Broader head, stronger bite: In vivo bite forces in European eel Anguilla anguilla.

This work examined three different phenotypes of the yellow-eel stage of the European eel Anguilla anguilla, broad-heads, narrow-heads and eels with an intermediate head shape. The aim was to see whether broad-headed A. anguilla, which generally consume harder, larger prey, such as crustaceans and fish, exerted greater bite force than the narrow-headed variant, which mainly consume soft, small prey such as chironomid larvae. It was found that in 99 yellow A. anguilla, in vivo bite force of broad-heads are higher compared with narrow-heads and intermediates.

Ontogenesis of opercular deformities in gilthead sea bream Sparus aurata: a histological description.

The aim of this study was to characterize histological changes during opercular osteogenesis in farmed gilthead sea bream Sparus aurata larvae from 7 to 69 days post hatching (dph) and compare normal osteogenesis with that of deformed opercles. Mild opercular deformities were first detected in 19 dph larvae by folding of the opercle's distal edge into the gill chamber. Here, the variation in the phenotype and the irregular bone structure at the curled part of the opercles is described and compared with the histology of normal opercles. Results indicated that deformed opercles still undergo bone growth with the addition of new matrix by osteoblasts at the opercular surface, especially at its edges. No significant difference was found in bone thickness between deformed and normal opercles. In addition to differences in bone architecture, differences in collagen fibre thickness between normal and deformed opercles were also found.

Grasping convergent evolution in syngnathids: a unique tale of tails.

Seahorses and pipehorses both possess a prehensile tail, a unique characteristic among teleost fishes, allowing them to grasp and hold onto substrates such as sea grasses. Although studies have focused on tail grasping, the pattern of evolutionary transformations that made this possible is poorly understood. Recent phylogenetic studies show that the prehensile tail evolved independently in different syngnathid lineages, including seahorses, Haliichthys taeniophorus and several types of so-called pipehorses. This study explores the pattern that characterizes this convergent evolution towards a prehensile tail, by comparing the caudal musculoskeletal organization, as well as passive bending capacities in pipefish (representing the ancestral state), pipehorse, seahorse and H. taeniophorus. To study the complex musculoskeletal morphology, histological sectioning, µCT-scanning and phase contrast synchrotron scanning were combined with virtual 3D-reconstructions. Results suggest that the independent evolution towards tail grasping in syngnathids reflects at least two quite different strategies in which the ancestral condition of a heavy plated and rigid system became modified into a highly flexible one. Intermediate skeletal morphologies (between the ancestral condition and seahorses) could be found in the pygmy pipehorses and H. taeniophorus, which are phylogenetically closely affiliated with seahorses. This study suggests that the characteristic parallel myoseptal organization as already described in seahorse (compared with a conical organization in pipefish and pipehorse) may not be a necessity for grasping, but represents an apomorphy for seahorses, as this pattern is not found in other syngnathid species possessing a prehensile tail. One could suggest that the functionality of grasping evolved before the specialized, parallel myoseptal organization seen in seahorses. However, as the grasping system in pipehorses is a totally different one, this cannot be concluded from this study.

Musculoskeletal structure of the feeding system and implications of snout elongation in Hippocampus reidi and Dunckerocampus dactyliophorus.

A thorough morphological description of the feeding apparatus in Hippocampus reidi, a long-snouted seahorse, and Dunckerocampus dactyliophorus, an extremely long-snouted pipefish, revealed specialized features that might be associated with the fast and powerful suction feeding, like the two ligamentous connections between the lower jaw and the hyoid, the saddle joint of the latter with the suspensorium and the vertebro-pectoral fusion that articulates on three points with the cranium. Despite the conserved morphology of the feeding apparatus, it was found that in H. reidi the orientation of the occipital joint is ventrocaudal, the sternohyoideus and epaxial muscles are more bulky and both have a short tendon. In D. dactyliophorus, on the other hand, the protractor hyoidei muscle is enclosed by the mandibulo-hyoid ligament, the sternohyoideus and epaxial tendons are long and a sesamoid bone is present in the latter. These features were compared to other syngnathid species with different snout lengths to evaluate the implications of snout elongation on the musculoskeletal structure of the cranium. The arched path of the adductor mandibulae and the greater rigidity of the lower jaw might be related to elongation of the snout, as it yields an increased mechanical advantage of the lower jaw system and a reduced torque between the elements of the lower jaw during protractor hyoidei muscle contraction, respectively. Nevertheless, most observed features did not seem to be related to snout length, but might be associated with different force-generating strategies.

Vitamine B12 deficiency in children: a diagnostic challenge.

Cobalamin or vitamin B12 (vitB12) is involved in DNA synthesis, haematopoiesis and myelinisation. Consequently, vitB12 deficiency causes various symptoms, such as megaloblastic anaemia, neurologic signs or pancytopenia. Despite possible severe symptoms, vitB12 deficiency can present asymptomatically. We report six paediatric patients with different aetiologies of vitB12 deficiency ranging from a subtle to a more overt presentation. VitB12 deficiency is a diagnostic challenge due to the lack of consensus on normal values of vitB12 and its co-markers (folate, holotranscobalamin, methylmalonic acid, homocysteine) and the lack in specificity and sensitivity of the serum vitB12 analysis. All cases were treated with parenteral vitB12. Last decades, evidence supporting high dose oral treatment being as effective as the intramuscular (IM) therapy, also in children, is growing.

Cervical myelopathy secondary to Hunter syndrome in an adult.

We present a case of type II mucopolysaccharidosis in which the diagnosis was delayed until the onset of cervical myelopathy in adulthood. Radiographic features were characteristic, with striking dural thickening shown on CT and MR imaging.

Intradural epidermoid cysts of the cerebellopontine angle: diagnosis and surgery.

We report on our recent experience with epidermoid cysts in the cerebellopontine angle. We operated on nine patients since 1985, seven of which were investigated with magnetic resonance imaging. Since the arrival of modern neuroimaging, large lesions can be found with only discrete symptoms, such as isolated tinnitus or unspecific headache. With computed tomography and magnetic resonance imaging, preoperative diagnosis was achieved for most patients; sometimes, however, epidermoid cysts may be very similar to arachnoid cysts. Surgery is the only possible treatment. The decision to operate should be carefully discussed for each patient, particularly if the patient is asymptomatic. The extent of the lesion at the anterior aspect of the brain stem, and sometimes above the tentorium cerebelli, fragile cortex, and vessels, and hazards of postoperative chemical meningitis often make such surgery difficult. The surgeon should not attempt total removal of the cyst membrane. Most patients who undergo surgery, however, recover well, with no or few sequelae. With a mean 3-year follow-up, no recurrence occurred, despite partial removal, as a result of the peculiarly slow growth of these lesions.

Traumatic extradural hematomas in infancy and childhood. Experience with 144 cases.

The authors report a series of 144 children with traumatic extradural hematomas operated on at the Lille Department of Neurosurgery between 1969 and 1982. The patients are divided into different groups according to age, and clinical findings were recorded for each age group. The overall mortality rate was 9%. The authors demonstrate that prognosis is related to age, neurological status at time of surgery, and duration of postoperative coma.

Control of tremor and involuntary movement disorders by chronic stereotactic stimulation of the ventral intermediate thalamic nucleus.

The authors report on the long-term results of chronic stereotactic stimulation of the ventralis intermedius thalamic nucleus performed in 14 cases of disabling and intractable tremor. There were 10 patients with parkinsonian tremor and four with essential tremor. Three of the 10 parkinsonian patients had previously undergone contralateral thalamotomy. Tremor was assessed by clinical evaluation, surface electromyography, accelerometer, and videotape recordings before and after stimulation. The deep-brain electrode was implanted in the ventralis intermedius nucleus according to stereotactic procedure and connected to a subcutaneous pulse generator after a stimulation test period. Tremor suppression or reduction was obtained in all cases with high-frequency (130 Hz) stimulation. Marked functional improvement was maintained in 11 patients with a mean follow-up interval of 17 months. Levodopa-induced dyskinesias observed in five parkinsonian patients prior to surgery were improved or suppressed in four cases by thalamic stimulation. Stimulation was continued during the day and stopped at night in eight cases. Six patients were stimulated night and day to avoid a rebound effect which appeared as soon as the pulse generator was stopped. The only side effects were hand tonic posture in one case and persistent paresthesia in another case. The mechanism of action of this attractive treatment may be a functional alteration of the thalamic discharging area. The authors conclude that this technique is a good alternative to thalamotomy, especially when the risks of high-frequency coagulation are severe in frail and older patients.

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.

Solitary brain metastasis as only recurrence of a carcinoma of the bladder.

A case of solitary brain metastasis from a transitional carcinoma of the bladder occurring 20 months after resection is presented. The patient underwent gross total removal followed by external irradiation and intravenous chemotherapy. The tumor in this quite unusual occurrence had a very characteristic aspect, both operatively and at pathologic examination. We believe that these patients should be managed aggressively whenever possible.

Traumatic aneurysm of the supraclinoid internal carotid artery. Case report.

A case of traumatic aneurysm of the supraclinoid portion of the internal carotid artery is reported. The diagnosis was established by angiography after delayed subarachnoid hemorrhage, 2 weeks after trauma. Surgical exploration revealed a false aneurysm and a linear defect in the posterior wall of the internal carotid artery. The vessel was repaired with a microvascular suture. Postoperative angiography demonstrated the patency of the artery.

Strategy of craniofacial reconstruction after resection of spheno-orbital "en plaque" meningiomas.

Surgical resection of spheno-orbital "en plaque" meningiomas should be as complete as possible to prevent tumor recurrence and therefore requires a bone reconstruction. We report a series of 20 patients operated on for spheno-orbital "en plaque" meningioma between 1981 and 1993. The surgical treatment included a resection of the involved dura and a wide resection of tumoral bone using a fronto-temporal craniotomy extended to the orbitozygomaticomalar bone ridge. The craniofacial reconstruction was performed in the same operative procedure using iliac bone autograft in 11 patients, internal cortical bone from the bone flap in 8 patients, and a coral graft in 1 patient. The cosmetic result was scored according to the following criteria: superior frontal paralysis, appearance of the orbitomalar bone ridge, shape of the external temporal fossa, and projection of the eyeballs. The cosmetic result was scored as excellent or good in 17 patients, average in 2 patients, and poor in 1 patient. The iliac bone autograft appeared to be the best material for craniofacial reconstruction because it could be modeled easily to the desired shape. However, the reconstruction technique was modified as necessary according to the extent of tumor removal, clinical presentation, and age of the patient.

[Neurosurgery for cancer pain (author's transl)]. / La chirurgie de la douleur en cancérologie.

Neurosurgical management of cancer pain is indicated when other therapeutic methods have failed. It requires a careful investigation of all the parameters of pain and an adaptation to suit each individual case. The decision of such a treatment is as important as the chosen procedure. The psychological features must be carefully known. The surgical procedures of sectioning nervous structures (spino-thalamic cordotomy, rhizotomy), unless they are done with the help of the operating microscope, are slowly being abandoned. Percutaneous techniques under radiographic and electrophysiological control (Gasser ganglion) and cerebral stereotaxic techniques (mesencephalotomy) are there indicated. Stimulation of th dorsal columns of the spinal cord or deep brain stimulation are too recent to demonstrate a definite opinion.

[Multifocal infarction of the basilar trunk region. Persistence of a trigeminal artery]. / Infarctus plurifocal dans le territoire du tronc basilaire. Persistance d'une artère trigéminée.

A multifocal haemorrhagic infarction of the basilar artery territory, linked to the persistence of a trigeminal artery is reported. This was associated to hypoplasia of the basilar artery and of the posterior communicating arteries. The trigeminal artery supplied most of the distal part of the basilar territory. At post mortem there was no arterial occlusion and the infarction probably resulted from embolism from the heart or from the carotid artery.

[Bilateral cavernous sinus syndrome: Burkitt's lymphoma]. / Syndrome du sinus caverneux bilatéral: lymphome de Burkitt.

Bilateral cavernous sinus syndrome is usually due to a vascular disease, such as thrombophlebitis or arteriovenous malformation. In a 29-year old woman this syndrome revealed a malignant non-Hodgkin's lymphoma of the Burkitt type. In this case, the physiopathological mechanism was metastatic extension to the dura mater of a systemic lymphoma. The contribution of MRI to the diagnosis is emphasized.

[Gonadotropic adenoma. Clinical and hormonal characteristics]. / Adénomes gonadotropes. Caractéristiques cliniques et hormonales.

The main clinical and hormonal features of gonadotropin secreting adenomas (GSA) are reviewed through the literature and our personal data. There is still no agreement about their definition and frequency. The most classical clinical presentation is that of men aged 50 years or more, bearing a large pituitary adenoma, the only biological expression of which is a moderately elevated serum FSH level. Female cases are less recognised and are underestimated because the serum LH and/or FSH elevated levels are not informative in menopausal women. The assay of the alpha subunit may help in these cases. In premenopausal women, few of them having been described so far, the GSA may be revealed by an amenorrhea-galactorrhea syndrome with a mild hyperprolactinaemia which may result from different mechanisms. The absence of gonadal hyperactivity, and, conversely, the frequent hypogonadism associated with GSA lead the clinician to raise some questions: are all GSA able to secret gonadotropins? How is the bioactivity of the LH and/or FSH secreted by GSA? How reliable are the radioimmunoassays routinely used for measurement of LH and FSH in patient's serum? Furthermore, therapeutical management of GSA is still impaired by the lack of documented medical treatments which could control their growth and prevent their recurrence.

[Dissociation of results obtained with an immunofluorescence technique by using anti-ACTH antibodies in three cases of pituitary "chromophobe" adenoma without hypercorticism; ultrastructural study (author's transl)]. / Dissociation des résultants obtenus en immunofluorescence avec des antisérums anti-ACTH dans trois cas d'adénomes "chromophobe" sans hypercorticisme. Etude ultrastructurale

Morphological studies of 3 pituitary "chromophobe" adenoma in patients without hypercorticism show positive immunofluorescenct cells with anti alpha, 17-39 ACTH antibody which are not revealed with anti beta, 1-24 ACTH antibody. These cells observed at the ultrastructural level contain secretory granules of 1,000 to 1,500 A in diameter. The existence in these cells of a substance having an immunological relationship with ACTH without biological activity is discussed.

[Pituitary adenoma with alpha, 17-39 ACTH and beta, MSH cells, without hypercorticism (author's transl)]. / Adénome hypophysaire à cellules à alpha, 17-39 ACTH et beta, MSH sans hypercorticisme.

In one case of pituitary basophil adenoma, the majority of the cells contains numerous small granulations which, by using immunohistoenzymatic technique, react with alpha, 17-39 ACTH and beta, MSH antisera. The reaction with anti beta, 1-24 ACTH is negative. The radioimmunoassay of ACTH reveals an increase of plasmatic ACTH, but the cortisol cycle stays low. This data suggests that this functional adenoma releases a product of which has an immunological relationship with ACTH, without biological activity.

[Cerebral aneurysms and pregnancy: 4 cases]. / Anévrysmes cérébraux et grossesse: 4 cas.

Haemorrhagic cerebral accidents are the commonest neurosurgical diagnoses made in pregnancy. The state of pregnancy makes it more likely that an arterial or an arteriovenous aneurysm will rupture and this is the principal cause of most haemorrhages. They occur more often in primiparae in the third trimester of pregnancy. The clinical picture is classical. The conformation of the diagnosis is made by scanning and angiography. The main differential diagnosis is eclampsia. Neurosurgical treatment should be carried out immediately whenever possible in order to avoid the two great risks that follow, namely recurrence of haemorrhage and secondly ischaemia. As far as the obstetric side is concerned, Caesarean section would only be indicated if: the clinical state of the mother is severe with coma and brain stem damage when the child is viable, if there is symptomatic vascular malformation diagnosed at term, if there is haemorrhagic arteriovenous malformation which is highly liable to occur and cannot be operated on without risks for the child if viable, if, finally, the interval between the surgical treatment of the condition and labour is less than 8 days. In all other cases a vaginal delivery is preferable under epidural anaesthetic which should be given if medical induction is carried out, and where instrumental delivery is being carried out systematically, unless radical treatment is being performed. The prognosis which is, in spite of all steps that may be taken, poor, depends on the initial neurosurgical stage and the nature of the causes of lesion and the possibilities of treatment.(ABSTRACT TRUNCATED AT 250 WORDS)