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Shlomi Constantini

Publications and source records attributed to Shlomi Constantini.

At least 19 recordsLinked to original sources
PubMed2006

The occurrence of obstructive vs absorptive hydrocephalus in newborns and infants: relevance to treatment choices.

BACKGROUND AND OBJECTIVE: The classification of hydrocephalus in newborns and in infants is different from the classification in adulthood. This difference exists due to disparity in the source pathologies that produce the hydrocephalus, and the practical distinctions in prognosis and treatment choices. The objective of this paper is to present the spectrum of obstructive-communicating hydrocephalus, which is more complex in the pediatric group, and to propose the relevance of this particular classification to treatment options. MATERIALS AND METHODS: The authors categorized infants with active hydrocephalus at time of presentation into the following four groups along the spectrum of communicating vs obstructive HCP. Group 1: patients with a purely absorptive (communicating) HCP. In these patients, tetraventricular dilatation is usually observed with occasional extraaxial fluid accumulation. An extracranial CSF diversion (shunt) is the treatment of choice. Group 2: patients with an obstructive component together with a persistent absorptive component. In these patients, a technically successful endoscopic procedure will not prevent progression of clinical symptoms of HCP. An extracranial CSF diversion (shunt) should be the treatment of choice even though some of these patients are currently treated by endoscopy. Group 3: patients with an obstructive component together with a temporary absorptive component. In these patients, a technically successful ETV should be followed by temporary CSF drainage [via LP, continuous spinal drainage (CLD), or ventriculostomy] with or without supplemental medical treatment (i.e., Diamox) for several days. Such temporary drainage may decrease failure rate in this subgroup. Group 4: patients with a purely obstructive HCP. In these patients, an endoscopic procedure (ETV) is the treatment of choice. According to this spectrum classification, the authors classify different entities with representative cases and discuss relevancy to treatment options and prognosis. RESULTS: The data suggest that obstructive hydrocephalus in the very young population may be rather a combination of obstructive and absorptive problem. The outcome of the patient depends mainly not only on the basic pathology causing the hydrocephalus but also on the treatment that is chosen and its complications. While bleeding and infection represent the major causes for communicating hydrocephalus, patients with complex pathologies of congenital type and intra- or interventricular obstructions may reflect obstructive hydrocephalus. Treatment of these patients may be successful by shuntless procedures if the absorptive problem is not the major component. In transient absorptive hydrocephalus, temporary measures were effective in many cases leading to successful procedures of ETV and/or posterior-fossa decompression in selected cases. CONCLUSIONS: Shuntless procedures are the dream of a pediatric neurosurgeon provided it solves the problem and does not imply unacceptable risk. However, the benefit has to be evaluated years after the procedure is performed, as only prospective multicenter studies will truly show which procedure may have the best overall results in the developing child. Until such studies are available, understanding the basic pathology or the combination of pathologies leading to hydrocephalus in a given child may open the window of opportunities for other than shunt surgery in many hydrocephalic children with major obstructive component.

Cerebrospinal Fluid Shunts↗
PubMed2006

Classical and real-time neuronavigation in pediatric neurosurgery.

INTRODUCTION: Neuronavigation has become a cornerstone of neurosurgery. Navigation systems are categorized into two main groups: those based on preoperative imaging and those based on real-time intraoperative acquired images. OBJECTIVES: The preoperative imaging systems, either computed tomography (CT)- or magnetic resonance imaging (MRI)-based, are straight-forward systems that are routinely used in most institutions. Image accuracy, however, decreases secondary to brain and lesion shifts that occur during surgery. Intraoperative, real-time navigation systems overcome anatomical shifts by updating the image base of the navigation during surgery, thus, maintaining precise navigation capabilities throughout the surgical procedure. CONCLUSIONS: In this article, we review the main neuronavigation systems and their applications, emphasizing their unique advantages and usage within the pediatric population.

Adolescent↗
PubMed2006

Paravertebral turnover flaps for closure of large spinal defects following tethered cord repair.

Reconstruction of large congenital spinal defects remains a challenge. We present our experience in closure of difficult spinal defects following repair of tethered cord, using paravertebral fascial or myofascial turnover flaps. Between 1996 and 2005, 23 patients were operated using paravertebral turnover flaps for closure of large spinal defects associated with tethered cord. Fifteen (65%) patients had lipomyelomeningoceles. Eleven (48%) patients had sacral defects, 10 (43%) had lumbosacral defects, and 2 (9%) had lumbar defects. Fourteen (61%) patients underwent closure using fascial turnover flaps. Myofascial turnover flaps were used in 9 (39%) patients. Following surgery, none of the patients developed cerebrospinal fluid (CSF) leaks, pseudomeningoceles, or subcutaneous infection. One patient suffered superficial necrosis and infection of the skin suture line, which healed secondarily. We conclude that fascial or myofascial paravertebral turnover flaps provide reliable coverage of difficult defects of the spinal CNS.

Adolescent↗
PubMed2006

Intraoperative portable 0.12-tesla MRI in pediatric neurosurgery.

OBJECTIVES: Intraoperative MRI (iMRI) is used mainly in the adult neurosurgical population. The main indications for iMRI usage are resection control and updated intraoperative navigation capabilities. In this paper we present our experience using this technique in children. Specific advantages of iMRI for this age group are discussed. METHODS AND RESULTS: We retrospectively reviewed 31 pediatric neurosurgical procedures in which a portable iMRI system was used. The indications for iMRI usage were preoperative navigation, resection control during tumor removal, shunt placements, and needle biopsy. In 7 children the use of the iMRI changed the course of the surgical procedure. Operative morbidity and mortality were not increased with use of the iMRI. CONCLUSIONS: iMRI systems have advantages for the pediatric neurosurgical population, including both real-time basic navigation and improved resection control.

Adolescent↗
PubMed2006

Impact of prenatal magnetic resonance imaging on postnatal neurosurgical treatment.

OBJECT: The goal of this study was to determine the importance magnetic resonance (MR) imaging holds as a complementary fetal imaging modality to ultrasonography in deciding postnatal neurosurgical management. METHODS: Between 1999 and 2003, 320 fetal MR imaging studies were performed at a single institution. Twenty-four fetuses were found to have central nervous system abnormalities that could potentially require a neurosurgical intervention. The diagnoses included spinal anomalies (scoliosis, myelomeningocele, and closed spinal dysraphism) and brain anomalies (ventriculomegaly with or without hemorrhage, intracranial cyst, craniosynostosis, and encephalocele). Fourteen of the 24 fetuses underwent surgery based on findings of prenatal MR imaging. In seven cases the pregnancy was terminated, and in three cases conservative follow up continues. CONCLUSIONS: In a variety of brain and spine disorders, prenatal MR imaging can delineate and characterize the abnormality, and thus assist in the diagnosis and in the planning of postnatal surgery and management. This modality provides important multiplanar images and may obviate the need for early postnatal computed tomography or MR imaging. Postnatal management can often be guided by prenatal MR imaging findings.

Brain↗
PubMed2005

Short-term dexamethasone treatment for symptomatic slit ventricle syndrome.

OBJECTIVE: The objective was to report our positive experience of using dexamethasone to treat 13 patients with symptomatic slit ventricle syndrome (SVS). METHODS: Thirteen SVS patients who received dexamethasone during acute episodes were studied. The etiology for hydrocephalus was prematurity and intraventricular hemorrhage in 9 patients and neonatal meningitis, chorioamnionitis, Dandy-Walker variant, and congenital in 1 case each. The shunt was inserted at 1.8+/-1.0 months of age and SVS was diagnosed at 4.9+/-3.2 years of age. RESULTS: All patients reported relief and shorter duration of symptoms with dexamethasone. Surgical intervention was decided upon and carried out within 11+/-8 months of SVS diagnosis in 9 out of 13 patients. The other 4 are being monitored and continue to receive dexamethasone when needed. CONCLUSIONS: Dexamethasone appears to be a useful treatment in acutely increased intracranial pressure caused by SVS. It can provide temporary relief during the decision-making process of whether and when to perform surgery.

Acute Disease↗
PubMed2005

Task switching after cerebellar damage.

The authors of this study investigated task switching following cerebellar damage. The study group consisted of 7 children and adolescents (M age=13.8 years) who underwent surgical removal of a benign posterior fossa tumor. They were tested at a sufficient interval after surgery (M lag=6.13 years) for restoration of normal cognitive skills and intelligence. Although all showed normal learning of the task compared with control participants, when rapid behavioral changes were required (short preparation time), they exhibited behavioral rigidity manifested by enhanced switching cost. These results are in line with another study on serial reaction time with the same patients (A. Berger et al., in press). They have important implications for our understanding of the cognitive sequelae of early cerebellar damage as well as the involvement of the cerebellum in task switching.

Adolescent↗
PubMed2005

Motor and non-motor sequence learning in children and adolescents with cerebellar damage.

Cerebellar involvement in motor and non-motor sequence learning was examined with serial reaction time tasks (SRT). Our sample consisted of 8 children and adolescents who had undergone surgical removal of a benign posterior fossa tumor (PFT) during childhood. None of them had undergone chemotherapy or cranial radiation therapy (CRT). Ages ranged from 1-11 years at surgery and 9-17 years at testing. The children were tested not earlier than 2.5 years after surgery (M = 5.9 years), enabling brain plasticity and recovery of functions. Their performance was compared with a matched control sample. The PFT group was not impaired in the implicit learning of sequences, as reflected in their performance in blocks with a repeated sequence, both before and after a random block. However, in the perceptual task, their performance deteriorated more than that of the control group when a random block was introduced, suggesting that it was more difficult for the patients to respond flexibly or change their response set when encountering changing task demands. These results are in line with another study by our group on task switching with the same patients.

Adolescent↗
PubMed2004

Risk of venous thromboembolism in pediatric patients with brain tumors.

BACKGROUND: Venous thromboembolism (VTE) is a common event in adults with malignant brain tumors approaching 24% throughout the course of the disease. The high morbidity and mortality of this complication yielded several protocols for prevention of the disease in adults undergoing neurosurgery for brain tumors and possible primary prevention afterwards. We investigated the incidence and complications of VTE in pediatric neuro-oncology patients. PROCEDURE: We analyzed, retrospectively, the files of all consecutive patients under the age of 18 years who were hospitalized for the treatment of brain tumors between the years 1990 and 2003 in two leading, closely related, Israeli neuro-oncology centers. RESULTS: A total of 462 children were analyzed. Three hundred eighty-four patients underwent surgery and 78 were treated medically. Only three (0.64%) of the patients developed clinical episodes of VTE that were treated conservatively. Two of these patients developed intracranial bleeding while on secondary prevention for the disease. CONCLUSIONS: Although this study has considerable limitations in terms of retrospective design, heterogeneous group of patients and diagnoses, the changing awareness for thrombosis over the last 14 years and the inclusion of symptomatic VTE events only, our surprising data suggest that, as opposed to adults, the risk of clinically significant VTE in children with brain tumors may be exceedingly low. These findings set the stage for future forthcoming evaluations in view of the prospective studies that were done in adults and the possible significant implications for the prevention and possible etiologies of the disease.

Brain Neoplasms↗
PubMed2004

Gamma probe localization of cranial bone lesions: technical note.

BACKGROUND: Intraoperative localization of cranial bone lesions may be challenging especially when the lesion is not well demonstrated on computed tomography (CT) scan but solely on a radio-isotope bone scan. We hereby demonstrate a technique for localizing such lesions using an intraoperative gamma probe reader and summarize the relevant literature. METHODS: A case report of a temporal osteoid osteoma causing local pain and unresponsive to conservative treatment is presented. The lesion was demonstrated preoperatively solely on a bone scan, and was intra-operatively localized by a gamma probe reader. RESULTS: The lesion was totally excised with normal background readings after lesion removal. Six months after total removal of the osteoid osteoma, the patient is asymptomatic. CONCLUSION: Intraoperative gamma probe reader is a simple, effective, and safe method for intra-operative localization of bone lesions, which are positive on bone scans. It is especially useful for skull lesions that are not demonstrated by other imaging methods.

Female↗
PubMed2004

Karyotypic evolution pathways in medulloblastoma/primitive neuroectodermal tumor determined with a combination of spectral karyotyping, G-banding, and fluorescence in situ hybridization.

Medulloblastomas (MBs) or primitive neuroectodermal tumors (PNETs) represent 15%-30% of pediatric brain tumors and are the most common brain tumors in children; they are rare in adults. Classification of these tumors is based on tissue morphology and is often controversial and problematic. Karyotypic analysis of these tumors using conventional cytogenetic methods is often a difficult process that may be hindered by a limited number of metaphase cells and poor chromosome morphology, often leading to only partial characterization of the chromosomal abnormalities. We investigated three primary human tumors and four cell lines (CHO-707, DAOY, D-341, and PFSK) utilizing a combination of conventional G-banding, spectral karyotyping (SKY), and fluorescence in situ hybridization (FISH) techniques. A high level of intratumoral heterogeneity was seen, with multiple numerical and structural chromosomal aberrations. The chromosomes most frequently involved in structural aberrations were chromosomes 1 (14 rearrangements), 7 (9 rearrangements), and 21 (9 rearrangements). The chromosomes most frequently involved in numerical aberrations were chromosomes 1, 12, and 13 (four cases) and chromosomes 14, 17, 19, 21, 22, and X (three cases). Numerous aberrant chromosomes were characterized only with the SKY analysis, and based on these findings multiple clones were identified, facilitating analysis of karyotypic evolution. The most frequent evolution mechanism was via polyploidization, followed by acquisition of additional numerical or structural aberrations (or both); however, the results showed that the karyotypic evolution process in these tumors is typically divergent and complex.

Adult↗
PubMed2004

Basic principles and equipment in neuroendoscopy.

In sum, understanding some of the basic principles of endoscopy and awareness of available resources can potentially be of considerable help to experienced neurosurgeons as well as beginners in selection of the most appropriate tools for different procedures and making cost-effective choices when browsing through multiple commercial advertisements and purchasing new equipment. Although numerous advantages in science and industry have made it possible to offer a wide variety of neuroendoscopes and tools, we believe the major achievements in this field are yet to occur. This particularly refers to the development of smaller fiberoptic scopes with better image quality and three-dimensional endoscopes and to the invention of more efficient tools for endoscopic tumor removal with the same degree of safety as in open surgery.

Central Nervous System Diseases↗
PubMed2003

Short-term subarachnoid space drainage: a potential treatment for extraventricular hydrocephalus.

INTRODUCTION: Extraventricular hydrocephalus (EVOH), defined as the enlargement of all CSF compartments in the absence of an obstructing lesion, is usually associated with an increased head circumference and a relatively benign clinical course. Occasionally, because of concern about increased intracranial pressure (ICP), treatment with diuretics is initiated. In most cases, surgical drainage or diversion is not indicated. EVOH may follow a more alarming clinical course and be associated with developmental delay and/or other symptoms of increased ICP. CASE REPORT: We describe a 6-month-old girl with EVOH and developmental delay who was treated with temporary drainage of the subarachnoid space. Clinical response was immediate, with stabilization of the head circumference and improvement in motor performance. We propose that such a surgical procedure might be considered for more frequent use in selected cases.

Algorithms↗
PubMed2003

Delineating gray and white matter involvement in brain lesions: three-dimensional alignment of functional magnetic resonance and diffusion-tensor imaging.

OBJECT: The role of functional magnetic resonance (fMR) imaging has become increasingly important in the presurgical mapping of gray matter. Neurosurgical interventions often involve fiber bundles that connect critical functional areas. Recently, diffusion-tensor (DT) imaging has enabled the visualization of fiber bundle direction and integrity, thus providing the ability to delineate clearly white matter from gray matter tissue. The main objective of this study was to improve the presurgical assessment of critical functionality in the vicinity of brain lesions by combining DT and fMR imaging methodologies. METHODS: Twenty patients with various space-occupying brain lesions underwent imaging for presurgical evaluation of motor and/or somatosensory functions. The authors focus on five patients with diverse space-occupying brain lesions. Diffusion tensor-based fiber tracking and fMR imaging activation maps were superimposed in three dimensions to visualize pyramidal tracts corresponding to motor and somatosensory regional activation. CONCLUSIONS: The combination of DT and fMR imaging for presurgical functional brain mapping provides valuable information that cannot be extracted using either method alone. The validity and sensitivity of noninvasive functional mapping for surgical guidance could be improved by considering results obtained with both methods. Furthermore, the use of three-dimensional visualization seems crucial and unique for viewing and understanding the complicated spatial relationship among the lesion, gray matter activation, and white matter fiber bundles.

Adolescent↗