Perinatal arterial ischemic stroke related to carotid artery occlusion.

BACKGROUND: The aetiology of perinatal arterial ischemic stroke remains speculative. It is however widely accepted that the aetiology is multifactorial, involving various maternal, placental, foetal and neonatal risk factors. A resulting thromboembolic process is hypothesized and the placenta identified as the most plausible source. An arteriopathy, as observed in a significant proportion of childhood ischemic stroke, is thought to be rare. METHODS: We report here five cases of perinatal stroke that differ from the vast majority by documented carotid occlusion, and add eleven other similar cases from the literature. RESULTS: In the majority, an intraluminal thrombus of placental origin is the most probable hypothesis, while in the remaining ones, one can reasonably presume a direct vessel wall injury related to a traumatic delivery, yet generally unproven by imaging. CONCLUSION: We hypothesize that most of these cases share similar pathophysiology with the more common perinatal arterial ischemic stroke but differ by a persistent identified thrombus in the carotid artery at the time of first imaging, leading to a more severe and extended ischemic damage responsible for an adverse neurological outcome.

Kingella kingae osteoarticular infections in young children: clinical features and contribution of a new specific real-time PCR assay to the diagnosis.

BACKGROUND: Kingella kingae is an emerging pathogen that may be recognized as the most common bacteria responsible for osteoarticular infections (OAI) in young children. However, its diagnosis remains a challenge and thus little evoked in infants, because K. kingae is a difficult germ to isolate on solid medium, and clinical signs are often mild. The main objective of this prospective study is to describe the clinical, biologic, and radiologic features of children with OAI caused by K. kingae. In addition, we describe the usage of a new specific real-time PCR assay in children under 4 years admitted for OAI with a probe that detects 2 independent gene targets from the K. kingae RTX toxin. PATIENTS AND METHODS: All children less than 4 years admitted in our institution between January 2007 and November 2009 for suspected OAI were enrolled in this prospective study (43 cases). Age, gender, clinical signs, duration of symptoms, bone or joint involved, imaging studies, and laboratory data, including bacterial investigations, full blood count, erythrocyte sedimentation rate, and serum C-reactive protein were collected for analysis. RESULTS: Identification of the microorganism was possible for 28 cases (65.1%) yielding K. kingae in 23 cases (82.1%). Mean age of children with K. kingae OAI was 19.6 months. Less than 15% of these patients were febrile during the admission, but 46% of them presented a history of fever-peak superior to 38.5 degrees C before admission. Thirty-nine percent of the children with K. kingae OAI had normal C-reactive protein; WBC was elevated in only 2 cases, whereas 21 patients had abnormal erythrocyte sedimentation rate, and 13 abnormal platelet counts. Direct Gram staining and classical isolation methods were negative for all cases subsequently detected as K. kingae OAI by specific real-time PCR. CONCLUSION: This study confirms that K. kingae is the major bacterial cause of OAI in children less than 4 years. The real-time PCR assay, specific to the K. kingae RTX toxin, provides interesting diagnostic performance when implemented in the routine microbiologic laboratory. Needless to say, a bigger cohort is required to adequately study this new qPCR assay, but the results so far seem promising. The most important additional finding is the mild-to-moderate clinical, radiologic, and biologic inflammatory response to K. kingae infection with the result that these children present few criteria evocative of OAI. LEVEL OF EVIDENCE: II.

Mild influenza-associated encephalopathy/encephalitis with a reversible splenial lesion in a Caucasian child with additional cerebellar features.

Mild influenza-associated encephalitis/encephalopathy with a reversible splenial lesion is a rare entity recently reported almost exclusively in Asiatic individuals. Hallmarks of this clinical-radiological syndrome include severe encephalopathy at onset, prompt and complete recovery, minimal to absent pleocytosis and rapidly reversible involvement of the splenium of the corpus callosum. We report herein a young Caucasian child who in addition had cerebellar involvement and presented a transient mutism during the recovery phase.

Alexander disease: early presence of cerebral MRI criteria.

Alexander disease is a rare neurodegenerative disorder. Its most frequent subtype, the infantile form, is characterized by an early onset and a rapid neurological deterioration during the first months of life. Since the publication of cerebral radiological criteria in 2001, the disease has often been recognized by magnetic resonance imaging (MRI) findings. We report the case of a girl who at the age of 3 months presented with partial seizures and a normal neurological examination. MRI revealed the presence of a periventricular rim, extensive frontal white matter abnormalities, abnormalities of the basal ganglia and thalami and contrast enhancement involving optic chiasm, fornix, hypothalamus and mamillary bodies, corresponding to four of the five reported MRI criteria for Alexander disease. Additional MRI abnormalities not described so far were also observed. The diagnosis was confirmed by genetic analysis. This case illustrates that diagnostic MRI abnormalities of Alexander disease may be present at a very young age, long before the appearance of characteristic clinical signs. Early diagnosis by MRI allows prompt counselling of families.

Unilateral focal polymicrogyria in a patient with classical Aarskog-Scott syndrome due to a novel missense mutation in an evolutionary conserved RhoGEF domain of the faciogenital dysplasia gene FGD1.

Faciogenital dysplasia or Aarskog-Scott syndrome (AAS) is an X-linked disorder characterized by craniofacial, skeletal, and urogenital malformations and short stature. Mutations in the only known causative gene FGD1 are found in about one-fifth of the cases with the clinical diagnosis of AAS. FGD1 is a guanine nucleotide exchange factor (GEF) that specifically activates the Rho GTPase Cdc42 via its RhoGEF domain. The Cdc42 pathway is involved in skeletal formation and multiple aspects of neuronal development. We describe a boy with typical AAS and, in addition, unilateral focal polymicrogyria (PMG), a feature hitherto unreported in AAS. Sequencing of the FGD1 gene in the index case and his mother revealed the presence of a novel mutation (1396A>G; M466V), located in the evolutionary conserved alpha-helix 4 of the RhoGEF domain. M466V was not found in healthy family members, in >300 healthy controls and AAS patients, and has not been reported in the literature or mutation databases to date, indicating that this novel missense mutation causes AAS, and possibly PMG. Brain cortex malformations such as PMG could be initiated by mutations in the evolutionary conserved RhoGEF domain of FGD1, by perturbing the signaling via Rho GTPases such as Cdc42 known to cause brain malformation.

[A new 2D and 3D imaging approach to musculoskeletal physiology and pathology with low-dose radiation and the standing position: the EOS system]. / Une nouvelle imagerie ostéo-articulaire basse dose en position debout: le systeme EOS.

Close collaboration between multidisciplinary specialists (physicists, biomecanical engineers, medical radiologists and pediatric orthopedic surgeons) has led to the development of a new low-dose radiation device named EOS. EOS has three main advantages: The use of a gaseous X-ray detector, invented by Georges Charpak (Nobel Prizewinner 1992), the dose necessary to obtain a 2D image of the skeletal system has been reduced by 8 to 10 times, while that required to obtain a 3D reconstruction from CT slices has fallen by a factor of 800 to 1000. The accuracy of the 3D reconstruction obtained with EOS is as good as that obtained with CT. The patient is examined in the standing (or seated) position, and is scanned simultaneously from head to feet, both frontally and laterally. This is a major advantage over conventional CT which requires the patient to be placed horizontally. -The 3D reconstructions of each element of the osteo-articular system are as precise as those obtained by conventional CT. EOS is also rapid, taking only 15 to 30 minutes to image the entire spine.

MRI of the fetal posterior fossa.

MRI is a useful tool to complement US for imaging of the fetal posterior fossa (PF). In France, the discovery of a PF malformation in the fetus frequently leads to termination of pregnancy (80% in a personal series). However, despite improved accuracy in the diagnosis of PF abnormalities, prognosis remains uncertain. The first objective of this review is to document the normal MRI landmarks of the developing fetal PF. Because of their thinness, the visibility of the cerebellar fissures is dramatically delayed on MRI compared to macroscopic data. An important landmark is identification of the primary fissure of the vermis, normally seen at around 25-26 weeks' gestation (WG) on the sagittal slice, separating the larger posterior lobe from the anterior lobe (volume ratio around 2:1). The prepyramidal and secondary fissures are usually only identifiable after 32 WG and the hemispheric fissures are difficult to see until the end of pregnancy. Considering the signal changes, high signal on T2-weighted (T2-W) sequences is seen from 25 WG in the posterior part of the brain stem (tegmentum and ascending sensory tracts) related to myelination. The low signal intensities seen within the cerebellum on T2-W images correspond to high cellularity of grey matter (deep nuclei), as there is no myelination within the white matter before 38 WG. The second objective is to highlight the signs highly predictive of a poor neurological prognosis. Lack of pontine curvature or vermian agenesis without a PF cyst (small volume of PF) is greatly associated with poor neurological status. The third objective is to propose a diagnostic strategy in difficult cases where prognosis is important, e.g. the Dandy Walker continuum. Analysis of the cerebellum is often impossible if a PF cyst is present (whatever its nature) as the mass effect usually blurs the foliation and even impairs evaluation of the normal ratio between the posterior and anterior lobes of the vermis. Isolated cerebellar hypoplasias raise the question of prognosis and genetic counselling. Such uncertainties require an amniocentesis and a careful search for other anomalies (cerebral and extracerebral). Unilateral abnormalities of a cerebellar hemisphere can be associated with good neurological status if they are isolated. The final objective is to discuss other rare PF fetal abnormalities, such as vascular malformations and tumours.

Aortic dilatation in Turner syndrome: the role of MRI in early recognition.

BACKGROUND: Aortic dilatation and dissection are rare but important complications of Turner syndrome that increase the risk of sudden death in young patients. OBJECTIVE: To assess the value of aortic MRI in patients with Turner syndrome; in particular to demonstrate early aortic dilatation. MATERIALS AND METHODS: A total of 21 patients with Turner syndrome underwent MRI of the thoracic aorta with measurement of vessel diameter at four levels. RESULTS: Measurements were normal for age in 15 cases, two patients presented with values at the upper limit of normal and four had obvious dilatation of the ascending aorta. All were symptom free. CONCLUSIONS: MRI allows the non-invasive demonstration of early aortic dilatation, which may lead to earlier surgery in asymptomatic individuals.

Lacrimal location of sinus histiocytosis (Rosai-Dorfman-Destombes disease).

A 7-year-old West African male patient presented with recurrence of multiple cervical lymphadenopathy. Cervical node biopsy disclosed a sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman-Destombes disease). During follow-up, the patient developed a left orbital mass corresponding to an enlarged lacrimal gland shown by CT. The histologic features of the gland were consistent with the diagnosis, and with steroid treatment, the gland decreased in size. Although rare, the diagnosis of sinus histiocytosis with massive lymphadenopathy has to be considered in cases of lacrimal gland enlargement.