Measurement of Lepton-Jet Correlation in Deep-Inelastic Scattering with the H1 Detector Using Machine Learning for Unfolding.

The first measurement of lepton-jet momentum imbalance and azimuthal correlation in lepton-proton scattering at high momentum transfer is presented. These data, taken with the H1 detector at HERA, are corrected for detector effects using an unbinned machine learning algorithm (multifold), which considers eight observables simultaneously in this first application. The unfolded cross sections are compared with calculations performed within the context of collinear or transverse-momentum-dependent factorization in quantum chromodynamics as well as Monte Carlo event generators.

Determination of the strong coupling constant α s ( m Z ) in next-to-next-to-leading order QCD using H1 jet cross section measurements: H1 Collaboration.

The strong coupling constant α s is determined from inclusive jet and dijet cross sections in neutral-current deep-inelastic ep scattering (DIS) measured at HERA by the H1 collaboration using next-to-next-to-leading order (NNLO) QCD predictions. The dependence of the NNLO predictions and of the resulting value of α s ( m Z ) at the Z-boson mass m Z are studied as a function of the choice of the renormalisation and factorisation scales. Using inclusive jet and dijet data together, the strong coupling constant is determined to be α s ( m Z ) = 0.1157 ( 20 ) exp ( 29 ) th . Complementary, α s ( m Z ) is determined together with parton distribution functions of the proton (PDFs) from jet and inclusive DIS data measured by the H1 experiment. The value α s ( m Z ) = 0.1142 ( 28 ) tot obtained is consistent with the determination from jet data alone. The impact of the jet data on the PDFs is studied. The running of the strong coupling is tested at different values of the renormalisation scale and the results are found to be in agreement with expectations.

[Young French neurosurgeons: Working conditions and outlook]. / Jeunes neurochirurgiens français: conditions de travail et perspectives.

INTRODUCTION: Due to the increase in the number of French neurosurgeon residents the neurosurgical workforce is changing. The main objective of this survey was to assess working conditions and perspectives for young French neurosurgeons. METHOD: An on-line survey was sent to young French neurosurgeons based on a mailing-list (219 mail addresses of Residents and Fellows obtained during previous meetings). The form contained questions about career, amount of work, salary, quality of life, teaching and university work. RESULTS: We received 78 replies from January to March 2014. A total of 56% from fellows saying they had undergone difficulties in obtaining a fellowship, although 78% were satisfied. Fellows considered a private career more often than residents. Overall, young neurosurgeons were worried about future employment. Some 33% admitted contemplating a different career from one they originally wanted. The average weekly working time of 76.8 hours was deemed to be excessive. Security rests after overnight shifts were lacking or incomplete in 91% of cases. The work atmosphere was good overall (3.7/5), and so was the quality of life (3.2/5). Theoretical teaching was unsatisfactory (2.43/5) as well as the time allowed for academic work (approximately 1.58 half-days per month). However, practical teaching was considered rewarding (3.63/5). CONCLUSION: This study provides some guidance for upcoming reforms, and should be considered again at a later date to evaluate progress.

[Intramedullary tumors. Results of a national investigation in private neurosurgery]. / Les tumeurs intramédullaires. Résultat d'une enquête nationale en neurochirurgie libérale.

UNLABELLED: The frequency of intramedullary tumors is 0.5 cases per year for 100,000 inhabitants. The study reported herein was a retrospective study conducted from January 1985 to September 2007. MATERIAL: Seventy-nine cases were distributed in the following manner: ependymomas, 38; astrocytomas, 22; oligodendrogliomas, four; gangliogliomas, two; hemangioblastomas, 10 (nine sporadic cases and one case of Von Hippel-Lindau disease); primitive melanoma, one; and intramedullary neurinomas, two. Three patients were lost to follow-up and 10 patients died. METHOD: All patients were explored using MRI and were operated using a microsurgical technique. Tumor removal was complete in the cases of ependymoma and hemangioblastoma and subtotal in the cases of astrocytoma. RESULTS: Ependymoma: 38 cases with three cases of ependymoblastoma. Mean age: 47 years (range, 17-74 years); 17 males and 21 females. Diagnostic delay: less than one year, 11; one year, 15 cases; two years, nine cases; three years, three cases. Seven recurrences with one 35 years after a prior removal. Localizations: cervical and cervicodorsal, 19; dorsal, ten; dorsolumbar, seven; holomedullary, one. Number of levels concerned: 5-12 (with the cysts associated). Mean follow-up was 10 years (range, two months to 35 years). Patients stabilized, 19; worse, six; improved, nine. Patients deceased: four, one by suicide, three cases of ependymoblastoma (survival, seven months). Astrocytomas: 22 cases, with 14 cases of astrocytoma, two pilocytic astrocytoma, four malignant astrocytoma, and two glioblastoma. Mean age: 44 years (range, 22-73 years); 14 males and eight females. Diagnostic delay: malignant tumors, one to nine months; low grades; three to six years (range, eight months to 25 years). Number of levels concerned: two to eight. Mean follow-up: seven years (range, six months to 10 years). Stabilized patients: 13; worse, five; deaths, four. Oligodendroglioma: four cases. Mean age: 58 years; two males and two females. Diagnostic delay: 10months. Localization: cervical, three; dorsal, one. Oligodendroglioma A, two; B, two. Results: two cases stabilized, one case with recurrence, and one patient deceased. Ganglioglioma: two. Both cases were associated with scoliosis. Recurrence in the eighth month and two years for the second case. One patient died. Hemangioblastoma: 10 cases, nine sporadic and one case of Von Hippel-Lindau disease. Nine cervical localizations, one on the medulla cone. Mean age: 45 years (range, 11-54 years); eight males and two females. Total removal in nine cases. One case of recurrence seven years after a prior surgery and operated a second time with no recurrence after 10 years of follow-up. Intramedullary neurinomas: two cases with a total removal and 15 years of follow-up. Primitive melanoma: one case with mediothoracic location. Treatment with surgery plus radiotherapy. Follow-up, seven years without recurrence. CONCLUSION: Total removal of the intramedullary tumors is a challenge. In cases of removal, the risk of worsening status is 18-19.5%. Subtotal or incomplete removal 27-40% risk of recurrence.

Primary Ewing's sarcoma of the skull in children. Utility of molecular diagnostics, surgery and adjuvant therapies.

Ewing's sarcoma (ES) of the skull is rare. Herein, we present 2 cases of ES that involved the cranium in young children. In one case, the lesion originated in the petrous temporal bone; in the other, the frontal bone. Both children were acutely compromised neurologically by signs and symptoms of raised intracranial pressure. In both cases, radiographs revealed massive tumors affecting the skull. Neurosurgical resection of the tumor was undertaken in both instances, and the diagnosis of ES was confirmed by immunohistochemistry, cytogenetic analysis (translocation 11;22), spectral karyotyping and RT-PCR (demonstration of a EWS/FLI1 fusion transcript). Following aggressive surgical resection, both children received intensive chemotherapy. No child has received radiation therapy. One child is alive and well 8 years after diagnosis without any evidence of residual disease. The other is currently undergoing chemotherapy for her tumor. The principles involved in the management of children with cranial-based ES are discussed. These 2 cases serve to illustrate the fact that even children with massive ES tumors of the cranium may be salvaged with aggressive combination therapy.

[Uncommon etiology of extradural hematoma]. / Etiologie inhabituelle d'un hématome extra-dural.

Intracranial or spinal epidural hematomas are almost always of post-traumatic origin, and rarely related to rupture of a dural vascular malformation or a hemostasis disorder. We report a case of spontaneous cerebral epidural hematoma observed in a young girl with homozygous sickle cell disease. After analysis of post-operative cerebral MRI, showing skull bone infarction inside and around the bone flap, it was considered that the skull bone infarction could be responsible for a diploic venous thrombosis with subsequent "spontaneous" epidural hematoma.

Visuvalve software: an aid to the diagnosis of shunt failure.

Software designed to help the neurosurgeon in the diagnosis of shunt malfunction is presented. This software allows the possibility to record on a 3.5 diskette a patient's clinical information and four views of a CT scan performed when the patient was doing perfectly well with his shunt. This diskette, operated by MS-DOS on any IBM-compatible personal computer, can be read at any time, anywhere. The evaluation of the system demonstrated it was safe, with an excellent adhesion of the patients and of their families.

Differential expression between PAX-6 and EN proteins in medulloblastoma.

A collection of 28 medulloblastomas was analyzed for expression of the developmental control genes PAX-6 and EN by immunohistochemical staining. Sixteen medulloblastomas expressed both EN and PAX-6 but, when differentiation could be assessed in the positive areas, PAX-6 is expressed in the less differentiated cells. Since Drosophila en encodes a negative regulator, we overexpressed the chicken en-1 in retinal pigmented epithelium cells. This resulted in Pax-6 down regulation. These results suggest a regulatory loop between PAX-6 and EN, two molecular markers of medulloblastoma.

Peritoneal pseudocyst--ventriculo-peritoneal shunt complications.

Pseudocyst formation is a rare complication of ventriculo-peritoneal shunt, occurring in only 22 cases of 1300 shunts from 1968 to 1992. The most common presentation is that of abdominal signs rather than neurological or infectious signs. The diagnosis is easy with ultrasonography. The difficulty is to evocate the cyst and to correlate symptoms and cyst. Treatment of the cyst was by aspiration (21 cases) and excision in 7 cases. The therapeutic choice is made according to the ultrasound findings. When the cyst was infected, an external ventricular shunt was used temporary, but this type of shunt must be avoided where possible. Three patients died.

[Nasofrontal dermoid fistulae and cysts. Apropos of 19 cases]. / Les fistules et kystes dermoïdes naso-frontaux. A propos de 19 cas.

A series of 19 children with congenital nasal dermoid cyst or fistulas admitted in our department between 1978 and 1992 was reviewed in a retrospective study. They were 8 females and 11 males, ages ranged from 9 months to 7 years (mean: 2 years and 4 months). At diagnosis 8 children presented with infection (superficial in 6 cases, neurological in 2 cases), and in 11 cases the malformation was discovered by the family physician. In 14 cases the cyst was located at the mid nasal ridge. Four children had associated malformations: neurodevelopmental delay (2 cases), hypertelorism (1 case) and external ear agenesia with facial palsy. The cyst was subcutaneous in 5 cases and was operated on through a nasal approach. The 14 other children were operated through associated intra and extracranial approaches. Surgical exploration disclosed a dural extension of the fistula in 9 cases. When performed, preoperative radiological explorations including CT Scan and/or MRI had not always predicted the dural extension. The mean follow-up is 5.3 years. No recurrence was recorded and the cosmetic result was always excellent. Preoperative radiological investigations are necessary to precise the location of these malformations and to detect associated disorders, but they appear unable to prove the extension of the fistula to the dura. Intracranial and extracranial approaches should be always planned to perform a total excision of the lesion.

Foraminal lumbar disc herniation. Experience with 83 patients.

STUDY DESIGN: This study analyzed a series of 83 patients operated on for foraminal lumbar disc herniation. OBJECTIVES: This study sought to develop clinical and radiologic diagnoses, evaluate interlaminar and extra-articular exposures, and evaluate postoperative results. SUMMARY OF BACKGROUND DATA: Some authors have reported a specific clinical syndrome, but other reports have indicated the clinical picture is indistinguishable from usual posterolateral disc herniation. Surgical management often has been compared between the interlaminar and extra-articular approaches. METHODS: Clinical findings were reviewed. All patients were evaluated with computed tomography, but radiologic diagnosis required computed tomographic discography for 26 patients. Interlaminar exposure with partial medial facetectomy was performed in 73 patients and an extra-articular approach was necessary in 10 patients. Postoperative results were evaluated with a 2-year follow-up. RESULTS: Foraminal lumbar disc herniations have a specific clinical picture, particularly severe radicular signs. Precise preoperative radiologic evaluation is essential for successful operative procedure. Postoperative results were good in 76% of the patients. The other patients felt mild residual radicular pain, although no residual root compression was found on postoperative computed tomography. Only 21% of the patients that had a radicular deficit recovered totally. CONCLUSIONS: Foraminal lumbar disc herniation involves characteristic clinical features. Radiologic diagnosis requires high-resolution computed tomography, computed tomographic discography, or magnetic resonance imaging. Most foraminal lumbar disc herniations are reached through the interlaminar exposure extended to the upper lamina and medial facet without total facetectomy. An extra-articular approach should be reserved for extra-foraminal herniations.

Cerebral arteriovenous malformations in children: report on 62 cases.

A series of 62 children with cerebral arteriovenous malformations admitted to our department in the course of 17 years (1975-1992) was reviewed in a retrospective study. In 54 cases hemorrhagic stroke was the first presenting symptom, followed by epilepsy in five cases. On admission 26 children presented with a neurological deficit, and 21 were admitted with a grade 3 status according to Botterell. Fifty-one malformations were supratentorial (41 hemispheric, 10 deep-seated) while 11 were infratentorial. According to Mori's criteria, 28 lesions were small, 19 medium, and 15 large. Fifty-two children were operated on, with total excision of the malformation achieved in 47 cases. In two children the malformation recurred. The evolution of neurological disorders has been studied with a mean follow-up of 8.5 years. Fifty patients had a satisfactory outcome on the Glasgow Outcome Scale. Four children died. These results were compared with those reported elsewhere in the pediatric literature.

[Brain abscess complicating dental caries in children]. / Abcès cérébraux de l'enfant compliquant des caries dentaires.

Brain abscess following dental or periapical infection is rare in childhood. This report describes brain abscesses found in two children with dental caries. Case 1.--A 12 year-old boy was admitted because he had suffered from acute meningitis for 3 days. Clinical examination showed symptoms of meningitis plus palsy of the right third and fourth cranial nerves and of the left facial nerve, and a defect in the left temporal field. Funduscopic examination showed papilledema; CT scan and MRI showed a ring-shaped lesion in the right occipital area. The patient was given cefotaxime and thiamphenicol. The abscess was drained; bacteriological examination showed Actinomyces viscosus and Peptostreptococcus magnus. The neurological condition and the CT scan lesion improved, but intracranial pressure increased again on the 17th day after the onset, requiring replacement of the antibiotics by rifampicin and ampicillin plus clavulanic acid for 2 months. This brain abscess appeared to be metastatic, derived from the infection of a large dental cyst due to a dental infection that had been treated 6 months earlier. Case 2.--A 8 1/2 year-old girl was admitted because she was suffering from palsy of the left facial nerve and left arm. She had had headaches and fever for a few days. Clinical examination showed the palsies and drowsiness. CT scan showed two brain abscesses. The patient was given ceftriaxone, fosfocin and metronidazole. She had been treated for a gingival abscess 1 month earlier, and had two infected teeth extracted. Improvement of the intracranial pressure was transient and the antibiotics were changed on the 12th day of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Osteoblastoma of the odontoid process.

A case of an osteoblastoma located in the odontoid process in a 7 year-old boy who presented with torticollis is reported. CT scan and MRI disclosed the lesion, but diagnosis was established by a CT-guided needle biopsy. Surgery through a transoral approach allowed total excision of the tumor. This is, to our knowledge, the first case reported of an osteoblastoma of the odontoid process.

[Traumatic atlanto-occipital dislocation]. / La dislocation occipito-atloïdienne traumatique.

Traumatic atloido-occipital dislocation is usually fatal with immediate cardio-respiratory arrest. The authors report 3 cases of children who survived such a spine injury despite neurological impairment. Clinical and radiological data including Magnetic Resonance Imaging are compared with 18 other cases reported in the literature.

Early hypopituitarism following cavernous sinus thrombosis: total recovery within 1 year.

Hypopituitarism related to cavernous sinus thrombosis is a very rare event which usually occurs at least 1 year after the acute stage. We report a case which distinguished itself from the previously reported cases through (i) its occurrence during the acute stage and (ii) its total recovery within 1 year. Early anterior hypopituitarism is probably more frequent than expected on the basis of reported cases and it may contribute to the high rate of mortality in cavernous sinus thrombosis. This underscores the need to consider hypopituitarism in every patient with cavernous sinus thrombosis.

Management of focal intracranial infections: is medical treatment better than surgery?

Three groups of patients with single hemispheric brain abscesses or subdural empyemas, from 1 to 5 cm large, with similar initial prognosis, have been treated either by medical treatment alone (20), aspiration (21), or excision (15). Differences in survival were not found, but medical treatment alone was better for long term sequelae. Surgical procedures (either aspiration or excision) were better for both isolation of the organism and the hospital stay before discharge. In spite of good results, it is unwise to conclude too strongly in favour of no surgical treatment as this study was not randomised.

[Opticochiasmatic apoplexy]. / Apoplexie opto-chiasmatique.

A 26-year-old patient presented with acute chiasmal syndrome. Computerized Tomography and Magnetic Resonance Imaging demonstrated an intrachiasmal hematoma which was evacuated via a right subfrontal approach. Histological examination revealed an arteriovenous malformation. In 21 similar cases in the literature, surgery generally resulted in the improvement of ophthalmological signs. In 3/4 of the cases, histology identified a subjacent lesion (arteriovenous malformation, cavernoma, venous angioma, glioma).

[Unilateral lesions of basal ganglia nuclei in children during myxovirus para-influenzae infection]. / Lésions unilatérales des noyaux gris centraux de l'enfant au cours d'une infection à myxovirus para-influenzae.

Unilateral disorders of the basal ganglia in childhood have received little attention. Infections are a rare cause where as infarction is the most common one. We report the case of a 11 year-old boy who presented an acute hemiplegia with hypodense areas limited to the left lenticular, caudate nuclei and internal capsule. Virologic investigations showed a recent infection due to myxovirus para influenzae. Angiography demonstrated no focal vascular disease. The course was favorable with full recovery.

[Racemous cysticercosis of the cauda equina and cystic arachnoiditis. Apropos of 2 cases]. / Cysticercose racemeuse de la queue de cheval et arachnoidite kystique. A propos de deux cas.

Central nervous system infection by the larval form of the pork tapeworm, taenia solium is a major public health problem in view of its prevalence. The high incidence of neurocysticercosis in Reunion Island has been precised by computerized tomography and Elisa test. Spinal involvement is an uncommon form of cysticercosis, occurring with a frequency of less than 1% in large series. The types of involvement that are most common are subarachnoid cysts which appear as intradural extramedullary masses and meningeal reaction with appearance of arachnoiditis at myelography. Intramedullary involvement is less frequent. Epidural and subpial masses have been reported very rarely. The authors report the two first cases of spinal cysticercosis in Reunion Island which are both extramedullary leptomeningeal forms. A radicular syndrome was present in both cases; incontinence and sacral hemihypoesthesia in one case. Myelography showed lumbosacral arachnoid cysts. Immunodiagnostic tests were positive in blood and C.S.F. in the two cases. Laminectomy was performed and the arachnoid membrane appeared opaque and thickened; the cysts were removed. Microscopically the cystic wall had a thin and curved cuticle, no scolex was found. Treatment was completed with the anti-helminthic agent Praziquantel. Full recovery was observed in one case. In the other case low back pain spread out to the lower extremities with a non radicular distribution and was associated with lumbosacral spinal fibrosis.