Background: Autonomic nervous system (ANS) dysfunction in people with epilepsy (PwE) is a likely contributor to sudden unexpected death in epilepsy (SUDEP). However, the nature of autonomic dysfunction among PwE remains poorly understood. We aimed to delineate self-reported ANS functioning among people with drug-resistant epilepsy, a patient group at increased risk for SUDEP. Methods: People with focal drug-resistant epilepsy undergoing stereoelectroencephalography at the Epilepsy Monitoring Unit in London, Ontario completed the Composite Autonomic Symptom Score (COMPASS-31), a widely used questionnaire for ANS function. Results: The mean total COMPASS-31 score (N=34; 13 females) was 27.36 (SD=13.77). There was no significant correlation between total COMPASS-31 score and current age (mean=32.71 years, SD=10.58; r(32)= -0.04) or age of epilepsy onset (mean=17.31 years, SD=8.26; r(30)=0). Females scored higher than males (t(32)=3.41, p<.05), but scores did not differ between participants with an epileptogenic zone in the temporal lobe(s) (N=20) and participants with multi-focal, extra-temporal or unknown epileptogenic zones (t(32)=0.18). Participants prescribed 2-3 sodium channel blocking anti-seizure medications (cardiotoxic; N=17), scored worse than participants on 0-1 sodium channel blockers (N=17) (t(32)= -2.15, p<.05). Conclusions: Autonomic testing should be a standard component of clinical care for people with drug-resistant epilepsy, especially for females and for those on sodium channel blockers.

Background: Drug-resistant epilepsy (DRE), defined by persistent seizures despite appropriate anti-seizure medication trials, affects about one-third of individuals with epilepsy. Deep brain stimulation (DBS) has emerged as a promising avenue for improved seizure control. This project reviews existing publications to better understand the neuromodulation parameters used in DBS, aiming to inform clinical decisions on optimizing treatment parameters in patients living with DRE. Methods: A comprehensive literature search of PubMed and Google Scholar was conducted using the keywords “DBS,” “epilepsy,” and “parameters.” Only original studies reporting specific stimulation parameters were included, with meta-analyses and review papers excluded. A weighted Pearson correlation, using study sample size as the weight, examined frequency, pulse width, seizure reduction, and responder rate. Results: So far, 28 studies (1997-2024) have been reviewed, encompassing a total of 1,054 patients, with study size ranging from 1-250 patients. Electrode targets included the hippocampus, ANT, amygdala, centromedian nucleus, and STN. DBS frequencies ranged from 60–333 Hz, and pulse widths from 40–450 µs. Pearson correlation results suggest moderate frequencies (130–145 Hz) and wider pulse widths (300–450 µs) correlate with better seizure reduction and higher responder rates. Conclusions: These results support a formal meta-analysis to further investigate neuromodulation parameters to improve outcomes for DRE patients.

Background: Radiofrequency ablation (RFA) is a minimally-invasive procedure that has been used to treat temporal lobe epilepsy (TLE), however its long-term efficacy is unknown. We aim to characterize the long-term outcomes of patients from the original series by Parrent and Blume (1999). Methods: Consecutive patients who underwent stereotactic RFA for TLE were retrospectively reviewed. Demographics, procedural details, and seizure outcomes until last follow-up were abstracted. Seizure-freedom after initial RFA treatment was estimated with Kaplan-Meier analysis. Results: 27 patients underwent RFA from 1994 to 2002. There were 14 female (52%) patients. 24 (89%) had mesial temporal sclerosis. Mean age at time of RFA was 33.1 years (range 12-45 years). 17 (63%) patients underwent left-sided RFA. 15 (56%) patients had further interventions: 4 (15%) underwent only repeat RFA, 1 (4%) had repeat RFA and anterior temporal lobectomy (ATL), and 10 (37%) underwent subsequent ATL only. Mean follow-up was 9.0 years (range 0.5-22.7 years). At last follow-up, 16 (59%) patients were seizure-free: 5 (19%) received one RFA treatment and 11 (41%) underwent additional procedures. Conclusions: Based on the original series describing the technique, stereotactic RFA for TLE is a safe, minimally-invasive procedure. The role of stereotactic RFA in the treatment of TLE remains to be determined.

Background: Responsive Neurostimulation (RNS) has proven efficacy in the treatment of medically resistant epilepsy as an intracranial system that detects, records and treats seizures automatically. No information exists pertaining to artifact characteristics of RNS findings in scalp EEG. Methods: A 30 year-old female was diagnosed, using intracranial electroencephalography (iEEG), with refractory bi-insular epilepsy, of unknown cause. Due to her large number of focal unaware non-motor seizures and frequent seizures with progression to bilateral tonic-clonic, she was implanted with bi-insular Responsive Neurostimulation (RNS). Results: Results: During scalp EEG recordings, a prominent artifact was seen corresponding to an automatized discharge suspectedly evoked by the RNS trying to minimize the frequent epileptiform activity in her case. Figure 1 and 2 depict these findings. Conclusions: The artifact seen by the RNS in scalp EEG has not been previously described in scientific literature. These findings must be identified to better characterize the role of the RNS in EEG and treatment of seizure activity visible on scalp recordings.

Background: In refractory epilepsy patients with possible autoimmune-associated epilepsy (AAE) but negative antibody testing(-AB), immunotherapy trials (IMT) may still be pursued.The value of (IMT) in such patients remains unclear. For this reason, we reviewed their immunotherapy responses. Methods: Retrospective review of epilepsy patients admitted to the Epilepsy Unit between (2018-2021) who received (IMT). All had (-AB) and received immunotherapy (methylprednisolone (IVMP)-immune globulin (IVIg)-plasma exchange (PLEX)- rituximab).We considered responders when their seizure reduction was ≥ 50%. Results: 14 patients identified. Of them, 50%(n=7) females. Median age (43.5 year. IQR= 28.75-63.25). All refractory to ≥ 2 anti-seizure medications (ASM). Median epilepsy onset was (39.5 years. IQR=23.75-60.25).Median time from diagnosis until received immunotherapy was (15.5 months. IQR=12.75 -21.75). Patients received either IVIG+IVMP (35.7%, n=5) or IVIG alone (28.5%, n=4) or IVIG+IVMP+PLEX (21.4%, n=3) or IVMP alone (7.1%, n=1) or IVIG+IVMP+rituximab (7.1%, n=1). Median follow-up was 25 months.Although early immunotherapy responses were common, sustained response to immunotherapy at last follow-up was only in 21.4% (n=3). Factors confounding determination of immunotherapy efficacy were present in all responders (e.g:concurrent changes in ASM). Conclusions: Our findings suggest that (IMT) in patients with suspected (AAE) but with (-AB) are largely unsuccessful. This suggests an insufficient therapeutic effect after (IMT) or alternatively,non-immune-mediated mechanisms causing this type of epilepsy. Critical evaluations of (IMT)in such cases are needed.

Background: For patients with generalized epilepsy who do not respond to anti-seizure medications, the therapeutic options are limited. Vagus nerve stimulation (VNS) is a treatment mainly approved for therapy resistant focal epilepsy. There is limited information on the use of VNS on generalized epilepsies, including Lennox Gastaut Syndrome(LGS) and genetic generalized epilepsy(GGE). Methods: We identified patients with a diagnosis of Lennox-Gastaut Syndrome or Genetic Generalized Epilepsy, who underwent VNS implantation, between1997 and July 2018. Results: A total of 46 patients were included in this study with a history of therapy resistant generalized epilepsy. The mean age at implantation was 24 years(IQR= 17.8-31 years) and 50%(n=23) were female. The most common etiologies were GGE in 37%(n=17) and LGS in 63%(n=29). Median follow-up since VNS implantation was 63 months(IQR:31-112.8months). 41.7%(n=12) of the LGS group became responders, and 64.7%(n=11) in the GGE group. The best response in seizure reduction was seen in generalized tonic-clonic seizures. There was a reduction of seizure-related hospital admissions from 89.7%(N=26) pre-implantation, to 41.4%(N=12) post-implantation (p<0.0001). The frequency of side effects due to the stimulation was similar in both groups(62.1% in LGS and 61.1% in GGE). Conclusions: VNS is an effective treatment in patients with therapy resistant generalized epilepsy, especially GGE.

Background: Interictal epileptiform discharges (IEDs) are known as epilepsy biomarkers for seizure detection, and It is essential for clinicians to detect them from from physiological events with similar temporal frequency characteristics. Methods: We analyzed the SEEG recordings obtained from patients with medically-resistant epilepsy (MRE) implanted with DE at the Western University Hospital Epilepsy Unit. The data were cleaned, denoised, montaged and segmented based on the clinical annotations, such as sleep intervals and observed Ictals. For event detection, the signal waveform and its power were extracted symmetrically in non-overlapping intervals of 500 ms. Each waveform’s power across all detected spikes was computed and clustered based on their energy distributions. Results: The recordings included thirteen sessions of 24 hours of extracellular recordings from two patients, with 312 hours extracted from four hippocampus electrodes anterior and posterior hippocampus. Our results indicate IEDs carrying the most different characteristics in the bands [25-75] Hz; SWR, on the other hand, are distributed between [80-170] Hz. Conclusions: Our algorithm detected and successfully distinguished IED from SWRs based on their carrying energy during non-sleep periods. Also, the most powerful spectral features that they were distinguished from occur in [15-30] Hz and [75-90] Hz.

Background: Background: Responsive Neurostimulation (RNS) has proven efficacy in treating medically resistant epilepsy as an intracranial system detecting, recording and treating seizures automatically. No information exists pertaining to artifact characteristics of RNS findings in scalp EEG. Methods: A 30 year-old female was diagnosed using intracranial electroencephalography(iEEG), with bi-insular epilepsy, of unknown cause. She presented large number of focal unaware non-motor seizures and seizures with progression to bilateral tonic-clonic. She was implanted with bi-insular RNS. Results: During scalp EEG recordings, a prominent artifact was seen corresponding to an automatized discharge suspectedly evoked by the RNS trying to minimize the frequent epileptiform activity in her case. Figure 1 and 2 depict these findings. Conclusions: Artifact seen by the RNS in scalp EEG has not been previously described in scientific literature. These findings must be identified to better characterize the role of the RNS in EEG and treatment of seizure activity visible on scalp recordings.

Background: The quality of sleep is frequently impacted in patients with epilepsy. Vagus Nerve Stimulation is a relatively common treatment used in patients with medically resistant epilepsy. Some studies show an improvement in quality of life, however, there is limited data on the impact on sleep quality. Methods: A database analysis was conducted on Medline, Embase, and Cochrane to find studies that examined the VNS’s effect on quality of sleep in medically resistant epilepsy. These studies included randomized clinical trails, case studies or reports, cohort studies, and systematic reviews. Results: 75 papers were reviewed and 16 studies from eight countries were included in the analysis. A total of 93 patients with ages ranged from 10 – 49 were included. Analyzing the change in the quality of sleep after VNS was evaluated using Multiple Sleep Latency Test. The literature showed that at low stimulus intensities, VNS treatment improves daytime sleepiness in patients. However, VNS setting titration has a dose-dependent effect on obstructive sleep apnea where higher VNS frequencies are related to higher apnea events. Conclusions: Limited data is available on the impact of VNS on the quality of sleep. Further studies are required to evaluate the improvement of sleep in patients with VNS.

Background: A significant part of the developmental delay (DD) population has epilepsy (26-70%) and live in an institution. These patients tend to have atypical presentation of epileptic seizures with higher risk of misdiagnosis. Distinguishing their ictal events from paroxysmal behaviors can be challenging.There often is a lack of description of the spells or inadequate history from the caregivers or the patients. These patients often have drug resistant epilepsy requiring polypharmacy with increased risk of morbidity and mortality. The aim of this study was to determine usefulness of Epilepsy Monitoring Unit (EMU) in diagnosis and management of these patients. Methods: This is a retrospective observational study of the patients with epilepsy and DD living in institutions that were admitted to the EMU. Results: Four patients met the inclusion criteria for this study. The mean age was 45(29-71), 3/4 (N=3) were male and 3/4 had focal epilepsy. All patients had mood disorders and 2 were taking antipsychotic medication. The mean admission-time was 6,25 days

(2-15) and there was a correlation with the events and seizures in 2/4 of the patients and the rest had a combination of behavioural-changes and seizures. Conclusions: EMU admission can provide an accurate diagnosis of spells in patients with DD and epilepsy, and improve their quality of life.