Responsive Neurostimulation Targeting the Anterior, Centromedian and Pulvinar Thalamic Nuclei and the Detection of Electrographic Seizures in Pediatric and Young Adult Patients

Background

Responsive neurostimulation (RNS System) has been utilized as a treatment for intractable epilepsy. The RNS System delivers stimulation in response to detected abnormal activity, via leads covering the seizure foci, in response to detections of predefined epileptiform activity with the goal of decreasing seizure frequency and severity. While thalamic leads are often implanted in combination with cortical strip leads, implantation and stimulation with bilateral thalamic leads alone is less common, and the ability to detect electrographic seizures using RNS System thalamic leads is uncertain.

Objective

The present study retrospectively evaluated fourteen patients with RNS System depth leads implanted in the thalamus, with or without concomitant implantation of cortical strip leads, to determine the ability to detect electrographic seizures in the thalamus. Detailed patient presentations and lead trajectories were reviewed alongside electroencephalographic (ECoG) analyses.

Results

Anterior nucleus thalamic (ANT) leads, whether bilateral or unilateral and combined with a cortical strip lead, successfully detected and terminated epileptiform activity, as demonstrated by Cases 2 and 3. Similarly, bilateral centromedian thalamic (CMT) leads or a combination of one centromedian thalamic alongside a cortical strip lead also demonstrated the ability to detect electrographic seizures as seen in Cases 6 and 9. Bilateral pulvinar leads likewise produced reliable seizure detection in Patient 14. Detections of electrographic seizures in thalamic nuclei did not appear to be affected by whether the patient was pediatric or adult at the time of RNS System implantation. Sole thalamic leads paralleled the combination of thalamic and cortical strip leads in terms of preventing the propagation of electrographic seizures.

Conclusion

Thalamic nuclei present a promising target for detection and stimulation via the RNS System for seizures with multifocal or generalized onsets. These areas provide a modifiable, reversible therapeutic option for patients who are not candidates for surgical resection or ablation.

Introduction of a Pediatric Neurology Hospitalist Service With Continuous Electroencephalography Monitoring at a Children's Hospital

Hospitalists, specializing in inpatient medicine, are increasingly being utilized in the hospital setting to improve efficiency, decrease costs and length of stay, and potentially improve outcomes. With these goals in mind and with the purpose of addressing the specific needs of patients on the inpatient pediatric neurology service, we established a pediatric neurohospitalist service in 2009. The primary purpose of this article is to describe the structure and the rationale for a pediatric neurohospitalist service with continuous electroencephalography at a pediatric teaching hospital and to discuss the categories of disease seen by the inpatient neurology service.

Anti-N-methyl-d-aspartate encephalitis with ovarian cystadenofibroma

We report the case of an adolescent girl with anti-N-methyl-D-aspartate-receptor (NMDAR) encephalitis who presented with focal seizures and hemichorea, followed by agitation, speech disturbance, mutism, and autonomic dysfunction. The institution of immunotherapy and removal of an ovarian cystadenofibroma led to full resolution of her symptoms with disappearance of serum NMDAR antibodies. This is the first report linking ovarian cystadenofibroma to anti-NMDAR encephalitis.

Treatment of infantile spasms

Infantile spasms are associated with a diverse range of conditions, and treatment options are available. However, outcomes remain generally poor, particularly for those with symptomatic etiologies. First-line therapy is considered to be hormonal (adrenocorticotropic hormone; ACTH), which some evidence suggests is more effective when started early. However, side effects may place limits on its use acutely and long-term. There is additional evidence for vigabatrin, specifically for infantile spasms secondary to tuberous sclerosis complex. In refractory cases, candidacy for surgical management should be explored, along with new-generation anticonvulsants (eg, topiramate, zonisamide) and the ketogenic diet. There is urgent need for further treatment trials comparing anticonvulsants with ACTH and a satisfactory animal model for the study of spasms.