No abstract

No abstract

Responsive neurostimulation (RNS) has well-established efficacy in patients with identifiable seizure foci. Emerging evidence suggests the feasibility of expanding this treatment to patients with nonfocal or multifocal epileptic profiles with thalamic targeting. Our institution performed two successful implantations of thalamic RNS (tRNS) targeting the centromedian nucleus of the thalamus (CMT), and 1-year postoperative outcomes are provided. Additionally, a literature review of all reported tRNS was conducted. Publications were excluded if they did not include demographic data and/or epilepsy outcomes at follow-up. In the literature, 19 adult and 3 pediatric cases were identified. These cases were analyzed for outcome, indications, previous operations, and surgical practice variations. Both of our patients had failed multiple previous pharmacological and neurosurgical interventions for epilepsy. Case #1 underwent tRNS with bilateral CMT stimulation. Case #2 underwent tRNS with simultaneous right CMT and right insular stimulation, although an additional lead was placed in the left CMT and left capped for potential future use. Each has achieved ≥90% reduction in seizure burden and approach seizure freedom. 71% of patients in the literature review had multifocal, bilateral, or cryptogenic seizure onset. Three patients were implanted for Lennox Gastaut (2 of 3 are pediatric). 16 patients underwent an average of 1.6 failed procedures prior to successful tRNS implantation. Taken together, the 21 adult patients reviewed have experienced an average seizure reduction of 77% at the latest follow-up. 95% of the adult patients reported in the literature experienced >50% reduction in seizure activity following tRNS and 52% experienced ≥90% reduction in seizure burden following tRNS. Pediatric patients have experienced 70–100% improvement.

Well-described complications of polyetheretherketone (PEEK) cranioplasty in pediatric patients include surgical site infection, post-operative hematoma, cerebral edema, and implant fracture. We present a rare case of hypersensitivity to PEEK presenting as an epidural effusion in a 7-year-old male receiving a PEEK cranioplasty following a decompressive craniectomy. Within three weeks, the patient experienced fever and emesis. Erythrocyte sedimentation rate (ESR) was high (>130 mm/Hr) as well as C-reactive protein (CRP) (6.4 mg/dL). A brain MRI with contrast demonstrated both subgaleal and epidural fluid collections with T2 isointense columns projecting from the galeal surface, through the holes in the implant to the dural surface. The patient appeared clinically well. A sterile tap of the pericranial fluid showed no growth, b2transferrin was negative, but the IgG level was high (>129.2 mg/dL) in the tap fluid. High-dose steroids reduced the epidural collection, but then the collection returned with steroid wean. A second cranioplasty operation replaced the PEEK flap with autologous bone. Postoperative imaging demonstrated markedly reduced fluid collections and a decreased midline shift. The patient remained clinically intact throughout the experience. PEEK allergy following cranioplasty is a rare entity and must be distinguished from infection or hematoma. Medical treatment with steroids can be attempted, but, if refractory, then appropriate treatment may necessitate removal of the offending PEEK implant.