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Objective:To describe the experience with Anterior Nucleus of the Thalamus-Deep Brain Stimulation (ANT-DBS) for the treatment of epilepsy at a Canadian Center.Methods:All patients who underwent ANT-DBS implantation between 2013 (first patient implanted at our center) and 2020 were included. These patients had therapy-resistant epilepsy (TRE), were not candidates for resective surgery, and failed vagus nerve stimulation (VNS) treatment. Baseline of monthly seizure frequency was calculated within 3 months prior to VNS placement. Monthly seizure frequency was assessed at different points along the timeline: 3 months before ANT-DBS implantation as well as 3, 6, 12, 24, 36, 48, 60, and 72 months after ANT-DBS device placement. At each time point, seizure frequency was compared to baseline.Results:Six patients were implanted with ANT-DBS. Three (50%) patients had multifocal epilepsy, one (16.6%) had focal epilepsy, and two (33.4%) had combined generalized and focal epilepsy. Two patients with multifocal epilepsy experienced a seizure reduction >50% in the long-term follow-up. Three (50%) patients did not showed improvement: two with combined generalized and focal epilepsy and one with focal epilepsy. There were not surgical or device-related side effects. Two (33.3%) patients presented mild and transient headaches as a stimulation-related side effect.Conclusion:ANT-DBS is an effective and safe treatment for focal TRE. Our experience suggests that patients with multifocal epilepsy due to regional lesion may benefit from ANT-DBS the most. Further investigations are required to determine optimal parameters of stimulation.

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 (pConclusions: 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: 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.