TEXS: in-vacuum tender X-ray emission spectrometer with 11 Johansson crystal analyzers.

The design and first results of a large-solid-angle X-ray emission spectrometer that is optimized for energies between 1.5 keV and 5.5 keV are presented.

High energy-resolution x-ray spectroscopy at ultra-high dilution with spherically bent crystal analyzers of 0.5 m radius.

We present the development, manufacturing, and performance of spherically bent crystal analyzers (SBCAs) of 100 mm diameter and 0.5 m bending radius. The elastic strain in the crystal wafer is partially released by a "strip-bent" method where the crystal wafer is cut into strips prior to the bending and the anodic bonding process.

Intracystic chemotherapy with bleomycin in the treatment of craniopharyngiomas.

Object: Since bleomycin has not yet been used very frequently in the treatment of patients with craniopharyngioma, it seemed important to document the course of a series of such patients treated with this preparation.

Methods And Results: Local chemotherapy with bleomycin was performed in 24 patients (20 children and 4 adults), 16 of whom presented with cystic or mixed (solid/cystic) craniopharyngioma and 8, with recurrent cystic craniopharyngioma. The drug was administered through an Ommaya reservoir, which was placed either by using a direct surgical approach (6 patients) or a stereotactic approach (16 patients), or with endoscopic assistance in patients with hydrocephaly (2 patients).

Central nervous system cavernomas in the pediatric age group.

Pediatric CNS cavernomas still are diagnostically and therapeutically challenging lesions. With the help of magnetic resonance imaging, the natural history of cavernomas now guiding therapeutic strategies is well documented in adults but remains poorly known in the pediatric age group, since most previous studies dealt with adult and pediatric patients together. This paper focuses on clinical, imaging, and therapeutic features and differential diagnosis of CNS cavernomas with an emphasis on their specificities in the pediatric age group.

Hypothalamic hamartoma: the role of surgery in a series of eight patients.

Hypothalamic hamartoma are rare lesions. We report a new series of eight patients treated for precocious puberty (six cases) or gelastic seizures (two cases). Surgical resection was total in four cases (three pediculated and one sessile).

Zero rate of shunt infection in the first postoperative year in children--dream or reality?

The rate of infectious complications following shunt implantations at the Pierre Wertheimer Hospital was 6.4% in 1992-1994. In order to improve this infection rate, new recommendations for surgery were applied and a new type of valve was used.

Syringomyelia associated with type I Chiari malformation. A 21-year retrospective study on 75 cases treated by foramen magnum decompression with a special emphasis on the value of tonsils resection.

The purpose of the present study is to evaluate retrospectively the effects of several intra-operative manipulations on the results of foramen magnum decompression (FMD) in patients having syringomyelia associated with type I Chiari malformation. Seventy-five patients having syringomyelia associated with Chiari I malformation were operated on between 1975 and 1996. This population was grouped into 4 subgroups according to the surgical protocol: group I = 42 patients with FMD alone; group II = 16 patients with FMD and third ventricle shunting; group III = 9 patients with FMD and syringosubarachnoid shunting (SSS); group IV = 8 patients with FMD and cerebellar tonsils resection.

[Tethered cord syndrome in adults].

A series of 25 adult patients surgically treated for a tethred cord syndrome is reported. Preoperatively 19 patients presented with a sensorimotor deficit in their lower limbs, 17 with sphincter disturbances, 12 with pain and/or neuroorthopedic symptoms and 9 with cutaneous lumbar anomalies. At surgery, an isolated anomaly (lipoma, anomalous or adherent filum terminale) was disclosed in 18 patients.

[Para-aortic paraganglioma found by arteriography. Apropos of a case and review of the literature].

A 53 years old man had an angiography for suspected renovascular hypertension (arteritis, renal insufficiency, duplex scanning). It showed a narrow right renal artery streched by a 45 mm mass arising from the adrenal. The computed tomography showed the tumor and the nuclear magnetic resonance imaging indicated a pheochromocytoma.

[Chiari I malformation with syringomyelia treated by decompression of the cranio-spinal junction and tonsillectomy. Apropos of 8 cases].

We report a series of 8 patients with syringomyelia and associated Chiari I malformation treated between 1992 and 1996 using a cranio-vertebral decompression with tonsil resection. The follow up period ranged from 6 months through 4 years (mean: 28 months). Neurological symptoms and signs improved in 7 patients (87%), and were stabilized in 1 (13%).

Cerebral oligodendrogliomas in children: an analysis of 15 cases.

The cases of 15 children operated on for cerebral pure oligodendroglioma were studied. Two groups of children were distinguished. Group I children presented with epilepsy (7 cases); their tumor was histologically benign in all cases.

Stereotactic radiosurgery for arteriovenous malformations of the brain using a standard linear accelerator: the Lyon experience.

Radiosurgery (RS) was initiated in Lyon in October 1989. The technique was adapted from that described by Lutz and Saunders in Boston (BRW stereotactic frame). Irradiation is delivered with 18-MV photons produced by a LINAC.

Late MR follow-up of hypothalamic hamartomas.

The absence of changes over time in the diagnostic features of suspected hypothalamic hamartomas is of paramount importance. Since magnetic resonance (MR) imaging is very sensitive to modifications in the brain parenchyma, a late MR follow-up study was performed in five children. In all cases, the diagnosis of hypothalamic hamartoma has been suspected on the basis of the association of central precocious puberty and the presence of a mass in the inferior aspect of the hypothalamus, demonstrated on previous MR studies.

[Anterior and antero-lateral surgery of the lower cervical spine (25 years after H. Verbiest). 2: Indications, results, complications)].

The present course on the anterior and antero-lateral surgical approach of the lower cervical spine was organized for the neurosurgery trainees by the French Speaking Neurosurgical Society, and was held during the winter meeting in December 1995. The aim of this course was to recall the basic technical principles of the microsurgical anterior cervical approach, and to discuss the main indications of this surgical treatment. Many theoretical points were strengthened by the author's personal experience and comments.

[Anterior and anterolateral surgery of the lower cervical spine (25 years after H. Verbiest). I: Technical bases].

The anterior approach to the cervical spine is currently a worldwide traditional surgical technique used by neurosurgeons or orthopedists in the treatment of traumatic, degenerative or tumoral cervical spinal lesions. Many original rules of these techniques were raised by pioneers as R. Cloward and H.

Endovascular treatment of an infantile nongalenic cerebral arteriovenous fistula with cyanoacrylate.

We report the radiological features, including Doppler sonography and magnetic resonance angiography (MRA) findings, of a nongalenic arteriovenous fistula diagnosed in the neonatal period. Hypertensive hydrocephalus developed in infancy. Emergent percutaneous transarterial embolization with n-butyl-2-cyanoacrylate was successfully performed and lead to clinical improvement.

Non-metastatic childhood ependymomas.

Purpose: Intracranial ependymomas of childhood are relatively infrequent. There are significant disagreements concerning optimal postoperative treatment as well as the patterns of relapse following treatment. The purpose of this retrospective study was the analysis of the recurrence pattern and therefore the implication on the extent of the radiotherapy fields.

Auditory evoked potentials in a patient with a unilateral lesion of the inferior colliculus and medial geniculate body.

Brain-stem, middle latency and late auditory evoked potentials (BAEPs, MLAEPs and LAEPs, respectively) were recorded in a patient 2 months after removal of affecting the quadrigeminal plate. Simultaneously, MRI showed a left unilateral lesion involving the inferior colliculus, brachium colliculi and the medial geniculate body (MGB). On dichotic listening, there was complete extinction of the right ear input, without subjective auditory disturbance.

Auditory early- and middle-latency evoked potentials in patients with quadrigeminal plate tumors.

Both early auditory evoked potentials (BAEPs) and middle-latency auditory evoked potentials (MLAEPs), were recorded in nine patients suffering from a quadrigeminal plate tumor. These recordings were performed before surgery in six cases and after surgery in three cases. The results of these examinations were correlated with impairments of the midbrain auditory pathways as shown by magnetic resonance imaging.

Tectal plate gliomas. Part I: Microsurgery of the tectal plate gliomas.

A series of 12 patients with tectal plate gliomas, is presented treated by direct surgery. Mean age was 19 years. All patients presented with signs of raised intracranial pressure and supratentorial hydrocephalus on CT scan.

Tectal plate gliomas. Part III: Apparent lack of auditory consequences of unilateral inferior collicular lesion due to localized glioma surgery.

The authors present one of their cases operated on for intrinsic tectal plate glioma. The complete resection of the right inferior colliculus (I.C.

Tectal plate gliomas. Part II: CT scans and MR imaging of tectal gliomas.

CT scans and MR images were analyzed in 12 patients with histologically proved tectal plate gliomas. In an attempt to identify the nature of these lesions, their radiological characteristics were correlated with the histological results. In four of our patients CT scan failed to show the tumour.