Stereo-electroencephalography (SEEG) in 65 children: an effective and safe diagnostic method for pre-surgical diagnosis, independent of age.

AIM: We report our experience of stereoelectroencephalography (SEEG) in 65 children with drug-resistant seizures, with a particular emphasis on young children. METHODS: We retrospectively studied all SEEG performed between 2009 and 2011 in our centre. As SEEG can have several indications, the patients were classified into three categories, according to the probability of surgery. The contribution of SEEG to the final decision regarding surgery was evaluated for each category separately. We also compared the main demographic and surgical data of children younger than 5 years of age (Group 1; 21 children) with those older than five years of age at the time of investigation (Group 2; 44 patients). RESULTS: MRI was not contributory in 20% of patients (9.5% in group 1; 25% in group 2). Electrical stimulations localised the motor area in all patients when performed (49% of patients), even in group 1 (62% of patients). SEEG led to surgery in 78% of patients (90.5% in group 1; 73% in group 2), after a second invasive investigation in 9.2 % of patients. The resection involved more than one lobe in 25% of patients (37% in group 1; 19% in group 2). Ultimately, 78% of patients with a low probability of having surgery before SEEG received surgery (88% in group 1). The surgical outcome of Engel class 1 was reported for 67% of patients (79% of patients in group 1 and 59% in group 2). No complications occurred. CONCLUSION: SEEG in children is safe and useful, and the surgical outcome in younger children is as good as, or sometimes even better than, that in older children. As a result of lower rates of complication and morbidity, SEEG appears to be more appropriate, in comparison to subdural grids, in situations where it is unclear if patients will have surgery after an invasive investigation.

Trigeminal nerve deficit in large and compressive acoustic neuromas and its correlation with MRI findings.

OBJECTIVES: Evaluate the prevalence of preoperative trigeminal nerve deficit in large/compressive acoustic neuromas and try to find a correlation between pre/postoperative magnetic resonance imaging (MRI) findings and pre/postoperative trigeminal nerve deficit. STUDY DESIGN: Case series with chart review. SETTING: University medical center. SUBJECTS AND METHODS: Retrospective study (1994-2009) including patients with stage 4 or 5 acoustic neuromas (Zini-Magnan classification). All patients underwent surgical resection. Pre- and postoperative trigeminal symptoms were sought. Imaging criteria were sought on pre- and 3-month postoperative MRI scans. Pearson χ(2) statistical test was used. RESULTS: Fifty-three patients (27 females, mean 51 years) were operated on. Preoperatively, 3 patients (5.7%) had trigeminal neuralgia, 1 (1.9%) trigeminal anesthesia, and 28 (52.8%) trigeminal hypoesthesia. Sixteen patients (30.2%) had no corneal reflex (ophthalmic branch); keratitis occurred in 1 patient (1.9%). Postoperatively, 2 patients (3.8%) had trigeminal neuralgia, 1 (1.9%) trigeminal anesthesia, and 24 (45.3%) trigeminal hypoesthesia. Twenty-six patients (49%) had no corneal reflex; keratitis occurred in 11 patients (20.7%). Preoperative trigeminal hypoesthesia was statistically correlated with impaction of the tumor on cerebellar peduncles on preoperative MRI. Postoperative trigeminal hypoesthesia was statistically correlated with nonvisibility of the trigeminal nerve on postoperative MRI. CONCLUSION: In large/compressive acoustic neuromas, trigeminal nerve deficit has to be sought to avoid corneal complications in particular. Trigeminal hypoesthesia occurs preoperatively in about half of the cases. It remains relatively stable after tumor removal, but there appears to be an increased rate of absent corneal reflex and keratitis postoperatively. We were able to correlate pre/postoperative trigeminal hypoesthesia with pre/postoperative MRI findings.

Effect of introduction of antibiotic-impregnated shunt catheters on cerebrospinal fluid shunt infection in children: a large single-center retrospective study.

OBJECT: Infection after both primary and revision shunt surgeries remains a major problem in pediatric neurosurgical practice. Antibiotic-impregnated shunt (AIS) tubing has been proposed to reduce infection rates. The authors report their experience with AIS catheters in their large pediatric neurosurgery department. METHODS: The authors conducted a retrospective case review of consecutive shunt operations performed before (1993-2003) and after (2005-2009) introduction of AIS tubing, with analysis of shunt infection rates and causative organisms identified. RESULTS: The historical control group consisted of 1592 consecutive shunt operations (657 primary insertions), and the AIS study group consisted of 500 consecutive shunt operations (184 primary insertions). Patients ranged in age from 0-17 years. In the historical group, 135 infections were identified (8.4%). In the AIS study group, 25 infections were identified (5%), representing a significant reduction (p < 0.005). The latency to diagnosis of infection was 23 days in the historical group and 139 days in the AIS study group. The infection rates in infants 0-6 months of age were 12.2% (historical group) and 6.7% (AIS group, p < 0.005), and in infants 7-12 months of age the rates were 7.9% (historical group) and 2.7% (AIS group, p < 0.005). In the historical control group, the frequency rank order of causative organisms was coagulase-negative staphylococcus (51.9%), Staphylococcus aureus (31.6%), streptococcus or enterococcus spp. (8.8%), gram-negative organisms (4.4%), and Propionibacterium acnes (2.2%). Organisms responsible for infections in AIS were S. aureus (40%), followed by streptococcus or enterococcus spp. (20%), P. acnes and coagulase-negative staphylococcus (both 16%), and gram-negative organisms (4%). No unusually antibiotic-resistant bacteria were identified in either group. The authors further subdivided the AIS group into those undergoing primary AIS insertion (Subgroup 1), those undergoing revision of non-AIS systems using AIS components (Subgroup 2), and those undergoing revision of AIS systems using AIS components (Subgroup 3). Infection rates were 1.6% in Subgroup 1, 2.5% in Subgroup 2, and 11.7% in Subgroup 3. Staphylococcus aureus was the most common organism identified in infections of the Subgroups 2 and 3. CONCLUSIONS: Use of AIS tubing significantly improves shunt infection rates in both general pediatric and infant populations with no evidence of increased antibiotic resistance, which is in agreement with previous studies. However, the increased infection rate in revision surgery in children with AIS catheters in situ raises questions about their long-term application.

Fourth ventricle rosette-forming glioneuronal tumour in children: an unusual presentation in an 8-year-old patient, discussion and review of the literature.

INTRODUCTION: Rosette-forming glioneuronal tumour of the fourth ventricle is a rarely described entity. While usually having an indolent course and hence classified as a WHO grade 1 tumour, the precise characteristics and risk of recurrence of this tumour are still unknown. In addition, the preferred treatment modality remains unclear. DISCUSSION: We present a case of an 8-year old with an early recurrence of 9 months after undergoing a sub-total resection of her tumour. Following further resection, there was no tumour present on the 3-month follow-up. In order to better characterise this tumour entity, we performed a review of the available literature on the subject. We found that it mainly affected young adults and had a female predominance. While initially these tumours were described in the fourth ventricle, the current literature suggests that they may be found in a larger variety of sites within the brain and spinal cord. There are several reports of recurrence occurring between 9 months and 10 years following surgery. There is as yet no feature of the tumour that appears to predict the risk of recurrence. CONCLUSION: This phenomenon warrants further examination to discover if there is a sub-section of tumours that is likely to recur, and until this is established, all patients should be followed up at regular intervals.

Adverse events occurring during invasive electroencephalogram recordings in children.

BACKGROUND: In cryptogenic epilepsy or when multifocal seizure onset is suspected, intracranial monitoring of the EEG is required. OBJECTIVE: To report on the adverse events related to electroencephalogram (EEG) intracranial recording in one of the largest pediatric series published and to discuss the avoidance of adverse events in our experience and with respect to a review of the literature. METHODS: A retrospective analysis of our department database and hospital charts of 95 children operated on between 1994 and 2009 was performed. RESULTS: Invasive recording was uneventful in 51.1% of cases. Observed frequency of infection was 14.9%, cerebrospinal fluid leak was 10.6%, brain swelling was 6.4%, and hemorrhage was 17%. Brain swelling was more frequent in older patients, whereas the length of recording, number of electrode contacts used, and presence of depth electrodes were not relevant. Cerebrospinal fluid leakage was completely prevented by the routine introduction of dural graft substitutes in 2003. CONCLUSION: Invasive recordings carry a noticeable rate of adverse events but provide invaluable information in delineating the epileptogenic zone. The low incidence of such events among younger children suggests that invasive recordings can be successfully performed with low morbidity in this age group.

Cervical myelocystocele: prenatal diagnosis and therapeutical considerations.

BACKGROUND: Cervical myelocystocele (CMC) is a very rare congenital malformation and belongs to the spectrum of skin-covered (occult) dysraphisms. Only 15 cases have been so far reported throughout the literature. We report the first case of CMC whose diagnosis was established prenatally by ultrasound imaging (US) followed by fetal magnetic resonance imaging (MR). CASE HISTORY: A 35-year-old woman was referred for further investigations following prenatal assessment of a fetal cervical mass observed on routine US during pregnancy. Fetal karyotype was normal. Fetal MR confirmed the ultrasonographic findings and led us to strongly suspect the diagnosis of CMC. The newborn was operated on 2 months after birth. The goal of surgical procedure was to remove the malformation and to obtain an untethering of the spinal cord. Twelve months later, the child is still neurologically intact. DISCUSSION: We discuss embryogenesis, different subtypes, associated malformations, and surgical strategy associated with myelocystoceles. CONCLUSIONS: This case adds to the existing literature in that it shows for the first time antenatal images of this rare condition and discusses treatment and follow-up implications.

Image-guided transoral surgery in childhood.

OBJECTIVE: The study aims to report a preliminary experience of image guidance during transoral surgery in a paediatric population. In paediatric practice, the small size of the oropharynx and the distortion of the craniocervical junction anatomy (whether congenital or acquired) are both factors that may compromise the transoral approach. Prior immobilisation of the craniocervical axis by virtue of posterior fixation or external halo body orthosis permits the use of intra-operative image guidance to navigate this region. METHOD: Neuronavigation was used during transoral surgery in six paediatric cases. Preliminary immobilisation of the craniocervical junction was ensured in all patients. Volumetric imaging was then obtained prior to the transoral procedure which was then carried out using neuronavigation assistance (Stealth Station Medtronic). Early post-operative imaging was obtained in each case to assess the extent of the surgical resection. RESULTS: Neuronavigation was found to correlate well with the intra-operative findings and, in all cases, the surgical objective, decompression of the neuraxis, was achieved. Post-operative imaging reflected the operating surgeon's perception regarding the extent of the decompression. In one case, there was a transient neurological deterioration; there was no mortality and no instances of wound-related complications or cerebrospinal fluid leakage. CONCLUSION: Intraoperative neuronavigation during transoral surgery is feasible in the paediatric population. In this unusual patient population, the technique appears to be of value in negotiating complex anatomy and achieving a safe and predictable decompression.

Direct-tissue SELDI-TOF mass spectrometry analysis: a new application for clinical proteomics.

BACKGROUND: New molecular profiling technologies can aid in analysis of small pathologic samples obtained by minimally invasive biopsy and may enable the discovery of key biomarkers synergistic with anatomopathologic analysis related to prognosis, therapeutic response, and innovative target validation. Thus proteomic analysis at the histologic level in healthy and pathologic settings is a major issue in the field of clinical proteomics. METHODS: We used surface-enhanced laser desorption ionization-time-of-flight mass spectrometry (SELDI-TOF MS) technology with surface chromatographic subproteome enrichment and preservation of the spatial distribution of proteomic patterns to detect discrete modifications of protein expression. We performed in situ proteomic profiling of mouse tissue and samples of human cancer tissue, including brain and lung cancer. RESULTS: This approach permitted the discrimination of glioblastomas from oligodendrogliomas and led to the identification of 3 potential markers. CONCLUSION: Direct tissue proteomic analysis is an original application of SELDI-TOF MS technology that can expand the use of clinical proteomics as a complement to the anatomopathological diagnosis.

Tectal plate lesions in children.

OBJECT: The authors characterized the clinical course of tectal plate lesions in a group of pediatric patients to identify the prognostic factors at presentation that predict progression, in an attempt to differentiate tectal hamartomas from tumors. METHODS: A retrospective review was conducted of the management of tectal plate lesions in children since the advent of magnetic resonance (MR) imaging at the authors' hospital (1984-2003). The lesion volume seen on MR images, the clinical and radiological features at presentation, and the clinical course of the population were analyzed for correlations. Forty children with tectal lesions presented in the typical delayed fashion (mean 8.5 months) with symptoms referable to hydrocephalus (93%). Fourteen children whose tumors demonstrated radiological progression (enlargement, contrast enhancement, or cystic change) were treated surgically. Histologically, 80% of the surgically treated lesions were low grade (with the other 20% consisting of one dysplasia, one high-grade tumor, and one unidentified tumor). Five patients required a second operation and one required a third. One patient died of a high-grade astrocytoma after undergoing surgery and radiotherapy; the other 39 patients remain clinically stable. The only factor predictive of tumor enlargement was lesion volume at presentation (p = 0.002). Distribution analysis revealed three subgroups based on lesion volume (< 4, 4-10, and > 10 cm3), which correlated with the clinical course of the disease. CONCLUSIONS: Children with tectal lesions should undergo contrast-enhanced MR imaging and volume assessment at the time of presentation. After hydrocephalus has been managed with endoscopic third ventriculostomy, these children require prolonged, close clinical and radiological surveillance. Lesions with a volume less than 4 cm3 were likely to be hamartomas and followed a predominantly benign course, with few atypical cases progressing. All large lesions, defined as having a volume greater than 10 cm3 at presentation, eventually required treatment, and all were histologically determined to be tumors. An argument is made for earlier treatment of larger lesions with the aim of improving outcome.