3-T intraoperative MRI (iMRI) for pediatric epilepsy surgery.

PURPOSE: Three-tesla intraoperative MRI (iMRI) is a promising tool that could help confirm complete resections and disconnections in pediatric epilepsy surgery, leading to improved outcomes. However, a large proportion of epileptogenic pathologies in children are poorly defined on imaging, which brings into question the utility of iMRI for these cases. Our aim was to compare postoperative seizure outcomes between iMRI- and non-iMRI-based epilepsy surgeries. METHODS: We performed a comparative retrospective analysis of non-iMRI- versus iMRI-based epilepsy surgeries with 2-year follow-up. Patients were stratified into well-defined cases (WDCs), poorly defined cases (PDCs), and diffuse hemispheric cases (DHCs). Primary outcomes were rates of complete seizure freedom and surgical complications. Secondary outcomes included good (Engel class I/II) seizure outcome, extent of resection/disconnection, and operative duration. Regression models were used to adjust for confounding. RESULTS: Thirty-nine iMRI-based and 39 non-iMRI-based surgeries were included. The distributions of age, sex, and lesion class in each era were similar, but the distributions of individual pathologies varied. Seizure freedom and complication rates at 2-year follow-up were not different between the groups, but Engel class I/II outcome was more common in the iMRI group. Extent of resection/disconnection and length of surgery were similar in both groups. PDCs had the worst outcomes, which were unchanged by the use of iMRI. CONCLUSION: Three-tesla iMRI-based epilepsy surgery may have the potential to improve patient outcomes. However, we conclude that iMRI, in its current state of use at our institute, does not improve outcomes for children undergoing epilepsy surgery. Given that its use appears safe, further research on this technology is warranted, particularly for the most challenging PDCs.

Adjuvant radiotherapy in the treatment of pediatric myxopapillary ependymomas.

OBJECTIVES: Assess the role of radiotherapy (RT) in the management of primary and recurrent myxopapillary ependymoma (MPE). MATERIALS AND METHODS: We conducted a retrospective review of patients with MPE treated at the Montreal Children's Hospital/McGill University Health Centre between 1985 and 2008. RESULTS: Seven children under the age of 18 were diagnosed and treated for MPE. All patients were treated with surgery to the primary site. Three patients underwent subtotal resection (STR) and received adjuvant post-operative RT. Only one patient who had spinal drop metastases received post-operative RT to the lumbosacral region following complete resection of the primary tumor. After a median follow up of 78 months (range 24-180 months), all patients were alive with controlled disease. The single patient treated with gross total resection (GTR) and adjuvant local radiation remained recurrence free. One of the three patients treated with STR and adjuvant RT had disease progression that was controlled with re-resection and further RT. Two of the three patients treated with surgery alone developed local and disseminated recurrent spinal disease that was controlled by salvage RT. CONCLUSION: Our data support the evolving literature which suggests that GTR alone provides suboptimal disease control in MPE. In our patients, RT resulted in control of residual, metastatic and/or recurrent disease. Routine adjuvant RT may improve outcomes in pediatric MPE.

Congenital tumors of the central nervous system: the MCH experience.

INTRODUCTION: Congenital brain tumors in the younger pediatric population are rare lesions that are histologically distinct from those in the older pediatric population. Malignant histology is common, with persistently poor outcomes despite accessible neuroimaging and evolving adjuvant therapy. There remains scant literature about the natural history of these patients because of rarity and varied institutional experiences. METHODS: A retrospective review was performed of congenital brain tumor patients surgically treated at the Montreal Children's Hospital (MCH) over a 22-year period. Patients presenting in the first year of life were evaluated for demographic information, presenting symptoms, lesion location, and management. Analysis was by median rank test and chi(2) statistics. RESULTS: 13 cases of congenital brain tumors were identified: 5 supratentorial and 8 infratentorial. Median age (p = 0.93) and gender (p = 0.57) did not differ by location, and predominant histologies were choroid plexus papilloma and primitive neuroectodermal tumor. Seizure activity was exclusive to supratentorial lesions (40%, p = 0.03), with hypotonia observed only among infratentorial lesions (50%, p = 0.02). There was equal incidence of hydrocephalus (69%, p = 0.57) and increasing head circumference (38%, p = 0.27) by lesion location. Supratentorial lesions were treated by total resection (n = 3), subtotal resection (n = 1), and biopsy (n = 1). Infratentorial lesions were treated by total resection (n = 1), subtotal resection (n = 2), biopsy (n = 1), no operation (n = 2), and decompressive laminectomy for two spinal lesions. CONCLUSIONS: Congenital brain tumor patients represent fewer than 2% of patients treated at MCH. An evolving understanding of management objectives for these lesions requires understanding institutional experiences. Patients with supratentorial lesions frequently present with seizures, hydrocephalus, and macrocrania, and more frequently underwent total resection at surgery.

Long-term outcome after surgical treatment of temporal lobe epilepsy in children.

OBJECT: Surgery is an accepted treatment for carefully selected patients with focal epilepsy. In the present study, the authors assessed clinical and surgery-related data obtained in a large series of children suffering from intractable temporal lobe epilepsy (TLE). METHODS: Etiological, pathological, and clinical features of possible prognostic significance were studied in 109 children who underwent surgery for TLE at the Montreal Neurological Institute and Hospital and the Montreal Children's Hospital between 1985 and 2000. The mean age of patients at seizure onset was 5.5 years and the duration of epilepsy ranged from 0.1 to 17.6 years. Preoperative magnetic resonance imaging revealed mesial sclerosis in 51 patients, a mass lesion in 45, and no visible abnormalities in 12. In six patients invasive monitoring was required. Cortical amygdalohippocampectomy was performed in 72% of patients, whereas 20% underwent transcortical selective amygdalohippocampectomy. In 23 patients a second surgical intervention was necessary. Low-grade tumors were found in 35% and mesial sclerosis was confirmed on pathological evaluation in 45%. Outcome was excellent (seizure free or > 90% reduction) in 94 patients (86%). The patients were followed prospectively for a median of 10.9 years (range 5-20.2 years). There were no permanent neurological complications and no deaths. CONCLUSIONS: Successful postsurgical outcomes, especially in patients treated for mesial temporal lobe sclerosis and lesion-related epilepsies, can be obtained in pediatric patients suffering minimal complications. Unfavorable outcomes are most likely to occur when epileptiform discharges are bitemporal or multifocal in distribution and in cases involving incomplete resection of mesiotemporal structures.

Reliability of clinical attachment level recordings: effects on prevalence, extent, and severity estimates.

BACKGROUND: Although unreliability of periodontal measurements is considered mainly to concern attempts to detect true changes in longitudinal studies, it is also a source of variability that may substantially decrease the precision of estimates obtained in cross-sectional studies. This study assessed the effects of measurement errors on estimates of prevalence, extent, and severity of clinical attachment loss. METHODS: Four examiners performed repeat attachment level recordings in 128, 122, 134, and 133 adolescents, respectively, who participated in a study of clinical attachment loss among 9,162 high school students from Santiago, Chile. A total of 48,954 duplicate recordings were made. Two examiner teams carried out repeat examinations among 292 and 254 subjects, respectively, corresponding to a total number of 51,600 duplicate recordings for interexaminer reliability assessment. RESULTS: A sizeable imprecision was noted regarding prevalence estimates, particularly at the > or = 1 mm level, whereas examiners were reasonably consistent in the assessment of the number of sites with clinical attachment loss. Ninety-five percent of the differences regarding the number of sites with clinical attachment loss > or = 1 mm were in the range from -5 to 5 sites for intraexaminer comparisons, and from -9 to 8 sites for interexaminer comparisons. These differences should be seen in light of the number of sites affected, which ranged from 0 to 85 sites. CONCLUSIONS: Examiner variation may preclude comparisons of prevalence estimates between studies. Valid comparisons may be made between studies of extent estimates provided that uniform parameters are used to express the extent of periodontal breakdown.

Vascularización del ángulo duodenoyeyunal: importancia anatomoquirúrgica / Duodenal Angle irrigation

Se investigó la irrigación del ángulo duodenoyeyunal en 14 cadáveres adultos formolizados, disecando la arteria mesentérica superior en la raíz del mesenterio, la arteria duodenoyeyunal, arteria primera yeyunal y sus correspondientes arcadas. En 8 casos se observó la existencia de una anastomosis entre la arteria del ángulo duodenoyeyunal con la primera yeyunal, en 4 la de esta última con la arcada al intestino se ubicó entre 1,7 4cm. La presencia de arcadas vasculares evidencian una buena vascularización en la zona, lo que permitiría anastomosis intestinales en la región