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ABSTRACT: BACKGROUND: In children, intramedullary spinal cord neoplasms are rare. These are typically low-grade neuroepithelial tumors, most commonly astrocytomas, ependymomas, and gangliogliomas. Malignant transformation, while common in recurrent adult low-grade gliomas, is an unusual event in pediatric low-grade neoplasms, specifically in intramedullary spinal cord tumors. ILLUSTRATIVE CASES: We report two cases of malignant transformation in low-grade neuroepithelial tumors of the pediatric intramedullary spinal cord. Two children with intramedullary tumors, one with a WHO grade I ganglioglioma and one with a low-grade astrocytoma, were treated surgically, diagnosed histologically, and followed through the course of their disease. Both patients' tumors transformed to higher grades without prior irradiation or chemotherapy, and without a genetic predisposition to tumorigenesis. DISCUSSION: Malignant transformation can occur in low-grade intramedullary neoplasms in children. This is a novel documented event for pediatric intramedullary spinal cord tumors and a rare event for all pediatric low-grade neuroepithelial tumors without induction by irradiation. A survey of the relevant literature reveals an underwhelming number of studies focusing on malignant transformation in children's CNS tumors relative to adults. Further investigation into molecular mechanisms of pediatric low-grade neoplasms may reveal more aggressive tumor sub-variants predisposed to malignant degeneration.
Child s Nervous System 07/2012; 28(10):1679-86. · 1.54 Impact Factor
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Child s Nervous System 03/2012; 28(8):1269-71. · 1.54 Impact Factor
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Acta Neurochirurgica 01/2012; 154(4):751-2. · 1.52 Impact Factor
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ABSTRACT: IIH is a disorder associated with increased intracranial pressure with no clinical, laboratory, or radiologic evidence of an intracranial space-occupying lesion. The aim of this study was to establish ONSD standards of healthy pediatric subjects and compare the normal measurements with those of patients with IIH.
One hundred fifteen MR imaging studies of children 4 months to 17 years of age were blinded and reviewed by a pediatric neuroradiologist. A total of 230 optic nerves were measured. Eighty-six MR imaging examinations were performed in apparently healthy subjects. This control group included subjects who underwent MR imaging for various reasons, and their MR imaging findings were interpreted as normal. Twenty-nine MR imaging examinations were performed in patients with documented IIH. The ONSD was measured 1 cm anterior to the optic foramina on an axial T2 sequence. For statistical analysis, both patients and controls were stratified into 4 age groups (I, 0-3 years; II, 3-6 years; III, 6-12 years; IV, 12-18 years).
The mean ONSD of the control group in all age groups (I, 3.1 mm; II, 3.41 mm; III, 3.55 mm; IV, 3.56 mm) was significantly smaller than the mean ONSD of patients (I, 4.35 mm; II, 4.37 mm; III, 4.25 mm; IV, 4.69 mm). A positive correlation between age and ONSD (r = 0.414, P < .01) was found in the control group.
According to our study, in pediatric patients with IIH, the ONSD is significantly larger than that in healthy controls regardless of age group and sex. This measurement might prove to be an auxiliary tool in the diagnosis of increased intracranial pressure in pediatric patients.
American Journal of Neuroradiology 11/2011; 33(2):366-9. · 2.93 Impact Factor
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ABSTRACT: This paper presents an automatic method for the segmentation, internal classification and follow-up of optic pathway gliomas (OPGs) from multi-sequence MRI datasets. Our method starts with the automatic localization of the OPG and its core with an anatomical atlas followed by a binary voxel classification with a probabilistic tissue model whose parameters are estimated from the MR images. The method effectively incorporates prior location, tissue characteristics, and intensity information for the delineation of the OPG boundaries in a consistent and repeatable manner. Internal classification of the segmented OPG volume is then obtained with a robust method that overcomes grey-level differences between learning and testing datasets. Experimental results on 25 datasets yield a mean surface distance error of 0.73 mm as compared to manual segmentation by experienced radiologists. Our method exhibits reliable performance in OPG growth follow-up MR studies, which are crucial for monitoring disease progression. To the best of our knowledge, this is the first method that addresses automatic segmentation, internal classification, and follow-up of OPG.
Medical image analysis 07/2011; 16(1):177-88. · 3.09 Impact Factor
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ABSTRACT: The incidence of pneumocephalus after supratentorial craniotomy has been reported to be as high as 100%. However, transformation of postoperative pneumocephalus into tension pneumocephalus (symptomatic intracranial air) is a rather rare phenomenon. Tension pneumocephalus after posterior fossa surgery is reported mainly when the surgery is performed in a sitting position. We hereby report on a patient who developed brain-stem tension pneumocephalus in the early postoperative period after posterior fossa craniotomy for an exophytic brainstem astrocytoma, operated in the prone position. A complete locked-in syndrome resolved following surgical relief of the trapped air.
Pediatric Neurosurgery 02/2007; 43(5):414-7. · 0.70 Impact Factor
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ABSTRACT: The optimal antibiotic prophylaxis for pediatric shunt-related procedures is not clear. There is much inconsistency among different medical centers. This paper summarizes and analyzes the various prophylactic antibiotic regiments used for shunt-related surgeries at different pediatric neurosurgery centers in the world.
A survey questionnaire was distributed through the Pediatric Neurosurgery list-server (an e-mail-based special interest group in pediatric neurosurgery). Forty-five completed questionnaires were received, one per medical center, primarily from pediatric neurosurgeons with the following geographic breakdown: 25 from North America, 13 from Europe, and 7 from Asia and other countries. All centers routinely administered prophylactic antibiotics for shunt-related procedures. The drugs of choice were first-generation cephalosporins (23), second-generation cephalosporins (10), naficillin/oxacillin (4), vancomycin (3), clindamycin (1), amoxicillin (1), and mixed protocols in three centers. The initial drug administration ("first dose") was: in the department before transfer to operating room (5), upon arrival to operating room (11), at induction of anesthesia (13), and at initial skin incision (16). The duration of antibiotic dosage also varied: single dose (13), 24-h administration (26), 48-h administration (2), and longer than 48 h in four centers.
Two general tendencies were noted, common to the majority of participating centers. There was a general trend to modify antibiotic treatment protocol in "high-risk" populations. The second common theme noted in more than half of responding centers was the use of long-term antibiotic treatment for externalized devices (such as externalized shunts, external ventricular drains or lumbar drains), usually till the device was in place.
Child s Nervous System 12/2006; 22(11):1465-71. · 1.54 Impact Factor
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ABSTRACT: Diffusion tensor imaging (DTI) is an MR imaging-based technique that provides an in vivo tool for visualization of white matter tracts. In this preliminary study, we used this technique to investigate the diffusion characteristics of white matter tracts in patients with hydrocephalus before and after surgery and compared them with age-matched volunteers.
Seven patients with different types of acute hydrocephalus (defined by acute clinical signs of increased intracranial pressure and imaging evidence of enlarged ventricles) underwent MR imaging including a DTI protocol before and after surgery for shunt placement/revision or ventriculostomy. Eight age-matched healthy subjects served as a control group. The DTI was acquired in a clinical setting that included 6 gradient directions with a b value of 1000 s/mm(2).
Before surgery, in fiber systems lateral to the ventricles (corona radiata), the diffusion parallel to the fibers was increased (+10%) and the diffusion perpendicular to the fibers was decreased (-25%) in all patients, resulting in an overall increase in the fractional diffusion anisotropy (FA, +28%). Following surgery, the FA values approached those of control values in all except 1 patient. In the corpus callosum, the presurgery FA values in patients with hydrocephalus (HCP) were lower than those of control values, and no significant changes were seen following surgery.
DTI can distinguish the compression characteristics of white matter before and after surgery in patients with HCP. At the acute stage of the disease, DTI characteristics point to white matter compression as a possible cause of the observed changes.
American Journal of Neuroradiology 10/2006; 27(8):1717-24. · 2.93 Impact Factor
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ABSTRACT: During the recent meetings of the International Study Group on Neuroendoscopy and the International Society for Pediatric Neurosurgery, the consensus view emerged that there is a need to assess the value and efficacy of neuroendoscopic procedures against shunting in a scientific manner, to resolve long-lasting debates on the subject.
A prospective randomized, controlled trial of endoscopic third ventriculostomy vs shunting in children presenting under the age of 2 years with pure aqueduct stenosis is been proposed and organized (the International Infant Hydrocephalus Study, IIHS). The participating surgeons must adhere to the philosophy of randomization and be suitably experienced in endoscopic techniques in infants. The primary outcome of the trial will be the overall health-related quality of life of these children at 5 years of age. Hence, the study is focusing on the effect of surgery on neurodevelopment, rather than the less important issue of shunt or stoma survival, that has been debated extensively with no conclusion so far. Intention-to-treat analysis will be performed according to the first surgery. Secondary outcomes such as complication and reoperation rate, total hospitalization time and cost, need for repeat imaging, and others will be analyzed as well.
Pure aqueduct stenosis is relatively rare, making recruitment problematic, but has been chosen to avoid other confounding factors that could influence outcome. More than 25 centers worldwide have committed already to patient recruitment to the study. It is anticipated that recruitment will last for 2 years, aiming for 91 patients per arm. The study has started recruiting patients already in some countries.
It is hoped that the trial will not only provide answers to unsettled debates on the value of neuroendoscopy but also create a network of collaborating pediatric neurosurgeons for future initiatives.
Child s Nervous System 05/2006; 22(4):338-45. · 1.54 Impact Factor
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ABSTRACT: The association of spinal dysraphism and terminal syringomyelia is a well-known entity, and untethering with or without syrinx drainage is usually the surgery of choice. However, progression of the previously existing syrinx after an untethering procedure is an uncommon course. The objective of this study was to discuss the diagnostic, surgical, and follow-up consequences of such an occurrence.
Four children with occult spina bifida associated with terminal syrinx at the time of initial presentation are included in this study. After the primary releasing procedure, all developed enlargement of the syrinx. Two of them were operated on for placement of a syringo-subarachnoid shunt, while the other two were followed up conservatively. One of the shunted patients also had a second releasing procedure.
Progression of the pre-existing terminal syrinx after the primary untethering procedure should be kept in mind even in the absence of overt neurological progression.
Child s Nervous System 03/2003; 19(2):106-8. · 1.54 Impact Factor
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ABSTRACT: Traumatic brain injury is one of the most common causes for chronic disability in young people. Despite this there are currently no widely available modes of therapy that would limit the extent of brain damage secondary to trauma. Therefore, new insights into the pathological mechanisms involved in head trauma possibly leading to the identification of new therapeutic targets are urgently needed. In order to attain these goals adequate animal models for traumatic brain injury are needed. In the following paper the authors will review the various animal models for head trauma and emphasize their potential strengths and weaknesses.
Acta neurochirurgica. Supplement 02/2002; 83:49-54.
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ABSTRACT: Therapeutic options available for acute stroke management are sparse and inadequate. Therefore, new insights into stroke pathophysiology leading to new therapeutic targets are needed. In order to attain these goals, adequate animal models for cerebral ischemia are needed. In the following paper the authors will review the various animal models for stroke and emphasize their potential strengths and weaknesses.
Acta neurochirurgica. Supplement 02/2002; 83:55-9.
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ABSTRACT: Achondroplasia is the most common genetic disorder associated with bone dysplasia. The mode of inheritance is autosomal dominance, while most cases appear to represent a new mutation. Achondroplastic patients suffer from dwarfism, and from typical features of the head and limbs (rhizomelia, macrocephaly, frontal bossing and kyphosis). Half of the patients show various neurological complications. The most serious complication of achondroplasia is respiratory impairment, apnea and sudden infant death, resulting from compression of the medulla oblongata. This study describes the neurosurgical sequels in 10 achondroplastic patients, who underwent 12 surgical procedures. The average age was 14 years (ages ranged from 3 months to 40 years). The patients suffered from back pain, muscle weakness, incontinence, hypotonia, psychomotor delay, apnea and respiratory arrest. Four patients were diagnosed as suffering from obstructive sleep apnea. Craniocervical MRI showed: narrowing of the foramen magnum, fusion of C1, spinal stenosis, and severe cervicomedullary or spinal cord compression. In 5 patients the MRI also showed ventriculomegaly of the lateral and third ventricles. Seven patients underwent foramen magnum decompression and C1 laminectomy. Three patients with severe spinal cord compression underwent laminectomy of the involved spines (T12-L5). Two of the patients required more then one operation due to the recurrence of their neurological symptoms. There was no need for duraplasty or shunt procedures. The average hospital stay was 6 days. Eight patients showed improvement or resolution of symptoms, with an average follow-up period of 13.5 months after the last operation (ranged 6-24 months). We conclude that early neurological and MRI evaluations are required in achondroplasia patients, in order to prevent the high morbidity and mortality during infancy and childhood. In adults, MRI evaluation is needed if the patient has neurological symptoms. Early identification and immediate cervicomedulary decompression procedure can prevent the serious complications occurring in achondroplasia, including respiratory failure, apnea and sudden death.
Harefuah 12/2001; 140(11):1026-31, 1118.
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ABSTRACT: Midsagittal morphologic changes often aid in the diagnosis of hydrocephalus. Stretching and upward displacement of the corpus callosum, widening of third ventricular recesses, and decreased mammillopontine distance have been described as indicating the possibility of hydrocephalus. Quantitative studies are scarce. We performed retrospective, quantitative analysis to verify and quantify changes in midline morphology that might differentiate hydrocephalus and ventriculomegaly due to atrophy.
Sagittal MR imaging studies of 22 patients with hydrocephalus and 32 patients with atrophy were analyzed, as were 42 studies with normal findings. The studied parameters included mammillopontine and mammillocommissural distances, callosal height at two points, and the distances between the lines passing through the chiasm (chiasmal line) and the edge of the callosal splenium. Various angles between the chiasmal line and surrounding structures were measured. Similar measurements were done with the line passing through the third ventricular floor segment anterior to the mammillary bodies (third ventricular line).
In hydrocephalus, mammillopontine distance decreased, mammillocommissural distance increased, the third ventricular floor segment was concave in most cases, and the chiasmal line rotated clockwise. These changes were not seen in atrophy. Callosal height was increased in hydrocephalus significantly more than in atrophy.
Specific changes of the midsagittal plane in hydrocephalus, some of which have not been described previously, can be observed and quantified, which might aid in differentiating this condition from atrophy.
American Journal of Neuroradiology 11/2001; 22(9):1674-9. · 2.93 Impact Factor
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V Siomin,
H Weiner,
J Wisoff,
G Cinalli,
A Pierre-Kahn,
C Saint-Rose,
R Abbott,
H Elran,
L Beni-Adani,
G Ouaknine, S Constantini
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ABSTRACT: The goal of this study was to evaluate the safety, efficacy, and indications for repeat endoscopic third ventriculostomies (ETV).
We reviewed the records of 20 patients who had undergone repeat ETV from 1987 to 1999. Their ages ranged from 8 months to 53 years (mean 17 years). The primary etiologies of hydrocephalus were: primary aqueductal stenosis (9 cases), tumor (5), Chiari malformation (2), prior infection (2), prior intraventricular hemorrhage (1), and blocked foramen of Monro (1 patient). The interval between the first and second ETVs ranged from 8 days to almost 6 years (mean 12.8 months). The intraoperative findings at repeat surgery were: occlusion of the primary orifice by scar (10 cases), virginal floor of the third ventricle (5 cases), pinhole ventriculostomy (3 cases), incompletely penetrated membrane (1 case), and blood clot occluding the orifice (1 case). The follow-up period ranged from 3 to 47 months (median 20 months). Repeat ETV was successful in 13 patients (65%). These patients did not require further shunting or other procedures during follow-up. Seven patients (35%) required placement of a shunt after repeat ETV. Several complications were observed in 1 patient (5%), including seizures, elevated ICP, bilateral pulmonary edema, and cardiac arrhythmia. This patient ultimately recovered fully; the ETV was successful, and the patient did not require a shunt.
Based on the experience of this group of patients, repeat ETV is as effective and as safe as a primary ETV procedure, and should be attempted in selected patients.
Child s Nervous System 10/2001; 17(9):551-5. · 1.54 Impact Factor
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ABSTRACT: Conventional shunting of isolated fourth ventricle is notorious for leading to frequent and severe complications. We present four patients with isolated fourth ventricle who have been treated with open posterior fossa surgery together with either outlet fenestration alone or outlet fenestration and a fourth ventricle-spinal subarachnoid space (SSS) shunt. A survey of the relevant literature did not yield any other case reports of fourth ventricle shunting to the SSS under such circumstances. This paper discusses the reasons for choosing this mode of treatment. The main advantage of this technique is that the catheter is inserted along the anatomical long axis of the fourth ventricle. This positioning lessens the possibility of irritating or penetrating the brain stem. Moreover, as a more physiological solution, the shunt does not require a valve system. Because of these advantages, internal fourth ventricle-SSS shunting is proposed as a valid alternative to the "classic" fourth ventriculo-peritoneal shunt.
Child s Nervous System 09/2001; 17(8):483-6. · 1.54 Impact Factor
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ABSTRACT: The relationship between increased central venous pressure (CVP) and development of hydrocephalus has been extensively discussed in the neuropediatric literature. However, the possibility of a direct connection has not been systematically examined. The purpose of this prospective study was to examine whether there was a correlation between elevated CVP and hydrocephalus in children undergoing cardiac catheterization.
We used cardiac catheterization to measure the right atrial and superior vena caval pressure in 37 children (mean age 30 months) with congenital heart malformations. The children had CVP higher than normal (mean 10.2+/-3.1 mmHg, range 4-18). To evaluate the size of the lateral and fourth ventricles, we performed CT scans of the brain on each child. Abnormal scans were found in 15/37 children, showing brain atrophy (12/37), ventriculomegaly (3/37), and focal infarction (1/37). Cerebral atrophy was more likely to occur in young children (P<0.001). The average head circumference among these children was less than 2SD below the mean for healthy children of comparable ages. Using a correlation coefficient regression model, no relationship was found between CVP and ventricular diameters or head circumference.
These results argue against the hypothesis that mild to moderately elevated venous pressure is involved in the mechanism and development of pediatric hydrocephalus.
Child s Nervous System 08/2001; 17(8):478-82. · 1.54 Impact Factor
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S Constantini,
A Kanner,
A Friedman,
Y Shoshan,
Z Israel,
E Ashkenazi,
M Gertel,
A Even,
Y Shevach,
M Shalit,
F Umansky,
Z H Rappaport
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ABSTRACT: Thromboembolic phenomena (TEPs) continue to be a significant source of morbidity and mortality in patients undergoing neurosurgery. Although the efficacy of low-dose heparin in preventing TEPs in neurosurgical patients is well established, neurosurgeons are reluctant to use it perioperatively because of concern for increased bleeding complications. To clarify this issue, the authors used a prospective, randomized, double-blind design to evaluate the safety of minidose heparin treatment in patients undergoing surgery for supratentorial brain tumors.
One hundred three patients, all 40 years of age or older, were treated with either 5000 U of heparin (55 patients) or placebo (48 patients) starting 2 hours before surgery and continuing until full mobilization or for 7 days. Both groups were well matched for sex, weight, duration of surgery, and tumor diagnosis. Subjective and objective parameters were used to estimate and calculate the perioperative bleeding tendency in all patients. Red blood cell mass loss was calculated by assessing the preoperative and postoperative hematocrit and the patient's weight. Intraoperative blood loss was determined by measuring the quantity of blood in the suction containers and subtracting the amount of irrigation fluids. Postoperative bleeding was measured by determining the amount of fluid in the subgaleal drain, and blood cell replacement was monitored during and after the procedure. Intracranial bleeding was graded according to findings on the postoperative computerized tomography scan obtained 48 to 72 hours after surgery. In addition, the senior surgeon in each case was asked to assess each patient's bleeding tendency during the operation. The results showed that perioperative administration of heparin did not significantly alter bleeding tendency by any measured parameter. The surgeon was blinded to which group individual patients had been allocated.
Perioperative minidose heparin is safe for use in patients undergoing craniotomy for supratentorial tumors. This relatively simple and inexpensive measure is recommended as a routine regimen for the prevention of TEPs in patients undergoing neurosurgery.
Journal of Neurosurgery 07/2001; 94(6):918-21. · 2.96 Impact Factor
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ABSTRACT: Optic pathway gliomas in children can involve the optic nerve, chiasm, and hypothalamus. This uncommon, slowly growing tumor can cause hydrocephalus, which usually requires placement of a ventriculoperitoneal (VP) shunt. Symptomatic ascites may occasionally develop as a complication of the VP shunt procedure. The purpose of this study was to assess the risk factors associated with CSF ascites in children with optic pathway gliomas.
Twenty-two children (ages 4 months to 20 years) with chiasmatic-hypothalamic optic gliomas participated in this study. Four children were diagnosed with a chiasmatic glioma, 7 with a hypothalamic glioma, and 11 with a glioma involving both the optic chiasm and hypothalamus. Twelve children (55%) developed hydrocephalus and required VP shunt placement. Of the 12 shunted children, 4 (33%) developed CSF ascites. The incidence of ascites was not associated with infection, tumor metastasis, or multiple shunt revisions. There was no correlation with the size of the tumor. All 4 children with ascites had tumor involving the optic chiasm or optic nerve. None of the 5 children with pure hypothalamic glioma who underwent VP shunt placement have developed ascites. Among the 7 children suffering from chiasmatic or optic nerve gliomas who developed hydrocephalus, the risk of developing ascites as a complication of VP shunt placement was 57% (4/7). Ventriculoatrial (VA) shunt was the treatment of choice for children with VP shunt-induced ascites. After placement of a VA shunt the ascites subsided. The children did not develop further complications.
We conclude that glioma involving the optic chiasm or nerve is associated with a high risk of developing ascites following VP shunt placement. VA shunt may be the treatment of choice for children with chiasmatic or optic nerve gliomas who require a CSF diversion procedure.
Child s Nervous System 07/2001; 17(7):395-8. · 1.54 Impact Factor
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ABSTRACT: Patients with ventriculo-peritoneal shunts are predisposed to various complications, including the appearance of seizures over time. The high rate of complications prompted an interest in alternative procedures such as endoscopic third venticulostomy (ETV) in selected patients. From 1996 to 1998, 42 patients underwent ETV in our center. Of the 27 operated children who were followed for an average of 32 months, none experienced seizures during that time. We conclude that, in addition to other benefits, ETV minimizes the risk of epilepsy following shunt insertion, probably due to the lack of direct cortical insult.
Pediatric Neurosurgery 04/2001; 34(3):121-3. · 0.70 Impact Factor
