Clinical outcomes of VNS therapy with AspireSR® (including cardiac-based seizure detection) at a large complex epilepsy and surgery centre.

PURPOSE: To compare the efficacy of AspireSR® to preceding VNS battery models for battery replacements, and to determine the efficacy of the AspireSR® for new implants. METHODS: Data were collected retrospectively from patients with epilepsy who had VNS AspireSR® implanted over a three-year period between June 2014 and June 2017 by a single surgeon. Cases were divided into two cohorts, those in whom the VNS was a new insertion, and those in whom the VNS battery was changed from a previous model to AspireSR®. Within each group, the seizure burden was compared between the periods before and after insertion of AspireSR®. RESULTS: Fifty-one patients with a newly inserted AspireSR® VNS model had a significant reduction in seizure frequency (p < 0.001), with 59% (n = 30) reporting ≥50% reduction. Of the 62 patients who had an existing VNS, 53% (n = 33) reported ≥50% reduction in seizure burden when the original VNS was inserted. After the battery was changed to the AspireSR®, 71% (n = 44) reported a further reduction of ≥50% in their seizure burden. The size of this reduction was at least as large as that resulting from the insertion of their existing VNS in 98% (61/62) of patients. CONCLUSION: The results suggest that approximately 70% of patients with existing VNS insertions could have significant additional benefit from cardiac based seizure detection and closed loop stimulation from the AspireSR® device. For new insertions, the AspireSR® device has efficacy in 59% of patients. The 'rule of thirds' used in counseling patients may need to be modified accordingly.

Early haemodynamic changes observed in patients with epilepsy, in a visual experiment and in simulations.

OBJECTIVE: The objective of this study was to investigate whether previously reported early blood oxygen level dependent (BOLD) changes in epilepsy could occur as a result of the modelling techniques rather than physiological changes. METHODS: EEG-fMRI data were analysed from seven patients with focal epilepsy, six control subjects undergoing a visual experiment, in addition to simulations. In six separate analyses the event timing was shifted by either -9,-6,-3,+3,+6 or +9 s relative to the onset of the interictal epileptiform discharge (IED) or stimulus. RESULTS: The visual dataset and simulations demonstrated an overlap between modelled haemodynamic response function (HRF) at event onset and at ± 3 s relative to onset, which diminished at ± 6s. Pre-spike analysis at -6s improved concordance with the assumed IED generating lobe relative to the standard HRF in 43% of patients. CONCLUSION: The visual and simulated dataset findings indicate a form of "temporal bleeding", an overlap between the modelled HRF at time 0 and at ± 3s which attenuated at ± 6s. Pre-spike analysis at -6s may improve concordance. SIGNIFICANCE: This form of analysis should be performed at 6s prior to onset of IED to minimise temporal bleeding effect. The results support the presence of relevant BOLD responses occurring prior to IEDs.

Acute, localised paroxysmal pain as the initial manifestation of focal seizures: a case report and a brief review of the literature.

Pain is a rare manifestation of epileptic seizures. Yet, despite its rarity as a clinical entity, the pain associated with such seizures can be both severe and disabling. It thus remains important to consider epilepsy in the differential diagnosis of unexplained paroxysmal pain. By way of illustration, we present here a report of acute localised paroxysmal pain as the initial manifestation of focal epilepsy with EEG abnormalities in an otherwise neurodevelopmentally normal child. A brief discussion of the literature on epileptic pain then follows.