Ear-EEG detects ictal and interictal abnormalities in focal and generalized epilepsy – A comparison with scalp EEG monitoring

Introduction. Although ictal blinking is significantly more frequent in generalized epilepsy, it has been reported as a rare but useful lateralizing sign in focal seizures when it is not associated with facial clonic twitching. This study aimed to raise awareness of eye blinking as a semiological lateralizing sign. Method. Our database over an 11-year period reviewed retrospectively to assess patients who had ictal blinking associated with focal seizures. Results. Among 632 patients, 14 (2.2%), who had 3 to 13 (7 ± 3) seizures during video-EEG monitoring, were included. Twenty-five percent of all 92 seizures displayed ictal blinking and each patient had one to five seizures with ictal blinking. Ictal blinking was unilateral in 17%, asymmetrical in 22% and symmetrical in 61%. The blinking appeared with a mean latency of 6.3 s (range 0-39) after the clinical seizure-onset, localized most often to fronto-temporal, then in frontal or occipital regions. Blinking was ipsilateral to ictal scalp EEG lateralization side in 83% (5/6) of the patients with unilateral/asymmetrical blinking. The exact lateralization and localization of ictal activity could not have been determined via EEG in most of the patients with symmetrical blinking, remarkably. Conclusions. Unilateral/asymmetrical blinking is one of the early components of the seizures and appears as a useful lateralizing sign, often associated with fronto-temporal seizure-onset. Symmetrical blinking, on the other hand, did not seem to be valuable in lateralization and localization of focal seizures. Future studies using invasive recordings and periocular electrodes are needed to evaluate the value of blinking in lateralization and localization.

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Signal regularity-based automated seizure detection system for scalp EEG monitoring

Cybernetics and Systems Analysis ◽

10.1007/s10559-010-9273-3 ◽

2010 ◽

Vol 46 (6) ◽

pp. 922-935 ◽

Cited By ~ 7

Author(s):

Deng-Shan Shiau ◽

J. J. Halford ◽

K. M. Kelly ◽

R. T. Kern ◽

M. Inman ◽

...

Keyword(s):

Detection System ◽

Seizure Detection ◽

Eeg Monitoring ◽

Scalp Eeg

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Intraoperative scalp EEG monitoring of the right side of the brain during lnnominate artery resection and removal en bloc of an invasive recurrent laryngeal tumor

Electroencephalography and Clinical Neurophysiology ◽

10.1016/0013-4694(96)85855-x ◽

1996 ◽

Vol 99 (3) ◽

pp. 21-22

Author(s):

J. Grabow ◽

A. Hille ◽

D. Wood

Keyword(s):

Eeg Monitoring ◽

Laryngeal Tumor ◽

En Bloc ◽

Scalp Eeg ◽

The Right ◽

The Brain ◽

Artery Resection

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Electroclinical Analysis of Postictal Noserubbing

Canadian Journal of Neurological Sciences / Journal Canadien des Sciences Neurologiques ◽

10.1017/s0317167100052239 ◽

2000 ◽

Vol 27 (2) ◽

pp. 131-136 ◽

Cited By ~ 14

Author(s):

Richard Wennberg

Keyword(s):

Temporal Lobe ◽

Seizure Onset ◽

Scalp Eeg ◽

Autonomic Activation ◽

Ictal Activity ◽

Primary Generalized Epilepsy ◽

Generalized Epilepsy ◽

Temporal Lobe Seizure ◽

Intracranial Electrodes ◽

Video Eeg

ABSTRACT:Background:Postictal noserubbing (PIN) has been identified as a good, albeit imperfect, lateralizing and localizing sign in human partial epilepsy, possibly related to ictal autonomic activation.Methods:PIN was studied prospectively in a group of consecutive patients admitted for video-EEG monitoring, with the laterality of noserubbing correlated with electrographic sites of seizure onset, intra- and interhemispheric spread, and sites of seizure termination.Results:PIN was significantly more frequent in temporal than extratemporal epilepsy (p<0.001; 23/41 (56%) patients and 41/197 (21%) seizures in temporal lobe epilepsy compared with 4/34 (12%) patients and 12/167 (7%) seizures in extratemporal epilepsy). The hand used to rub the nose was ipsilateral to the side of seizure onset in 83% of both temporal and extratemporal seizures. Seizures with contralateral PIN correlated with spread to the contralateral temporal lobe on scalp EEG (p<0.04). All extratemporal seizures with PIN showed spread to temporal lobe structures. One patient investigated with intracranial electrodes showed PIN only when ictal activity spread to involve the amygdala: seizures confined to the hippocampus were not associated with PIN. PIN was not observed in 63 nonepileptic events in 17 patients. Unexpectedly, one patient with primary generalized epilepsy showed typical PIN after 1/3 recorded absence seizures.Conclusions:This study confirms PIN as a good indicator of ipsilateral temporal lobe seizure onset. Instances of false lateralization and localization appear to reflect seizure spread to contralateral or ipsilateral temporal lobe structures, respectively. Involvement of the amygdala appears to be of prime importance for induction of PIN.

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F11. Scalp EEG recording of direct current shifts during generalized spike-and-wave complexes in adult idiopathic generalized epilepsy

Clinical Neurophysiology ◽

10.1016/j.clinph.2018.04.174 ◽

2018 ◽

Vol 129 ◽

pp. e70

Author(s):

Ai Demura ◽

Masako Kinoshita ◽

Kazunori Enoki ◽

Kazuhiro Fukuda ◽

Sayaka Mukai ◽

...

Keyword(s):

Direct Current ◽

Idiopathic Generalized Epilepsy ◽

Scalp Eeg ◽

Generalized Epilepsy

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Baboon model of generalized epilepsy: Continuous intracranial video-EEG monitoring with subdural electrodes

Epilepsy Research ◽

10.1016/j.eplepsyres.2012.02.016 ◽

2012 ◽

Vol 101 (1-2) ◽

pp. 46-55 ◽

Cited By ~ 15

Author(s):

C. Ákos Szabó ◽

Felipe S. Salinas ◽

M. Michelle Leland ◽

Jean-Louis Caron ◽

Martha A. Hanes ◽

...

Keyword(s):

Eeg Monitoring ◽

Subdural Electrodes ◽

Baboon Model ◽

Generalized Epilepsy ◽

Video Eeg

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Video-EEG monitoring in diagnostics and treatment efficacy evaluation in newly-diagnosed generalized epilepsy in adults

Epilepsia and paroxyzmal conditions ◽

10.17749/2077-8333/epi.par.con.2021.046 ◽

2021 ◽

Vol 13 (1) ◽

pp. 21-32

Author(s):

A. B. Kozhokaru ◽

V. A. Karlov ◽

P. N. Vlasov ◽

A. S. Orlova

Keyword(s):

Seizure Frequency ◽

Treatment Efficacy ◽

Activity Index ◽

Epileptiform Activity ◽

Sleep Cycle ◽

Cycle Duration ◽

Eeg Monitoring ◽

Newly Diagnosed ◽

Group I ◽

Generalized Epilepsy

Introduction. Video-electroencephalography (EEG) monitoring (VEEGM) is an indispensable functional method in epileptology. However, virtually no trials on assessing efficacy of antiepileptic drugs (AED) by using VEEGM are available.Objective: to improve efficacy of EEG-diagnostics and evaluate the epileptiform activity index (EAI) in newly-diagnosed idiopathic generalized epilepsy in adult patients receiving alproic acid and levetiracetam.Material and methods. T here w ere e nrolled 130 p atients: 6 0 (46.2%) m ales a nd 7 0 (53.8%) f emales w ith n ewlydiagnosedidiopathic generalized epilepsy (IGE), aged 22.51±8.9 years. All patients underwent VEEGM with quantitative EAI analysis at baseline visit and 1 3, 6 and 12 months later after treatment. Each seizure episode developed during the VEEGM study were assessed for type, time of seizure onset, relation to wake-sleep cycle, duration, ictal EEG pattern followed by diagnosing epileptic syndrome. Valproic acid and levetiracetam were used for initial therapy in groups per 65 patients in each. Treatment efficacy was assessed using parameters such as retention on therapy, absence of seizures, decrease of seizure frequency by >50%, decrease of seizure frequency by <50% – insufficient efficacy.Results. It was found that seizures during baseline VEEGM were recorded in 43.1% (n=56) patients, who were assigned to group 1, whereas remaining 74 (56.9%) patients were assigned to group 2. EAI was significantly higher in patients with seizures recoded at baseline VEEGM, compared to those lacking seizure episodes during initial VEEGM (p<0,001), mean EAI was also higher in group I at second (p<0.001) and third (p<0.001) visits. EAI magnitude at 6 and 12 months of study became virtually comparable in all groups and did not depend on AED prescribed. Treatment efficacy was higher in patients with IGE, with no eizures recorded during the initial VEEGM.Conclusion. Long-term VEEGM allows unbiased assessment of treatment dynamics based on EAI analysis. The first 6 months of initial treatment titration in represent most crucial period for patients with newly-diagnosed IGE.

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Long-Term Inpatient Audiovisual Scalp EEG Monitoring

Journal of Clinical Neurophysiology ◽

10.1097/00004691-199903000-00001 ◽

1999 ◽

Vol 16 (2) ◽

pp. 91-99 ◽

Cited By ~ 15

Author(s):

James L. Thompson ◽

John S. Ebersole

Keyword(s):

Eeg Monitoring ◽

Scalp Eeg

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Flexible Multi-Layer Semi-Dry Electrode for Scalp EEG Measurements at Hairy Sites

Micromachines ◽

10.3390/mi10080518 ◽

2019 ◽

Vol 10 (8) ◽

pp. 518 ◽

Cited By ~ 2

Author(s):

Haoqiang Hua ◽

Wei Tang ◽

Xiangmin Xu ◽

David Dagan Feng ◽

Lin Shu

Keyword(s):

Temporal Correlation ◽

Acquisition Time ◽

Eeg Monitoring ◽

Foam Layer ◽

Contact Impedance ◽

Lower Electrode ◽

Scalp Eeg ◽

Dry Electrodes ◽

Dry Electrode

One of the major challenges of daily wearable electroencephalogram (EEG) monitoring is that there are rarely suitable EEG electrodes for hairy sites. Wet electrodes require conductive gels, which will dry over the acquisition time, making them unstable for long-term EEG monitoring. Additionally, the electrode–scalp impedances of most dry electrodes are not adequate for high quality EEG collection at hairy sites. In view of the above problems, a flexible multi-layer semi-dry electrode was proposed for EEG monitoring in this study. The semi-dry electrode contains a flexible electrode body layer, foam layer and reservoir layer. The probe structure of the electrode body layer enables the electrode to work effectively at hairy sites. During long-term EEG monitoring, electrolytes stored in the reservoir layer are continuously released through the foam layer to the electrode–scalp interface, ensuring a lower electrode–scalp contact impedance. The experimental results showed that the average electrode–scalp impedance of the semi-dry electrode at a hairy site was only 23.89 ± 7.44 KΩ at 10 Hz, and it was lower than 40 KΩ over a long-term use of 5 h. The electrode performed well in both static and dynamic EEG monitoring, where the temporal correlation with wet electrode signals at the hairy site could reach 94.25% and 90.65%, respectively, and specific evoked EEG signals could be collected. The flexible multi-layer semi-dry electrode can be well applied to scalp EEG monitoring at hairy sites, providing a promising solution for daily long-term monitoring of wearable EEGs.

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