scholarly journals Circadian and multiday seizure periodicities, and seizure clusters in canine epilepsy

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Nicholas M Gregg ◽  
Mona Nasseri ◽  
Vaclav Kremen ◽  
Edward E Patterson ◽  
Beverly K Sturges ◽  
...  
Keyword(s):  
Focal Epilepsy ◽  
Statistical Significance ◽  
Fano Factor ◽  
Circular Statistics ◽  
Intracranial Eeg ◽  
Treatment Protocols ◽  
Endogenous Rhythms ◽  
Rayleigh Test ◽  
Naturally Occurring ◽  
Factor Index

Abstract Advances in ambulatory intracranial EEG devices have enabled objective analyses of circadian and multiday seizure periodicities, and seizure clusters in humans. This study characterizes circadian and multiday seizure periodicities, and seizure clusters in dogs with naturally occurring focal epilepsy, and considers the implications of an animal model for the study of seizure risk patterns, seizure forecasting and personalized treatment protocols. In this retrospective cohort study, 16 dogs were continuously monitored with ambulatory intracranial EEG devices designed for humans. Detailed medication records were kept for all dogs. Seizure periodicity was evaluated with circular statistics methods. Circular non-uniformity was assessed for circadian, 7-day and approximately monthly periods. The Rayleigh test was used to assess statistical significance, with correction for multiple comparisons. Seizure clusters were evaluated with Fano factor (index of dispersion) measurements, and compared to a Poisson distribution. Relationships between interseizure interval (ISI) and seizure duration were evaluated. Six dogs met the inclusion criteria of having at least 30 seizures and were monitored for an average of 65 weeks. Three dogs had seizures with circadian seizure periodicity, one dog had a 7-day periodicity, and two dogs had approximately monthly periodicity. Four dogs had seizure clusters and significantly elevated Fano factor values. There were subject-specific differences in the dynamics of ISI and seizure durations, both within and between lead and clustered seizure categories. Our findings show that seizure timing in dogs with naturally occurring epilepsy is not random, and that circadian and multiday seizure periodicities, and seizure clusters are common. Circadian, 7-day, and monthly seizure periodicities occur independent of antiseizure medication dosing, and these patterns likely reflect endogenous rhythms of seizure risk.

scholarly journals A Sheep Model for the Study of Focal Epilepsy with Concurrent Intracranial EEG and Functional MRI

Epilepsia ◽  
2002 ◽  
Vol 43 (8) ◽  
pp. 779-787 ◽  
Author(s):  
Helen I. Opdam ◽  
Paolo Federico ◽  
Graeme D. Jackson ◽  
Joanne Buchanan ◽  
David F. Abbott ◽  
...  
Keyword(s):  
Functional Mri ◽  
Focal Epilepsy ◽  
Sheep Model ◽  
Intracranial Eeg

scholarly journals Thalamic deep brain stimulation modulates cycles of seizure risk in epilepsy

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Nicholas M. Gregg ◽  
Vladimir Sladky ◽  
Petr Nejedly ◽  
Filip Mivalt ◽  
Inyong Kim ◽  
...  
Keyword(s):  
Deep Brain Stimulation ◽  
Brain Stimulation ◽  
Human Subject ◽  
Phase Locking ◽  
Intracranial Eeg ◽  
Pet Dogs ◽  
Circadian Phase ◽  
Naturally Occurring ◽  
Human Participant ◽  
Deep Brain

AbstractChronic brain recordings suggest that seizure risk is not uniform, but rather varies systematically relative to daily (circadian) and multiday (multidien) cycles. Here, one human and seven dogs with naturally occurring epilepsy had continuous intracranial EEG (median 298 days) using novel implantable sensing and stimulation devices. Two pet dogs and the human subject received concurrent thalamic deep brain stimulation (DBS) over multiple months. All subjects had circadian and multiday cycles in the rate of interictal epileptiform spikes (IES). There was seizure phase locking to circadian and multiday IES cycles in five and seven out of eight subjects, respectively. Thalamic DBS modified circadian (all 3 subjects) and multiday (analysis limited to the human participant) IES cycles. DBS modified seizure clustering and circadian phase locking in the human subject. Multiscale cycles in brain excitability and seizure risk are features of human and canine epilepsy and are modifiable by thalamic DBS.

scholarly journals Spatiotemporal Patterns of High-Frequency Activity (80-170 Hz) in Long-term Intracranial EEG

Neurology ◽  
2020 ◽  
pp. 10.1212/WNL.0000000000011408
Author(s):  
Zhuying Chen ◽  
David B. Grayden ◽  
Anthony N. Burkitt ◽  
Udaya Seneviratne ◽  
Wendyl J. D'Souza ◽  
...  
Keyword(s):  
Circadian Rhythms ◽  
High Frequency ◽  
Focal Epilepsy ◽  
High Amplitude ◽  
Oscillatory Behavior ◽  
Patient Specific ◽  
Intracranial Eeg ◽  
Large Variability ◽  
High Frequency Activity

Objective:To determine the utility of high-frequency activity (HFA) and epileptiform spikes as biomarkers for epilepsy, we examined the variability in their rates and locations using long-term ambulatory intracranial EEG (iEEG) recordings.Methods:This study used continuous iEEG recordings obtained over an average of 1.4 years from 15 patients with drug-resistant focal epilepsy. HFA was defined as 80-170 Hz events with amplitudes clearly larger than the background, which was automatically detected using a custom algorithm. The automatically detected HFA was compared with visually annotated high-frequency oscillations (HFOs). The variations of HFA rates were compared with spikes and seizures on patient-specific and electrode-specific bases.Results:HFA included manually annotated HFOs and high-amplitude events occurring in the 80-170 Hz range without observable oscillatory behavior. HFA and spike rates had high amounts of intra- and inter-patient variability. Rates of HFA and spikes had large variability after electrode implantation in most of the patients. Locations of HFA and/or spikes varied up to weeks in more than one-third of the patients. Both HFA and spike rates showed strong circadian rhythms in all patients and some also showed multiday cycles. Furthermore, the circadian patterns of HFA and spike rates had patient-specific correlations with seizures, which tended to vary across electrodes.Conclusions:Analysis of HFA and epileptiform spikes should consider post-implantation variability. HFA and epileptiform spikes, like seizures, show circadian rhythms. However, the circadian profiles can vary spatially within patients and their correlations to seizures are patient-specific.

scholarly journals Contribution of ictal source imaging for localizing seizure onset zone in patients with focal epilepsy patients

Neurology ◽  
2020 ◽  
pp. 10.1212/WNL.0000000000011109
Author(s):  
Shuai Ye ◽  
Lin Yang ◽  
Yunfeng Lu ◽  
Michal T. Kucewicz ◽  
Benjamin Brinkmann ◽  
...  
Keyword(s):  
Surgical Resection ◽  
Focal Epilepsy ◽  
High Density ◽  
Concordance Rate ◽  
Added Value ◽  
Seizure Onset ◽  
Source Imaging ◽  
Intracranial Eeg ◽  
Seizure Onset Zone ◽  
Eeg Recordings

ObjectiveTo determine whether seizure onset zone can be accurately localized prior to surgical planning in focal epilepsy patients, we performed non-invasive EEG recordings and source localization analyses on 39 patients.MethodsIn a total of 39 focal epilepsy patients, we recorded and extracted 138 seizures and 1,325 interictal epileptic discharges using high-density EEG. We have investigated a novel approach for directly imaging sources of seizures and interictal spikes from high density EEG recordings, and rigorously validated it for noninvasive localization of seizure onset zone (SOZ) determined from intracranial EEG findings and surgical resection volume. Conventional source imaging analyses were also performed for comparison.ResultsIctal source imaging showed a concordance rate of 95% when compared to intracranial EEG or resection results. The average distance from estimation to seizure onset (intracranial) electrodes is 1.35 cm in patients with concordant results, and 0.74 cm to surgical resection boundary in patients with successful surgery. About 41% of the patients were found to have multiple types of interictal activities; coincidentally, a lower concordance rate and a significantly worse performance in localizing SOZ were observed in these patients.ConclusionNoninvasive ictal source imaging with high-density EEG recording can provide highly concordant results with clinical decisions obtained by invasive monitoring or confirmed by resective surgery. By means of direct seizure imaging using high-density scalp EEG recordings, the added value of ictal source imaging is particularly high in patients with complex interictal activity patterns, who may represent the most challenging cases with poor prognosis.

scholarly journals Characterizing the role of the structural connectome in seizure dynamics

Brain ◽  
2019 ◽  
Vol 142 (7) ◽  
pp. 1955-1972 ◽  
Author(s):  
Preya Shah ◽  
Arian Ashourvan ◽  
Fadi Mikhail ◽  
Adam Pines ◽  
Lohith Kini ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Structure Function ◽  
Focal Epilepsy ◽  
Diffusion Imaging ◽  
Structural Connectivity ◽  
Patient Specific ◽  
High Angular Resolution ◽  
Intracranial Eeg ◽  
Structural Connectome ◽  
The Relationship

Abstract How does the human brain’s structural scaffold give rise to its intricate functional dynamics? This is a central question in translational neuroscience that is particularly relevant to epilepsy, a disorder affecting over 50 million subjects worldwide. Treatment for medication-resistant focal epilepsy is often structural—through surgery or laser ablation—but structural targets, particularly in patients without clear lesions, are largely based on functional mapping via intracranial EEG. Unfortunately, the relationship between structural and functional connectivity in the seizing brain is poorly understood. In this study, we quantify structure-function coupling, specifically between white matter connections and intracranial EEG, across pre-ictal and ictal periods in 45 seizures from nine patients with unilateral drug-resistant focal epilepsy. We use high angular resolution diffusion imaging (HARDI) tractography to construct structural connectivity networks and correlate these networks with time-varying broadband and frequency-specific functional networks derived from coregistered intracranial EEG. Across all frequency bands, we find significant increases in structure-function coupling from pre-ictal to ictal periods. We demonstrate that short-range structural connections are primarily responsible for this increase in coupling. Finally, we find that spatiotemporal patterns of structure-function coupling are highly stereotyped for each patient. These results suggest that seizures harness the underlying structural connectome as they propagate. Mapping the relationship between structural and functional connectivity in epilepsy may inform new therapies to halt seizure spread, and pave the way for targeted patient-specific interventions.

scholarly journals Spider Communities and Biological Control in Native Habitats Surrounding Greenhouses

Insects ◽  
2018 ◽  
Vol 9 (1) ◽  
pp. 33 ◽  
Author(s):  
Belén Cotes ◽  
Mónica González ◽  
Emilio Benítez ◽  
Eva De Mas ◽  
Gemma Clemente-Orta ◽  
...  
Keyword(s):  
Habitat Management ◽  
Frankliniella Occidentalis ◽  
Generalized Additive Model ◽  
Statistical Significance ◽  
Additive Model ◽  
Conservation Strategies ◽  
Generalist Predators ◽  
Niche Complementarity ◽  
Naturally Occurring ◽  
Spider Abundance

The promotion of native vegetation as a habitat for natural enemies, which could increase their abundance and fitness, is especially useful in highly simplified settings such as Mediterranean greenhouse landscapes. Spiders as generalist predators may also be involved in intra-guild predation. However, the niche complementarity provided by spiders as a group means that increased spider diversity may facilitate complementary control actions. In this study, the interactions between spiders, the two major horticultural pests, Bemisia tabaci and Frankliniella occidentalis, and their naturally occurring predators and parasitoids were evaluated in a mix of 21 newly planted shrubs selected for habitat management in a highly disturbed horticultural system. The effects of all factors were evaluated using redundancy analysis (RDA) and the generalized additive model (GAM) to assess the statistical significance of abundance of spiders and pests. The GAM showed that the abundance of both pests had a significant effect on hunter spider’s abundance, whereas the abundance of B. tabaci, but not F. occidentalis, affected web-weavers’ abundance. Ordination analysis showed that spider abundance closely correlated with that of B. tabaci but not with that of F. occidentalis, suggesting that complementarity occurs, and thereby probability of biocontrol, with respect to the targeted pest B. tabaci, although the temporal patterns of the spiders differed from those of F. occidentalis. Conservation strategies involving the establishment of these native plants around greenhouses could be an effective way to reduce pest populations outdoors.

scholarly journals Bilateral intracranial EEG with corpus callosotomy may uncover seizure focus in nonlocalizing focal epilepsy

Seizure ◽  
2015 ◽  
Vol 24 ◽  
pp. 63-69 ◽  
Author(s):  
Po Ching Chen ◽  
James Baumgartner ◽  
Joo Hee Seo ◽  
Milena Korostenskaja ◽  
Ki Hyeong Lee
Keyword(s):  
Focal Epilepsy ◽  
Corpus Callosotomy ◽  
Intracranial Eeg ◽  
Seizure Focus

scholarly journals Impact of daily high dose oral vitamin D therapy on the inflammatory markers in patients with COVID 19 disease

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Maheshwar Lakkireddy ◽  
Srikanth Goud Gadiga ◽  
R. D. Malathi ◽  
Madhu Latha Karra ◽  
I. S. S. V. Prasad Murthy Raju ◽  
...  
Keyword(s):  
Vitamin D ◽  
Inflammatory Markers ◽  
Standard Treatment ◽  
Statistical Significance ◽  
Hypovitaminosis D ◽  
High Dose ◽  
Treatment Protocols ◽  
Dose Oral ◽  
The Difference ◽  
The Impact

AbstractCOVID 19 is known to cause immune dysregulation and vitamin D is a known immunomodulator. This study aims to objectively investigate the impact of Pulse D therapy in reducing the inflammatory markers of COVID-19. Consented COVID-19 patients with hypovitaminosis D were evaluated for inflammatory markers (N/L ratio, CRP, LDH, IL6, Ferritin) along with vitamin D on 0th day and 9th/11th day as per their respective BMI category. Subjects were randomised into VD and NVD groups. VD group received Pulse D therapy (targeted daily supplementation of 60,000 IUs of vitamin D for 8 or 10 days depending upon their BMI) in addition to the standard treatment. NVD group received standard treatment alone. Differences in the variables between the two groups were analysed for statistical significance. Eighty seven out of one hundred and thirty subjects have completed the study (VD:44, NVD:43). Vitamin D level has increased from 16 ± 6 ng/ml to 89 ± 32 ng/ml after Pulse D therapy in VD group and highly significant (p < 0.01) reduction of all the measured inflammatory markers was noted. Reduction of markers in NVD group was insignificant (p > 0.05). The difference in the reduction of markers between the groups (NVD vs VD) was highly significant (p < 0.01). Therapeutic improvement in vitamin D to 80–100 ng/ml has significantly reduced the inflammatory markers associated with COVID-19 without any side effects. Hence, adjunctive Pulse D therapy can be added safely to the existing treatment protocols of COVID-19 for improved outcomes.

Sign in / Sign up

Export Citation Format

Share Document