Here we critique recent arguments proposing to distinguish ictal from non-ictal generalized periodic discharges (GPDs) based on etiology and stimulation response, arguing that these are unreliable. We advocate for an empirical approach to GPDs: describe objectively, interpret through medication trials, and base further treatment on response. We call for evidence-based approaches considering meaningful clinical outcomes.
View Article and Find Full Text PDFStudy Objectives: Seizures are rare in rapid eye movement (REM) sleep. However, seizures sometimes occur in REM sleep, and a small number of focal epilepsy patients display their maximum rate of interictal epileptiform discharges in REM sleep. We sought to systematically identify and characterize seizures in REM sleep.
View Article and Find Full Text PDFThough unified by challenges in the treatment of status epilepticus (SE), rural Canada is simultaneously massive and diverse, spanning the Pacific, Atlantic, and Arctic Oceans. According to the national statistical agency, the most rural jurisdiction in Canada is the Arctic territory of Nunavut. In particular, the Kivalliq region of Nunavut represents a unique epidemiologic SE space because any treatment beyond typical first-line lorazepam and second-line phenytoin by a non-neurologist locum tenens requires airborne evacuation over a thousand kilometers away to a single hospital with a single electroencephalographic (EEG) laboratory.
View Article and Find Full Text PDFRecently, we showed that high-definition transcranial direct current stimulation (hd-tDCS) can acutely reduce epileptic spike rates during and after stimulation in refractory status epilepticus (RSE), with a greater likelihood of patient discharge from the intensive care unit compared to historical controls. We investigate whether electroencephalographic (EEG) desynchronization during hd-tDCS can help account for observed anti-epileptic effects. Defining desynchronization as greater power in higher frequencies such as above 30 Hz ("gamma") and lesser power in frequency bands lower than 30 Hz, we analyzed 27 EEG sessions from 10 RSE patients who had received 20-minute session(s) of 2-milliamperes of transcranial direct current custom-targeted at the epileptic focus as previously determined by a clinical EEGer monitoring the EEG in real-time.
View Article and Find Full Text PDFAnn Clin Transl Neurol
November 2023
Circannual status epilepticus (SE) patterns in communities near Earth's poles best test the hypothesis that SE susceptibility varies with light exposure because these communities are routinely subject to large changes in annual light exposure, which may result in changes to daily sleep time. We compared northern hemispheric circannual SE occurrence in Kivalliq, Canada (latitude-62.8° N) to southern hemispheric Auckland, New Zealand (latitude-36.
View Article and Find Full Text PDFCan J Neurol Sci
March 2024
Background: Subclinical seizures are common in hospitalized patients and require electroencephalography (EEG) for detection and intervention. At our institution, continuous EEG (cEEG) is not available, but intermittent EEGs are subject to constant live interpretation. As part of quality improvement (QI), we sought to estimate the residual missed seizure rate at a typical quaternary Canadian health care center without cEEG.
View Article and Find Full Text PDFAlthough not classically considered together, there is emerging evidence that Alzheimer's disease (AD) and epilepsy share a number of features and that each disease predisposes patients to developing the other. Using machine learning, we have previously developed an automated fluorodeoxyglucose positron emission tomography (FDG-PET) reading program (i.e.
View Article and Find Full Text PDFAims: We aimed to systematically synthesize the current published literature on neonatal growth outcomes associated with antiseizure medication (ASM) use during pregnancy.
Methods: We searched seven databases, from inception to 23 March 2022. We investigated small for gestational age (SGA) and low birth weight (LBW) as primary outcomes and birth weight, birth height, cephalization index and head circumference as secondary outcomes.
Background And Objectives: Seizures (SZs) and other SZ-like patterns of brain activity can harm the brain and contribute to in-hospital death, particularly when prolonged. However, experts qualified to interpret EEG data are scarce. Prior attempts to automate this task have been limited by small or inadequately labeled samples and have not convincingly demonstrated generalizable expert-level performance.
View Article and Find Full Text PDFBackground And Objectives: The validity of brain monitoring using electroencephalography (EEG), particularly to guide care in patients with acute or critical illness, requires that experts can reliably identify seizures and other potentially harmful rhythmic and periodic brain activity, collectively referred to as "ictal-interictal-injury continuum" (IIIC). Previous interrater reliability (IRR) studies are limited by small samples and selection bias. This study was conducted to assess the reliability of experts in identifying IIIC.
View Article and Find Full Text PDFRefractory status epilepticus (RSE) is a life-threatening emergency with high mortality and poor functional outcomes in survivors. Treatment is typically limited to intravenous anesthetic infusions and multiple anti-seizure medications. While ongoing seizures can cause permanent neurological damage, medical therapies also pose severe and life-threatening side effects.
View Article and Find Full Text PDFStudy Objectives: To compare estimated epileptic source localizations from 5 sleep-wake states (SWS): wakefulness (W), rapid eye movement sleep (REM), and non-REM 1-3.
Methods: Electrical source localization (sLORETA) of interictal spikes from different SWS on surface EEG from the epilepsy monitoring unit at spike peak and take-off, with results mapped to individual brain models for 75% of patients. Concordance was defined as source localization voxels shared between 2 and 5 SWS, and discordance as those unique to 1 SWS against 1-4 other SWS.
Objectives: Emerging evidence suggests that circadian rhythms affect seizure propensity in addition to, and possibly independent of, sleep-wake states. Subject to extreme seasonal changes in light and dark, the northerly Arctic can serve as a "natural experiment" to assess the real-life impact of environmental influences on seizure severity. Therefore, we evaluated the timing of seizure evacuations over 11.
View Article and Find Full Text PDFClin Neurophysiol Pract
November 2021
Objectives: In refractory status epilepticus (RSE), the optimal degree of suppression (EEG burst suppression or merely suppressing seizures) remains unknown. Many centers lacking continuous EEG must default to serial intermittent recordings where uncertainty from lack of data may prompt more aggressive suppression. In this study, we sought to determine whether the quantitative burst suppression ratio (QBSR) from serial intermittent EEG recording is associated with RSE patient outcome.
View Article and Find Full Text PDFEpilepsia Open
December 2021
Objective: The World Health Organization, International League Against Epilepsy (ILAE), and International Bureau for Epilepsy have called epilepsy a public health imperative, with appropriate emphasis on low-to-middle-income countries (LMIC). Although Canada is a high-income country (HIC), income is not distributed uniformly. Furthermore, epilepsy data from the national statistical agency explicitly overlook the Arctic by excluding these territories.
View Article and Find Full Text PDFAs continuous brain monitoring becomes a routine part of clinical care, continuous EEG has allowed better detection and characterization of nonconvulsive seizures, and patterns along the ictal-interictal continuum in critically ill patients. However, this increased workload has led many to turn to quantitative EEG whose central tool is the "spectrogram." Although in relatively wide use, many clinicians lack a detailed understanding of how spectrograms relate to the underlying "raw" EEG signal.
View Article and Find Full Text PDFEpilepsy is a common and debilitating neurological disease. When medication cannot control seizures in up to 40% of cases, surgical resection of epileptogenic tissue is a clinically and cost- effective therapy to achieve seizure freedom. To simultaneously resect minimal yet sufficient cortex, exquisite localization of the epileptogenic zone (EZ) is crucial.
View Article and Find Full Text PDFDespite growing use of critical care electroencephalography (ccEEG) to detect seizures and status epilepticus in the intensive care unit (ICU), integrating ccEEG findings with traditionally described benign EEG variants (BEVs) is a relatively new concept. BEV-like waveforms are now increasingly encountered in the ICU, and have also been explicitly included in proposed definitions of brief potentially ictal rhythmic discharges (BIRDs) in the ICU, bringing to the fore the question of if and which EEG patterns in critically ill patients can be safely deemed "benign". Though well-characterized as benign in healthy outpatients at low pre-test risk for neurologic disease, the significance of BEVs in the ICU remains largely unknown.
View Article and Find Full Text PDFIn Canada, recreational use of cannabis was legalized in October 2018. This policy change along with recent publications evaluating the efficacy of cannabis for the medical treatment of epilepsy and media awareness about its use have increased the public interest about this agent. The Canadian League Against Epilepsy Medical Therapeutics Committee, along with a multidisciplinary group of experts and Canadian Epilepsy Alliance representatives, has developed a position statement about the use of medical cannabis for epilepsy.
View Article and Find Full Text PDFDiagnosis of paroxysmal events in epilepsy patients is often made through video-telemetry electroencephalography in the epilepsy monitoring unit. This case report describes the first-ever diagnosis of exploding head syndrome in a patient with longstanding epilepsy and novel nocturnal events. In this report, we describe the presentation of exploding head syndrome and its prevalence and risk factors.
View Article and Find Full Text PDFPurpose: This study sought to determine the state of quantitative EEG (QEEG) use in Canada, as QEEG may provide a partial solution to the issue of escalating EEG demand against insufficient health care resources.
Methods: A 10-item survey questionnaire was administered to participants at the annual meeting of the Canadian Association of Electroneurophysiology Technologists, which was held in parallel with the annual meeting of the Canadian Neurological Sciences Federation.
Results: At least 70% of the Canadian population has QEEG access through academic medical institutions with applicability to adults and children.
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