Importance of access to epilepsy monitoring units during the COVID-19 pandemic: consensus statement of the International League Against Epilepsy and the International Federation of Clinical Neurophysiology.

Restructuring of healthcare services during the COVID-19 pandemic has led to lockdown of epilepsy monitoring units (EMUs) in many hospitals. The ad-hoc taskforce of the International League Against Epilepsy (ILAE) and the International Federation of Clinical Neurophysiology (IFCN) highlights the detrimental effect of postponing video-EEG monitoring of patients with epilepsy and other paroxysmal events. The taskforce calls for action for continued functioning of EMUs during emergency situations, such as the COVID-19 pandemic. Long-term video-EEG monitoring is an essential diagnostic service. Access to video-EEG monitoring of the patients in the EMUs must be given high priority. Patients should be screened for COVID-19, before admission, according to the local regulations. Local policies for COVID-19 infection control should be adhered to during the video-EEG monitoring. In cases of differential diagnosis in which reduction of antiseizure medication is not required, home video-EEG monitoring should be considered as an alternative in selected patients.

Neurophysiological assessment in a patient affected by Marfan syndrome.

BACKGROUND: Marfan syndrome (MS) is a hereditary connective tissue disorder characterized by different multiorgan patterns. The guidelines for MS diagnosis do not highlight the usefulness-or even the use-of any neurophysiological techniques for diagnosing this disease. Moreover, few neurophysiological studies assessing the central and peripheral nervous systems in MS subjects have been reported to date.Case presentation: We describe a male patient affected by MS. To assess sensory and nociceptive pathways in this patient, a neurophysiological assessment was performed using electroencephalogram, nerve conduction studies, and somatosensory and laser-evoked potentials. To the best of our knowledge, this is the first published case report to evaluate the role of evoked potential assessments for the study of sensory and nociceptive pathways in MS. CONCLUSION: Future studies should investigate the use of a complete neurophysiological approach for the clinical and therapeutic management of MS patients in a large sample.

Cost-effectiveness analysis of multimodal prognostication in cardiac arrest with EEG monitoring.

OBJECTIVE: To determine cost-effectiveness parameters for EEG monitoring in cardiac arrest prognostication. METHODS: We conducted a cost-effectiveness analysis to estimate the cost per quality-adjusted life-year (QALY) gained by adding continuous EEG monitoring to standard cardiac arrest prognostication using the American Academy of Neurology Practice Parameter (AANPP) decision algorithm: neurologic examination, somatosensory evoked potentials, and neuron-specific enolase. We explored lifetime cost-effectiveness in a closed system that incorporates revenue back into the medical system (return) from payers who survive a cardiac arrest with good outcome and contribute to the health system during the remaining years of life. Good outcome was defined as a Cerebral Performance Category (CPC) score of 1-2 and poor outcome as CPC of 3-5. RESULTS: An improvement in specificity for poor outcome prediction of 4.2% would be sufficient to make continuous EEG monitoring cost-effective (baseline AANPP specificity = 83.9%). In sensitivity analysis, the effect of increased sensitivity on the cost-effectiveness of EEG depends on the utility (u) assigned to a poor outcome. For patients who regard surviving with a poor outcome (CPC 3-4) worse than death (u = -0.34), an increased sensitivity for poor outcome prediction of 13.8% would make AANPP + EEG monitoring cost-effective (baseline AANPP sensitivity = 76.3%). In the closed system, an improvement in sensitivity of 1.8% together with an improvement in specificity of 3% was sufficient to make AANPP + EEG monitoring cost-effective, assuming lifetime return of 50% (USD $70,687). CONCLUSION: Incorporating continuous EEG monitoring into cardiac arrest prognostication is cost-effective if relatively small improvements in sensitivity and specificity are achieved.

Current status of pediatric neurocritical care in Argentina. / Estado actual del soporte neurológico crítico en pediatría en la Argentina.

INTRODUCTION: Patients with neurocritical injuries account for 10-16 % of pediatric intensive care unit (PICU) admissions and frequently require neuromonitoring. OBJECTIVE: To describe the current status of neuromonitoring in Argentina. METHODS: Survey with 37 questions about neuromonitoring without including patients' data. Period: April-June 2017. RESULTS: Thirty-eight responses were received out of 71 requests (14 districts with 11 498 annual discharges). The PICU/hospital bed ratio was 21.9 (range: 4.2-66.7). Seventy-four percent of PICUs were public; 61 %, university-affiliated; and 71 %, level I. The availability of monitoring techniques was similar between public and private (percentages): intracranial pressure (95), electroencephalography (92), transcranial Doppler (53), evoked potentials (50), jugular saturation (47), and bispectral index (11). Trauma was the main reason for monitoring. CONCLUSION: Except for intracranial pressure and electroencephalography, neuromonitoring resources are scarce and active neurosurgery availability is minimal. A PICU national registry is required.

Introducción. Los pacientes con lesiones neurocríticas representan el 10-16 % de los ingresos a unidades de cuidados intensivos pediátricas (UCIP) y, frecuentemente, requieren neuromonitoreo. Objetivo. Describir el estado actual del neuromonitoreo en la Argentina. Métodos. Encuesta con 37 preguntas sobre neuromonitoreo sin incluir datos de pacientes. Período: abril-junio, 2017. Resultados. Se recibieron 38 respuestas a 71 solicitudes (14 distritos con 11 498 egresos anuales). La relación camas de UCIP/hospitalarias fue 21,9 (rango: 4,2-66,7). El 74 % fueron públicas; el 61 %, universitarias, y el 71 %, nivel 1. La disponibilidad fue similar entre públicas y privadas (porcentajes): presión intracraneana (95), electroencefalografía (92), doppler transcraneano (53), potenciales evocados (50), saturación yugular (47) e índice bispectral (11). El principal motivo de monitoreo fue trauma. Conclusión. Excepto la presión intracraneana y la electroencefalografía, los recursos de neuromonitoreo son escasos y la disponibilidad de neurocirugía activa es mínima. Se necesita un registro nacional de UCIP.

Intraoperative neuromonitoring for one-level lumbar discectomies is low yield and cost-ineffective.

BACKGROUND: Intraoperative neuromonitoring is a common, well-established modality used in spine surgery to prevent intraoperative neural injury. Neuromonitoring use in lumbar discectomy, however, is based on surgeon preference, without evidence-based data. The purpose of this research was to determine intraoperative utility and overall cost effectiveness of neuromonitoring for lumbar discectomy. METHODS: We retrospectively reviewed adult patients who underwent a lumbar discectomy, with at least 1 month of follow-up at a single tertiary care center. Patient age, sex, body mass index (BMI), lumbar level operated, and operative time and cost were collected. Neuromonitoring and operative reports were reviewed for any electromyography (EMG) abnormalities noted intraoperatively, pre- and post-operative motor exam and post-operative pain relief were collected. RESULTS: Ninety-one (47 with and 44 without neuromonitoring) lumbar discectomy cases were reviewed. There was no significant difference between mean age, sex, and BMI between the two groups. There was a significant (p = 0.006) increase in operating room time (174 min; with vs. 144 min; without neuromonitoring). Neuromonitoring was associated with a significant (p = 0.006) overall operative cost ($21,949; with vs. $18,064; without). Of the 47 cases with neuromonitoring; one had abnormal intraoperative EMG activity, which returned to normal by case conclusion. No patient in either group demonstrated new post-operative motor weakness. There was no difference in the number of patients who endorsed post-operative pain relief between the two groups. CONCLUSIONS: Neuromonitoring for lumbar discectomy confers greater operative time and cost, without any difference in neurological outcome.

A standardised assessment scheme for conventional EEG in preterm infants.

OBJECTIVE: To develop a standardised scheme for assessing normal and abnormal electroencephalography (EEG) features of preterm infants. To assess the interobserver agreement of this assessment scheme. METHODS: We created a standardised EEG assessment scheme for 6 different post-menstrual age (PMA) groups using 4 EEG categories. Two experts, not involved in the development of the scheme, evaluated this on 24 infants <32 weeks gestational age (GA) using random 2 hour EEG epochs. Where disagreements were found, the features were checked and modified. Finally, the two experts independently evaluated 2 hour EEG epochs from an additional 12 infants <37 weeks GA. The percentage of agreement was calculated as the ratio of agreements to the sum of agreements plus disagreements. RESULTS: Good agreement in all patients and EEG feature category was obtained, with a median agreement between 80% and 100% over the 4 EEG assessment categories. No difference was found in agreement rates between the normal and abnormal features (p = 0.959). CONCLUSIONS: We developed a standard EEG assessment scheme for preterm infants that shows good interobserver agreement. SIGNIFICANCE: This will provide information to Neonatal Intensive Care Unit (NICU) staff about brain activity and maturation. We hope this will prove useful for many centres seeking to use neuromonitoring during critical care for preterm infants.

Global Survey of Outcomes of Neurocritical Care Patients: Analysis of the PRINCE Study Part 2.

BACKGROUND: Neurocritical care is devoted to the care of critically ill patients with acute neurological or neurosurgical emergencies. There is limited information regarding epidemiological data, disease characteristics, variability of clinical care, and in-hospital mortality of neurocritically ill patients worldwide. We addressed these issues in the Point PRevalence In Neurocritical CarE (PRINCE) study, a prospective, cross-sectional, observational study. METHODS: We recruited patients from various intensive care units (ICUs) admitted on a pre-specified date, and the investigators recorded specific clinical care activities they performed on the subjects during their first 7 days of admission or discharge (whichever came first) from their ICUs and at hospital discharge. In this manuscript, we analyzed the final data set of the study that included patient admission characteristics, disease type and severity, ICU resources, ICU and hospital length of stay, and in-hospital mortality. We present descriptive statistics to summarize data from the case report form. We tested differences between geographically grouped data using parametric and nonparametric testing as appropriate. We used a multivariable logistic regression model to evaluate factors associated with in-hospital mortality. RESULTS: We analyzed data from 1545 patients admitted to 147 participating sites from 31 countries of which most were from North America (69%, N = 1063). Globally, there was variability in patient characteristics, admission diagnosis, ICU treatment team and resource allocation, and in-hospital mortality. Seventy-three percent of the participating centers were academic, and the most common admitting diagnosis was subarachnoid hemorrhage (13%). The majority of patients were male (59%), a half of whom had at least two comorbidities, and median Glasgow Coma Scale (GCS) of 13. Factors associated with in-hospital mortality included age (OR 1.03; 95% CI, 1.02 to 1.04); lower GCS (OR 1.20; 95% CI, 1.14 to 1.16 for every point reduction in GCS); pupillary reactivity (OR 1.8; 95% CI, 1.09 to 3.23 for bilateral unreactive pupils); admission source (emergency room versus direct admission [OR 2.2; 95% CI, 1.3 to 3.75]; admission from a general ward versus direct admission [OR 5.85; 95% CI, 2.75 to 12.45; and admission from another ICU versus direct admission [OR 3.34; 95% CI, 1.27 to 8.8]); and the absence of a dedicated neurocritical care unit (NCCU) (OR 1.7; 95% CI, 1.04 to 2.47). CONCLUSION: PRINCE is the first study to evaluate care patterns of neurocritical patients worldwide. The data suggest that there is a wide variability in clinical care resources and patient characteristics. Neurological severity of illness and the absence of a dedicated NCCU are independent predictors of in-patient mortality.

Feasibility of individualised severe traumatic brain injury management using an automated assessment of optimal cerebral perfusion pressure: the COGiTATE phase II study protocol.

INTRODUCTION: Individualising therapy is an important challenge for intensive care of patients with severe traumatic brain injury (TBI). Targeting a cerebral perfusion pressure (CPP) tailored to optimise cerebrovascular autoregulation has been suggested as an attractive strategy on the basis of a large body of retrospective observational data. The objective of this study is to prospectively assess the feasibility and safety of such a strategy compared with fixed thresholds which is the current standard of care from international consensus guidelines. METHODS AND ANALYSIS: CPPOpt Guided Therapy: Assessment of Target Effectiveness (COGiTATE) is a prospective, multicentre, non-blinded randomised, controlled trial coordinated from Maastricht University Medical Center, Maastricht (The Netherlands). The other original participating centres are Cambridge University NHS Foundation Trust, Cambridge (UK), and University Hospitals Leuven, Leuven (Belgium). Adult severe TBI patients requiring intracranial pressure monitoring are randomised within the first 24 hours of admission in neurocritical care unit. For the control arm, the CPP target is the Brain Trauma Foundation guidelines target (60-70 mm Hg); for the intervention group an automated CPP target is provided as the CPP at which the patient's cerebrovascular reactivity is best preserved (CPPopt). For a maximum of 5 days, attending clinicians review the CPP target 4-hourly. The main hypothesis of COGiTATE are: (1) in the intervention group the percentage of the monitored time with measured CPP within a range of 5 mm Hg above or below CPPopt will reach 36%; (2) the difference in between groups in daily therapy intensity level score will be lower or equal to 3. ETHICS AND DISSEMINATION: Ethical approval has been obtained for each participating centre. The results will be presented at international scientific conferences and in peer-reviewed journals. TRIAL REGISTRATION NUMBER: NCT02982122.

Acquisition of sensorimotor fMRI under general anaesthesia: Assessment of feasibility, the BOLD response and clinical utility.

We evaluated whether task-related fMRI (functional magnetic resonance imaging) BOLD (blood oxygenation level dependent) activation could be acquired under conventional anaesthesia at a depth enabling neurosurgery in five patients with supratentorial gliomas. Within a 1.5 T MRI operating room immediately prior to neurosurgery, a passive finger flexion sensorimotor paradigm was performed on each hand with the patients awake, and then immediately after the induction and maintenance of combined sevoflurane and propofol general anaesthesia. The depth of surgical anaesthesia was measured and confirmed with an EEG-derived technique, the Bispectral Index (BIS). The magnitude of the task-related BOLD response and BOLD sensitivity under anaesthesia were determined. The fMRI data were assessed by three fMRI expert observers who rated each activation map for somatotopy and usefulness for radiological neurosurgical guidance. The mean magnitudes of the task-related BOLD response under a BIS measured depth of surgical general anaesthesia were 25% (tumour affected hemisphere) and 22% (tumour free hemisphere) of the respective awake values. BOLD sensitivity under anaesthesia ranged from 7% to 83% compared to the awake state. Despite these reductions, somatotopic BOLD activation was observed in the sensorimotor cortex in all ten data acquisitions surpassing statistical thresholds of at least p < 0.001uncorr. All ten fMRI activation datasets were scored to be useful for radiological neurosurgical guidance. Passive task-related sensorimotor fMRI acquired in neurosurgical patients under multi-pharmacological general anaesthesia is reproducible and yields clinically useful activation maps. These results demonstrate the feasibility of the technique and its potential value if applied intra-operatively. Additionally these methods may enable fMRI investigations in patients unable to perform or lie still for awake paradigms, such as young children, claustrophobic patients and those with movement disorders.

Monitoring neurocognitive functioning in childhood cancer survivors: evaluation of CogState computerized assessment and the Behavior Rating Inventory of Executive Function (BRIEF).

BACKGROUND: Many childhood cancer survivors develop neurocognitive impairment, negatively affecting education and psychosocial functioning. Recommended comprehensive neuropsychological testing can be time- and cost- intensive for both institutions and patients and their families. It is important to find quick and easily administered surveillance measures to identify those in need of evaluation. METHODS: We evaluated, individually and in combination, the sensitivity and specificity of the 1) Behavior Rating Inventory of Executive Functioning-Metacognition Index (BRIEF-MCI), and 2) CogState Composite Index (computerized assessment of cognition) in identifying below grade-level performance on state-administered tests of reading and mathematics among childhood cancer survivors. RESULTS: The 45 participants (39% female) were a mean age of 7.1 ± 4.4 years at diagnosis, 14.0 ± 3.0 at evaluation, with a history of leukemia (58%), lymphoma (9%), central nervous system tumors (20%), and other tumors (13%). Impairment on the BRIEF-MCI was associated with low sensitivity (26% reading, 41% mathematics) but stronger specificity (88% reading, 96% mathematics). We found similar associations for the CogState Composite Index with sensitivity of 26% for reading and 29% for mathematics and specificity of 92% for both reading and mathematics. Combining the two measures did not improve sensitivity appreciably (47% reading, 59% mathematics) while reducing specificity (84% reading, 88% mathematics). CONCLUSIONS: While individuals identified from the BRIEF-MCI or CogState Composite would likely benefit from a full neuropsychological evaluation given the strong specificity, use of these measures as screening tools is limited. With poor sensitivity, they do not identify many patients with academic difficulties and in need of a full neuropsychological evaluation. Continued effort is required to find screening measures that have both strong sensitivity and specificity.

Practice guidelines for the supervising professional: intraoperative neurophysiological monitoring.

The American Society of Neurophysiological Monitoring (ASNM) was founded in 1989 as the American Society of Evoked Potential Monitoring. From the beginning, the Society has been made up of physicians, doctoral degree holders, Technologists, and all those interested in furthering the profession. The Society changed its name to the ASNM and held its first Annual Meeting in 1990. It remains the largest worldwide organization dedicated solely to the scientifically-based advancement of intraoperative neurophysiology. The primary goal of the ASNM is to assure the quality of patient care during procedures monitoring the nervous system. This goal is accomplished primarily through programs in education, advocacy of basic and clinical research, and publication of guidelines, among other endeavors. The ASNM is committed to the development of medically sound and clinically relevant guidelines for the performance of intraoperative neurophysiology. Guidelines are formulated based on exhaustive literature review, recruitment of expert opinion, and broad consensus among ASNM membership. Input is likewise sought from sister societies and related constituencies. Adherence to a literature-based, formalized process characterizes the construction of all ASNM guidelines. The guidelines covering the Professional Practice of intraoperative neurophysiological monitoring were initially published January 24th, 2013, and subsequently that document has undergone review and revision to accommodate broad inter- and intra-societal feedback. This current version of the ASNM Professional Practice Guideline was fully approved for publication according to ASNM bylaws on February 22nd, 2018, and thus overwrites and supersedes the initial guideline.

Continuous Assessment of "Optimal" Cerebral Perfusion Pressure in Traumatic Brain Injury: A Cohort Study of Feasibility, Reliability, and Relation to Outcome.

BACKGROUND: Guidelines recommend maintaining cerebral perfusion pressure (CPP) between 60 and 70 mmHg in patients with severe traumatic brain injury (TBI), but acknowledge that optimal CPP may vary depending on cerebral blood flow autoregulation. Previous retrospective studies suggest that targeting CPP where the pressure reactivity index (PRx) is optimized (CPPopt) may be associated with improved recovery. METHODS: We performed a retrospective cohort study involving TBI patients who underwent PRx monitoring to assess issues of feasibility relevant to future interventional studies: (1) the proportion of time that CPPopt could be detected; (2) inter-observer variability in CPPopt determination; and (3) agreement between manual and automated CPPopt estimates. CPPopt was determined for consecutive 6-h epochs during the first week following TBI. Sixty PRx-CPP tracings were randomly selected and independently reviewed by six critical care professionals. We also assessed whether greater deviation between actual CPP and CPPopt (ΔCPP) was associated with poor outcomes using multivariable models. RESULTS: In 71 patients, CPPopt could be manually determined in 985 of 1173 (84%) epochs. Inter-observer agreement for detectability was moderate (kappa 0.46, 0.23-0.68). In cases where there was consensus that it could be determined, agreement for the specific CPPopt value was excellent (weighted kappa 0.96, 0.91-1.00). Automated CPPopt was within 5 mmHg of manually determined CPPopt in 93% of epochs. Lower PRx was predictive of better recovery, but there was no association between ΔCPP and outcome. Percentage time spent below CPPopt increased over time among patients with poor outcomes (p = 0.03). This effect was magnified in patients with impaired autoregulation (defined as PRx > 0.2; p = 0.003). CONCLUSION: Prospective interventional clinical trials with regular determination of CPPopt and corresponding adjustment of CPP goals are feasible, but measures to maximize consistency in CPPopt determination are necessary. Although we could not confirm a clear association between ΔCPP and outcome, time spent below CPPopt may be particularly harmful, especially when autoregulation is impaired.

Non-invasive Cerebrovascular Autoregulation Assessment Using the Volumetric Reactivity Index: Prospective Study.

BACKGROUND: This prospective study of an innovative non-invasive ultrasonic cerebrovascular autoregulation (CA) monitoring method is based on real-time measurements of intracranial blood volume (IBV) reactions following changes in arterial blood pressure. In this study, we aimed to determine the clinical applicability of a non-invasive CA monitoring method by performing a prospective comparative clinical study of simultaneous invasive and non-invasive CA monitoring on intensive care patients. METHODS: CA was monitored in 61 patients with severe traumatic brain injuries invasively by calculating the pressure reactivity index (PRx) and non-invasively by calculating the volumetric reactivity index (VRx) simultaneously. The PRx was calculated as a moving correlation coefficient between intracranial pressure and arterial blood pressure slow waves. The VRx was calculated as a moving correlation coefficient between arterial blood pressure and non-invasively-measured IBV slow waves. RESULTS: A linear regression between VRx and PRx averaged per patients' monitoring session showed a significant correlation (r = 0.843, p < 0.001; 95% confidence interval 0.751 - 0.903). The standard deviation of the difference between VRx and PRx was 0.192; bias was - 0.065. CONCLUSIONS: This prospective clinical study of the non-invasive ultrasonic volumetric reactivity index VRx monitoring, based on ultrasonic time-of-flight measurements of IBV dynamics, showed significant coincidence of non-invasive VRx index with invasive PRx index. The ultrasonic time-of-flight method reflects blood volume changes inside the acoustic path, which crosses both hemispheres of the brain. This method does not reflect locally and invasively-recorded intracranial pressure slow waves, but the autoregulatory reactions of both hemispheres of the brain. Therefore, VRx can be used as a non-invasive cerebrovascular autoregulation index in the same way as PRx and can also provide information about the CA status encompassing all intracranial hemodynamics.

Human-Machine Interaction Assessment by Neurophysiological Measures: A Study on Professional Air Traffic Controllers.

This study aims at investigating the possibility to employ neurophysiological measures to assess the humanmachine interaction effectiveness. Such a measure can be used to compare new technologies or solutions, with the final purpose to enhance operator's experience and increase safety. In the present work, two different interaction modalities (Normal and Augmented) related to Air Traffic Management field have been compared, by involving 10 professional air traffic controllers in a control tower simulated environment. Experimental task consisted in locating aircrafts in different airspace positions by using the sense of hearing. In one modality (i.e. "Normal"), all the sound sources (aircrafts) had the same amplification factor. In the "Augmented" modality, the amplification factor of the sound sources located along the participant head sagittal axis was increased, while the intensity of sound sources located outside this axis decreased. In other words, when the user oriented his head toward the aircraft position, the related sound was amplified. Performance data, subjective questionnaires (i.e. NASA-TLX) and neurophysiological measures (i.e. EEG-based) related to the experienced workload have been collected. Results showed higher significant performance achieved by the users during the "Augmented" modality with respect to the "Normal" one, supported by a significant decreasing in experienced workload, evaluated by using EEG-based index. In addition, Performance and EEG-based workload index showed a significant negative correlation. On the contrary, subjective workload analysis did not show any significant trend. This result is a demonstration of the higher effectiveness of neurophysiological measures with respect to subjective ones for Human-Computer Interaction assessment.

Noninvasive Intracranial Pressure Assessment in Acute Liver Failure.

BACKGROUND: Elevated intracranial pressure (ICP) is an important cause of death following acute liver failure (ALF). While invasive ICP monitoring (IICPM) is most accurate, the presence of coagulopathy increases bleeding risk in ALF. Our objective was to evaluate the accuracy of three noninvasive ultrasound-based measures for the detection of concurrent ICP elevation in ALF-optic nerve sheath diameter (ONSD) using optic nerve ultrasound (ONUS); middle cerebral artery pulsatility index (PI) on transcranial Doppler (TCD); and ICP calculated from TCD flow velocities (ICPtcd) using the estimated cerebral perfusion pressure (CPPe) technique. METHODS: In this retrospective study, consecutive ALF patients admitted over a 6-year period who underwent IICPM as well as measurement of ONSD, TCD-PI or ICPtcd were included. ONSD was measured offline by a blinded investigator from deidentified videos. The ability of highest ONSD, TCD-PI, and ICPtcd to detect concurrent invasive ICP > 20 mmHg was assessed using receiver operating characteristic (ROC) curves. The ROC area under the curve (AUC) was calculated with 95% confidence interval (95% CI) and evaluated against the null hypothesis of AUC = 0.5. Noninvasive measures were also evaluated as predictors of in-hospital death. RESULTS: Forty-one ALF patients were admitted during the study period. In total, 27 (66%) underwent IICPM, of these, 23 underwent ONUS and 21 underwent TCD. Eleven out of 23 (48%) patients died (two from intracranial hypertension). Results of ROC analysis for detection of concurrent ICP > 20 mmHg were as follows: ONSD AUC = 0.59 (95% CI 0.37-0.79, p = 0.54); TCD-PI AUC = 0.55 (95% CI 0.34-0.75, p = 0.70); and ICPtcd AUC = 0.90 (0.72-0.98, p < 0.0001). None of the noninvasive measures were significant predictors of death. CONCLUSIONS: In patients with ALF, neither ONSD nor TCD-PI reliably detected concurrent ICP elevation on invasive monitoring. Estimation of ICP (ICPtcd) using the TCD CPPe technique was associated with concurrent ICP elevation. Additional studies of TCD CPPe in larger numbers of ALF patients may prove worthwhile.

Does Continuous Video-EEG in Patients With Altered Consciousness Improve Patient Outcome? Current Evidence and Randomized Controlled Trial Design.

Continuous video-EEG is recommended for patients with altered consciousness; as compared to routine EEG (lasting <30 minutes), it improves seizure detection, but is time- and resource-consuming. Although North American centers increasingly implement continuous video-EEG, most other (including European) hospitals have insufficient resources. Only one study suggested that continuous video-EEG could improve outcome in adults, and recent assessments challenge this view. This article reviews current evidence on the added value for continuous video-EEG in clinical terms and describes a design for a prospective study.In a multicenter randomized clinical trial (NCT03129438), adults with a Glasgow Coma Scale ≤11 will be randomized 1:1 to continuous video-EEG (cEEG) for 30 to 48 hours or 2 routine EEG (rEEG), assessed through standardized American Clinical Neurophysiology Society (ACNS) guidelines. The primary outcome will be mortality at 6 months, assessed blindly. Secondary outcomes will explore functional status at 4 weeks and 6 months, intensive care unit (ICU) length of stay, infection rates, and hospitalization costs. Using a 2-sided approach with power of 0.8 and a error of 0.05, 2 × 174 patients are needed to detect an absolute survival difference of 14%, suggested by the single available study on the topic.This study should help clarifying whether cEEG has a significant impact on outcome and define its cost effectiveness. If the trial will result positive, it will encourage broader implementation of cEEG with consecutive substantial impact on health care and resource allocations. If not, it may offer a rationale to design a larger trial, and - at least for smaller centers - to avoid widespread implementation of cEEG, rationalizing personnel and device costs.

Trends in intracranial monitoring for pediatric medically intractable epilepsy: 2000-2012.

OBJECTIVE: To retrospectively examine nationwide trends in intracranial monitoring (ICM) for pediatric medically intractable epilepsy (MIE) from 2000 to 2012. METHODS: The Healthcare Cost and Utilization Project Kids' Inpatient Database was analyzed to identify admissions with ICD-9-CM codes corresponding to MIE and ICM from 2000 to 2012, inclusive. Associations between independent variables and outcomes were tested using χ2 test or Fisher exact test. A multivariate logistic regression analysis of variables associated with ICM was completed using stepwise selection. The Cochran-Armitage test was used to test for trend of a variable over the study period. RESULTS: The number of ICM procedures increased over the study period; however, secondary to large increases in the number of MIE admissions, the rate of ICM declined from 5.39% in 2000 to 2.56% in 2012 (p < 0.001). Despite this decline, ICM increasingly resulted in resective epilepsy procedures. In 2000, only 45.18% of ICM cases led to resective epilepsy surgery, which increased to 75.83% by 2012 (p < 0.001). ICM complication rates were comparable to, if not lower than, standard resective surgery. Disparities in access to ICM exist, with African American individuals and those with Medicaid significantly less likely to undergo ICM. CONCLUSION: In this nationwide characterization of pediatric ICM trends, we identified a slight, significant downward trend in the rate of utilization of ICM for MIE. This was secondary to substantial increases in the number of hospital admissions for MIE. Reasons for this large increase and why it has not led to increased rates of ICM warrant further investigation.

Differences in blood pressure by measurement technique in neurocritically ill patients: A technological assessment.

Blood pressure data may vary by measurement technique. We performed a technological assessment of differences in blood pressure measurement between non-invasive blood pressure (NIBP) and invasive arterial blood pressure (ABP) in neurocritically ill patients. After IRB approval, a prospective observational study was performed to study differences in systolic blood pressure (SBP), mean arterial pressure (MAP), and cerebral perfusion pressure (CPP) values measured by NIBP arm, ABP at level of the phlebostatic axis (ABP heart) and ABP at level of the external auditory meatus (ABP brain) at 30 and 45-degree head of bed elevation (HOB) using repeated measure analysis of covariance and correlation coefficients. Overall, 168 patients were studied with median age of 57 ±â€¯15 years, were mostly female (57%), with body mass index ≤30 (66%). Twenty-three percent (n = 39) had indwelling intracranial pressure monitors, and 19.7% (n = 33) received vasoactive agents. ABP heart overestimated ABP brain for SBP (11.5 ±â€¯2.7 mmHg, p < .001), MAP (mean difference 13.3 ±â€¯0.5 mmHg, p < .001) and CPP (13.4 ±â€¯3.2 mmHg, p < .001). ABP heart overestimated NIBP arm for SBP (8 ±â€¯1.5 mmHg, p < .001), MAP (mean difference 8.6 ±â€¯0.8 mmHg, p < .001), and CPP (mean difference 9.8 ±â€¯3.2 mmHg, p < .001). Regardless of HOB elevation, ABP heart overestimates MAP compared to ABP brain and NIBP arm. Using ABP heart data overestimates CPP and may be responsible for not achieving SBP, MAP or CPP targets aimed at the brain.

Novel Noninvasive Method of Cerebrovascular Blood Volume Assessment Using Brain Bioimpedance.

Cerebrovascular autoregulation (CAR) is the ability of vessels to modulate their tone in response to changes in pressure. As an auto-protective mechanism, CAR is critical in preventing secondary brain injury post-trauma. Monitoring of changes in cerebral blood volume might be valuable in evaluating CAR and response to various therapies. In this study, we utilized an ocular-brain bioimpedance interface to assess real time changes in cerebral blood volume in response to a number of physiological challenges. We hypothesize that changes in brain bioimpedance (dz) would track changes in cerebral blood volume. Anesthetized animals were instrumented for monitoring of intracranial pressure (ICP), mean arterial blood pressure, cerebral perfusion pressure (CPP) and cerebral blood flow (CBF). Bioimpedance was monitored continuously through electrocardiographic electrodes placed over the eyelids. Interventions such as hyperventilation, vasopressor administration, creation of an epidural hematoma, and systemic hemorrhage were used to manipulate levels of ICP, CPP, and CBF. The dz correlated with changes in ICP, CPP, and CBF (r = -0.72 to -0.88, p < 0.0001). The receiver operating characteristic for dz at different thresholds of CPP and CBF showed high impedance performance with area under the curve between 0.80-1.00 (p < 0.003) and sensitivity and specificity varying between 83%-100% and 70%-100%, respectively. Our preliminary tests show that brain bioimpedance as measured through the ocular-brain interface tracks changes in CPP and CBF with high precision and may prove to be valuable in the future in assessing changes in cerebral blood volume and CAR.