Magnetic resonance imaging-guided stereotactic laser ablation therapy for the treatment of pediatric epilepsy: a retrospective multiinstitutional study.

OBJECTIVE: The authors of this study evaluated the safety and efficacy of stereotactic laser ablation (SLA) for the treatment of drug-resistant epilepsy (DRE) in children. METHODS: Seventeen North American centers were enrolled in the study. Data for pediatric patients with DRE who had been treated with SLA between 2008 and 2018 were retrospectively reviewed. RESULTS: A total of 225 patients, mean age 12.8 ± 5.8 years, were identified. Target-of-interest (TOI) locations included extratemporal (44.4%), temporal neocortical (8.4%), mesiotemporal (23.1%), hypothalamic (14.2%), and callosal (9.8%). Visualase and NeuroBlate SLA systems were used in 199 and 26 cases, respectively. Procedure goals included ablation (149 cases), disconnection (63), or both (13). The mean follow-up was 27 ± 20.4 months. Improvement in targeted seizure type (TST) was seen in 179 (84.0%) patients. Engel classification was reported for 167 (74.2%) patients; excluding the palliative cases, 74 (49.7%), 35 (23.5%), 10 (6.7%), and 30 (20.1%) patients had Engel class I, II, III, and IV outcomes, respectively. For patients with a follow-up ≥ 12 months, 25 (51.0%), 18 (36.7%), 3 (6.1%), and 3 (6.1%) had Engel class I, II, III, and IV outcomes, respectively. Patients with a history of pre-SLA surgery related to the TOI, a pathology of malformation of cortical development, and 2+ trajectories per TOI were more likely to experience no improvement in seizure frequency and/or to have an unfavorable outcome. A greater number of smaller thermal lesions was associated with greater improvement in TST. Thirty (13.3%) patients experienced 51 short-term complications including malpositioned catheter (3 cases), intracranial hemorrhage (2), transient neurological deficit (19), permanent neurological deficit (3), symptomatic perilesional edema (6), hydrocephalus (1), CSF leakage (1), wound infection (2), unplanned ICU stay (5), and unplanned 30-day readmission (9). The relative incidence of complications was higher in the hypothalamic target location. Target volume, number of laser trajectories, number or size of thermal lesions, or use of perioperative steroids did not have a significant effect on short-term complications. CONCLUSIONS: SLA appears to be an effective and well-tolerated treatment option for children with DRE. Large-volume prospective studies are needed to better understand the indications for treatment and demonstrate the long-term efficacy of SLA in this population.

Magnetic resonance-guided stereotactic laser ablation therapy for the treatment of pediatric brain tumors: a multiinstitutional retrospective study.

OBJECTIVE: This study aimed to assess the safety and efficacy of MR-guided stereotactic laser ablation (SLA) therapy in the treatment of pediatric brain tumors. METHODS: Data from 17 North American centers were retrospectively reviewed. Clinical, technical, and radiographic data for pediatric patients treated with SLA for a diagnosis of brain tumor from 2008 to 2016 were collected and analyzed. RESULTS: A total of 86 patients (mean age 12.2 ± 4.5 years) with 76 low-grade (I or II) and 10 high-grade (III or IV) tumors were included. Tumor location included lobar (38.4%), deep (45.3%), and cerebellar (16.3%) compartments. The mean follow-up time was 24 months (median 18 months, range 3-72 months). At the last follow-up, the volume of SLA-treated tumors had decreased in 80.6% of patients with follow-up data. Patients with high-grade tumors were more likely to have an unchanged or larger tumor size after SLA treatment than those with low-grade tumors (OR 7.49, p = 0.0364). Subsequent surgery and adjuvant treatment were not required after SLA treatment in 90.4% and 86.7% of patients, respectively. Patients with high-grade tumors were more likely to receive subsequent surgery (OR 2.25, p = 0.4957) and adjuvant treatment (OR 3.77, p = 0.1711) after SLA therapy, without reaching significance. A total of 29 acute complications in 23 patients were reported and included malpositioned catheters (n = 3), intracranial hemorrhages (n = 2), transient neurological deficits (n = 11), permanent neurological deficits (n = 5), symptomatic perilesional edema (n = 2), hydrocephalus (n = 4), and death (n = 2). On long-term follow-up, 3 patients were reported to have worsened neuropsychological test results. Pre-SLA tumor volume, tumor location, number of laser trajectories, and number of lesions created did not result in a significantly increased risk of complications; however, the odds of complications increased by 14% (OR 1.14, p = 0.0159) with every 1-cm3 increase in the volume of the lesion created. CONCLUSIONS: SLA is an effective, minimally invasive treatment option for pediatric brain tumors, although it is not without risks. Limiting the volume of the generated thermal lesion may help decrease the incidence of complications.

Robotic-Guided Bihippocampal and Biparahippocampal Depth Placement for Responsive Neurostimulation in Bitemporal Lobe Epilepsy.

BACKGROUND: Patients with bitemporal lobe epilepsy are generally not considered for surgical resection. Fortunately, responsive neurostimulation provides another avenue for the management of this challenging disease process. In conjunction with our epileptologist, we consider responsive neurostimulation for patients who have clinical features of temporal lobe epilepsy without clear localization on imaging and stereoelectroencephalography. METHODS: Here we describe our technique for implanting a responsive neurostimulator (NeuroPace, NeuroPace Inc., Mountain View, California) with depth electrodes monitoring the hippocampus and parahippocampus using stereotactic robotic guidance (ROSA, Medtech SA, Montpeillier, France). RESULTS: We have used this technique with 5 patients without morbidity. Four of 5 patients have received clinical benefit (Engel classification I-III). Promisingly, long-term seizure monitoring with use of the NeuroPace system has suggested lateralizing information on 3 of these patients that was not apparent on previous invasive monitoring. CONCLUSIONS: Robotically implanted responsive neurostimulation is a safe and effective treatment for bitemporal epilepsy and can possibly lead to valuable diagnostic information to guide future surgical management in patients who previously were not considered candidates for resective or ablative surgery.

Intractable myoclonic seizures in an allogeneic stem cell transplant recipient: A rare case of myoclonic epilepsy.

INTRODUCTION: Myoclonus may be a rare complication of stem cell transplant but has limited discussion in the scientific literature. CASE: We present a case of an acute myeloid leukemia survivor who developed refractory myoclonic epilepsy four years after graft versus host disease (GVHD) developed six days following matched unrelated allogeneic hematopoietic stem cell transplant. DISCUSSION: Graft versus host disease occurs in 30-50% of allogenic hematopoietic stem cell transplant patients and may cause pharmacoresistant myoclonic epilepsy; however, the mechanisms by which GVHD leads to recurrent myoclonic seizures are not well understood (Lee, 2005) [1]. The paucity of clinical reports of such manifestation makes it difficult to diagnose and effectively manage these patients.

Intracranial leptomeningeal metastasis from thymic carcinoma: case report and review.

BACKGROUND: Thymic carcinoma is an uncommon malignant tumor of the anterior mediastinum. Meningeal metastasis from this type of neoplasm is extraordinarily rare and the prognosis is abysmal. CASE DESCRIPTION: This article presents the case of a 45-year-old man with known metastatic thymic carcinoma who presented with intractable headaches. An MRI scan was highly suggestive of a meningioma, and it was initially suspected that this patient had 2 primary tumors. Surgical resection of the mass both demonstrated a metastatic thymic lesion and ameliorated the patient's quality of life. CONCLUSION: The authors report a case of intracranial meningeal metastasis from a lymphoepithelioma-like poorly differentiated metastatic thymic carcinoma, which was treated by resection and WBRT. A review of the current literature revealed no other cases of this uncommon alhistologic subtype of thymic carcinoma metastatic to the cranium. The incidence, histologic classification of subtypes, and treatment are discussed. This case also illustrates the importance of maintaining a high degree of suspicion for a metastasis in patients with known primary malignancy who present with an MRI highly suspicious for meningioma.