The Preoperative Evaluation of Drug-Resistant Epilepsy.

Antiepileptic drugs afford good seizure control for approximately 70% of individuals with epilepsy. Epilepsy surgery is extremely helpful for appropriate individuals with drug resistance. Since antiquity, trephination was a crude and invasive technique to manage epilepsy. The late 1800s saw the advent of a more evidence-based approach with attempts to define seizure foci and determine areas of function. Seizure localization initially required direct brain stimulation during surgery before resection. Fortunately, improved knowledge of seizure semiology and advancements in preoperative investigations have enabled epilepsy specialists to better analyze the benefit of seizure reduction versus risk of functional harm. This preoperative phase and the investigative techniques used to analyze surgical candidacy will be discussed in this article.

Open Resection versus Laser Interstitial Thermal Therapy for the Treatment of Pediatric Insular Epilepsy.

BACKGROUND: Various studies suggest that the insular cortex may play an underappreciated role in pediatric frontotemporal/parietal epilepsy. Here, we report on the postsurgical outcomes in 26 pediatric patients with confirmed insular involvement by depth electrode monitoring. OBJECTIVE: To describe one of the largest series of pediatric patients with medically refractory epilepsy undergoing laser interstitial thermal therapy (LITT) or surgical resection of at least some portion of the insular cortex. METHODS: Pediatric patients in whom invasive insular sampling confirmed insular involvement and who subsequently underwent a second stage surgery (LITT or open resection) were included. Complications and Engel Class outcomes at least 1 yr postsurgery were compiled as well as pathology results in the open surgical cases. RESULTS: The average age in our cohort was 10.3 yr, 58% were male, and the average length of follow-up was 2.43 ± 0.20 (SEM) yr. A total of 14 patients underwent LITT, whereas 12 patients underwent open resection. Complications in patients undergoing either LITT or open resection were mostly minimal and generally transient. Forty-three percent of patients who underwent LITT were Engel Class I, compared to 50% of patients who underwent open insular resection. CONCLUSION: Both surgical resection and LITT are valid management options in the treatment of medically refractory insular/opercular epilepsy in children. Although LITT may be a less invasive alternative to craniotomy, further studies are needed to determine its noninferiority in terms of complication rates and seizure freedom, especially in cases of cortical dysplasia that may involve extensive regions of the brain.

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.

Heart, brain, and mind: a case series of multifactorial ischemic strokes in children.

Ischemic strokes in children, although generally rare events, are more prevalent than commonly believed and can adversely affect brain development. Ischemic strokes in children have been associated with various risk factors, including coagulation defects, cardiac anomalies, inborn errors of metabolism, infections, trauma, and even migraine headaches. We present four children with two or more of these risk factors, indicating multifactorial causes of strokes in children. Neuropsychologic testing in two of our cases also underscores cognitive decline as a result of recurrent strokes.

Passive language mapping with magnetoencephalography in pediatric patients with epilepsy.

OBJECT: Functional mapping is important for determining surgical candidacy and also in epilepsy surgery planning. However, in young children and uncooperative patients, language mapping has been particularly challenging despite the advances in performing noninvasive functional studies. In this study the authors review a series of children with epilepsy who underwent language mapping with magnetoencephalography (MEG) while sedated or sleeping, to determine receptive language localization for presurgical evaluation. METHODS: The authors undertook a retrospective review of patients who underwent MEG between December 2007 and July 2009, and identified 15 individuals who underwent passive language testing as part of their presurgical evaluation because they were unable to participate in traditional language testing, such as Wada or functional MRI. Factors necessitating passive language testing included age and neurocognitive development. RESULTS: Three of the 15 patients were deemed candidates for epilepsy surgery based on the results from standard preoperative testing, including video electroencephalography, MRI, and passive receptive language testing using MEG technology. The MEG studies were used successfully to localize language in all 3 patients, creating opportunities for seizure freedom through surgery that would not otherwise have been available. All 3 patients then underwent resective epilepsy surgery without experiencing postoperative language deficits. CONCLUSIONS: This case series is the first to look at language mapping during sleep (passive language mapping) in which MEG was used and is the first to evaluate passive language testing in a patient population with intracranial pathological entities. This case series demonstrates that MEG can provide an alternative method for receptive language localization in patients with barriers to more traditional language testing, and in these 3 cases surgery was performed safely based on the results.