Temporal lobe pleomorphic xanthoastrocytoma and acquired BRAF mutation in an adolescent with the constitutional 22q11.2 deletion syndrome.

DiGeorge syndrome, or velocardiofacial syndrome (DGS/VCFS), is a rare and usually sporadic congenital genetic disorder resulting from a constitutional microdeletion at chromosome 22q11.2. While rare cases of malignancy have been described, likely due to underlying immunodeficiency, central nervous system tumors have not yet been reported. We describe an adolescent boy with DGS/VCFS who developed a temporal lobe pleomorphic xanthoastrocytoma. High-resolution single nucleotide polymorphism array studies of the tumor confirmed a constitutional 22q11.21 deletion, and revealed acquired gains, losses and copy number neutral loss of heterozygosity of several chromosomal regions, including a homozygous deletion of the CDKN2A/B locus. The tumor also demonstrated a common V600E mutation in the BRAF oncogene. This is the first reported case of a patient with DiGeorge syndrome developing a CNS tumor of any histology and expands our knowledge about low-grade CNS tumor molecular genetics.

Magnetic resonance imaging-guided laser interstitial thermal therapy as treatment for intractable insular epilepsy in children.

OBJECTIVE Seizure onset within the insula is increasingly recognized as a cause of intractable epilepsy. Surgery within the insula is difficult, with considerable risks, given the rich vascular supply and location near critical cortex. MRI-guided laser interstitial thermal therapy (LiTT) provides an attractive treatment option for insular epilepsy, allowing direct ablation of abnormal tissue while sparing nearby normal cortex. Herein, the authors describe their experience using this technique in a large cohort of children undergoing treatment of intractable localization-related epilepsy of insular onset. METHODS The combined epilepsy surgery database of Cook Children's Medical Center and Dell Children's Hospital was queried for all cases of insular onset epilepsy treated with LiTT. Patients without at least 6 months of follow-up data and cases preoperatively designated as palliative were excluded. Patient demographics, presurgical evaluation, surgical plan, and outcome were collected from patient charts and described. RESULTS Twenty patients (mean age 12.8 years, range 6.1-18.6 years) underwent a total of 24 LiTT procedures; 70% of these patients had normal findings on MRI. Patients underwent a mean follow-up of 20.4 months after their last surgery (range 7-39 months), with 10 (50%) in Engel Class I, 1 (5%) in Engel Class II, 5 (25%) in Engel Class III, and 4 (20%) in Engel Class IV at last follow-up. Patients were discharged within 24 hours of the procedure in 15 (63%) cases, in 48 hours in 6 (24%) cases, and in more than 48 hours in the remaining cases. Adverse functional effects were experienced following 7 (29%) of the procedures: mild hemiparesis after 6 procedures (all patients experienced complete resolution or had minimal residual dysfunction by 6 months), and expressive language dysfunction after 1 procedure (resolved by 3 months). CONCLUSIONS To their knowledge, the authors present the largest cohort of pediatric patients undergoing insular surgery for treatment of intractable epilepsy. The patient outcomes suggest that LiTT can successfully treat intractable seizures originating within the insula and offers an attractive alternative to open resection. This is the first description of LiTT applied to insular epilepsy and represents one of only a few series describing the use of LiTT in children. The results indicate that seizure reduction after LiTT compares favorably to that after conventional open surgical techniques.

Relapsing-remitting, corticosteroid-sensitive, varicella zoster virus optic neuritis.

We report a 13-year-old male who presented with bilateral disc edema after a febrile illness. Rapid loss of vision prompted corticosteroids treatment, which reversed the visual loss and optic disc findings. Both his visual function and disc edema proved exceedingly sensitive to steroids, and he required increasingly slow and prolonged corticosteroids taper to avoid relapse over a period of 1 year. Ultimately, profound visual loss was reversed three times and only after exceptionally slow steroid weaning. Comprehensive systemic investigations and neuroimaging were initially unrevealing. Late in the course of disease, evidence of seroconversion was identified in his serum and cerebrospinal fluid with positive varicella zoster virus antibodies titers. Varicella zoster virus-related optic nerve pathology may present clinically with profound visual loss and disc edema and may reverse only with high-dose corticosteroids treatment. Physicians should carefully consider retesting with late varicella zoster virus titer in patients with relapsing-remitting, steroid-sensitive optic neuritides.

Phenytoin and phenobarbital stable isotope studies in neonates.

A pharmacokinetic study of phenytoin and phenobarbital with nonradioactive isotopes was performed in nine neonates in an intensive care unit setting. A single-pulse dose of either labeled phenobarbital (1,3-(15)N, 2-(13)C) or labeled phenytoin (2-(13)C, 1, 3-(15)N) was administered to neonates who manifested gestation between 25 and 40 weeks and were receiving maintenance medication. Blood samples were collected at fixed intervals, and with a computerized gas chromatography mass spectrometry system, plasma concentrations of the labeled and unlabeled drug in relation to time administered were obtained. According to the calculations obtained from labeled analogue, several kinetic characteristics related to drug absorption, clearance, and elimination were determined. The use of a nonradioactive labeled isotope overcomes the limitations of conventional pharmacokinetic methodology and can be specifically useful in neonates and infants in whom volumes of distribution are rapidly changing and steady state is not achieved.

Epilepsy surgery for early infantile epileptic encephalopathy (ohtahara syndrome).

Early infantile epileptic encephalopathy or Ohtahara syndrome is the earliest form of the age-dependent epileptic encephalopathies. Its manifestations include tonic spasms, focal motor seizures, suppression burst pattern, pharmaco-resistance, and dismal prognosis. The purpose of this study was to evaluate the effectiveness of epilepsy surgery in selected infants. We identified 11 patients, 9 from the literature and 2 from our institution that fulfilled diagnostic criteria of Ohtahara syndrome and had undergone epilepsy surgery in infancy. Seven of the 11 infants have remained seizure free (Engel class IA) and four are reportedly having rare to infrequent seizures (Engel class IIB). All patients experienced "catch up" development. In contrast to Ohtahara's15 pharmacotherapy managed patients, who had a mortality rate of approximately fifty percent, and those that survived continued to have seizures and were severely impaired, the outcome of selected surgically managed patients is much more favorable.

Atypical imaging evolution of sturge-weber syndrome without facial nevus.

We report a patient with Sturge-Weber syndrome without facial angioma, who presented with seizures and normal initial imaging results. The patient experienced several years without seizures before a sudden increase in seizure frequency, followed by an atypical evolution of imaging findings prompting biopsy to establish the diagnosis. This case highlights not only the rare presentation of isolated leptomeningeal angiomatosis, but also the potential for atypical evolution of imaging findings through the course of the disease. We detail the imaging findings of our case and review the potential pathophysiological basis for this appearance. Our experience suggests that repeat imaging is warranted in patients with suspected Sturge-Weber syndrome or those with intractable cryptogenic epilepsy, because some imaging features of Sturge-Weber syndrome may manifest over time.

Amantadine for the treatment of refractory absence seizures in children.

Amantadine has demonstrated efficacy in small series for absence and myoclonic type seizures. We examined the efficacy of amantadine for treating refractory absence seizures in a cohort of pediatric patients. We retrospectively reviewed medical records for patients with absence seizures treated with amantadine at Cook Children's Medical Center after January 2007. Abstracted data included sex, age at initiation, concomitant antiepileptic drugs, amantadine dosing, and seizure frequency. Outcomes at 3, 6, and 12 months after initiation were categorized as >90%, ≥50%, or <50% reduction in seizure frequency. Of 13 patients included in the study, many were exposed to multiple antiepileptic drugs (median, 3; range, 1-6). Three were implanted with a vagus nerve stimulator. A response of at least 50% seizure reduction was reported in more than 50% of patients reviewed at 3, 6, and 12 months after initiating treatment. Among responders, a majority had >90% reduction in seizure frequency. Amantadine may constitute an efficacious alternative treatment for refractory absence seizures.