intracranial tumors that mostly occur in the first 2 years of life and involve superficial cerebral cortex. Despite the large size of these lesions and some worrisome histological and radiological features, prognosis is generally favorable after gross total resection. We report an original observation of a desmoplastic infantile astrocytoma in a 5-year-old boy with multiple localizations on initial presentation, including the unusual subtentorial region. Magnetic resonance imaging showed a temporal tumor with prepontine and interpeduncular extension, and two other distinct localizations in cisterna magna and left cerebellar hemisphere. Leptomeningeal enhancements were present around the basal cistern. The surgical samples, corresponding exclusively to subtentorial lesions, were devoid of anaplastic features; the temporal lesion was untouched because of the interpeduncular extension. Adjuvant chemotherapy was applied, with shrinkage of lesions. DIA and DIG are more generally unifocal at initial presentation. When the tumor is large, multilobular involvement is common, but multiple location of DIG is, on the contrary, very rare. Previously, only five cases of DIG/DIA located in two or more separate locations have been published. We report the sixth, and first noninfantile, case of DIA/DIG with multifocal initial presentation.

[Retro- and parapharyngeal infections: standardization of their management]. / Infections rétro- et parapharyngées: vers une harmonisation des pratiques.

AIM: To analyze the changes in the management of retropharyngeal and parapharyngeal infections and propose a decisional algorithm for their diagnosis and treatment. PATIENTS AND METHODS: A retrospective survey was carried out in a tertiary care pediatric hospital between January 2001 and December 2005. All children aged less than 15 years and affected by a retro- or parapharyngeal infection were included. Clinical, biological, and radiological data, medical and surgical treatment, and complications were extracted from the review of medical charts. The results of the surgical findings were correlated with a cervical computed tomographic scan (CT scan). RESULTS: Thirty-one patients were included, 64.5% during the last 2 years of the study period. All children presented fever and a stiff neck. The pharyngeal examination revealed a retropharyngeal bulge in a quarter of the population and an upper respiratory tract infection was concomitant in 68% of cases. A CT scan was carried out in 29 of 31 children (93.5%), with the radiological diagnosis of an abscess in 16 children (55.2%), presuppurative adenitis in 8 children (27.6%), and cellulitis in 5 children (17.2%). The CT scan was performed within 0.75 days of admission in 2001 and 2.3 days in 2005. All children were treated with intravenous antibiotic therapy: an association of amoxicillin/clavulanic acid and an aminoglycoside in most cases. The mean duration of intravenous antibiotic therapy was 5.2 days. Seventeen patients (93.5%) underwent surgical drainage and purulent material was found in 82.3% of cases. The accuracy of the CT scan, confirmed by surgical finding of a purulent material, was 71.4% in correctly identifying an abscess. The mean duration of surgical treatment after admission increased from 1.7 days in 2001 to 3.3 days in 2005. The number of patients who underwent surgery was divided by a factor of 3 in the second period of the study. Two groups were compared: group A (n=12) treated with antibiotic therapy and group B (n=17) treated with antibiotics and surgical drainage. No significant difference was found between the two groups considering the duration of parenteral and oral antibiotic therapy, the standardization of cervical mobility, the mean time for apyrexia, and the length of hospitalization. There was one recurrence in group B 1 month later, and one case of sepsis in group A. None of the patients with retropharyngeal infection died. CONCLUSION: Without clinical evidence of severe sepsis, parenteral antibiotic therapy is recommended as the first-line treatment for children over 6 months of age presenting with retropharyngeal and parapharyngeal infections. If the clinical and/or biological conditions do not improve within 48-72h, a CT scan is indicated to assess the extent of infection and exclude complications. The decision to initiate surgical drainage depends on the patient's clinical status and the accessibility of the abscess.

Prenatal diagnosis of craniosynostosis: value of MR imaging.

INTRODUCTION: The aim of our study was to assess the utility and reliability of magnetic resonance imaging (MRI) in antenatal diagnosis of craniosynostosis. METHODS: We retrospectively reviewed the MRI examinations of the head of 15 fetuses requested over a period of 11 years on the basis of sonographic suspicion of craniosynostosis. The postnatal diagnosis was available for 14 neonates. RESULTS: No termination of pregnancy was performed. There were four neonates with sporadic multisuture craniosynostoses, three of which were syndromic, including one Crouzon and one Pfeiffer syndrome. Eight neonates were normal, two showed cranial vault deformities without synostosis, and one was lost to follow-up. MRI showed a high predictive value for craniosynostosis, as there were no false-negative or false-positive diagnoses. However, the severity of the abnormalities were underestimated in two neonates. CONCLUSION: We suggest that prenatal MRI has diagnostic value when synostosis is suspected on ultrasonography. Moreover, MRI is accurate in the detection of associated brain abnormalities, which is an important prognostic issue in this diagnosis. Prenatal diagnosis of craniosynostosis is difficult and could benefit from three-dimensional ultrasonography and three-dimensional CT.

[Orbital tumors in children: CT and MR imaging features]. / Tumeurs orbitaires chez l'enfant: revue iconographique en TDM et IRM.

The purpose of the article is to review the CT and MR imaging features of orbital tumors in children. Tumors in children are usually different than those in adults. Clinical symptoms are usually non-specific. Clinical examination combined with US may be sufficient for diagnosis and follow-up of benign and superficial lesions. CT and/or MRI are needed for deep or malignant lesions. CT is valuable for osseous and/or calcified lesions. MR is advantageous because of its superior spatial resolution and non-ionizing nature. Malignant tumors correspond to about 20% of lesions and include primary tumors (retinoblastoma, rhabdomyosarcoma) and metastases. Benign pathology is more frequent (80%) with dermoid cyst corresponding to about 50% of orbital masses.

[Spontaneous resolution of syringomyelia in a child with Chiari I malformation: a case report]. / Résolution spontanée d'une cavité syringomyélique dans le cadre d'une malformation de Chiari I chez un enfant: à propos d'un cas.

Cervicothoracic syringomyelia is a frequent feature in Chiari I malformation. It can be symptomatic or not, and is well demonstrated by magnetic resonance imaging (MRI). Its spontaneous resolution is uncommon. The authors report a case of spontaneous resolution of a thoracic syrinx in an 18-year-old patient with a Chiari I malformation. MRI study performed 6 years previously because of worsening headaches demonstrated a Chiari I malformation associated with a syrinx cavity. The cavity disappearance was noted after improvement of the symptoms.

[Optic pathway gliomas in neurofibromatosis type I. Longitudinal study of 30 cases in two multidisciplinary practices]. / Les gliomes des voies optiques dans la neurofibromatose de type 1. Etude longitudinale de 30 cas suivis dans deux consultations multidisciplinaires.

UNLABELLED: The aim of this study was to analyse the outcome of optic pathway gliomas in 30 children with neurofibromatosis type 1, the indications of treatment, and the follow-up and screening protocol. PATIENTS AND METHODS: All patients with a minimal two years follow-up (median six years, range two to 19 years), in two multidisciplinary consultations of Saint-Vincent-de-Paul (Paris) and Purpan (Toulouse) hospitals, were included in the study. In our series, we practiced systematic screening MRI in children under six years' of age or with neuropsychological deficiency that may imply an unreliable ophthalmological examination. RESULTS: Thirty-seven percent (11 patients) had progressive ophthalmological signs and were treated, and 63% (19 patients) were not progressive. Our study confirmed that most of optic pathway gliomas were stable during evolution, but rare cases may have bad prognosis. CONCLUSION: Our study supported the importance of close ophthalmological follow-up during childhood for which screening methods are discussed. There is a consensus to limit treatment for patients with progressive ophthalmological symptoms.

CTM brace effect on scoliotic intervertebral discs using MRI method.

MRI has been clinically only used for investigation of intervertebral disc disorders. In this study, MR images were used and a new 3D modelling of the intervertebral discs was proposed. MRI examination had been performed on fourteen girls presenting an idiopathic scoliosis and wearing a first CTM brace. Using an in-house image processing software and the pre-post processing software Patran, geometrical models were obtained with and without brace for each patient. These models included the outline of the intervertebral high intensity zone, composed of the nucleus and a part of the annulus. The shift forward between disc high intensity zone centres and body centres was found to be varying from 0 to 8mm. The sagittal and coronal shifts forward appeared in the curvature convexity and were maximum at the curvature apex. The intervertebral disc wedging was found to be varying from -10 degrees to +10 degrees. On these fourteen analysed patients, the CTM brace decreased the coronal shift forward between disc high intensity zone centres and body centres, and increased the sagittal intervertebral wedging. The intervertebral disc informations obtained represented new data in the scoliotic deformation description. But this method was not adapted for a clinical use. The qualitative and quantitative data obtained will help the orthopaedist in the brace design and also the clinician in the scoliosis comprehension.

[Superficial siderosis of the central nervous system: a case report]. / Sidérose superficielle du système nerveux central: à propos d'un cas.

Superficial siderosis of the central nervous system is secondary to chronic subarachnoid bleeding. However, the underlying etiology is not always detected. Superficial siderosis can be diagnosed at MRI by the presence of a hypointense rim along the brain surface on gradient echo T2W images. The authors report a case of superficial cerebral siderosis where the underlying etiology remained undiagnosed in spite of extensive neuroradiological work up.

[Reliability of CT scan in the diagnosis of conductive hearing loss with normal tympanic membrane]. / Fiabilité du scanner dans le diagnostic des surdités de transmission à tympan normal.

The goal of this study was to assess the reliability of CT-Scan in the cases of conductive hearing losses with normal tympanic membrane. A computed tomography of the temporal bone (CT-Scan) has been performed in a prospective manner in all patients who underwent surgery for a conductive hearing loss with a normal tympanic membrane in our department. Out of 474 cases, 437 cases (92.2%) presented with otosclerosis. In 25 cases a minor malformation (5.3%) was found at surgery, and in 12 cases (2.5%), another diagnosis was made. Sensitivity of CT-Scan was 91.3% in otosclerosis and 57% in minor malformations. In 8.7% of cases, a superficial and beginning surgical focus was put in evidence whereas CT-Scan was normal. Theses cases represent infra-radiological cases of otosclerosis. In case of radiological otosclerosis, fenestral otosclerosis was found in 83.5% of the cases. CT-Scan was found specific on the operated and deaf side, but in 11.3% of the cases, a radiologic focus did not have a clinical consequence on the controlateral side. A radiological focus is not systematically responsible for a hearing loss. Finally, CT-Scan remains a reliable, sensitive and specific exam in the diagnosis of cases of conductive hearing losses with normal tympanic membrane.

MRI in Lyme disease of the spinal cord.

We report a case of Lyme myelitis in a 31-year-old man, presenting with a conus medullaris syndrome. MRI demonstrated contrast enhancement on the pial surface of the lower thoracic cord and conus medullaris. Elevated blood immunoglobulins and IgM antibodies against Borrelia burgdorferi in the cerebrospinal fluid (CSF) were found. Leptomeningitis may be the first stage of spinal infection in Lyme disease, preceding parenchymal infection leading to myelitis. Vasculitis is probably the major mechanism. MRI findings are nonspecific and the diagnosis is given by serum and CSF analyses. Early treatment with antibiotics and high doses steroids may result in complete recovery, as in this case.

Sensorineural hearing loss and otosclerosis: a clinical and radiologic survey of 437 cases.

The aim of this study was to determine if a relationship exists between bone level thresholds and the extension of otosclerotic foci within the otic capsule. The study consisted of a retrospective case review in a university hospital. We included patients who underwent surgery for otosclerosis in our department and who had a CT scan prior to surgery. We analyzed the data charts and CT scans of 437 cases (386 patients). On CT scan, we distinguished patients with fenestral otosclerosis and/or with a pericochlear focus. A pericochlear focus could be extended (Group 2) or not (Group 1) to the cochlear endosteum. Data for Groups 1 and 2 were compared with those for the control group of all patients for whom CT scan showed no cochlear focus (Group 3). Of the 437 CT scans, 399 were positive (91.3%). An anterior focus was reported in 305 cases (69.8%), a footplate thickening in 21 cases (4.8%) and both anomalies were encountered in 60 cases (13.7%). A pericochlear focus was reported in 53 examinations. This focus was extended to the endosteum in 14 cases (26.4% of the pericochlear foci). In Group 1, preoperative air conduction (AC) thresholds were significantly lower than in the control group (p < 0.05). The air--bone gap was also significantly larger in Group 1 (p < 0.05). Bone conduction (BC) thresholds were lower in Group 1 than in the control group but the difference was not significant. In Group 2, preoperative AC thresholds were significantly lower than in the control group (p < 0.05). BC thresholds were also lower in Group 2 than in the control group and the difference was significant (p < 0.05). As a result of this study, we assume that there may be a relationship between bone level thresholds and the radiological extension of otosclerosis within the otic capsule.