The field of epilepsy surgery has seen tremendous growth in recent years. Innovative new devices have driven much of this growth, but some has been driven by revisions of existing products. Devices have also helped to rejuvenate existing procedures, as in the case of robotic assistance for electrode placement for stereo-electroencephalography, and these devices have brought significant attention along with their introduction. Other devices, such as responsive neurostimulators or laser interstitial thermal therapy systems, have introduced novel treatment modalities and broadened the surgical indications. Collectively, these advances are rapidly changing much of the landscape in the world of pediatric neurosurgery for medically refractory epilepsy. The foundations for indications for neurosurgical intervention are well supported in strong research data, which has also been expanded in recent years. In this article, the authors review advances in the neurosurgical treatment of pediatric epilepsy, beginning with trials that have repeatedly demonstrated the value of neurosurgical procedures for medically refractory epilepsy and following with several recent advances that are largely focused on less-invasive intervention.
JNSPG 75th Anniversary Invited Review Article
Jarod L. Roland and Matthew D. Smyth
Jarod L. Roland and Matthew D. Smyth
Spiros l. Blackburn and Matthew D. Smyth
✓The use of an absorbable hydrogel dural sealant has been approved for neurosurgical applications with no published reports of complications to date. The authors present the case of a 13-year-old girl with syringomyelia and quadriparesis who underwent posterior fossa decompression and dural augmentation for Chiari malformation Type I. Dural closure was performed with a dural substitute patch, hydrogel dural sealant, and gelatin sponge. Magnetic resonance imaging, performed after initial postoperative improvement in the patient's quadriparesis deteriorated, demonstrated an expanding epidural mass collection causing cervicomedullary compression. Exploration on postoperative Day 15 revealed an expanded layer of hydrogel underlying a layer of gelatin sponge. The authors conclude that hydrogel dural sealants should be used cautiously in spaces that cannot tolerate significant mass effect.
Matthew R. Reynolds, Spiros L. Blackburn and Matthew D. Smyth
The authors present the case of a 3-year-old child with Kleeblattschädel, or cloverleaf skull deformity, and a Chiari malformation Type I who developed an ossified pseudomeningocele after posterior fossa decompression. To their knowledge, this is the first report of a postoperative ossified pseudomeningocele in a patient with Kleeblattschädel and the only case of an ossified pseudomeningocele located outside the lumbosacral region. A genetic basis for the ossification process seems likely given the child's history of premature cranial suture closure. The authors draw attention to this rare complication and review the available body of literature on this topic.
M. Mohsin Shah, Matthew D. Smyth and Albert S. Woo
✓The authors present a case of scalp and facial edema following craniofacial reconstruction for metopic craniosynostosis in which recombinant human bone morphogenetic protein–2 (rhBMP-2) was used to treat cranial defects related to the frontoorbital reconstruction. The extent of swelling, the onset, and duration were unusual for such cases and suggested a possible role of rhBMP-2 in inducing a local inflammatory response. The edema rapidly resolved after the patient underwent surgery to remove the rhBMP-2 implants.
Thomas L. Beaumont, Jakub Godzik, Sonika Dahiya and Matthew D. Smyth
The authors report the case of a 14-year-old male with a subependymal giant cell astrocytoma (SEGA) that occurred in the absence of tuberous sclerosis complex (TSC). The patient presented with progressive headache and the sudden onset of nausea and vomiting. Neuroimaging revealed an enhancing left ventricular mass located in the region of the foramen of Monro with significant mass effect and midline shift. The lesion had radiographic characteristics of SEGA; however, the diagnosis remained unclear given the absence of clinical features of TSC. The patient underwent gross-total resection of the tumor with resolution of his symptoms. Although tumor histology was consistent with SEGA, genetic analysis of both germline and tumor DNA revealed no TSC1/2 mutations. Similarly, a comprehensive clinical evaluation failed to reveal any clinical features characteristic of TSC. Few cases of SEGA without clinical or genetic evidence of TSC have been reported. The histogenesis, genetics, and clinical approach to this rare lesion are briefly reviewed.
Brandon A. Miller, Afshin Salehi, David D. Limbrick Jr. and Matthew D. Smyth
The ROSA device is a robotic stereotactic arm that uses a laser system to register the patient’s head or spine with MR or CT images. In this study, the authors analyze their experience with this system in pediatric neurosurgical applications and present selected cases that exemplify the usefulness of this system.
The authors reviewed all cases that utilized the ROSA system at their institution. Patient demographics, pathology, complications, electrode placement, laser ablation, and biopsy accuracy were analyzed. Patient disposition and condition at follow-up were also analyzed.
Seventeen patients underwent 23 procedures using the ROSA system. A total of 87 electroencephalography electrodes were placed, with 13% deviating more than 3 mm from target. Six patients underwent stereotactic needle biopsy, and 9 underwent laser interstitial thermotherapy (LITT). One patient who underwent LITT required a subsequent craniotomy for tumor resection. Another patient experienced an asymptomatic extraaxial hematoma that spontaneously resolved. No patient suffered neurological complications during follow-up. Follow-up from the last procedure averaged 180 days in epilepsy patients and 309 days in oncology patients.
The precision, ease of use, and versatility of the ROSA system make it well suited for pediatric neurosurgical practice. Further work, including long-term analysis of results and cost-effectiveness, will help determine the utility of this system and if its applications can be expanded.