Continuous Electroencephalogram Research Articles

Utility of Clinical Features in Identifying Electrographic Seizures in Hospitalized Patients Admitted for Non-Neurological Diagnoses.

Electrographic seizures (ESz) are seizures without prominent motor activity diagnosed with electroencephalogram and are a common complication in critically ill patients with alterations of consciousness. Previous studies suggested clinical signs, including ocular movement abnormalities, facial/periorbital twitching, or remote seizure risk factors, are sensitive for presence of ESz. To assess the utility of clinical features in identifying ESz in critically ill patients with alterations of consciousness. This is a retrospective case-control study of 50 patients admitted to the University of North Carolina (UNC) Medical Center and UNC Rex Hospital. Inpatients older than 18 years old undergoing continuous video electroencephalogram (cEEG) were included. Patients admitted for neurologic diagnoses were excluded. A total of 25 patients with ESz (Sz-EEG) were matched with 25 controls by electroencephalogram duration ± 12 hours (No-Sz-EEG). Elements of patient's history and physical findings previously shown to be sensitive for presence of ESz were collected. Descriptive statistical analyses were used. Most patients were admitted to medical ICUs (72%; n = 36). There was no difference between groups in clinical findings previously shown to be sensitive for ESz. Positive and negative likelihood ratios for these findings generally fell between 1-2 and 0.5-1, respectively, indicating they are inaccurate predictors for ESz. Patients with ESz had significantly higher mortality (p = 0.012). Our matched case-control study showed that in the critically ill patient population hospitalized in tertiary care centers and admitted for non-neurologic primary diagnoses, incidence of ocular movement abnormalities, facial/periorbital twitching, and presence of remote risk factors for seizures had low predictive accuracy for ESz. However, these findings are not generalizable to patients with neurologic diseases or to other practice settings with different levels of access to cEEG. We concluded that in this exploratory analysis of hospitalized critically ill patients with non-neurologic diagnoses, these clinical signs did not reliably stratify risk for ESz on cEEG. However, further prospective studies are needed to better evaluate these conclusions.

Neuro-Behcet's Masquerading as Status Epilepticus and Meningoencephalitis in the Emergency Department

BackgroundBehcet disease (BD) is a rare small vessel vasculitis that commonly manifests as recurrent painful oral or genital ulcerations, uveitis, and skin lesions. Some patients with BD develop neurological symptoms termed neuro-Behcet's disease. In the emergency department (ED) setting, these symptoms can be mistaken for other common acute issues including stroke, infection, epilepsy, multiple sclerosis, toxin ingestion, or psychiatric conditions. Case ReportWe present a case of a 28-year-old male with neuro-Behcet disease mimicking status epilepticus and meningoencephalitis. He was actively seizing on arrival and febrile at 103.8 F. The patient also had a history of vasculitis, uveitis and genital lesions which raised suspicion for a rheumatological process. Cerebrospinal fluid (CSF) samples were obtained and computed tomography (CT) of the head revealed no acute findings. The patient was started on treatment for seizure and meningoencephalitis and admitted to neurology for continuous electroencephalogram (EEG) monitoring with additional consults placed for rheumatology, ophthalmology, and infectious disease. The patient was ultimately diagnosed with neuro-Behcet's disease and treated appropriately.Why should an emergency physician be aware of this?: In a patient presenting with neurological symptoms and signs of rheumatological disease providers should consider neuro-Behcet's disease as a differential diagnosis. This case exemplifies the vital role of reviewing past medical history to expand differential diagnoses and early coordination with specialists so treatment can be initiated early to prevent morbidity and mortality. The case will also review different presentations of this unfamiliar diagnosis for a more comprehensive understanding.

Cochlear Implant Artifacts in Continuous Electroencephalogram Recording.

Cochlear implants to aid sensorineural hearing loss are becoming commonplace. In this study, we describe two cases that showed artifacts related to the cochlear implant device during scalp EEG recording. To our knowledge, cochlear implant artifacts have not been reported previously. Recognizing cochlear implant artifacts will avoid misinterpretation and resultant inappropriate treatment.

Vigilant Attention During Cognitive and Language Processing in Aphasia.

Persons with aphasia (PWA) experience differences in attention after stroke, potentially impacting cognitive/language performance. This secondary analysis investigated physiologically measured vigilant attention during linguistic and nonlinguistic processing in PWA and control participants. To evaluate performance and attention in a language task, seven PWA read sentences aloud (linguistic task) and were compared to a previous data set of 10 controls and 10 PWA. To evaluate performance and attention in a language-independent task, 11 controls and nine PWA completed the Bivalent Shape Task (nonlinguistic task). Continuous electroencephalogram (EEG) data were collected during each session. A previously validated EEG algorithm classified vigilant-attention state for each experiment trial into high, moderate, distracted, or no attention. Dependent measures were task accuracy and amount of time spent in each attention state (measured by the number of trials). PWA produced significantly more errors than controls on the linguistic task, but groups performed similarly on the nonlinguistic task. During the linguistic task, controls spent significantly more time than PWA in a moderate-attention state, but no statistically significant differences were found between groups for other attention states. For the nonlinguistic task, amount of time controls and PWA spent in each attention state was more evenly distributed. When directly comparing attention patterns between linguistic and nonlinguistic tasks, PWA showed significantly more time in a high-attention state during the linguistic task as compared to the nonlinguistic task; however, controls showed no significant differences between linguistic and nonlinguistic tasks. This study provides new evidence that PWA experience a heightened state of vigilant attention when language processing demands are higher (during a linguistic task) than when language demands are lower (during a nonlinguistic task). Collectively, results of this study suggest that when processing language, PWA may allocate more attentional resources than when completing other kinds of cognitive tasks.

ICU-Electroencephalogram Unit Improves Outcome in Status Epilepticus Patients: A Retrospective Before-After Study.

Continuous electroencephalogram (cEEG) monitoring is recommended for status epilepticus (SE) management in ICU but is still underused due to resource limitations and inconclusive evidence regarding its impact on outcome. Furthermore, the term "continuous monitoring" often implies continuous recording with variable intermittent review. The establishment of a dedicated ICU-electroencephalogram unit may fill this gap, allowing cEEG with nearly real-time review and multidisciplinary management collaboration. This study aimed to evaluate the effect of ICU-electroencephalogram unit establishing on SE outcome and management. Single-center retrospective before-after study. Neuro-ICU of a Swiss academic tertiary medical care center. Adult patients treated for nonhypoxic SE between November 1, 2015, and December 31, 2023. None. Data from all SE patients were assessed, comparing those treated before and after ICU-electroencephalogram unit introduction. Primary outcomes were return to premorbid neurologic function, ICU mortality, SE duration, and ICU SE management. Secondary outcomes were SE type and etiology. Two hundred seven SE patients were included, 149 (72%) before and 58 (38%) after ICU-electroencephalogram unit establishment. ICU-electroencephalogram unit introduction was associated with increased detection of nonconvulsive SE ( p = 0.003) and SE due to acute symptomatic etiology ( p = 0.019). Regression analysis considering age, comorbidities, SE etiology, and SE semeiology revealed a higher chance of returning to premorbid neurologic function ( p = 0.002), reduced SE duration ( p = 0.024), and a shift in SE management with increased use of antiseizure medications ( p = 0.007) after ICU-electroencephalogram unit introduction. Integrating neurology expertise in the ICU setting through the establishment of an ICU-electroencephalogram unit with nearly real-time cEEG review, shortened SE duration, and increased likelihood of returning to premorbid neurologic function, with an increased number of antiseizure medications used. Further studies are warranted to validate these findings and assess long-term prognosis.

A Wirelessly Powered Scattered Neural Recording Wearable System.

This paper introduces a wirelessly powered scattered neural recording wearable system that can facilitate continuous, untethered, and long-term electroencephalogram (EEG) recording. The proposed system, including 32 standalone EEG recording devices and a central controller, is incorporated in a wearable form factor. The standalone devices are sparsely distributed on the scalp, allowing for flexible placement and varying quantities to provide extensive spatial coverage and scalability. Each standalone device featuring a low-power EEG recording application-specific integrated circuit (ASIC) wirelessly receives power through a 60 MHz inductive link. The low-power ASIC design (84.6 μW) ensures sufficient wireless power reception through a small receiver (Rx) coil. The 60 MHz inductive link also serves as the data carrier for wireless communication between standalone devices and the central controller, eliminating the need for additional data antennas. All these efforts contribute to the miniaturization of standalone devices with dimensions of 12×12×5 mm3, enhancing device wearability. The central controller applies the pulse width modulation (PWM) scheme on the 60 MHz carrier, transmitting user commands at 4 Mbps to EEG recording ASICs. The ASIC employs a novel synchronized PWM demodulator to extract user commands, operating signal digitization and data transmission. The analog frontend (AFE) amplifies the EEG signal with a gain of 45 dB and applies band-pass filtering from 0.03 Hz to 400 Hz, with an input-referred noise (IRN) of 3.62 μVRMS. The amplified EEG signal is then digitized by a 10-bit successive approximation register (SAR) analog-to-digital converter (ADC) with a peak signal-to-noise and distortion ratio (SNDR) of 55.4 dB. The resulting EEG data is transmitted to an external software-defined radio (SDR) Rx through load-shift-keying (LSK) backscatter at 3.75 Mbps. The system's functionality is fully evaluated in human experiments.

Incidence of seizures in ICU patients with diffuse encephalopathy and its predictors.

Encephalopathy is a diffuse brain dysfunction that results from systemic disorder. Patients with diffuse encephalopathy are at risk of developing clinical and electrographic seizures. The aim of this study is to assess the prevalence of electrographic seizures in a setting of encephalopathy and the clinical and electroencephalogram predictors. We retrospectively reviewed all continuous electroencephalograms done between 2019 and 2022. Continuous electroencephalograms with diffuse encephalopathy were included in the study. A total of 128 patients with diffuse encephalopathy were included in this study. Patients' ages ranged from 18 to 96 years old with a mean age of 55.3 ± 19.2 years old. Nine out of 128 patients had seizures with an incidence of 7%. Sixty-six point six percent were nonconvulsive electrographic seizures. Fourteen point three percent of the female patients with diffuse encephalopathy had seizures as compared to none of the male patients (P = .002). Also, 12% of patients with a history of epilepsy experienced seizures versus 5.8% of patients without this history (P = .049). Among electrographic features, 25% of patients with delta background had seizures versus 2.3% of the other patients (P = .048). Likewise, 90% of patients with periodic discharges developed seizures in comparison with none of the patients without (P = .001). Seizures are seen in 7% of patients with diffuse encephalopathy. Female gender, past history of epilepsy, delta background and periodic discharges are significant predictors of seizure development in patients with diffuse encephalopathy.

Practice Variations for Therapeutic Hypothermia in Neonates with Hypoxic-ischemic Encephalopathy: An International Survey

To evaluate variations in management of therapeutic hypothermia (TH) for neonatal hypoxic-ischemic encephalopathy (HIE) among international clinical sites and to identify areas for harmonization. An electronic survey was sent to Children's Hospitals Neonatal Consortium site sponsors, Canadian Neonatal Network site investigators, members of the Newborn Brain Society, and American Academy of Pediatrics Neonatology chiefs. One hundred five sites responded, with most from high-income regions (n=95). Groupings were adapted from the United Nations regional groups: US (n=52 sites); Canada (n=20); Western Europe and other states excluding Canada and US Group (WEOG, n=18); and non-WEOG (central and eastern Europe, Asia, Africa, Latin America, and Caribbean, n=15). Regional variations were seen in the eligibility criteria for TH, such as the minimum gestational age, grading of HIE severity, use of electroencephalography, and the frequency of providing TH for mild HIE. Active TH during transport varied among regions and was less likely in smaller volume sites. Amplitude-integrated electroencephalogram and/or continuous electroencephalogram to determine eligibility for TH was used by most sites in WEOG and non-WEOG but infrequently by the US and Canada Groups. For sedation during TH, morphine was most frequently used as first choice but there was relatively high (33%) use of dexmedetomidine in the US Group. Timing of brain magnetic resonance imaging and neurodevelopmental follow-up were variable. Neurodevelopmental follow occurred earlier and more frequently, although for a shorter duration, in the non-WEOG. We found significant variations in practices for TH for HIE across regions internationally. Future guidelines should incorporate resource availability in a global perspective.

Continuous Electroencephalogram (cEEG) Findings and Neurodevelopmental Outcomes in Neonates with Congenital Heart Disease (CHD) at 12-24 Months of Age.

This study aims to assess the role of continuous EEG (cEEG) background patterns and duration of cross-clamp time and cardiopulmonary bypass (CPB) in children with congenital heart disease (CHD) undergoing cardiac surgery and its correlation with abnormal neurodevelopmental outcomes at 12-24 months on Bayley Scales of Infant and Toddler Development (BSID-III). This retrospective cohort study included infants with CHD and cEEG monitoring, who underwent surgery by 44 weeks gestational age. 34 patients were included, who were operated at median age - 7 days. Longer duration of cross- camp time was associated with poor language composite scores (LCS) (p value = 0.036). A significant association existed between severity of encephalopathy in 24-hour post-operative period and poor LCS (p value = 0.026). Majority of neonates with CHD have below average cognitive, language and motor composite scores on BSID-III. Longer duration of cross-clamp time and severity of encephalopathy during 24-hour post-operative EEG monitoring are associated with poor LCS.

End-to-end model for automatic seizure detection using supervised contrastive learning

Epilepsy is a chronic neurological disorder characterized by recurrent and unpredictable seizures, caused by abnormal electrical activity in cerebral neurons. Given that it is one of the most common neurological disorders globally, the efficient and accurate automatic seizure detection is urgently needed in the diagnosis of epilepsy to reduce the workload of continuous electroencephalogram (EEG) monitoring. Current deep learning based seizure detection approaches usually employ cross-entropy loss as objective function, which generally suffer from inadequate utilization of sample labels and poor classification margins, resulting in decreased performance in seizure detection. In this study, we propose an end-to-end automatic seizure detection framework based on supervised contrastive learning, which effectively utilizes labeled EEG to cluster similar samples while separating dissimilar ones. A supervised contrastive learning loss is employed to optimize classification boundaries by making full use of EEG labels. We employ long-term continuous EEG for evaluation. Given the presence of various noise and interferences, assessment on long-term continuous EEG proves to be more challenging. Post-processing techniques such as smoothing filter, threshold judgment, and collar technique are further adopted to diminish the artifact impacts on seizure detection performance. The proposed method is evaluated on the publicly available Children's Hospital Boston and the Massachusetts Institute of Technology (CHB-MIT) scalp EEG dataset, achieving an event-based sensitivity of 99.71% and a false detection rate (FDR) of 0.35/h.

Cerebral malaria presenting as nonconvulsive status epilepticus: a case report

BackgroundMalaria is an infectious malady caused by Plasmodium parasites, cerebral malaria standing out as one of its most severe complications. Clinical manifestation include elevated body temperature, loss of consciousness, and seizures. However, reports of cerebral malaria presenting as nonconvulsive status epilepticus are extremely rare. The case presented involves psychiatric symptoms, with the electroencephalogram indicated nonconvulsive status epilepticus associated with cerebral malaria.Case presentationA 53-year-old male, was urgently admitted, due to confusion and abnormal behaviour for 10 h. The patient returned to China after developing a fever while working in Tanzania two months ago. The blood smear revealed Plasmodium vivax and Plasmodium falciparum, and he was diagnosed with malaria. He recovered following anti-malarial treatment. After admission, the patient was confused, unable to communicate normally, and unwilling to cooperate with the physical examination. Plasmodium was not found in the blood smear, but the DNA sequence of P. falciparum was discovered using metagenomic next-generation sequencing of cerebrospinal fluid. Brain MRI revealed no significant abnormalities. Continuous electroencephalogram monitoring revealed that the patient had non-convulsive status epilepticus, which was treated with diazepam and levetiracetam. The patient had normal consciousness and behaviour. He received anti-malarial treatment for two weeks and fully recovered.ConclusionsThis case demonstrates that nonconvulsive status epilepticus can be a manifestation of cerebral malaria. It is imperative for attending physicians to heighten vigilance when encountering patients with a history of travel to malaria-endemic regions or a prior malaria infection, especially in the presence of unusual clinical presentations.

Seizure prediction based on improved vision transformer model for EEG channel optimization

Epileptic seizures are unpredictable events caused by abnormal discharges of a patient’s brain cells. Extensive research has been conducted to develop seizure prediction algorithms based on long-term continuous electroencephalogram (EEG) signals. This paper describes a patient-specific seizure prediction method that can serve as a basis for the design of lightweight, wearable and effective seizure-prediction devices. We aim to achieve two objectives using this method. The first aim is to extract robust feature representations from multichannel EEG signals, and the second aim is to reduce the number of channels used for prediction by selecting an optimal set of channels from multichannel EEG signals while ensuring good prediction performance. We design a seizure-prediction algorithm based on a vision transformer (ViT) model. The algorithm selects channels that play a key role in seizure prediction from 22 channels of EEG signals. First, we perform a time-frequency analysis of processed time-series signals to obtain EEG spectrograms. We then segment the spectrograms of multiple channels into many non-overlapping patches of the same size, which are input into the channel selection layer of the proposed model, named Sel-JPM-ViT, enabling it to select channels. Application of the Sel-JPM-ViT model to the Boston Children’s Hospital–Massachusetts Institute of Technology scalp EEG dataset yields results using only three to six channels of EEG signals that are slightly better that the results obtained using 22 channels of EEG signals. Overall, the Sel-JPM-ViT model exhibits an average classification accuracy of 93.65%, an average sensitivity of 94.70% and an average specificity of 92.78%.

The diagnostic yield of a 2-h versus a 30-min electroencephalogram for patients with altered mental status in neurological intensive care unit

BackgroundThe continuous electroencephalogram (cEEG) monitoring is recommended for critical ill patients with altered mental status, The cEEG detects seizure activity and nonconvulsive status epilepticus (NCSE) more efficiently than routine electroencephalogram (rEEG). Yet, cEEG is not widely available in many neurological intensive care units (NICU) in limited resource countries. Ideal study duration, and whether cEEG is useful and cost-effective in terms of patient outcome compared to (rEEG), is still questions under research. The main objective in our study was the relative diagnostic yield of the 2 h, prolonged EEG recording, compared to the 30-min rEEG recording in the NICU.ResultsThere was no significant diagnostic yield for the 2-h electroencephalogram (EEG) over the 30-min EEG for patient with altered mental status in the NICU. Being with altered mental state in an NICU carries a poor outcome, we found that death occurred in 68.9% of patients. Acute ischemic stroke is the most common cause of altered mental status in NICU by about 53.3% of patients. Less than half of the patients (42.2%) were receiving anti-seizure medications (ASM).ConclusionsAs long as the cEEG is not available in the NICU, the 30-min EEG has a good diagnostic yield and it is almost equivalent to the prolonged 2-h EEG, and if the EEG is recommended for a longer duration, we recommend a long-term EEG more than 2 h.

Relationship of Neonatal Seizure Burden Before Treatment and Response to Initial Antiseizure Medication

To assess among a cohort of neonates with hypoxic-ischemic encephalopathy (HIE) the association of pretreatment maximal hourly seizure burden and total seizure duration with successful response to initial antiseizure medication (ASM). This was a retrospective review of data collected from infants enrolled in the HEAL Trial (NCT02811263) between January 25, 2017, and October 9, 2019. We evaluated a cohort of neonates born at ≥36weeks of gestation with moderate-to-severe HIE who underwent continuous electroencephalogram monitoring and had acute symptomatic seizures. Poisson regression analyzed associations between (1) pretreatment maximal hourly seizure burden, (2) pretreatment total seizure duration, (3) time from first seizure to initial ASM, and (4) successful response to initial ASM. Among 39 neonates meeting inclusion criteria, greater pretreatment maximal hourly seizure burden was associated with lower chance of successful response to initial ASM (adjusted relative risk for each 5-minute increase in seizure burden 0.83, 95% CI 0.69-0.99). There was no association between pretreatment total seizure duration and chance of successful response. Shorter time-to-treatment was paradoxically associated with lower chance of successful response to treatment, although this difference was small in magnitude (relative risk 1.007, 95% CI 1.003-1.010). Maximal seizure burden may be more important than other, more commonly used measures in predicting response to acute seizure treatments.

Dexmedetomidine Sedation in Dogs: Impact on Electroencephalography, Behavior, Analgesia, and Antagonism with Atipamezole.

This study aimed to assess the impact of dexmedetomidine constant rate infusion (CRI) on key parameters in dogs. Six dogs received a 60 µg/kg/h dexmedetomidine infusion over 10 min, followed by three 15 min decremental CRIs (3, 2, and 1 µg/kg/h). A subsequent reversal phase employed 600 µg/kg/h atipamezole over 5 min. Continuous electroencephalogram (EEG) assessment, and cardiorespiratory and analgesia monitoring (every 3 min) were conducted, including analgesia evaluation through responses to electric stimulation. Dexmedetomidine induced profound sedation, evidenced by lateral recumbency and immobility. Patient State Index (PSI) decreased from awake (90.4 ± 4.3) to Phase 1 (50.9 ± 30.7), maintaining sedation (29.0 ± 18.1 to 33.1 ± 19.1 in Phases 2-4). Bradycardia (37.8 ± 3.5 bpm, lowest at Phase 3) and hypertension (133.7 ± 17.0 mmHg, highest at Phase 1) were observed, with minimal analgesia. Atipamezole promptly reversed sedation, restoring cognitive function (tail wagging behavior), and normalizing cardiovascular parameters. During atipamezole CRI, the EEG exhibited a transition from delta waves to alpha and low beta waves. This transition was observed alongside gradual increases in PSI and electromyographic activities. Additionally, spindle activities disappeared during this process. This study's results suggest potential clinical utility for EEG-guided dexmedetomidine sedation with reversal using atipamezole, warranting further investigation.

EEG brain network variability is correlated with other pathophysiological indicators of critical patients in neurology intensive care unit

Continuous electroencephalogram (cEEG) plays a crucial role in monitoring and postoperative evaluation of critical patients with extensive EEG abnormalities. Recently, the temporal variability of dynamic resting-state functional connectivity has emerged as a novel approach to understanding the pathophysiological mechanisms underlying diseases. However, little is known about the underlying temporal variability of functional connections in critical patients admitted to neurology intensive care unit (NICU). Furthermore, considering the emerging field of network physiology that emphasizes the integrated nature of human organisms, we hypothesize that this temporal variability in brain activity may be potentially linked to other physiological functions. Therefore, this study aimed to investigate network variability using fuzzy entropy in 24-hour dynamic resting-state networks of critical patients in NICU, with an emphasis on exploring spatial topology changes over time. Our findings revealed both atypical flexible and robust architectures in critical patients. Specifically, the former exhibited denser functional connectivity across the left frontal and left parietal lobes, while the latter showed predominantly short-range connections within anterior regions. These patterns of network variability deviating from normality may underlie the altered network integrity leading to loss of consciousness and cognitive impairment observed in these patients. Additionally, we explored changes in 24-hour network properties and found simultaneous decreases in brain efficiency, heart rate, and blood pressure between approximately 1 pm and 5 pm. Moreover, we observed a close relationship between temporal variability of resting-state network properties and other physiological indicators including heart rate as well as liver and kidney function. These findings suggest that the application of a temporal variability-based cEEG analysis method offers valuable insights into underlying pathophysiological mechanisms of critical patients in NICU, and may present novel avenues for their condition monitoring, intervention, and treatment.

Errors elicit frontoparietal theta-gamma coupling that is modulated by endogenous estradiol levels

Cognitive control-related error monitoring is intimately involved in behavioral adaptation, learning, and individual differences in a variety of psychological traits and disorders. Accumulating evidence suggests that a focus on women's health and ovarian hormones is critical to the study of such cognitive brain functions. Here we sought to identify a novel index of error monitoring using a time-frequency based phase amplitude coupling (t-f PAC) measure and examine its modulation by endogenous levels of estradiol in females. Forty-three healthy, naturally cycling young adult females completed a flanker task while continuous electroencephalogram was recorded on four occasions across the menstrual cycle. Results revealed significant error-related t-f PAC between theta phase generated in fronto-central areas and gamma amplitude generated in parietal-occipital areas. Moreover, this error-related theta-gamma coupling was enhanced by endogenous levels of estradiol both within females across the cycle as well as between females with higher levels of average circulating estradiol. While the role of frontal midline theta in error processing is well documented, this paper extends the extant literature by illustrating that error monitoring involves the coordination between multiple distributed systems with the slow midline theta activity modulating the power of gamma-band oscillatory activity in parietal regions. They further show enhancement of inter-regional coupling by endogenous estradiol levels, consistent with research indicating modulation of cognitive control neural functions by the endocrine system in females. Together, this work identifies a novel neurophysiological marker of cognitive control-related error monitoring in females that has implications for neuroscience and women's health.

Low-Intensity Focused Ultrasound to the Human Dorsal Anterior Cingulate Attenuates Acute Pain Perception and Autonomic Responses.

The dorsal anterior cingulate cortex (dACC) is a critical brain area for pain and autonomic processing, making it a promising noninvasive therapeutic target. We leverage the high spatial resolution and deep focal lengths of low-intensity focused ultrasound (LIFU) to noninvasively modulate the dACC for effects on behavioral and cardiac autonomic responses using transient heat pain stimuli. A N = 16 healthy human volunteers (6 M/10 F) received transient contact heat pain during either LIFU to the dACC or Sham stimulation. Continuous electroencephalogram (EEG), electrocardiogram (ECG), and electrodermal response (EDR) were recorded. Outcome measures included pain ratings, heart rate variability, EDR response, blood pressure, and the amplitude of the contact heat-evoked potential (CHEP).LIFU reduced pain ratings by 1.09 ± 0.20 points relative to Sham. LIFU increased heart rate variability indexed by the standard deviation of normal sinus beats (SDNN), low-frequency (LF) power, and the low-frequency/high-frequency (LF/HF) ratio. There were no effects on the blood pressure or EDR. LIFU resulted in a 38.1% reduction in the P2 CHEP amplitude. Results demonstrate LIFU to the dACC reduces pain and alters autonomic responses to acute heat pain stimuli. This has implications for the causal understanding of human pain and autonomic processing in the dACC and potential future therapeutic options for pain relief and modulation of homeostatic signals.

Assessing risk factors associated with breakthrough early post-traumatic seizures in patients receiving phenytoin prophylaxis.

Post-traumatic seizure (PTS) is a well-known complication of traumatic brain injury (TBI). The objective of this study was to identify risk factors associated with breakthrough early PTS in TBI patients receiving phenytoin prophylaxis. This was a single-centered retrospective study including adult patients admitted to the intensive care unit (ICU), had a TBI, and started on phenytoin for seizure prophylaxis within 24 h of admission. The primary outcome was the incidence and factors associated with early PTS, defined as a confirmed seizure on a continuous electroencephalogram within 7 days of TBI. Secondary outcomes included the association between early post-traumatic seizures and ICU length of stay, hospital length of stay, and in-hospital mortality. A total of 105 patients were included in the final analysis. Patients with early PTS were older (65 vs. 48 years old, p = 0.01), had a higher Marshall score (5 vs. 2, p = 0.01), were more likely to have a Marshall score > 2 (73 vs. 37%, p = 0.01), and had more neurosurgeries for hematoma evacuation (57 vs. 19%, p = 0.01). In patients with early PTS, 57% had a level at the time of seizure, and of those, 87.5% had a therapeutic level (>10 mcg/mL). Patients with early PTS had a longer ICU length of stay (14.7 vs. 5.9 days, p = 0.04) and a greater proportion of hospital mortality (21 vs. 2%, p = 0.02). Patients with higher age, Marshall score, and neurosurgical procedures for hematoma evacuation had higher incidences of breakthrough early PTS despite the use of phenytoin prophylaxis. The majority of patients with early PTS had therapeutic phenytoin levels at the time of seizure when a level was available; however, approximately half (43%) did not have a level.

Cardiac Abnormalities in Refractory Status Epilepticus-an Exploratory Study.

Cardiac abnormalities have been reported during ongoing seizures and refractory status epilepticus (RSE). Reduced heart rate variability (HRV) and cardiac arrhythmias may contribute to sudden unexpected death in epilepsy. We sought to explore the utility of electrocardiographic and echocardiographic changes in patients with RSE prognosis and functional outcome. Patients of RSE underwent electrocardiogram (ECG), holter, troponin-I (Trop I), N-terminal prohormone of brain natriuretic peptide (NT-proBNP), and 2-dimensional echocardiogram (2D Echo) along with continuous electroencephalogram in first 24 hours and admission. Heart rate changes/arrhythmias, corrected QT interval (QTc) and HRV, ventricular dysfunction or regional motion wall abnormality were studied on 2D Echo. These parameters were also at baseline, at discharge or death and 30 days post discharge. This prospective observational study conducted over 18 months enrolled 20 patients with RSE, fulfilling the inclusion criteria. Mean age was 47.75±17.2 years with male: female ratio of 1:1. Mean time to presentation from seizure onset was 8.80±7.024 hours. Central nervous system infection (35.0%), autoimmune encephalitis (20.0%) and cerebrovascular disease (20.0%) were the common etiologies. Amongst cardiac injury markers, cardiac enzymes and QTc prolongation were the commonest abnormalities in RSE. Both reduced HRV and presence of cardiac injury markers had significant correlation with poor outcome along with poor Glasgow coma scale (GCS) and modified Rankin scale (mRS) at presentation, and presence of non convulsive status epilepticus (NCSE). Presence of poor GCS, poor mRS, markers of cardiac injury, reduced HRV and occurrence of NCSE have a consistent correlation with mortality and poor clinical outcome. Therefore, routine assessment of cardiac abnormalities using affordable, easily accessible and non-invasive tools such as ECG, 2D Echo, holter NT-proBNP and Trop I is recommended in RSE patients.