Reliability of patient self-report of cognition, awareness, and consciousness during seizures

Real-Time Seizure Detection Using Behind-the-Ear Wearable System

INTRODUCTION

This study examines the usability and comfort of a behind-the-ear seizure detection device called brain seizure detection (BrainSD) that captures ictal electroencephalogram (EEG) data using four scalp electrodes.

METHODS

This is a feasibility study. Thirty-two patients admitted to a level 4 Epilepsy Monitoring Unit were enrolled. The subjects wore BrainSD and the standard 21-channel video-EEG simultaneously. Epileptologists analyzed the EEG signals collected by BrainSD and validated it using video-EEG data to confirm its accuracy. A poststudy survey was completed by each participant to evaluate the comfort and usability of the device. In addition, a focus group of UT Southwestern epileptologists was held to discuss the features they would like to see in a home EEG-based seizure detection device such as BrainSD.

RESULTS

In total, BrainSD captured 11 of the 14 seizures that occurred while the device was being worn. All 11 seizures captured on BrainSD had focal onset, with three becoming bilateral tonic-clonic and one seizure being of subclinical status. The device was worn for an average of 41 hours. The poststudy survey showed that most users found the device comfortable, easy-to-use, and stated they would be interested in using BrainSD. Epileptologists in the focus group expressed a similar interest in BrainSD.

CONCLUSIONS

Brain seizure detection is able to detect EEG signals using four behind-the-ear electrodes. Its comfort, ease-of-use, and ability to detect numerous types of seizures make BrainSD an acceptable at-home EEG detection device from both the patient and provider perspective.

Automatic responsiveness testing in epilepsy with wearable technology: The ARTiE Watch

OBJECTIVE

An accurate evaluation of behavioral responsiveness during and after seizures in people with epilepsy is critical for diagnosis and management. Current methods for assessing behavioral responsiveness are characterized by substantial variation, subjectivity, and limited reliability and reproducibility in ambulatory and epilepsy monitoring unit settings. In this study, we aimed to develop and implement a novel mobile platform for deployment of automated responsiveness testing in epilepsy-the ARTiE Watch-to facilitate standardized, objective assessments of behavioral responsiveness during and after seizures.

METHODS

We prospectively recruited patients admitted to the epilepsy monitoring units for diagnostic evaluation and long-term video-electroencephalographic monitoring at Mayo Clinic and Yale New Haven Hospital. Participants wore the ARTiE Watch, a smartwatch paired with custom smartphone software integrated with cloud infrastructure allowing for remote activation of standardized assessment on the participants' smartwatches. The assessment consisted of 18 command prompts that test behavioral responsiveness across motor, language, and memory domains. Upon visually identifying an electrographic seizure during EMU monitoring, the BrainRISE platform was used to deploy the ARTiE Watch behavioral testing sequence. Responsiveness scoring was conducted on smartwatch files.

RESULTS

Eighteen of 56 participants had a total of 39 electrographic seizures assessed with the ARTiE Watch. The 18 subjects with ARTiE Watch-tested seizures had a total of 67 baseline (interictal) ARTiE Watch tests collected for analysis. The analysis showed distinct ARTiE Watch behavioral responsiveness phenotypes: (1) decreased responsiveness across all ARTiE Watch commands during seizure (ictal-postictal) periods compared (to baseline (p < .0001), (2) decreased responsiveness in bilateral tonic-clonic seizures compared to baseline (p < .0001) and compared to focal seizures (p < .0001), and (3) decreased responsiveness during focal impaired awareness seizures compared to baseline (p < .0001) and compared to focal aware seizures (p < .001).

SIGNIFICANCE

ARTiE Watch behavioral testing deployed utilizing a mobile cloud-based platform is feasible and can provide standardized, objective behavioral responsiveness assessments during seizures.

Can scent-detection dogs detect the stress associated with trauma cue exposure in people with trauma histories? A proof-of-concept study

Introduction

Post-traumatic stress disorder (PTSD) is an impairing mental health condition with high prevalence among military and general populations alike. PTSD service dogs are a complementary and alternative intervention needing scientific validation. We investigated whether dogs can detect putative stress-related volatile organic compounds (VOCs) in the breath of people with trauma histories (54% with PTSD) exposed to personalized trauma cues.

Methods

Breath samples were collected from 26 humans over 40 experimental sessions during a calm (control breath sample) and stressed state induced by trauma cue exposure (target breath sample). Two scent detection canines were presented with the samples in a two alternative forced choice (2AFC) discrimination and yes/no detection task. The 2AFC task assessed the dogs' ability to discriminate between the two states within the breath samples of one individual. The detection task determined their ability to generalize the target odour across different individuals and different stressful events of one individual. Signal Detection Theory was applied to assess dogs' sensitivity, specificity, precision, and response bias.

Results

The dogs performed at ∼90% accuracy across all sample sets in the discrimination experiment, and at 74% and 81% accuracy, respectively, in the detection experiment. Further analysis of dog olfactory performance in relation to human donor self-reported emotional responses to trauma cue exposure suggested the dogs may have been detecting distinct endocrine stress markers. One dog's performance correlated with the human donors' self-reported fear responses and the other dog's performance correlated with the human donors' self-reported shame responses. Based on these correlations between dog performance and donor self-report measures, we speculate that the VOCs each dog was detecting likely originated from the sympathetico-adreno-medullary axis (SAM; adrenaline, noradrenaline) in the case of the first dog and the hypothalamo-pituitary-adrenal axis (HPA; glucocorticoids) in the case of the second dog.

Conclusion

Our proof-of-concept study is the first to demonstrate that some dogs can detect putative VOCs emitted by people with trauma histories when experiencing distress theoretically associated with the intrusion and arousal/reactivity symptoms of PTSD. Results have potential to improve the effectiveness and training protocol of PTSD service dogs with a focus on enhancing their alert function.

The promises and pitfalls of seizure phenomenology

The typical adult patient presenting with a first seizure has a normal clinical examination, uninformative investigations, and often has no witness to their episode. The assessing clinician, therefore, has one primary source of information to guide their assessment; the patient's experience. However, seizure phenomenology - the subjective seizure experience - has received relatively less attention by researchers than objective semiology or investigations. This essay reviews the clinical importance of seizure phenomenology, and the challenges clinicians face in eliciting accurate and clinically relevant descriptions of ictal experience. I conclude by discussing tools that clinicians may use to support the clinical application of seizure phenomenology, and exploring the subjectivity of epilepsy more broadly.

Consciousness alteration in focal epilepsy is related to loss of signal complexity and information processing

Alteration of awareness is a main feature of focal epileptic seizures. In this work, we studied how the information contained in EEG signals was modified during temporal lobe seizures with altered awareness by using permutation entropy (PE) as a measure of the complexity of the signal. PE estimation was performed in thirty-six seizures of sixteen patients with temporal lobe epilepsy who underwent SEEG recordings. We tested whether altered awareness (based on the Consciousness Seizure Score) was correlated with a loss of signal complexity. We estimated global changes in PE as well as regional changes to gain insight into the mechanisms associated with awareness impairment. Our results reveal a positive correlation between the decrease of entropy and the consciousness score as well as the existence of a threshold on entropy that could discriminate seizures with no alteration of awareness from seizures with profound alteration of awareness. The loss of signal complexity was diffuse, extending bilaterally and to the associative cortices, in patients with profound alteration of awareness and limited to the temporal mesial structures in patients with no alteration of awareness. Thus PE is a promising tool to discriminate between the different subgroups of awareness alteration in TLE.

Evaluating consciousness and awareness during focal seizures: responsiveness testing versus recall testing

Objective

The current International League Against Epilepsy (ILAE) guidelines classify focal seizures based on awareness, defined as successful postictal recall of ictal experiences, and exclude the use of responsiveness during seizures for classification. One reason for this exclusion is that responsiveness was thought to not be commonly tested during seizures. Our goal was to determine whether, in at least some settings, responsiveness testing during seizures is relatively common.

Methods

We assessed how often responsiveness and recall were each evaluated in patients with focal epilepsy undergoing surface and intracranial EEG-video monitoring. We performed this evaluation by retrospectively reviewing video recordings from 121 seizures from 48 patients during their stay in the epilepsy monitoring unit between September 2012 and November 2019.

Results

We found that responsiveness during seizures was tested more frequently than recall of ictal events after seizures. Of 121 seizures in 48 patients, responsiveness was tested in 101 seizures, whereas recall was tested in only 38.

Significance

Evaluating if consciousness is impaired during seizures is of critical importance for guiding recommendations for people with epilepsy, such as whether it is safe for them to drive or operate machinery. The ILAE classification guidelines are intended to be broadly useful, but our findings demonstrate that at least in one important clinical setting, responsiveness was used more commonly than recall to evaluate patients during focal seizures. Although our preliminary findings should be replicated in a larger sample and in other patient groups, they suggest that responsiveness testing during focal seizures might be relatively common in at least some clinical practice settings. With further study, this may lead to a re-evaluation of criteria for classifying focal seizures to include both responsiveness and recall of experiences during seizures, as both may provide important information to guide clinical care.

Testing awareness in focal seizures: Clinical practice and interpretation of current guidelines

The International League Against Epilepsy (ILAE) classification of focal seizures uses recall of experiences post-ictally to assess for awareness and not ictal responsiveness to external stimuli, stating that responsiveness is often not tested. We investigated how clinicians assess for seizure awareness by administering an online survey. We found that most respondents use both responsiveness and recall to assess for awareness in the clinic (78%) and in the epilepsy monitoring unit (72%). Furthermore, 60% of respondents believe that the ILAE recommends using both measures. Given our results, we believe that using both responsiveness and recall would provide a more practical classification of impaired consciousness in focal seizures.