Ambulatory Electroencephalography Research Articles

Duration of N1 sleep is a factor for excessive daytime sleepiness in epilepsy patients with interictal epileptiform discharges: A polysomnographic study

PurposeThis study aimed to identify the occurrence of excessive daytime sleepiness (EDS) in epilepsy patients with interictal epileptiform discharges and to explore the impact of interictal sleep architecture and sleep-related events on EDS. MethodsThis study included 101 epilepsy patients with interictal epileptiform discharges (IED) and 100 control patients who underwent simultaneous polysomnography and video ambulatory electroencephalography for >7 h throughout a single night. Multiple sleep latency tests were used to assess EDS. Comorbid EDS was present in 25 and 11 patients in the IED epilepsy and control groups, respectively. In addition, univariate and multivariate logistic regression analyses were performed to explore the factors influencing EDS. ResultsThe epilepsy group had a higher prevalence of comorbid EDS and shorter R sleep duration. Univariate logistic regression analysis indicated that an increased risk of EDS may be associated with prolonged N1 sleep duration, higher arousal index, lower mean saturation (mSaO2), higher oxygen desaturation index (ODI), and duration of wake after sleep onset (WASO). Multivariate logistic regression analysis revealed that N1 sleep duration was significantly correlated with EDS. ConclusionIn epilepsy patients with IED, the arousal index, mSaO2, ODI, and duration of WASO were weakly correlated with EDS, and the duration of N1 sleep demonstrated a significant positive correlation with EDS, which requires further research.

Supplementary Motor Area Activity Differs in Parkinson's Disease with and without Freezing of Gait.

The study aimed to investigate the neural changes that differentiate Parkinson's disease patients with freezing of gait and age-matched controls, using ambulatory electroencephalography event-related features. Compared to controls, definite freezers exhibited significantly less alpha desynchronization at the motor cortex about 300 ms before and after the start of overground walking and decreased low-beta desynchronization about 300 ms before and about 300 and 700 ms after walking onset. The late slope of motor potentials also differed in the sensory and motor areas between groups of controls, definite, and probable freezers. This difference was found both in preparation and during the execution of normal walking. The average frontal peak of motor potential was also found to be largely reduced in the definite freezers compared with the probable freezers and controls. These findings provide valuable insights into the underlying structures that are affected in patients with freezing of gait, which could be used to tailor drug development and personalize drug care for disease subtypes. In addition, the study's findings can help in the evaluation and validation of nonpharmacological therapies for patients with Parkinson's disease.

The long-term outcomes of patients with negative prolonged ambulatory electroencephalography tests: A cross-sectional follow-up study.

Ambulatory electroencephalography (AEEG) recording is an essential aid for detecting interictal discharges and providing a clinical diagnosis. This study aimed to describe long-term outcomes among a cohort of patients who yielded negative results on AEEG at the time of assessment and identify factors associated with contemporary quality of life (QOL) and ultimate epilepsy diagnosis. This cross-sectional telephone follow-up study was conducted in June-November 2021 at the Neurology Department in a metropolitan hospital in Sydney, Australia. In total, 47 of 105 eligible (45%) participants were enrolled. Overall, 21 (45%) participants had been diagnosed with epilepsy at a 12-year follow-up. Taking anti-seizure medication, having experienced a seizure event, and having marriage and education-related characteristics were associated with an epilepsy diagnosis. QOL was found to be associated with age, employment status and history of experience of a seizure event. QOL and an epilepsy diagnosis were not shown to be statistically related. Nearly half of the participants had received an epilepsy diagnosis at long-term follow-up, despite having tested negative on AEEG at the time of assessment. Prolonged AEEG testing is an important tool to aid the diagnostic process. However, clinical examination, including accurate history taking, is vital in establishing an epilepsy diagnosis.

Ambulatory video EEG extended to 10 days: A retrospective review of a large database of ictal events

ObjectiveThis work aims to determine the ambulatory video electroencephalography monitoring (AVEM) duration and number of captured seizures required to resolve different clinical questions, using a retrospective review of ictal recordings. MethodsPatients who underwent home-based AVEM had event data analyzed retrospectively. Studies were grouped by clinical indication: differential diagnosis, seizure type classification, or treatment assessment. The proportion of studies where the conclusion was changed after the first seizure was determined, as was the AVEM duration needed for at least 99% of studies to reach a diagnostic conclusion. ResultsThe referring clinical question was not answered entirely by the first event in 29.6% (n = 227) of studies. Diagnostic and classification indications required a minimum of 7 days for at least 99% of studies to be answered, whilst treatment-assessment required at least 6 days. ConclusionsAt least 7 days of monitoring, and potentially multiple events, are required to adequately answer these clinical questions in at least 99% of patients. The widely applied 72 h or single event recording cut-offs may be inadequate to adequately answer these three indications in a substantial proportion of patients. SignificanceExtended duration of monitoring and capturing multiple events should be considered when attempting to capture seizures on video-EEG.

How accurately do adult patients report their absence seizures?

We depend upon self-reporting to determine seizure frequency for epilepsy management decisions, but people often misreport their seizures. Here, we determined misreporting rates in adults with absence seizures, undergoing inpatient video-EEG telemetry (VET) or outpatient ambulatory electroencephalography (aEEG). Under-reporting rates were based on VET data, where behavior could be assessed, whilst over-reporting was assessed using both VET and aEEG. Forty-two patients (31 female and 11 males, median age 28.5 years) and 759 reported absence seizures were included in this study. Overall, only 24% of the 759 reported seizures had an associated EEG correlate, indicating a high over-reporting rate, which occurred in 57% of patients. Age, sex, time of epilepsy, VET versus aEEG, epilepsy syndrome, or medication were not significant predictors of over-reporting. In the VET group in which we could assess both over- and under-reporting (22 patients), only 2 patients correctly reported their seizures, and patients were predominantly over-reporters or under-reporters, not both. Only 26% of 423 absence seizures were reported. Use of zonisamide or valproate was associated with under-reporting, possibly through an impact on attention. These findings indicate that self-reported absence seizures are a poor measure to use for treatment decisions due to both over- and under-reporting.

Late-onset seizures and epilepsy: Electroclinical features suggestive of autoimmune etiology.

IntroductionLate-onset epilepsy (LOE) has recently become a topic of intense research. Besides stroke, tumors, and dementia, autoimmune encephalitis (AE) has emerged as another possible cause of recurrent seizures in the elderly, and may account for a proportion of cases of LOE of unknown origin (LOEUO). This 24-h ambulatory electroencephalography (AEEG)-based study compared patients with LOEUO and AE to identify features suggestive of immune-mediated seizures in the elderly.Materials and methodsWe retrospectively reviewed 232 AEEG examinations performed in patients over 55 years with ≥6-month follow-up, and selected 21 subjects with AE and 25 subjects with LOEUO. Clinical charts and AEEG recordings were carefully analyzed.ResultsTwenty-five patients with LOEUO (12 women, mean age at onset 67.9 years) and 21 AE subjects (8 women, mean age at onset 65.7 years) were enrolled. High-frequency seizures were reported in 20/21 AE and 7/25 LOEUO cases (p < 0.00001). Focal aware seizures were more common in AE (14/21 vs. 6/25, p = 0.00058), whereas “isolated” focal-to-bilateral tonic-clonic seizures occurred in 5/25 patients with LOEUO only (p = 0.053). AE subjects reported ictal autonomic manifestations more frequently (p = 0.0033). Three-hundred-seventy and 24 seizures were recorded in 13/21 patients with AE and 3/25 patients with LOEUO, respectively (p = 0.0006). Interictal epileptiform discharges were observed in 70% of both groups, but their sleep activation was more common in AE (p = 0.06).ConclusionOur study shows that high-frequency focal seizures with autonomic manifestations should raise the suspicion of AE in the elderly with new-onset seizures. It also highlights the relevant contribution of AEEG, which might reduce the diagnostic delay and provide useful clues to recognize AE.

Does Deep Brain Stimulation Work in Lennox-Gastaut Syndrome? Well…it Depends.

DBS of Thalamic Centromedian Nucleus for Lennox–Gastaut Syndrome (ESTEL Trial) Dalic LJ, Warren AEL, Bulluss KJ, Thevathasan W, et al. Ann Nuerol. 2022;91(2):253-267. doi:10.1002/ana.26280. PMID: 34877694.Objective:Prior uncontrolled studies have reported seizure reductions following deep brain stimulation (DBS) in patients with Lennox-Gastaut syndrome (LGS), but evidence from randomized controlled studies is lacking. We aimed to formally assess the efficacy and safety of DBS to the centromedian thalamic nucleus (CM) for the treatment of LGS.Methods:We conducted a prospective, double-blind, randomized study of continuous, cycling stimulation of CM-DBS, in patients with LGS. Following pre- and post-implantation periods, half received 3 months of stimulation (blinded phase), then all received 3 months of stimulation (unblinded phase). The primary outcome was the proportion of participants with ≥50% reduction in diary-recorded seizures in stimulated vs control participants, measured at the end of the blinded phase. A secondary outcome was the proportion of participants with a ≥50% reduction in electrographic seizures on 24-hour ambulatory electroencephalography (EEG) at the end of the blinded phase.Results:Between November 2017 and December 2019, 20 young adults with LGS (17-37 years;13 women) underwent bilateral CM-DBS at a single center in Australia, with 19 randomized (treatment, n = 10 and control, n = 9). Fifty percent of the stimulation group achieved ≥50% seizure reduction, compared with 22% of controls (odds ratio [OR] = 3.1, 95% confidence interval [CI] = .44-21.45, P = .25). For electrographic seizures, 59% of the stimulation group had ≥50% reduction at the end of the blinded phase, compared with none of the controls (OR= 23.25, 95% CI = 1.0-538.4, P = .05). Across all patients, median seizure reduction (baseline vs study exit) was 46.7% (interquartile range [IQR] = 28-67%) for diary recorded seizures and 53.8% (IQR = 27-73%) for electrographic seizures.Interpretation:CM-DBS in patients with LGS reduced electrographic rather than diary-recorded seizures, after 3 months of stimulation. Fifty percent of all participants had diary-recorded seizures reduced by half at the study exit, providing supporting evidence of the treatment effect.

Study and analysis of motion artifacts for ambulatory electroencephalography

Motion artifacts contribute complexity in acquiring clean electroencephalography (EEG) data. It is one of the major challenges for ambulatory EEG. The performance of mobile health monitoring, neurological disorders diagnosis and surgeries can be significantly improved by reducing the motion artifacts. Although different papers have proposed various novel approaches for removing motion artifacts, the datasets used to validate those algorithms are questionable. In this paper, a unique EEG dataset was presented where ten different activities were performed. No such previous EEG recordings using EMOTIV EEG headset are available in research history that explicitly mentioned and considered a number of daily activities that induced motion artifacts in EEG recordings. Quantitative study shows that in comparison to correlation coefficient, the coherence analysis depicted a better similarity measure between motion artifacts and motion sensor data. Motion artifacts were characterized with very low frequency which overlapped with the Delta rhythm of the EEG. Also, a general wavelet transform based approach was presented to remove motion artifacts. Further experiment and analysis with more similarity metrics and longer recording duration for each activity is required to finalize the characteristics of motion artifacts and henceforth reliably identify and subsequently remove the motion artifacts in the contaminated EEG recordings.

Generalized Fast Discharges Along the Genetic Generalized Epilepsy Spectrum: Clinical and Prognostic Significance.

ObjectiveTo investigate the electroclinical characteristics and the prognostic impact of generalized fast discharges in a large cohort of genetic generalized epilepsy (GGE) patients studied with 24-h prolonged ambulatory electroencephalography (paEEG).MethodsThis retrospective multicenter cohort study included 202 GGE patients. The occurrence of generalized paroxysmal fast activity (GPFA) and generalized polyspike train (GPT) was reviewed. GGE patients were classified as having idiopathic generalized epilepsy (IGE) or another GGE syndrome (namely perioral myoclonia with absences, eyelid myoclonia with absences, epilepsy with myoclonic absences, generalized epilepsy with febrile seizures plus, or GGE without a specific epilepsy syndrome) according to recent classification proposals.ResultsGPFA/GPT was found in overall 25 (12.4%) patients, though it was significantly less frequent in IGE compared with other GGE syndromes (9.3 vs. 25%, p = 0.007). GPFA/GPT was found independently of seizure type experienced during history, the presence of mild intellectual disability/borderline intellectual functioning, or EEG features. At multivariable analysis, GPFA/GPT was significantly associated with drug resistance (p = 0.04) and with a higher number of antiseizure medications (ASMs) at the time of paEEG (p < 0.001) and at the last medical observation (p < 0.001). Similarly, GPFA/GPT, frequent/abundant generalized spike-wave discharges during sleep, and a higher number of seizure types during history were the only factors independently associated with a lower chance of achieving 2-year seizure remission at the last medical observation. Additionally, a greater number of GPFA/GPT discharges significantly discriminated between patients who achieved 2-year seizure remission at the last medical observation and those who did not (area under the curve = 0.77, 95% confidence interval 0.57–0.97, p = 0.02)ConclusionWe found that generalized fast discharges were more common than expected in GGE patients when considering the entire GGE spectrum. In addition, our study highlighted that GPFA/GPT could be found along the entire GGE continuum, though their occurrence was more common in less benign GGE syndromes. Finally, we confirmed that GPFA/GPT was associated with difficult-to-treat GGE, as evidenced by the multivariable analysis and the higher ASM load during history.

A Prospective Randomized Controlled Trial: Alternative Approach to EEG Application to Reduce Electrode-induced Skin Injury among Ambulatory EEG Patients

ABSTRACT Ambulatory electroencephalography (AEEG) is a technique of continuous EEG recording of patients in their natural setting, outside the controlled environment of the hospital. Electrode-induced skin injury is a common complication of prolonged EEG monitoring. This randomized study aimed to investigate the performance of two methods of electrode application in reducing electrode-induced skin injury among patients undergoing 4-day AEEG monitoring. A randomized interventional study was conducted from November 2020 to May 2021 in the Neurosciences Ambulatory Care Unit at a metropolitan hospital in Sydney, Australia. We enrolled patients into two groups: i) Group 1 (standard protocol group) received Ten20 Conductive PasteTM with Tensive® adhesive gel as the primary approach to electrode application and ii) Group 2 (intervention group) received Ten20 Conductive PasteTM with Tensive® adhesive gel and hydrogel electrodes on hairless locations as the primary approach to electrode application. A total of 79 patients participated in this study. The group that received the addition of hydrogel electrodes (Group 2) performed better than the standard protocol group on electrode site inflammation for the frontal region, particularly FP1, FP2, F8, and the ground electrode sites. EEG quality and self-reports of patient comfort and mood did not differ significantly between the two groups. The addition of hydrogel electrodes using a Ten20 Conductive PasteTM with a Tensive® adhesive gel protocol results in reduced inflammation at frontal lobe and ground electrode sites.

DBS of Thalamic Centromedian Nucleus for Lennox-Gastaut Syndrome (ESTEL Trial).

Prior uncontrolled studies have reported seizure reductions following deep brain stimulation (DBS) in patients with Lennox-Gastaut syndrome (LGS), but evidence from randomized controlled studies is lacking. We aimed to formally assess the efficacy and safety of DBS to the centromedian thalamic nucleus (CM) for the treatment of LGS. We conducted a prospective, double-blind, randomized study of continuous, cycling stimulation of CM-DBS, in patients with LGS. Following pre- and post-implantation periods, half received 3 months of stimulation (blinded phase), then all received 3 months of stimulation (unblinded phase). The primary outcome was the proportion of participants with ≥50% reduction in diary-recorded seizures in stimulated versus control participants, measured at the end of the blinded phase. A secondary outcome was the proportion of participants with a ≥50% reduction in electrographic seizures on 24-hour ambulatory electroencephalography (EEG) at the end of the blinded phase. Between November 2017 and December 2019, 20 young adults with LGS (17-37 years;13 women) underwent bilateral CM-DBS at a single center in Australia, with 19 randomized (treatment, n=10 and control, n=9). Fifty percent of the stimulation group achieved ≥50% seizure reduction, compared with 22% of controls (odds ratio [OR] = 3.1, 95% confidence interval [CI] = 0.44-21.45, p=0.25). For electrographic seizures, 59% of the stimulation group had ≥50% reduction at the end of the blinded phase, compared with none of the controls (OR= 23.25, 95% CI=1.0-538.4, p=0.05). Across all patients, median seizure reduction (baseline vs study exit) was 46.7% (interquartile range [IQR] = 28-67%) for diary-recorded seizures and 53.8% (IQR=27-73%) for electrographic seizures. CM-DBS in patients with LGS reduced electrographic rather than diary-recorded seizures, after 3 months of stimulation. Fifty percent of all participants had diary-recorded seizures reduced by half at the study exit, providing supporting evidence of the treatment effect. ANN NEUROL 2022;91:253-267.

Accelerated long-term forgetting in adult patients with genetic generalized epilepsy.

Accelerated long-term forgetting (ALF) has been demonstrated among children but not adults with genetic generalized epilepsy (GGE). We investigated (1) how forgetting patterns of verbal and visuospatial material differ between patients with GGE and healthy controls (HCs) and (2) whether ALF is associated with ictal or interictal epileptic activity. Forty-two patients with GGE (39, 92.9% experiencing seizures) were compared to 57 HCs in word, logical story, and Rey-Osterrieth complex figure recall tasks by testing after intervals of 30min and 4 weeks. Ambulatory electroencephalography (EEG) was performed before testing to detect generalized epileptic activity, and patients were asked to document the number of seizures during the 4-week interval. A two-way repeated measures ANOVA indicated that individuals with GGE have different forgetting patterns in comparison to HCs in tasks of word (delay by group interaction F1.5, 142.5 =4.5, p=.02, =.04) and figure (F2, 194 =15.9, p<.001, = .14) but not story (F1.6 151.1 =.5, p=.58, =.005) recall. Last learning trial-adjusted scores of word recall were comparable between HCs and patients with epilepsy (PWEs) at 30min (p=.21) but not at 4weeks (p=.006). Individuals with GGE performed worse than HCs in figure recall at 30min and 4weeks (p<.001), with lower performance after the 4-week interval present only among seizure-positive and EEG-positive individuals (p<.001) during subgroup analysis. Performance on memory tests was unrelated to overall seizure frequency, the number of antiseizure drugs used, and epilepsy duration. Our study supports the presence of ALF in a task of word recall among adult patients with GGE. The pattern of forgetting visuospatial information suggests greater forgetting of material before the first delay and ongoing deficits among PWEs with epileptic activity. Future studies should confirm our findings and investigate the functional or pathological mechanisms of memory dysfunction in GGE.

Driving-Induced Neurological Biomarkers in an Advanced Driver-Assistance System.

Physiological signals are immediate and sensitive to neurological changes resulting from the mental workload induced by various driving environments and are considered a quantifying tool for understanding the association between neurological outcomes and driving cognitive workloads. Neurological assessment, outside of a highly-equipped clinical setting, requires an ambulatory electroencephalography (EEG) headset. This study aimed to quantify neurological biomarkers during a resting state and two different scenarios of driving states in a virtual driving environment. We investigated the neurological responses of seventeen healthy male drivers. EEG data were measured in an initial resting state, city-roadways driving state, and expressway driving state using a portable EEG headset in a driving simulator. During the experiment, the participants drove while experiencing cognitive workloads due to various driving environments, such as road traffic conditions, lane changes of surrounding vehicles, the speed limit, etc. The power of the beta and gamma bands decreased, and the power of the delta waves, theta, and frontal theta asymmetry increased in the driving state relative to the resting state. Delta-alpha ratio (DAR) and delta-theta ratio (DTR) showed a strong correlation with a resting state, city-roadways driving state, and expressway driving state. Binary machine-learning (ML) classification models showed a near-perfect accuracy between the resting state and driving state. Moderate classification performances were observed between the resting state, city-roadways state, and expressway state in multi-class classification. An EEG-based neurological state prediction approach may be utilized in an advanced driver-assistance system (ADAS).

Associations between daily affect and sleep vary by sleep assessment type: What can ambulatory EEG add to the picture?

Objective/BackgroundDisrupted sleep can be a cause and a consequence of affective experiences. However, daily longitudinal studies show sleep assessed via sleep diaries is more consistently associated with positive and negative affect than sleep assessed via actigraphy. The objective of the study was to test whether sleep parameters derived from ambulatory electroencephalography (EEG) in a naturalistic setting were associated with day-to-day changes in affect. Participants/MethodEighty adults (mean age = 32.65 years, 63% female) completed 7 days of affect and sleep assessments. We examined bidirectional associations between morning positive affect and negative affect with sleep assessed via diary, actigraphy, and ambulatory EEG. ResultsMornings with lower positive affect than average were associated with higher diary- and actigraphy-determined sleep efficiency that night. Mornings with higher negative affect than average were associated with longer actigraphy-determined total sleep time that night. Nights with longer diary-determined total sleep time, greater sleep efficiency, and shorter sleep onset latency than average were associated with higher next-morning positive affect, and nights with lower diary-determined wake-after-sleep-onset were associated with lower next-morning negative affect. EEG-determined sleep and affect results were generally null in both directions: only higher morning negative affect was associated with longer rapid eye movement (REM) sleep that night. ConclusionsSelf-reported sleep and affect may occur in a bidirectional fashion for some sleep parameters. EEG-determined sleep and affect associations were inconsistent but may still be important to assess in future studies to holistically capture sleep. Single-channel EEG represents a novel, ecologically valid tool that may provide information beyond diaries and actigraphy.

Performance of an ambulatory electroencephalogram sleep monitor in patients with psychiatric disorders.

Key clinical symptoms observed among individuals with psychiatric disorders include difficulty falling asleep or maintaining sleep, poor sleep quality and nightmares. Those suffering from sleep disorders often present with symptoms of discontent with regard to sleep quality, timing and quantity, and these symptoms have an adverse impact on function and quality of life. A minimally invasive technique would be preferable in patients with psychiatric disorders, who tend to be sensitive to environmental change. Accordingly, we evaluated the performance of Zmachine Insight Plus, an ambulatory electroencephalography sleep monitor, in patients with psychiatric disorders. One hundred and three patients undergoing polysomnography were enrolled in this study. Zmachine Insight Plus was performed simultaneously with polysomnography. Total sleep time, sleep efficiency, wake after sleep onset, rapid eye movement (REM) sleep, light sleep (stages N1 and N2) and deep sleep (stage N3) were assessed. Total sleep time, sleep efficiency, wake after sleep onset, REM sleep duration and non-REM sleep duration of Zmachine Insight Plus showed a significant correlation with those of polysomnography. Lower sleep efficiency and increased frequency of waking after sleep onset, the arousal index and the apnea-hypopnea index on polysomnography were significantly associated with the difference in sleep parameters between the two methods. Among patients with psychiatric disorders who are sensitive to environmental change, Zmachine Insight Plus would be a useful technique to objectively evaluate sleep quality.

Case 284: Posterior Quadrantic Dysplasia

History A 36-year-old left-handed woman with a history of developmental delay and medical refractory seizures since birth most recently presented with continuous simple partial seizures and occasional breakthrough complex partial seizures with postictal migraines. These were described as the patient "becoming pale with sinking to the floor and staring for approximately 1 minute with confusion thereafter." The patient had years of reported seizure freedom until 2010 when she was evaluated for intractable headaches, and electroencephalography revealed her focal subclinical status. At that time, ambulatory electroencephalography findings showed asymmetric left parietal-occipital high-amplitude spike-and-wave discharges in her best awake and alert state. Since that time, the patient developed and continues to have complex partial seizures every 2-3 months that are persistent despite the implementation of several medical regimens. At the time of recent presentation, the patient initially underwent unenhanced head CT in the emergency department followed by unenhanced MRI of the brain due to increased seizure activity at the patient's group home despite continued compliance with her antiepileptic regimen. Contrast material-enhanced imaging was not available at the time of recent presentation, so comparison was made with gadolinium-enhanced brain MRI performed approximately 9 years earlier.

Reducing EEG (Electroencephalogram) Electrode-induced Skin Injury among Ambulatory EEG Monitored Patients: A Non-randomized Interventional Study of Two Commonly Used Cream-based Products for Electrode Application

ABSTRACT Ambulatory electroencephalography (AEEG) seeks to capture inter-ictal epileptiform activity or paroxysmal events when patients are not in the clinic. Skin inflammation is a common complication of prolonged EEG monitoring. This non-randomized study aimed to investigate the performance of two commonly used cream-based methods of electrode application in reducing electrode-induced skin injury among patients undergoing AEEG monitoring. A non-randomized interventional study was conducted from July to December 2019 in the Neurosciences Ambulatory Care Unit at Royal Prince Alfred Hospital, Australia. Patients were enrolled into two groups: i) Group T, which received Ten20® Conductive Paste with Tensive® Conductive Adhesive Gel as the primary approach to electrode application; ii). Group E, which received EC2⁺® Conductive Cream as the primary approach to electrode application. Patients in Group T were enrolled in the 1st and 3rd week of the month, and patients in Group E were enrolled in the 2nd and 4th week for each month of the study. A total of 152 patients participated in this study. Two sub-groups were established: those who were monitored for two days (Group T; n = 36, Group E; n = 30) and those who were monitored for four days (Group T; n = 43, Group E; n = 43). Significant (p < 0.05) differences indicating greater inflammation in the Group E were noted for both Day 2 and Day 4 participants. Skin injury/inflammation was significantly less using the standard method (Group T: Ten20® with Tensive® gel) when compared to EC2⁺® (Group E) as the conductive material at the electrode site.

The Cycle of Daily Stress and Sleep: Sleep Measurement Matters.

Disturbed sleep can be a cause and a consequence of elevated stress. Yet intensive longitudinal studies have revealed that sleep assessed via diaries and actigraphy is inconsistently associated with daily stress. We expanded this research by examining daily associations between sleep and stress using a threefold approach to assess sleep: sleep diaries, actigraphy, and ambulatory single-channel electroencephalography (EEG). Participants were 80 adults (mean age = 32.65 years, 63% female) who completed 7 days of stressor and sleep assessments. Multilevel models were used to examine bidirectional associations between occurrence and severity of daily stress with diary-, actigraphy-, and EEG-determined sleep parameters (e.g., total sleep time [TST], sleep efficiency, and sleep onset latency, and wake after sleep onset [WASO]). Participants reported at least one stressor 37% of days. Days with a stressor were associated with a 14.4-min reduction in actigraphy-determined TST (β = -0.24, p = 0.030), but not with other actigraphy, diary, or EEG sleep measures. Nights with greater sleep diary-determined WASO were associated with greater next-day stressor severity (β = 0.01, p = 0.026); no other diary, actigraphy, or EEG sleep measures were associated with next-day stressor occurrence or severity. Daily stress and sleep disturbances occurred in a bidirectional fashion, though specific results varied by sleep measurement technique and sleep parameter. Together, our results highlight that the type of sleep measurement matters for examining associations with daily stress. We urge future researchers to treat sleep diaries, actigraphy, and EEG as complementary-not redundant-sleep measurement approaches.

Case 284.

History A 36-year-old left-handed woman with a history of developmental delay and medical refractory seizures since birth most recently presented with continuous simple partial seizures and occasional breakthrough complex partial seizures with postictal migraines. These were described as the patient "becoming pale with sinking to the floor and staring for approximately 1 minute with confusion thereafter." The patient had years of reported seizure freedom until 2010 when she was evaluated for intractable headaches, and electroencephalography revealed her focal subclinical status. At that time, ambulatory electroencephalography findings showed asymmetric left parietal-occipital high-amplitude spike-and-wave discharges in her best awake and alert state. Since that time, the patient developed and continues to have complex partial seizures every 2-3 months that are persistent despite the implementation of several medical regimens. At the time of recent presentation, the patient initially underwent unenhanced head CT in the emergency department followed by unenhanced MRI of the brain due to increased seizure activity at the patient's group home despite continued compliance with her antiepileptic regimen. Contrast material-enhanced imaging was not available at the time of recent presentation, so comparison was made with gadolinium-enhanced brain MRI performed approximately 9 years earlier (Figs 1-5).

Effect of prior general anesthesia or sedation and antiseizure drugs on the diagnostic utility of wireless video electroencephalography in dogs.

BackgroundAmbulatory wireless video electroencephalography (AEEG) is the method of choice to discriminate epileptic seizures from other nonepileptic episodes. However, the influence of prior general anesthesia (GA), sedation, or antiseizure drug (ASD) on the diagnostic ability of AEEG is unknown.Hypothesis/ObjectivesThe use of sedation/GA or ASD treatment before AEEG recording may affect the diagnostic ability of AEEG and the time to first abnormality on AEEG.AnimalsA total of 108 client‐owned dogs undergoing ambulatory AEEG for paroxysmal episodes.MethodsRetrospective cohort study. Proportions of diagnostic AEEG and time to first abnormality were compared between dogs that received sedation/GA or neither for instrumentation as well as dogs receiving at least 1 ASD and untreated dogs.ResultsAmbulatory EEG was diagnostic in 60.2% of all dogs including 49% of the sedation/GA dogs and 68% of dogs that received neither (odds ratio [OR], 2.25; 95% confidence interval [CI], 1.02‐5.00; P = .05). The AEEG was diagnostic in 51% of dogs receiving at least 1 ASD and 66% of untreated dogs (OR, 1.95; 95% CI, 0.9‐4.3; P = .11). No difference was found in time to first abnormality between sedation/GA or neither or ASD‐treated or untreated dogs (P = .1 and P = .3 respectively). Ninety‐five percent of dogs had at least 1 abnormality within 277 minutes.Conclusion and Clinical ImportanceSedation/GA and concurrent ASD administration were not identified as confounding factors for decreasing AEEG diagnostic capability nor did they delay the time to first abnormality. A 4‐hour minimal recording period is recommended.