Embryonal tumors in Canadian children less than 36 months of age: results from the Canadian Pediatric Brain Tumor Consortium (CPBTC).

Embryonal tumors are a heterogeneous group of central nervous system (CNS) tumors whose subgroups have varying incidence and outcome. Despite these differences, they are often grouped as a single entity for study purposes. To date, there are no Canadian multi-institutional studies examining the incidence and outcome of all embryonal subtypes. The current study is an observational study reviewing embryonal tumors in all patients less than 36 months of age diagnosed with a CNS tumor in Canada from 1990 to 2005. Embryonal tumors accounted for 26.9% of all CNS tumors. Medulloblastomas were the highest proportion of the embryonal tumors at 61.5%. Atypical teratoid/rhabdoid tumors (AT/RT) had the second highest proportion of embryonal tumors at 18%. The proportion of primitive neuroectodermal tumors (PNET) was 16%, with 2.6 and 1.9% for congenital medulloepithelioma and ependymoblastoma tumors, respectively. AT/RT and PNET were more common in younger age groups. Medulloblastoma became more prevalent with increasing age, with its highest prevalence in the 25 to 36 month age group. Survival rates for our Canadian population at 18 and 24 months were 0.74 and 0.68 for medulloblastoma, 0.64 and 0.60 for PNET, and 0.36 and 0.29 for AT/RT, respectively. Overall, our data are comparable with published international rates for embryonal tumors. These incidence and outcome figures can guide future research into these rare tumors.

Brainstem compression: a predictor of postoperative cerebellar mutism.

PURPOSE: Cerebellar mutism is a common complication of posterior fossa tumor resection. We observed marked, preoperative brainstem compression on MR imaging, among patients who developed postoperative mutism. This study was designed to investigate if an association was indeed present. MATERIALS AND METHODS: Patients (18 months-18 years) undergoing resection of a midline, posterior fossa tumor were retrospectively reviewed. Demographic data, tumor pathology, mutism onset and duration, and postoperative complications were obtained from hospital records. Pre- and postoperative MR images were studied to assess tumor size and the severity of pons compression (an estimate of the mechanical and distortional forces imparted by the tumor). RESULTS: Patients with mutism showed greater preoperative pons compression and a greater increase in postoperative pons diameter. CONCLUSION: We predict that brainstem compression may represent white-matter injury from (1) surgical manipulation and traction, and (2) axonal damage caused by the release of the tumor's compressive force and ensuing axon distortion and dysfunction. The results provide support that mutism may be largely caused by white-matter damage disrupted axon integrity and function.

Ophthalmoplegic migraine: inflammatory neuropathy with secondary migraine?

BACKGROUND: This critical review provides a summary of the clinical presentation, neuroimaging, treatment and prognosis in pediatric ophthalmoplegic migraine (OM). The features of OM are not in keeping with its classification as a migraine-variant. METHOD: We review 3 new and 37 reported pediatric OM cases. RESULTS: Headache was an inconsistent feature, with 25% patients showing no evidence of pain at the initial OM episode. Patients demonstrated: 1) prolonged time for symptom resolution to occur (median time 3 weeks); 2) tendency for recurrent episodes to have more severe and persistent nerve involvement; 3) evidence of permanent neurological sequelae with recurrent episodes (30% of patients); 4) rapid improvement and shortened duration with corticosteroid therapy and; 5) transient, reversible MRI contrast enhancement of the affected cranial nerve (86% of patients). These features would not be expected in primary migraine headache. CONCLUSION: A detailed understanding of the natural history of OM is essential for the clinical. This review provides support that OM may result from cranial nerve inflammation with headache a secondary and later feature of this condition.

Severe myoclonic epilepsy of infancy: extended spectrum of GEFS+?

PURPOSE: Severe myoclonic epilepsy of infancy (SMEI) is an intractable epilepsy of early childhood of unknown etiology. It is often associated with a family history of seizure disorders, but epilepsy phenotypes have not been well described. We sought to characterize the seizure phenotypes of relatives to better understand to the genetic basis of SMEI. METHODS: Probands with SMEI were identified, and systematic family studies were performed. Epilepsy syndromes were characterized in affected family members. RESULTS: Twelve probands with SMEI were identified. Eleven of the 12 probands with SMEI had a family history of seizures, and the twelfth was the result of a consanguineous marriage. We found that 16.7% of full siblings and 8.3% of parents had definite seizures. A total of 39 affected family members was identified. The most common phenotype was febrile seizures in 14, febrile seizures plus in seven, partial epilepsy in two, and there were single individuals with SMEI, myoclonic-astatic epilepsy, Lennox-Gastaut syndrome, and 13 cases with unclassified or unconfirmed seizures. CONCLUSIONS: The family history of seizures in SMEI is in keeping with the spectrum of seizure phenotypes seen in generalized epilepsy with febrile seizures plus (GEFS+). Our findings suggest that SMEI is the most severe phenotype in the GEFS+ spectrum.

Cerebral vascular events associated with ulcerative colitis in children.

Although peripheral vascular thrombic events are recognized as a serious extra-intestinal complication of inflammatory bowel disease, the occurrence of cerebral vascular events in association with acute exacerbations of this group of diseases is rare. In this article, relevant literature is reviewed and three children, 5, 12, and 13 years of age, who presented with clinical and magnetic resonance imaging evidence of an acute cerebrovascular event in association with an acute exacerbation of their inflammatory bowel disease are described. Except for the presence of anemia, hematologic and coagulation studies were unremarkable, and a search for evidence of a systemic vasculitis proved negative.

Electrocorticography.

Electrocorticography (ECOG), the intra-operative recording of cortical potentials, has played an important role in the surgical management of patients with medically refractory epilepsy. It has been used 1) to localize the epileptogenic tissue; 2) map out cortical functions; and 3) predict the success of the surgery. Despite its common use, few studies have been done to prove its effectiveness in these areas. The technique used in children for recording ECOG is very similar to that used in adults except for the limitations imposed by the child's age. Anaesthesia must often be used. Based upon a computerized medical literature search, a review of this procedure was done. Pre-resection localization, and post-resection prediction of outcome was done for temporal and extra-temporal resection, both lesional and nonlesional. Most of the available studies were in adult patients. All were retrospective in nature. Evidence for the role of pre-resection ECOG in determining the degree of resection felt necessary to obtain good clinical outcome was limited. Similarly the post-resection ECOG predication of surgical outcome was restricted.

The preoperative assessment in the planning of surgical management of medically refractory epilepsy in the pediatric patient.

Surgical intervention in refractory epilepsy in children offers the hope of seizure control. For the patient, the preoperative assessment is a major factor in whether he or she is selected as a patient who will potentially benefit. It also plays an important part in the choice of the surgical intervention to be used. This paper reviews the investigations available and suggests an investigational algorithm for use in the pediatric population.

Ketogenic diet in the treatment of refractory epilepsy in childhood.

There has been renewed interest in the ketogenic diet in the treatment of medically refractory seizure disorders in childhood. This article reports the results of a retrospective chart review of 52 patients who were treated with the ketogenic diet. The vast majority (49 of 52) were treated with the classic 4:1 diet. Seizure control improved in 67.3% of patients with complete abolition of seizures in six. Adverse reactions were uncommon and included the development of renal stones, gall bladder stones, and hypoproteinemia in one patient each. Routine biochemical screening during the diet did not identify or prevent adverse events. The authors' experiences with the diet emphasize the need for close ongoing medical and dietary supervision.

Hydrocephalus and epileptic seizures.

Is there an association between shunted hydrocephalus and the development of epileptic seizures? To answer this question a retrospective review of the medical records of 197 patients with shunted hydrocephalus was undertaken. In this series 17% of patients with hydrocephalus developed seizures. No correlation was found between the occurrence of epileptic seizures and a shunt malfunction, the number of shunts placed, the age of the patient at the initial shunt procedure or the location of the shunt. Patients with hydrocephalus who had significant cognitive delay or significant motor disability were significantly more likely to develop seizures than patients who did not. The findings of this review support the hypothesis that the occurrence of seizures in children with hydrocephalus is related to an underlying diffuse encephalopathy and not to the hydrocephalus or to procedures related to the treatment of this disorder.

Brain tumors in childhood and adolescence.

Brain tumors are the second most common neoplasm in childhood and adolescence. With the recent advances in technology, changes in tumor incidence have been reported. This study examines this statement. A 19-year retrospective case review of primary brain tumors in persons younger than 18 years of age at time of diagnosis, who had permanent residence in our catchment area, was performed. Data were examined for changes in presenting symptoms and signs and incidence rates for tumors on the basis of anatomic location and histologic tumor type. An incidence rate of 2.76 per 100,000 people younger than 18 years of age was found. During the period of this study a small, but significant, trend toward increasing incidence was evident. No changes in patterns of presentation or duration of symptoms before diagnosis was observed. The incidence rate based on histologic tumor diagnosis remained fairly constant during the study period.

MRI diagnosis of gliomatosis cerebri.

Until recently the diagnosis of gliomatosis cerebri has been made on postmortem examination. This article reviews the use of serial magnetic resonance imaging studies to suggest premorbid diagnosis of this condition. The following is a case report of a 14-year-old female who had a subtotal cortical resection of tumor and several years later developed a progressive dementia. At postmortem examination the diagnosis of gliomatosis cerebri was made. Diffuse progressive white matter changes involving both hemispheres and brainstem, with increased thickness of the corpus callosum and without changes in cortical markings on T2-weighted magnetic resonance images, in this patient were highly suggestive of the diagnosis of gliomatosis cerebri.

Cortical microdysplasia and surgical outcome in refractory epilepsy of childhood.

This paper examines the relationship between the degree and type of cortical microdysplasia as reported on pathological examination and the degree of seizure control after cortical resection in 70 children with medically refractory epilepsy. Cases selected for this review had to have had medically refractory epilepsy; had their first cortical resection before the age of 18 years, and have sufficient pathological material available for review. The pathological review was done blinded as to results of seizure control outcome postsurgery. Pathological material was classified to type and degree of microdysplasia, according to the classification scheme of Brannstrom. 11% of patients had no evidence of dysplasia; 77% had microdysplasia type 2, and 12% had focal dysplasia (type 3). No significant correlation between degree of seizure control postoperatively and type of microdysplasia was seen in this series.

Unusual association of intractable temporal lobe seizures and intracranial aneurysms in an adolescent: is it a coincidence?

Intracranial aneurysms in the pediatric age group are rare occurrences. They usually present with subarachnoid hemorrhage or mass effect. Their association with epilepsy has rarely been reported; such concurrence may not be a coincidence. We present a 16-year-old girl with a 5-year history of medically intractable complex partial seizures. Preoperative electrophysiological and neuroimaging studies demonstrated an epileptogenic focus and atrophy in the right mesial temporal lobe, and ipsilateral incidental aneurysm at the carotid artery bifurcation. The patient underwent a complete right anterior temporal lobectomy, followed by clipping of the aneurysm. We concluded that the epilepsy management in association with cerebral aneurysms is controversial, but when surgery is indicated, clipping of the aneurysm and resection of the epileptogenic focus may provide the optimal outcome. The relevant literature is reviewed and the possible mechanisms of production of epilepsy by intracranial aneurysms are discussed.

Long-term socioeconomic outcome following surgical intervention in the treatment of refractory epilepsy in childhood and adolescence.

Surgical treatment of refractory epilepsy in childhood and adolescence has been shown to be effective in reducing the seizure frequency. This paper examines the question: "Does this result in a better socioeconomic outcome in later years?" Patients who underwent a surgical procedure for the treatment of their medically refractory epilepsy at our hospital, had more than 2-years' follow-up, and were less than 18 years old at time of survey were included. From a retrospective chart review, age at onset and at surgery, duration of seizures prior to surgery, years of follow-up, type of surgery, and neurological status were obtained. From a telephone survey, seizure frequency after surgery, marital, financial and driving status, level of education, and employment status were ascertained. Sixty-four patients in our epileptic surgical series meet entry criteria. Significantly higher levels of education, employment status and independence were found in patients with a class I Engel outcome compared to other Engel outcomes.

Patient satisfaction with surgical treatment of refractory epilepsy done in childhood and early adolescence.

The results of a retrospective self-controlled telephone satisfaction survey of 63 patients who had undergone an earlier resection for the treatment of medically refractory epilepsy before the age of 18 years was reported. The survey items consisted of a global rating scale and a series of open-ended questions about positive and negative outcomes as a result of the surgery. Most (80%) of the patients felt the surgery had had a positive effect on their lives. The mean global score was 6.24+2.4 (scale 0-9). Strong positive correlations were found between seizure control and degree of satisfaction and between perceived postsurgical neurological deficits and dissatisfaction.

Outcome and life prospects after surgical management of medically intractable epilepsy in patients under 18 years of age.

A retrospective analysis of seizure outcome and quality of life assessment was done in 64 patients under 18 years of age with medically refractory epilepsy who underwent 64 primary and 16 repeat operative procedures in an attempt to control their epilepsy. At least 2 years' follow-up data were available for each patient. Operative procedures were 44 temporal lobe resections; 16 extratemporal resections; and 4 hemispherectomies. Effective control of previously intractable seizures was obtained in most patients: 55%, 11%, and 17% achieved Engel class I, II, and III status, respectively. Successful seizure control was thus obtained in 83%, while 17% (Engel class IV) failed to improve significantly after operation. Quality-of-life measures parallelled the improvements in seizures control, being highest in Engel I, outcome group and lowest in Engel IV outcome group. In appropriately selected pediatric and adolescent patients with medical refractory epilepsy, surgical management can offer a safe and effective adjunct to medication.

Alfentanil mediated activation of epileptiform activity in the electrocorticogram during resection of epileptogenic foci.

PURPOSE: Alfentanil is a potent, short-acting opioid agent which has been used during balanced anaesthesia in children undergoing the surgical excision of epileptic foci. After the observation that this agent had the potential to induce epileptic seizures, we questioned the frequency of this occurrence in this group of patients. METHOD: Twelve patients (6 males, 6 females) undergoing surgical excision of an epileptic foci were prospectively followed. For each patient an electrocorticogram was recorded for 30 minutes before and after receiving alfentanil 20 micrograms/kg intravenously. The frequency of epileptiform abnormalities before and after drug administration was evaluated. When the electrocorticogram no longer showed the effects of alfentanil administration, methohexital 0.5 microgram/kg was given intravenously. RESULTS: Alfentanil induced significant activation of epileptiform discharges among 83% of these patients. Twenty-five per cent had an electrographic seizure. In comparison, methohexital induced significant activation of epileptiform discharges in 50% of these patients. None experienced electrographic seizures. CONCLUSIONS: As alfentanil can induce electrographic seizures in patients known to have epilepsy, caution is advised in its use in this group of patients.

Iron deficiency: a cause of stroke in infants and children.

Iron deficiency is a common pediatric problem affecting 20%-25% of the world's infants. Most commonly causing anemia, iron deficiency is also implicated in such neurologic sequelae as irritability, lethargy, headaches, developmental delay, and infrequently papilledema, pseudotumor cerebri, and cranial nerve abnormalities. Rarely has iron deficiency been recognized as a significant cause of stroke in the adult or pediatric populations. We report a series of 6 children, 6 to 18 months of age, who presented with an ischemic stroke or venous thrombosis after a viral prodrome. All patients had iron deficiency as a consistent finding among the group, and other known etiologies of childhood stroke were excluded. These patients provide evidence of a strong association between iron deficiency and ischemic events in children between 6 and 18 months of age.