Mechanical properties of fused sagittal sutures in scaphocephaly.

BACKGROUND: Craniosynostosis in newborns is caused by the premature closure of the cranial sutures leading to cranial vault deformity. It results in aesthetic imbalance and developmental disabilities and surgery is frequent during the first months of growth. Our study focused on scaphocephaly defined as the premature closure of the sagittal suture. We hypothesised that the effective mechanical properties of sutures were altered as compared to those of the parietal adjacent tissue considered as control. METHODS: The population consisted of seven males and four females (mean age 4.9 months). Sixteen suture samples and thirty-four parietal tissue samples were harvested during corrective surgery and investigated by using three-point bending tests to obtain the structure-stiffness of specimens. An energy model was used to derive the effective Young's modulus. A histological study complemented the experimental protocol. FINDINGS: Fused sutures were thicker than adjacent bone and the natural curvature of sutures did not influence the static mechanical response. The stiffness of stenotic sutures was significantly higher than that of the parietal bone. The effective Young's modulus of stenotic sutures was significantly lower than that of the parietal adjacent tissue. The parietal tissue showed a parallel bone architecture whereas the central stenotic tissue was disorganised with more vascularisation. INTERPRETATION: The stenotic suture differed in structural and mechanical terms from the adjacent bone during calvarial growth in the first year of life. Our study emphasised the alteration of effective tissue properties in craniosynostosis.

One-step primary reconstruction for complex craniofacial resection with PEEK custom-made implants.

PURPOSE: Reconstruction of large craniofacial defects has largely improved since custom-made implants have been developed in the past decade. For large lesions in fronto-orbital region (such as osteomeningioma), we applied a simple and reliable protocol to perform optimal primary reconstruction with PEEK (polyetheretherketone) specific implant at the same time of the resection. MATERIAL AND METHODS: Our protocol is based on virtual preoperative surgery with a planned bone resection that allows engineering of a specific implant to accurately fit to the defect during the surgery. Thus tumour removal and optimal immediate reconstruction are performed easily in a single-step procedure. The use of navigation is required to perform accurate resection according to the planning. We report our experience in five patients requiring complex orbito-frontal reconstruction. RESULTS: Planned resection was always achieved with accurate placement of the implant. Optimal orbital reconstruction is allowed and permits exophthalmos correction and orbital contour symmetry. No major complication was observed. CONCLUSION: We provide a simple one-step technique to reconstruct the orbit while achieving symmetric cosmetic and functional results, reducing operative time and avoiding donor site morbidity.

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.

Isolated lymphocytic infiltration of pituitary stalk preceding the diagnosis of germinoma in 2 prepubertal children treated with growth hormone.

We report the clinical course of 2 patients with central diabetes insipidus and evolving to panyhypopituitarism which prompted the diagnosis of an isolated pituitary stalk thickening (PST). In both patients, all etiological investigations were normal and the first biopsy revealed an isolated lymphocytic infiltrate with no sign of malignancy. Close clinical follow-up accompanied by serial brain MRIs was proposed to determine a precise diagnosis and for early detection and treatment of neoplastic disease. In our first case, the diagnosis of germinoma was made 9 months after the PST diagnosis owing to tumor progression. In the second case, the time course was even longer with the diagnosis of germinoma 6 years following initial presentation. In these cases, it is speculated that the lymphocytic infiltrates represent the first sign of a host reaction to an occult germinoma. To our knowledge, this is the third case reported of lymphocytic infiltrates preceding a germinoma in a prepubertal girl, and the only case reported in a prepubertal boy. These cases underline the difficulties in establishing the diagnosis of germinoma in a patient with isolated PST.

[Natural history of intramedullary cavernomas. Results of the French Multicentric Study]. / Histoire naturelle des cavernomes intramédullaires et traitement chirurgical. Résultats de l'étude française multicentrique.

INTRODUCTION: The prevalence of cerebral cavernomas is about 0.5% in the general population. In contrast, spinal cord cavernomas are considered as rare. The objective of this study was to determine the natural history of spinal cord cavernomas in a multicentric study. METHODS: Clinical and neuroradiological findings were retrospectively collected. Diagnosis was based on pathological criteria or magnetic resonance (MR) findings. RESULTS: Fifty-three patients were included (26 males, 27 females). Mean age at onset of symptoms was 40.2 years (range: 11-80). Initial symptoms were progressive (32) and acute myelopathy (20). One patient was asymptomatic. Clinical symptoms were related to spinal cord compression (24) and hematomyelia (19). Cavernoma location was dorsal (41) and cervical (12.). MR findings consisted of hyperintense signal on T1 and T2 sequences (19 cases), mixed hyperintense and hypointense signal (33 cases), and hypointense signal on T1 and T2 sequences in 1 case. Mean size was 16.3 mm (range: 3-54). Forty patients underwent surgical resection. Improvement was observed in 20 patients and worsening of neurological symptoms in 11. Length of follow up was 7.1 years. At the end of the study, 26 patients were autonomous, 18 handicapped and 1 bedridden. CONCLUSION: This study provided precise data on the clinical and MR patterns of these lesions. The natural history is associated with a higher risk of hemorrhage recurrence, but is favorable in many operated patients. Microsurgery is the treatment of choice for most of these lesions.

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.

Immunodetection of SV40 large T antigen in human central nervous system tumours.

BACKGROUND/AIMS: DNA sequences from Simian virus 40 (SV40) have been previously isolated from various human tumours of the central nervous system (CNS). This study aimed to investigate a series of tumours of the CNS for the expression of the SV40 large T antigen (Tag), which is an oncogenic protein of the virus. METHODS: A French series of 82 CNS tumours was investigated for Tag expression using a monoclonal antibody and immunohistochemistry. A Tag positive hepatocellular carcinoma cell line from transgenic mice and a kidney biopsy from a patient infected by SV40 were used as positive controls. RESULTS: None of the tumours (20 ependymomas, 20 glioblastomas, 12 oligodendrogliomas, three plexus choroid adenomas, two plexus choroid carcinomas, 15 meningiomas, and 10 medulloblastomas) contained SV40 Tag positive cells. CONCLUSIONS: The lack of SV40 Tag in 82 CNS tumours of various types is at variance with previous studies from different countries, and suggests that the virus may not be an important factor in CNS tumorigenesis, at least in French cases.

Mutations within the programmed cell death 10 gene cause cerebral cavernous malformations.

Cerebral cavernous malformations (CCMs) are hamartomatous vascular malformations characterized by abnormally enlarged capillary cavities without intervening brain parenchyma. They cause seizures and cerebral hemorrhages, which can result in focal neurological deficits. Three CCM loci have been mapped, and loss-of-function mutations were identified in the KRIT1 (CCM1) and MGC4607 (CCM2) genes. We report herein the identification of PDCD10 (programmed cell death 10) as the CCM3 gene. The CCM3 locus has been previously mapped to 3q26-27 within a 22-cM interval that is bracketed by D3S1763 and D3S1262. We hypothesized that genomic deletions might occur at the CCM3 locus, as reported previously to occur at the CCM2 locus. Through high-density microsatellite genotyping of 20 families, we identified, in one family, null alleles that resulted from a deletion within a 4-Mb interval flanked by markers D3S3668 and D3S1614. This de novo deletion encompassed D3S1763, which strongly suggests that the CCM3 gene lies within a 970-kb region bracketed by D3S1763 and D3S1614. Six additional distinct deleterious mutations within PDCD10, one of the five known genes mapped within this interval, were identified in seven families. Three of these mutations were nonsense mutations, and two led to an aberrant splicing of exon 9, with a frameshift and a longer open reading frame within exon 10. The last of the six mutations led to an aberrant splicing of exon 5, without frameshift. Three of these mutations occurred de novo. All of them cosegregated with the disease in the families and were not observed in 200 control chromosomes. PDCD10, also called "TFAR15," had been initially identified through a screening for genes differentially expressed during the induction of apoptosis in the TF-1 premyeloid cell line. It is highly conserved in both vertebrates and invertebrates. Its implication in cerebral cavernous malformations strongly suggests that it is a new player in vascular morphogenesis and/or remodeling.

Third ventriculocisternostomy in cerebellar haematomas.

BACKGROUND: We prospectively evaluated the role of endoscopic third ventriculocisternostomy in the management of acute obstructive hydrocephalus created by cerebellar hematomas. METHOD: Following a therapeutic diagram based on clinical and radiological signs, endoscopic third ventriculocisternostomy was used to treat hydrocephalus associated with cerebellar hematomas in 8 patients (male: 5, female: 3, mean age: 67 years-old). Causes of cerebellar hemorrhage were spontaneous in 6 cases, traumatic in 1 case, and acute bleeding of a posterior fossa tumor (lung metastasis) in the remaining case. Deeply comatose patients (Glasgow Coma Score between 3 and 5) and patients with signs of brainstem compression were initially excluded from this study. FINDINGS: Overall clinical improvement after third ventriculocisternostomy was achieved in all patients and was associated with the decrease of the ventricle size on follow-up CT scans. One patient who initially had a clot evacuation associated with an external ventricular drainage and persistant hydrocephalus had a successful third ventriculocisternostomy in the post operative course. No complication related to the procedure was noted. INTERPRETATION: In selected patients, third ventriculocisternostomy can be used to treat hydrocephalus associated with posterior fossa hematomas.

International study of emergency department care for pediatric traumatic brain injury and the role of CT scanning.

OBJECTS: Our objective was to investigate the use of CT and its relationship to head injury severity and age. METHOD: The multi-center group International Study of Head Injury Project (ISHIP) serves as the administrative body for research design, data collection and analysis. This is a nonrandomized prospective study of longitudinal outcomes following examination and care in emergency department in five different countries. The subjects of our study were 4,690 children from birth to 15 years of age, all of whom were systematically evaluated. Each child was medically evaluated and categorized as to injury severity, mechanism of injury and findings on X-ray and CT scan. Follow-up interview and assessment was completed for comparison with the presenting clinical state. RESULTS: CT scans were performed for 674 (14.3%) of the children: 438 scans were normal and 236 were abnormal (P<0.001). Of the children with abnormal CT scans, 23.3% had mild head injuries, 42.7% had moderate injuries, and 33.8% had severe injuries, as determined by the GCS. By age, 10.5% of the positive CTs were in children aged 0-2 years, 56.3% in 3- to 9-year-olds, and 33% in 10- to 15-year-olds; only in 2% of cases were both CT and X-ray positive. CONCLUSIONS: The majority of children did not need significant medical intervention. Physicians ordered X-ray investigations more frequently than CT scanning. The use of X-ray to decide whether or not CT is necessary is not warranted. The implications of positive CTs in mild or moderate injuries were most noteworthy, as were age-related interactions with positive CT findings.

[French neurosurgery in the Bosnia-Herzegovina conflict]. / Les missions neurochirurgicales françaises dans le conflit en Bosnie-HerzEgovine.

Seven French neurosurgical missions, from June 1994 to December 1996, were sent successively to Bosnia-Herzegovina with the help of a non-governmental organisation Médecins du Monde. The aim of this article is to present the working conditions, make an overall evaluation of the missions and then to draw lessons and discuss the limits. The initial aim of these neurosurgical missions was: i) to provide human and logistic support to the Bosniac teams in the field; ii) to exchange knowledge and help in the training of local young neurosurgeons; iii) to be present as witnesses. The towns of Tuzla and Zenica in Eastern and Central Bosnia respectively were chosen as the missions bases. One hundred five neurosurgical operations were carried out in precarious conditions, particularly concerning anesthesia. The largest number of the operations (52%) concerned standard neurosurgical pathologies, without any direct link to the war but which had been put off or made difficult due to the war. Cranioplasties and peripheric nerve injuries were the main lesions directly related to the war situation which the French missions had to deal with. Actually, war neurosurgical pathologies were very often dealt with in emergency by Bosniac teams in the field hospitals near the front. Previously existing neurosurgical environment, in particular with access to a scanner is an absolute necessity to carry out a good quality neurosurgical mission. Precarious anesthesia and operating conditions require the surgical team to adapt to local conditions, but are not a contra-indication to such missions. Although help in the field can prove useful on occasions, training the resident teams is important. This can be done locally, but additional training in a neurosurgically developed country is fundamental. Missions such as these require relatively major funding (about 150 000 French francs for each of our missions) and suitable infrastructures. Prior to undertaking this type of mission, a neurosurgeon must evaluate local human and equipment needs.

International Multicenter Study of Head Injury in Children. ISHIP Group.

With the object of evaluating different epidemiological factors in the acute phase of head injury (HI) in the pediatric age group in five countries (Argentina, Brazil, France, Hong-Kong and Spain), we carried out a prospective and descriptive study, in which we analyzed the clinical and radiological risk factors versus management and outcome 7-30 days after trauma. We included all children seen in the emergency department and hospitalized who were aged between 0 and 15 years and had sustained HI. Data were compiled from the clinical records and analyzed for neurological evaluation with the Glasgow Coma Scale (GCS) and the Glasgow Paediatric Coma Score (GPCS), and also by means of dynamics, symptoms, skull X-rays, CT scans. The total of 2478 patients enrolled in the study was made up of 60.9% boys and 39.1 % girls. Age distribution was as follows: 55.2% aged 0-4 years; 28.3% aged 5-9 years, and 16.4% aged 10-15 years. Most (75.3%, or 1768) of these patients completed follow-up. The total sample included 1058 children (42.7%) who required hospitalization. Skull fractures were identified in 11.8% (298) of the cases, and 6.4% (158) of CT scans were pathologic. Minor HI accounted for 56.4% of these children, moderate HI for 38.9%, and severe HI for the remaining 4.7%. The lethality rate was 1.6%. Our preliminary data reveal that it is very important for new guidelines on the treatment of minor HI to be prepared, because patients with minor HI had undergone the most skull X-rays and also most frequently been admitted to hospital for unnecessarily long periods of time, though the incidence of brain damage (1.6%) was lowest in this group of the study population. We intend to carry out a full analysis of the various risk factors at the end of the study.

Clear-cell meningioma of the cauda equina.

Meningiomas are rare tumours in children and lumbar lesions are exceptional. We report a clear-cell meningioma (CCM) of the cauda equina in a 10-year-old girl. The tumour was diagnosed by MRI, showing an enhancing intradural mass extending from L1 to L4. Pathology and immunohistochemical study demonstrated a CCM. The patient had a recurrence 6 months after the operation requiring further surgery. CCM are rare lesions, characterised by abundant cytoplasmic glycogen particles. Complete surgical removal is necessary because, despite their benign histological appearance, CCM are potentially aggressive and may recur, spread locally and even metastasize.

[Clear cell meningioma: recurrent intraspinal tumor in a child]. / Méningiome à cellules claires: tumeur rachidienne récidivante chez un enfant.

BACKGROUND: Meningiomas represent 1.5% to 4.3% of cerebral and medullar primary tumors in children. CASE REPORT: A 9-year-old girl had a history of thoracolumbar scoliosis. An intracanalar and extramedullar tumor was confined to the lumbar region. Resection identified a clear cell meningioma. A symptomatic and tumoral recurrence occurred 5 months later in the same region. After a second resection, the patient received radiotherapy. At 8 months follow-up, no recurrence was documented. CONCLUSIONS: A stiff and painful scoliosis can be predictive of expansive intracanalar tumor. The recurrent or multifocal evolution of clear cell meningioma show the "aggressive behavior" of this histological type. A preventive radiotherapy could be proposed, depending on the age of the patient and the localization of the tumor.

Diffusion- and magnetisation transfer-weighted MRI in childhood moya-moya.

MRI in two children with moya-moya demonstrated low signal on T2-weighted images in the acute and subacute phases of ischaemia. Gradient-echo sequences, more sensitive to magnetic susceptibility, demonstrated these abnormalities better. Signal loss, due to temporary accumulation of iron, decreases progressively and disappears in the chronic stage of the disease. Diffusion-weighted MRI allows early detection of ischaemic lesions and can be used to monitor progressive spreading of the lesions. Magnetisation transfer maps provide sharp contrast, useful for demonstrating cortical atrophy.

[Pseudotumor forms of neurosarcoidosis in children. Diagnostic difficulties and therapeutic management]. / Formes pseudo-tumorales de la neurosarcoïdose chez l'enfant. Difficultés diagnostiques et prise en charge thérapeutique.

In systemic sarcoidosis, neurologic manifestations are possible and occurred in 5 p. 100 of cases. The diagnosis is easier when sarcoiddosis is known, but in half case neurologic symptoms are inaugural. In these cases, involvement of other sites (liver, lung, eyes or skin) by the disease is needed to confirm sarcoidosis. Main manifestations in neurosarcoidosis are cranial nerve palsy, diabetes insipidus or chronic aseptic meningitis, but sometimes sarcoidosis can present as an intracranial mass. The diagnosis of neurosarcoidosis may be difficult and could be confused with infection (such tuberculosis or mycosis), with inflammatory diseases (such multiple sclerosis) or with neoplasm, particularly in case of oedema. Brain biopsy may be necessary in isolated neurosarcoidosis if no peripheral histology evidence of noncaseating granulomas has been obtained. Treatment with steroids alone is the best choice for initial therapy but must be prolonged. It is difficult to predict accurately the response to steroids and relapse may be possible after a long time. Other immunosuppressive therapeutics or radiotherapy have been used in patient with refractory neurosarcoidosis. Sequential magnetic resonance imaging is the useful mean for the follow-up of neurosarcoidosis.

[Association of venous angioma and cavernoma of the posterior fossa]. / Association d'un angiome veineux et d'un cavernome au niveau de la fosse postérieure.

BACKGROUND: Association of venous angioma to cavernous malformation is rare. If bleeding occurs, it must be assigned to the cavernous malformation. CASE REPORT: A 4 year-old boy suffered from an acute ataxia. Investigation showed a venous angioma and a cavernoma malformation in the posterior fossa. The patient was admitted again at the age of 8 years for a new episode of acute ataxia due to cerebellar hematoma. A conservative treatment was settled because of the risk of venous infarction. CONCLUSION: Venous angiomas are rarely symptomatic and are considered as normal venous variants. Indeed, the cavernomas are true malformations with a high bleeding potential. When both lesions are associated and bleeding occurs, only the cavernous malformation has to be removed if surgically accessible.

[Value of the study of somatosensory evoked potentials during surgical correction of scoliosis associated with syringomyelia. Apropos of 4 cases]. / Intérêt de l'étude des potentiels évoqués somesthésiques au cours de la correction chirurgicale des scolioses associées à une syringomyélie. A propos de quatre observations.

PURPOSE OF THE STUDY: The presence of a syringomyelia cavity increases the rate of neurological complications on the course of surgical treatment of scoliosis. We have evaluated the results of monitoring of somatosensory evoked potentials (SEP) in these situations. MATERIAL AND METHODS: Four patients presenting a scoliosis associated with syringomyelia have been operated through a posterior-approach with CD instrumentation. SEP monitoring was performed pre and intraoperatively. We studied the latency and the amplitude of P40. RESULTS: Preoperative SEP showed in all cases posterior spinal cord involvement (even without clinical manifestations). During monitoring, we noted in one case no variation. In one case a flattening of the response with normalisation within 5 minutes. In two cases a persistent flattening with normalisation within 10 and 15 minutes following modification of the instrumentation. In all cases, postoperative neurological status was identical to preoperative one. DISCUSSION: Preoperative SEP can make the diagnosis of posterior spinal cord involvement even when clinical status is normal. The extent of the preoperative SEP abnormalities may preclude the risk of intraoperative neurological complications. Intraoperative SEP can be performed with the same anesthetic protocol and the same technique used when operating idiopathic scoliosis. The results seem reliable. When alteration occur as for idiopathic scoliosis alteration of the amplitude appears earlier than alteration of the P40 latency. Restoration of normal responses appears later than in idiopathic scoliosis. CONCLUSION: SEP monitoring should diminish the risk for neurological complications in the course of surgical treatment of scoliosis associated with syringomyelia.