Modulation of the thalamus by microburst vagus nerve stimulation: a feasibility study protocol

Vagus nerve stimulation (VNS) was the first device-based therapy for epilepsy, having launched in 1994 in Europe and 1997 in the United States. Since then, significant advances in the understanding of the mechanism of action of VNS and the central neurocircuitry that VNS modulates have impacted how the therapy is practically implemented. However, there has been little change to VNS stimulation parameters since the late 1990s. Short bursts of high frequency stimulation have been of increasing interest to other neuromodulation targets e.g., the spine, and these high frequency bursts elicit unique effects in the central nervous system, especially when applied to the vagus nerve. In the current study, we describe a protocol design that is aimed to assess the impact of high frequency bursts of stimulation, called “Microburst VNS”, in subjects with refractory focal and generalized epilepsies treated with this novel stimulation pattern in addition to standard anti-seizure medications. This protocol also employed an investigational, fMRI-guided titration protocol that permits personalized dosing of Microburst VNS among the treated population depending on the thalamic blood-oxygen-level-dependent signal. The study was registered on clinicaltrials.gov (NCT03446664). The first subject was enrolled in 2018 and the final results are expected in 2023

Tongue biting as a lateralizing sign in partial epilepsy

Lateral tongue biting is associated with seizures. This analysis investigates lateral tongue biting as a lateralizing sign in partial seizures. Of 106 consecutively monitored patients, seven had partial epilepsy and sustained a tongue injury during a seizure. The relationship between the side of tongue injury and the hemisphere of seizure onset in these seven patients was analysed. The tongue injury was ipsilateral to the epileptogenic zone in 5 and contralateral in 2, for a predictive value of 71%. Lateral tongue biting may be a useful adjunctive lateralizing sign in partial seizures

Rebuttals and a final commentary

The preceding manuscripts by Drs. Benbadis and Leeman reflect the ongoing controversy of the merits, limitations and ethical problems associated with the induction of psychogenic nonepileptic seizures (PNES) using “placebos”. Each author backed their opinions with conviction and often passion, and when available, published studies in the literature, which was covered in a comprehensive manner between the two manuscripts. Yet, no debate is complete without a rebuttal, which is included in this third manuscript followed by a final commentary