Artefact subspace reconstruction for both EEG and fNIRS co-registred signals.

Combining electroencephalography (EEG) to functional near-infrared spectroscopy (fNIRS) is a promising technique that has gained momentum thanks to their complementarity. While EEG measures the electrical activity of the brain, fNIRS records the variations in cerebral blood flow and related hemoglobin concentrations. However, both modalities are typically contaminated with artefacts. Muscle and eye artefacts, affect the EEG signals, while hemodynamic and oxygenation changes in the extracerebral compartment due to systemic changes (superficial layer) corrupt the fNIRS signals. Moreover, both signals are sensitive to sensor motion artefacts characterized by large amplitude. There are several well-established methods for removing artefacts for both modalities. The objective of this paper is to apply a common approach to denoise both EEG and fNIRS signals. Indeed Artifact Subspace Reconstruction (ASR) method, which is an automatic, online-capable and efficient method for deleting transient or large-amplitude EEG artefacts, can be a good alternative to also denoise fNIRS signals. In this paper, we first propose, a new more comprehensive formulation of ASR. Then, we study the effectiveness of the method in denoising both the EEG and fNIRS signals.

[Currarino syndrome a rare cause of recurrent purulent meningitis]. / Syndrome de Currarino cause rare de méningites purulentes récidivantes.

The authors report a case of partial Currarino syndrome in a three and a half year old child with a left hemisacrum agenesis and a presacral mature teratoma. The special aspect of the observation was the apparition of repetitive polymicrobial purulent meningitis (Escherichia coli, Streptococcus B, Haemophilus influenzae) treated several times with non-specific antibiotics without normalization of CSF, particularly the CSF glucose, which remained low, justifying the use of an antimycobacterial treatment, especially since there was no local or general cause explaining the relapse. During a relapse of meningitis after ten months of antituberculosis treatment, the teratoma was discovered by a spine MRI done to detect any cerebrospinal defect. The authors insist on the fact that the Currarino syndrome must be investigated in case of repetitive purulent meningitis after ruling out the usual causes of meningitis.

[Febrile osseous pain in children with sickle cell disease: MRI findings]. / Douleurs osseuses fébriles chez l'enfant drépanocytaire: apport de l'IRM.

PURPOSE: The aim of this study was to report the MRI findings that can suggest a vaso-occlusive crisis in cases of febrile osseous pain in children suffering from sickle cell disease. MATERIALS AND METHODS: MRI (T1 and T2 weighted sequences and T1 weighted sequence with fat saturation before and after gadolinium injection) was performed in 10 children with sickle cell disease, presenting with febrile osseous pain. The diagnosis of vaso-occlusive crisis was made after fast improvement due to symptomatic treatment and negative bacteriological result. RESULTS: MRI was abnormal in all cases. A multifocal localisation was found in 2 cases. Bone marrow abnormalities were constant. In 10 cases, high T1 and T2 signal and metaphyso-diaphysial lesions were noted. Heterogeneous medullar enhancement with "ink stain" feature was constant. Early periosteal abnormalities were noted in 8 cases with inflammatory or stratified features. Cortical thinning was found in 1 case. Soft tissue abnormalities were observed in 5 cases with inflammatory features in 4. CONCLUSION: Multifocal synchronous localisation, medullar abnormalities resulting from hemoglobin degradation, heterogeneous enhancement, early periosteal abnormalities and associated soft tissues swelling are MRI findings suggesting acute vaso-occlusive disease.

[Heterotopic gray matter. Report of four pediatric cases]. / Hétérotopies de la substance grise. A propos de quatre observations pédiatriques.

Severe infant epilepsy is included within difficult etiologic diagnosis. Gray matter heterotopias are an uncommon cause. The authors report four observations of gray matter heteropias concerning three-, six-, seven- and nine-year-old girls, presenting no particular antecedents. No consanguinity was noted. The first occurrence of epilepsy ranged from the age of nine months to the age of four years. A mild mental retardation was found in three cases, and mental regression in one case. A status epilepticus was noted in three children. Magnetic resonance imaging scans showed subependymal heterotopias in one case and diffuse cortical heterotopias in three cases associated to a partial agenesis of corpus calloseum in one case and pachygyria in two cases.

[Apropos of a mediastinal teratoma invading the lung]. / A propos d'un cas de tératome médiastinal rompu dans le poumon.

Mediastinal mature teratomas are rare in children. Diagnosis is often made in the presence of a complication. We report a case of a mature mediastinal teratoma, complicated by its opening in the lung. The patient was a four-year-eight-month-old girl. She was admitted for fever, cough and dyspnea. The chest radiography showed a large mediastinal mass with calcifications. The CT scans and MRI aided in establishing the diagnosis. Biological tests (alpha-foetoproteins and beta-HCG) confirmed the benignity of the tumor. The child was operated on with full success.

[Acute osteomyelitis in children: early MRI diagnosis]. / Douleurs osseuses fébriles chez l'enfant: apport de l'IRM.

PURPOSE: To assess the value of MRI for early diagnosis of osteomyelitis in children presenting with sepsis and acute onset of musculoskeletal pain. MATERIALS AND METHODS: MRI including fat suppressed T2W, and fat suppressed pre- and postcontrast T1W sequences was performed within 48 hours of admission in 26 children with clinical (fever and acute musculoskeletal pain) and biological (elevated WBC count and ESR in all cases, and elevated CRP in 12 patients) suspicion of acute osteomyelitis. None of the patients had sickle cell disease. RESULTS: MRI was normal in 7 children (26%). Bone marrow signal abnormality was noted in 19 cases (74%) consistent with acute osteomyelitis in 18 cases and metastatic neuroblastoma in 1 case. CONCLUSION: MRI is useful for evaluation of children presenting with sepsis and acute musculoskeletal pain, early diagnosis of osteomyelitis and to prevent unnecessary hospital admission and work-up.

[Tuberculosis of the knee: MRI findings in two pediatric cases]. / Tuberculose ostéo-articulaire du genou: aspects IRM de deux cas pédiatriques.

Osteo-articular tuberculosis is rare in infants. The MRI findings reported for adolescents and young adults mainly relate to spinal involvement. Two cases of osteo-articular tuberculosis of infants located at the knee are presented. Vaccination has been correctly done. Skin test and chest radiography were normal. Evolution was insidious for one case. Osseous, medullary, cartilaginous and soft tissue abnormalities revealed by MRI were suspicious for tuberculosis. Diagnosis was confirmed at histology for both cases and bacteriology for one case. The aim of this study is to report the MRI features of osteo-articular tuberculosis in pediatric patients.