Nurse follow-up visit after the atrial complex ablation: a cross-sectional descriptive study

Funding Acknowledgements

Type of funding sources: None.

Background

Atrial fibrillation (AF) and flutter are complex arrhythmias to ablation because their anatomical location. A navigation system is required to map the ablationable area and in addition, the patient are under general anesthesia. In our hospital, the expert nurse control these patients 10 days afters discharge.

Purpose

To identify the complications and recurrences of arrhythmia that the nurse has detected early and how it has been managed.

Methods

Cross-sectional descriptive study, from September 2020 to January 2022, all patients who underwent complex atrial ablation under total anaesthesia and who were assessed by a nurse 10 days later were included. In the event that any problem arises, the nurse is in charge of managing the network of referrals to specialist doctors.

Results

A total of 159 patients were included with a mean age of 62 years (SD 10.4) and 34% were women. Arrhythmias were 73.5% AF, 11.3% flutter, 14.5% re-do ablations mixed AF/Flutter. CHA2DS2-VASc scale mean 2 points (SD 1.2). Nine cardioversions were scheduled due to early AF recurrence documented. 35% (n=55) of the patients underwent a blood test to control risk factors such as cholesterol, diabetes, kidney failure or thyroid problems. 17.6% (n=28) were programmed for a polysomnography. Cardiologist was consulted in 6.3% (n=10) due to edema of the lower legs, ventricular extrasystoles, asthenia and bradycardia. Interconsultations were also made with endocrinology 1.2%, urology 0.6%, vascular surgery 6.2% and neurology 2.5%. Finally, 12% of patients were referred to their GP for minor controls.

Conclusion

There is little evidence to suggest that nursing consultation could be useful for the early detection of complications and the management of arrhythmia recurrences. More experimental studies are necessary to know the impact of nurse follow-up in the management of patients undergoing complex atrial ablation.

The FhaB/FhaC two-partner secretion system is involved in adhesion of Acinetobacter baumannii AbH12O-A2 strain

Acinetobacter baumannii is a hospital-acquired pathogen that shows an extraordinary capacity to stay in the hospital environment. Adherence of the bacteria to eukaryotic cells or to abiotic surfaces is the first step for establishing an infection. The A. baumannii strain AbH12O-A2 showed an exceptional ability to adhere to A549 epithelial cells. The AbFhaB/FhaC 2-partner secretion (TPS) system involved in adhesion was discovered after the screening of the recently determined A. baumannii AbH12O-A2 strain genome (CP009534.1). The AbFhaB is a large exoprotein which transport to the bacterial surface is mediated by the AbFhaC protein. In the present study, the role of this TPS system in the AbH12O-A2 adherence phenotype was investigated. The functional inactivation of this 2-partner secretion system was addressed by analyzing the outer membrane vesicles (OMV) proteomic profile from the wild-type strain and its derivative mutant AbH12O-A2ΔfhaC demonstrating that AbFhaB is no longer detected in the absence of AbFhaC. Scanning electron microscopy (SEM) and adhesion experiments demonstrated that inactivation of the AbFhaB/FhaC system significantly decreases bacterial attachment to A549 alveolar epithelial cells. Moreover, it has been demonstrated that this 2-partner secretion system is involved in fibronectin-mediated adherence of the A. baumannii AbH12O-A2 isolate. Finally, we report that the AbFhaB/FhaC system is involved in virulence when tested using invertebrate and vertebrate hosts. These data suggest the potential role that this AbFhaB/FhaC secretion system could play in the pathobiology of A. baumannii.

Purification and characterization of a milk-clotting protease from Bacillus licheniformis strain USC13

AIM

The study of a milk-clotting protease secreted by Bacillus licheniformis strain USC13.

METHODS AND RESULTS

Growth of B. licheniformis USC13 in LB medium resulted in the production of a serine protease with a molecular weight of 62 kDa processed to its mature form of 34 kDa, both forms were found in the extracellular medium. The enzyme exhibited typical milk-clotting kinetics.

CONCLUSIONS

The capacity of this protease to produce milk curds could make it useful as a new source of milk coagulants.

SIGNIFICANCE AND IMPACT OF THE STUDY

Cheese-making industry seeks for novel enzyme sources, and microbial coagulants have several advantages over animal and plant counterparts. The protease from B. licheniformis has the ability to produce milk curds although more studies about quality of both the enzyme and the milk curds formed should be carried out in the future to confirm its usefulness in the dairy industry.

Cloning and expression of the XPR2 gene from Yarrowia lipolytica in Pichia pastoris

Yarrowia lipolytica is a dimorphic yeast able to secrete different types of proteases depending on the pH of the environment. At neutral pH, the production of an extracellular alkaline protease (AEP) is induced. This protease could be useful in the leather, detergent, or food industries. The XPR2 gene, coding for AEP, was extracted from the pINA154 vector and cloned into the pHIL-D2 vector to obtain a new protease-producing recombinant Pichia pastoris strain. The gene was efficiently integrated in the P. pastoris genome and expressed from the AOX1 promoter actively induced by methanol. Finally, the protease was successfully secreted by P. pastoris GS115.

Fluorescein Thiocarbamoyl-Kappa-Casein Assay for the Specific Testing of Milk-Clotting Proteases

Milk-clotting proteases, which are widely used in the cheese-making industry, are enzymes that use soluble caseins as their preferential substrates. Here, we propose a modification to a method previously described for the specific determination of milk-clotting proteases by using kappa-casein labeled with fluorescein isothiocyanate as substrate. Validation of the modified method was confirmed using natural bacterial, fungal, plant, and animal milk-clotting proteases, as well as a milk-clotting enzyme of recombinant origin. The new modified method described here allowed specific quantification of the activity of milk-clotting proteases in a very sensitive way and permitted determination of the appropriate kinetic parameters of all the enzymes tested, consistent with their origin and degree of purity.

Proposal of a method for the genetic transformation of Gordonia jacobaea

AIMS

Gordonia jacobaea is a recently isolated bacterial species with potential industrial application on account of its ability to store large quantities of trans-canthaxanthin. Its genetic manipulation is, however, difficult and cumbersome owing to the presence of mycolic acids in the cell wall and, especially, because of current lack of knowledge about its basic genetics. The present work describes a method for the genetic transformation of G. jacobaea.

METHODS AND RESULTS

Gordonia jacobaea was grown in media supplemented with different glycine, penicillin G and isoniazid concentrations. The temperature, carbon source, growth phase and ultrasounds were analyzed for improving the method efficiency. The cells were finally transformed by electroporation. Finally, the method was applied to Brevibacteriumlactofermentum and Gordonia bronchialis.

CONCLUSIONS

The growth of G. jacobaea in the presence of glycine and isoniazid is essential for obtaining electrocompetents cells. The temperature, growth phase and ultrasounds appeared as the main factors for increasing the transformation efficiency. The use of shuttle plasmids became necessary. The method described can be used with other Corynebacteria species.

SIGNIFICANCE AND IMPACT OF THE STUDY

Because of the importance of the CNM group (Corynebacteria, Nocardia and Mycobacteria genera) in different areas such as industry, bioremediation improve the knowledge of their molecular mechanisms are becoming essential. The method described here improves the genetic manipulation of this group of bacteria.

Meningiomas after radiation-therapy for benign astrocytomas

A 4.5 year-old-girl was submitted to subtotal removal of a benign astrocytoma of the left temporal lobe with basal ganglia extension and given radiotherapy. At age 27, she was found to harbor a right posterior frontal meningioma that was totally removed. A recurrence of the right convexity meningioma was again excised after a 4-year interval. The authors report this case to illustrate the possibility of the appearance of radiation-induced meningiomas after an interval of 22 years and briefly discuss 16 previous reports on this occurrence in benign astrocytomas.

Cloning and expression of clt genes encoding milk-clotting proteases from Myxococcus xanthus 422

The screening of a gene library of the milk-clotting strain Myxococcus xanthus 422 constructed in Escherichia coli allowed the description of eight positive clones containing 26 open reading frames. Only three of them (cltA, cltB, and cltC) encoded proteins that exhibited intracellular milk-clotting ability in E. coli, Saccharomyces cerevisiae, and Pichia pastoris expression systems.

Ancient genes of Saccharomyces cerevisiae

Amber is a plant resin mainly produced by coniferous trees that, after entrapping a variety of living beings, was subjected to a process of fossilization until it turned into yellowish, translucent stones. It is also one of the best sources of ancient DNA on which to perform studies on evolution. Here a method for the sterilization of amber that allows reliable ancient DNA extraction with no actual DNA contamination is described. Working with insects taken from amber, it was possible to amplify theATP9,PGU1andrRNA18Sancient genes ofSaccharomyces cerevisiaecorresponding to samples from the Miocene and Oligocene. After comparison of the current genes with their ancient (up to 35–40 million years) counterparts it was concluded that essential genes such asrRNA18Sare highly conserved and that even normal ‘house-keeping’ genes, such asPGU1, are strikingly conserved along the millions of years thatS. cerevisiaehas evolved.

Measurement of motor disability in MPTP-treated macaques using a telemetry system for estimating circadian motor activity

The parkinsonian symptoms of primates after MPTP exposure can be measured by several visual methods (classical motor scores). However, these methods have a subjective bias, especially as regards the evaluation of the motor activity. Computerized monitoring systems represent an unbiased method for measuring the motor disability of monkeys after MPTP administration. In this work the motor activity of monkeys before and after MPTP administration is measured and compared with the activity of a control intact group by means of a telemetry system. A pronounced decrease in motor activity was observed after MPTP administration. These results suggest the monitoring method used is suited for characterizing the motor incapacity and possible improvements following treatments to test different therapies to control Parkinson's disease in MPTP models involving primates.

Cystic mature teratoma of the filum terminale in an adult. Case report and review of the literature

Intradural spinal teratoma is a very rare entity, more prevalent in childhood, that may associate with dysraphic defects. The authors report a 46 years old man with a cauda equina syndrome and an L1-2 tumor. An L1-2 laminectomy was performed and a mass was resected at the base of the filum terminale, which was in contact with the conus medullaris. Histopathological diagnosis was of cystic mature teratoma. Spinal teratomas may be found anywhere along the spine, but are more frequent in the cauda equina. We discuss the origin of these tumors and review the literature concerning these lesions.

Production and characterization of the milk-clotting protease of Myxococcus xanthus strain 422

The cheese industry is seeking novel sources of enzymes for cheese production. Microbial rennets have several advantages over animal rennets. (1) They are easy to generate and purify and do not rely on the availability of animal material. (2) The production of microbial clotting enzymes may be improved by biotechnological techniques. In this work, the biochemical characterization of a novel milk-clotting extracellular enzyme from Myxococcus xanthus strain 422 and a preliminary evaluation of its cheese-producing ability are reported. Strain 422 was selected from four M. xanthus strains as the best producer of extracellular milk-clotting activity, based on both its enzyme yield and specific milk-clotting activity, which also afforded lower titration values than enzymes from the three other M. xanthus strains. The active milk-clotting enzyme from M. xanthus strain 422 is a true milk-clotting enzyme with a molecular mass of 40 kDa and a pI of 5.0. Highest milk-clotting activity was at pH 6 and 37 degrees C. The enzyme was completely inactivated by heating for 12 min at 65 degrees C. The crude enzyme preparation was resolved by anion-exchange chromatography into two active fractions that were tested in cheese production assays of compositional (dry matter, fat content, fat content/dry-matter ratio, and moisture-non-fat content) and physicochemical properties (firmness, tensile strength, pH and Aw) of the milk curds obtained. Purified protein fraction II exhibited a significantly higher milk-clotting ability than either protein fraction I or a total protein extract, underlining the potential usefulness of M. xanthus strain 422 as a source of rennet for cheese production.

Anesthetic technique and development of pneumocephalus after posterior fossa surgery in the sitting position

OBJECTIVE

Pneumocephalus is a well-known complication of surgical procedures performed with the patients placed in the sitting position. Its incidence and intensity were prospectively studied in 90 consecutive patients undergoing a posterior fossa procedure in this position. Various anesthetic agents, with different effects on cerebral hemodynamics, were used.

MATERIAL AND METHODS

Patients were randomly assigned to one of three groups. In group 1 (n=30), anesthesia was induced and maintained with propofol. In group 2 (n=30), anesthesia was induced with thiopental and maintained with isoflurane. In group 3 (n=30), anesthesia was induced with thiopental and maintained with nitrous oxide and low-dose isoflurane. All patients received a load dose and an infusion of fentanyl. A cerebral computed tomography scan was performed to all patients 8 hours after surgery for detecting the presence and location of intracranial air. The size of pneumocephalus was ascertained using the formula for calculating the volume of a spheroid: v = PI / 6. x. y. z. Preoperative diagnosis, existence of shunted or non-shunted hydrocephalus, type and duration of the surgical procedure, detection of intraoperative venous air embolism, and appearance of new neurological symptoms in the postoperative period, were recorded.

RESULTS

All patients included in the study developed postoperative pneumocephalus. There were no significant differences (P = 0.133) in the estimated volume of intracranial air between the groups (group 1, volume = 38.3 -/+ 35.4 ml; group 2, volume = 48.9 -/+ 36.3 ml; group 3, volume = 31.5 -/+ 28.4 ml). Only two patients in the group 2 manifested symptoms of neurological involvement due to the pressure exerted by the intracranial air.

CONCLUSIONS

Despite the hypothetical diverse effects of the three anesthetic techniques used in this series on cerebral hemodynamics, our results suggest that none of them has a substantial effect on the amount of intracranial air detected after posterior fossa procedures performed in seated individuals. To the best of our knowledge this is the first report that addresses in a prospective manner the effects of several habitual anesthetic techniques on the development of pneumocephalus in patients submitted to posterior fossa procedures performed in the sitting position.

Heterologous expression of the Saccharomyces cerevisiae PGU1 gene in Schizosaccharomyces pombe yields an enzyme with more desirable properties for the food industry

The Saccharomyces cerevisiae PGU1 gene was successfully expressed in Schizosaccharomyces pombe. The optimum pH and temperature for the recombinant enzyme were 5 and 40 degrees C, respectively, these being around 0.5 U higher and 5 degrees C lower than those shown by the native enzyme. The K(m) value was about fourfold higher than that of the S. cerevisiae enzyme. The recombinant endopolygalacturonase was more efficient in reducing the viscosity of polygalacturonic acid and was also more stable at different pHs and temperatures than the native enzyme.

Genetic basis of microbial carotenogenesis

The synthesis of carotenoids begins with the formation of a phytoene from geranylgeranyl pyrophosphate, a well conserved step in all carotenogenic organisms and catalyzed by a phytoene synthase, an enzyme encoded by the crtB ( spy) genes. The next step is the dehydrogenation of the phytoene, which is carried out by phytoene dehydrogenase. In organisms with oxygenic photosynthesis, this enzyme, which accomplishes two dehydrogenations, is encoded by the crtP genes. In organisms that lack oxygenic photosynthesis, dehydrogenation is carried out by an enzyme completely unrelated to the former one, which carries out four dehydrogenations and is encoded by the crtI genes. In organisms with oxygenic photosynthesis, dehydrogenation of the phytoene is accomplished by a zeta-carotene dehydrogenase encoded by the crtQ ( zds) genes. In many carotenogenic organisms, the process is completed with the cyclization of lycopene. In organisms exhibiting oxygenic photosynthesis, this step is performed by a lycopene cyclase encoded by the crtL genes. In contrast, anoxygenic photosynthetic and non-photosynthetic organisms use a different lycopene cyclase, encoded by the crtY ( lyc) genes. A third and unrelated type of lycopene beta-cyclase has been described in certain bacteria and archaea. Fungi differ from the rest of non-photosynthetic organisms in that they have a bifunctional enzyme that displays both phytoene synthase and lycopene cyclase activity. Carotenoids can be modified by oxygen-containing functional groups, thus originating xanthophylls. Only two enzymes are necessary for the conversion of beta-carotene into astaxanthin, using several ketocarotenoids as intermediates, in both prokaryotes and eukaryotes. These enzymes are a beta-carotene hydroxylase ( crtZ genes) and a beta-carotene ketolase, encoded by the crtW (bacteria) or bkt (algae) genes.

[Ventriculopleural shunt to treat hydrocephalus]

INTRODUCTION

Ventriculoatrial and ventriculopleural shunts (VPS) are alternatives to ventriculoperitoneal shunts for draining cerebrospinal fluid from patients with hydrocephalus. VPS has seldom been used because of the risk of respiratory insufficiency due to pneumothorax or pleural effusion. However, valves are currently available with anti-siphon devices for use with standard shunting systems to prevent the development of pleural effusion. The aim of this study was to analyze outcome after VPS in eight patients in whom we used the new valves for avoiding overdrainage of cerebrospinal fluid.

MATERIAL AND METHOD

Nine VPS procedures were performed in eight hydrocephalic patients between 1988 and 2000. We used differential pressure valves in eight procedures and a flow regulator valve in one. The externally adjustable Sophy valve was used in six cases. The indication for VPS was peritoneal adhesions in four cases, persistent ascites in two, ventriculoatrial valve obstruction in one, and infection of the peritoneal shunt (peritonitis) in one. The ninth case involved replacement of a previously obstructed valve.

RESULTS

After a follow-up period of 22 months all shunts were functioning well and the only patient with symptoms of hydrocephalus was the one who required valve replacement at six months. No surgical morbidity or mortality was observed, and only one patient developed transitory signs of excessive cerebrospinal fluid drainage, which was corrected by regulating the magnetic valve gradient. The death of one patient 36 months after surgery was unrelated to pleural drainage.

CONCLUSIONS

Valves newly designed to prevent overdrainage of cerebrospinal fluid give satisfactory results, such that VPS should be considered as an alternative to peritoneal drainage.

Medulloblastomas in neurofibromatosis type 1. Case report and literature review

A 6-year-old girl, previously diagnosed with neurofibromatosis type 1 (NF-1) presented with ataxia and symptoms of raised intracranial pressure. Diagnostic work up disclosed a posterior fossa tumor. Histopathological study of the excised neoplasm showed a cerebellar medulloblastoma. We review the current literature and suggest that the association of medulloblastoma with NF-1 is not a chance occurrence, and that it might be pathogenically related. We propose that medulloblastoma should be added to the list of malignancies that are apt to occur in NF-1.

Atlanto-axial rotatory subluxation in children: early management

Atlanto-axial rotatory subluxation (AARS) is an uncommon condition involving dislocation and abnormal fixation of the atlas on the axis. AARS is difficult to diagnose and if improperly treated it may lead to permanent neck deformity. We report a retrospective series of patients diagnosed with AARS seen during the last five years. The children presented with neck pain, head tilt, and reduction in neck mobility. In three of the cases the condition was secondary to cervical trauma and in the fourth it was associated with otitis (Grisel syndrome). The diagnosis was established by three-dimensional computerised tomography. In three cases, the atlanto-axial fixation was cured after cervical immobilisation and physiotherapy. A posterior cervical fusion was required in the remaining case. Early detection and intensive conservative treatment constitutes the mainstay of management of AARS. Surgery is reserved for cases with irreducible or recurrent subluxation.

Characterization of a broad pH range protease of Candida caseinolytica

AIMS

The study of a protease secreted by Candida caseinolytica for use in future industrial applications.

METHODS AND RESULTS

Growth of Candida caseinolytica on a medium containing milk induced a rapid production of an extracellular enzyme able to hydrolyse casein. The crude extract was applied to both Sephacryl S-200 and DEAE-Biogel A columns, obtaining one peak of activity showing a molecular mass of approximately 30 kDa and three active peaks, respectively. These four peaks showed the same biochemical parameters. In all cases, an extremely broad pH range of action was determined.

CONCLUSIONS

Candida caseinolytica secretes high levels of an extracellular protease when grown either in rotary shakers or in batch-fermenters.

SIGNIFICANCE AND IMPACT OF THE STUDY

The biochemical properties of this enzyme suggest its possible industrial application in the brewing industry, in the formulation of certain type of detergents and in the fur and leather industries, among others.

[Training of neurosurgery residents]

It is not a trivial matter to think about the topic of training neurosurgeons in Spain. To raise the question, I review the requirements in several countries. I comment on the process of selection, the length of training, the control of quality in the training program and the opportunities for clinical research in hospitals and in basic neurosciences. I express my opinion against a compulsory final exam. I propose that residents should inform the local or regional Health and Education Authorities about the dedication of staff members to training of postgraduate doctors and that this report should be taken into account and compensated economically in a proportional way to their efforts.

Lumbar canal stenosis: a cause of late neurological deterioration in patients with spina bifida

BACKGROUND

Patients diagnosed with spina bifida may show late deterioration. This worsening in their clinical symptoms has been attributed to a multiplicity of causes such as secondary tethering of the spinal cord, Chiari II anomaly, hydromyelia, diastematomyelia, arachnoid cysts, and dermoid tumors.

METHODS

We searched the clinical records of patients diagnosed with spina bifida who were treated at our hospital for a period of 25 years for the purpose of ascertaining the number and etiology of cases of late neurological deterioration.

RESULTS

Six of 144 patients with open spina bifida presented with late neurological deterioration. In one of these cases and in another patient with occult spina bifida the most relevant factor noted during surgery was the presence of marked lumbar canal stenosis.

CONCLUSION

We suggest that certain cases of late clinical worsening in spina bifida patients are because of lumbar canal stenosis and that this condition should be added to the list of causes that may produce delayed neurological deterioration in patients with spinal dysraphism.

Analysis of canthaxanthin and related pigments from Gordonia jacobaea mutants

A collection of 43 mutant strains of the bacterium Gordonia jacobaea was obtained by means of ethyl methanesulfonate treatment, and the strains were selected for their different pigmentation with respect to the wild-type strain. None of the mutants showed auxotrophy. They all showed good genetic stability and a growth rate similar to that of the parental strain. Canthaxanthin and other carotenoids from these mutants were extracted with acetone and ethanol and separated by high-performance liquid chromatography (HPLC). These HPLC analyses, together with spectrophotometric detection at 480 nm, revealed variations in the pigment contents of the different mutant strains.

Ventriculopleural shunting with new technology valves

Ventriculoperitoneal shunting constitutes the standard procedure for draining cerebrospinal fluid (CSF) in children with hydrocephalus. Ventriculoatrial and ventriculopleural shunting are alternative methods of CSF drainage, which have gained less acceptance. Ventriculopleural shunts are seldom used owing to justified fears of pneumothorax and symptomatic effusions of CSF. The addition of an antisiphon device to standard shunt systems seems to have prevented CSF pleural effusion. From 1988 to 1998, we treated each of six hydrocephalic children with a ventriculopleural shunt. In five cases we used new-technology valves designed to prevent the effects of siphoning with current differential pressure valves. Peritoneal adhesions, recent peritonitis, ascites, and obstruction of a previous ventriculoatrial shunt were the indications for pleural shunting. After a mean follow-up period of 2.5 years all shunts were functioning adequately. Only one patient showed transient symptoms of CSF overdrainage, which were corrected by up-grading the valve setting with the magnet. A late death was unrelated to the pleural shunting procedure. The use of valves of a new design designed to prevent overdrainage seems to account for the satisfactory outcomes observed in this series. We suggest that ventriculopleural shunting should be considered as the preferred alternative to peritoneal drainage in children with intra-abdominal adhesions or with a history of recent peritoneal infection.

Isolation and taxonomic study of a new canthaxanthin-containing bacterium, Gordonia jacobaea MV-1 sp. nov

This article describes the isolation and taxonomic study of a coryneform isolate of a new Gordonia species (G. jacobaea), strain MV-1, which accumulates several carotenoids, including the ketocarotenoid trans-canthaxanthin. Identification of this new isolate by morphobiochemical methods did not allow unambiguous taxon assignment, but sequencing of the 16S rRNA gene clearly pointed to the genus Gordonia, Gordonia sputi being the closest fit. Differences in certain transversions/transitions in otherwise very well-conserved sequences of the described Gordonia species supported the proposal of this new taxon. The fact that both the best growth and best pigmentation were obtained with glucose, an inexpensive carbon source and at an industrially suitable temperature, suggests that this new bacterial strain may have good potential for the industrial production of canthaxanthin.

Penetrating craniocerebral injury from an underwater fishing harpoon

Weapon injuries other than gunshot wounds or low-velocity stab wounds to the head are extremely rare. We report the case of a 6-year-old girl who sustained a penetrating craniocerebral injury after being accidentally shot with an underwater fishing harpoon. This mechanism of injury seems to share characteristics of both high- and low-velocity projectiles. We discuss the management of this unusual injury in a child, remarking that foreign body removal in these cases must be carried out following the original direction of the projectile trajectory. We review the current literature on craniocerebral injuries caused by similar objects, especially those occurring in children.

Development of a middle fossa arachnoid cyst. A theory on its pathogenesis

The progression of congenital arachnoid cysts has seldom been documented. We report the case of a child who was diagnosed with arrested hydrocephalus at the age of 13 months. Neuroimaging studies performed when the girl was 22 months old showed the appearance of an arachnoid cyst in the right middle fossa, while the previously enlarged ventricles seemed to have decreased in size. To the best of our knowledge, the paradoxical expansion of an arachnoid pouch following a reduction in the size of the ventricular system has not previously been documented. We advance the hypothesis that the development of some cases of arachnoid cyst might be pathogenically related to impaired CSF dynamics associated with pre-existing hydrocephalus. We also briefly review the pertinent literature on the formation and evolution of congenital cerebral arachnoid cysts.

Raised intracranial pressure in minimal forms of craniosynostosis

Most cases of craniosynostosis are diagnosed during early infancy, but occasionally craniosynostosis evolves with minimal cranial involvement and goes unnoticed until late childhood. Seemingly these mild forms of craniosynostosis cause few, if any, symptoms of neurological involvement. We describe the cases of a 9-year-old girl and a 6-year-old boy who presented with evident signs of raised intracranial pressure (ICP), together with a negligible skull deformity. We have termed these cases as occult craniosynostosis. Differential diagnosis in our patients was established against known causes of benign intracranial hypertension. Bilateral expanding craniotomies afforded total relief from the symptoms and signs of raised ICP. Neurosurgeons treating children with symptoms and signs of benign intracranial hypertension should be aware of the possibility of minimal forms of craniosynostosis evolving with marked manifestations of raised ICP.

Prevention of intraventricular hemorrhage during CSF shunt revisions by means of a flexible coagulating electrode. A preliminary report

We report the preliminary results of a prospective study in 19 patients (22 procedures) undergoing ventricular catheter replacement at the time of CSF shunt revision to determine the value of intraluminal coagulation by means of a flexible monopolar coagulating electrode in preventing ventricular hemorrhage following catheter removal. These patients had their first shunt implanted during infancy, and underwent shunt revision during the 1-year period between October 1996 and October 1997. Sixteen patients were found to have adherent ventricular catheters, that necessitated the use of diathermy for their removal. In 10 procedures electrocoagulation was applied to the stylet of the ventricular catheter thus permitting tube extraction. In the remaining 8 shunt revisions catheter removal was readily accomplished by coagulation applied to a flexible monopolar endoscopic electrode introduced into the lumen of the tube. Two patients developed mild intraventricular hemorrhage following the use of each of the two methods described above. Both coagulation techniques used during the routine withdrawal of ventricular catheters seem to be equally effective. The flexible coagulating electrode has the additional advantage over the stylet of being moldable, allowing its use in cases in which the catheter does not follow a straight course within the ventricular cavity.

Avulsed lumbar vertebral rim plate in an adolescent: trauma or malformation?

Avulsion of lumbar vertebral rim plate is an uncommon lesion, seen specially in young adults. Its occurrence in pediatric age is very infrequent. As with intervertebral disc herniation in children, an accurate diagnosis may be often delayed due to concerns for neoplasm, infection, and spondylolisthesis. We report a 15-year-old boy with symptoms and myelographic details of disc protrusion. Plain radiographs, computerized tomography of the lumbar spine, and operative findings showed that the cause of root compression was a slipping of the entire disc together with the posterior rim plate at the L4-5 space. Pertinent literature on the subject is briefly reviewed. The proposed mechanism for apophyseal ring fracture is a combination of two factors: congenital insufficiency of the rim plate and injury to the lumbar spine.

Cranial fasciitis of the anterior fontanel

The most common lesions found over the anterior fontanel in children are dermoid cysts. Cranial fasciitis is an uncommon subscalp tumor that occurs exclusively in children. All previous cases have been reported away from the midline. We have recently treated a 6-year-old boy with a nonmobile mass at the anterior fontanel. Its slow evolution and its clinical and radiological features were the classic ones described for anterior fontanel dermoid cysts. Only after histopathological study was the diagnosis of cranial fasciitis of childhood established. This is the first report of cranial fasciitis arising at the anterior fontanel.

Extradural dermoid tumours of the posterior fossa

Dermoid tumours in children usually occur in two locations: at the anterior fontanelle and on the occipital squama. An exceptional site of origin for a posterior fossa dermoid cyst is the extradural space. There are only six previous cases of this situation reported in the literature. A series of 103 subscalp and calvarial masses in children were reviewed and three children are reported with extradural dermoids of the posterior fossa, which communicated with the skin through midline occipital dermal sinuses. All three children were seen after the rapid growth or the formation of an abscess in a previously noted occipital subcutaneous mass present since birth. Although computed tomography or magnetic resonance imaging showed the dermal sinus and the intracranial tumour, these studies were unable to ascertain the intradural or extradural nature of the tumours, their exact origin only being established at operation. Histopathological study showed preclinical signs of infection in the two patients that had not yet formed an abscess. It is suggested that early neurosurgical treatment of these neoplasms should be done to prevent the development of severe intracranial infection. The previously reported simplicity of surgical removal of occipital extradural dermoids was not confirmed in this series.

Iatrogenic intradiploic meningoencephalocele. Case report

The authors present the case of a 6-year-old girl who developed a right frontal intradiploic meningoencephalocele following an accidental dural tear produced during surgery for craniosynostosis. Although rare, growing skull fractures have been described in at least eight cases following the accidental laceration of the dura mater in the course of craniosynostosis repair. These cases closely resemble those produced by accidental trauma to the growing skull. However, the intradiploic location of a meningoencephalocele following surgery for craniosynostosis has not been documented previously. This patient presented with headache and a frontal tumor of bonelike consistency. Radiographs and computerized tomography scans of the skull revealed an intraosseous cyst, whereas magnetic resonance imaging demonstrated cerebral tissue herniation within the intradiploic tumor. Surgical treatment consisted of duraplasty and cranioplasty, which achieved good functional and cosmetic results. The pathogenesis of this unusual lesion is discussed and compared with the hypotheses advanced for explaining posttraumatic intradiploic cysts.

Primary malignant rhabdoid tumor of the cerebellum

Malignant rhabdoid tumor (MRT) is a recently described variety of childhood renal neoplasm. MRT arising primarily in the central nervous system (CNS) is still a rather unfamiliar pathological entity and is frequently misdiagnosed as medulloblastoma or primitive neuroectodermal tumor (PNET). We describe a 7-month-old boy who harbored a CNS-MRT that originated within the IV ventricle and invaded the brain stem and the cerebellar hemispheres. After an initial documented good response to chemotherapy the tumor recurred locally 9 months after operation. We discuss clinical and histopathological features distinguishing between PNET/medulloblastoma and MRTs. Current literature on MRT of the CNS is briefly reviewed.