Quantitative Electroencephalography After Pediatric Anterior Circulation Stroke.

OBJECTIVE: Regional differences were investigated in quantitative EEG (QEEG) characteristics and associations of QEEG to hemodynamics after pediatric acute stroke. METHODS: Quantitative EEG was analyzed, including power in delta, theta, alpha, and beta bands, alpha-delta power ratio, total power, and spectral edge frequency from 11 children with unilateral, anterior circulation strokes during the first 24 hours of continuous EEG recording. Differences between injured and uninjured hemispheres were assessed using multivariate dynamic structural equations modeling. Dynamic structural equations modeling was applied to six children with hemorrhagic stroke undergoing arterial blood pressure, heart rate, and cerebral oximetry monitoring to investigate associations between hemodynamics with QEEG adjacent to anterior circulation regions. RESULTS: All patients with acute ischemic stroke ( n = 5) had lower alpha and beta power and spectral edge frequency on injured compared with uninjured regions. This was not consistent after hemorrhagic stroke ( n = 6). All hemorrhagic stroke patients demonstrated negative association of total power with arterial blood pressure within injured regions. No consistency was observed for direction or strength of association in other QEEG measures to arterial blood pressure nor were such consistent relationships observed for any QEEG measure studied in relation to heart rate or cerebral oximetry. CONCLUSIONS: After pediatric anterior circulation acute ischemic stroke, reduced spectral edge frequency and alpha and beta power can be observed on injured as compared with noninjured regions. After pediatric anterior circulation hemorrhagic stroke, total power can be negatively associated with arterial blood pressure within injured regions. Larger studies are needed to understand conditions in which QEEG patterns manifest and relate to hemodynamics and brain penumbra.

Transdermal Electrical Neuromodulation for Anxiety and Sleep Problems in High-Functioning Autism Spectrum Disorder: Feasibility and Preliminary Findings.

BACKGROUND: Autism spectrum disorder (ASD) is associated with anxiety and sleep problems. We investigated transdermal electrical neuromodulation (TEN) of the cervical nerves in the neck as a safe, effective, comfortable and non-pharmacological therapy for decreasing anxiety and enhancing sleep quality in ASD. METHODS: In this blinded, sham-controlled study, seven adolescents and young adults with high-functioning ASD underwent five consecutive treatment days, one day of the sham followed by four days of subthreshold TEN for 20 min. Anxiety-provoking cognitive tasks were performed after the sham/TEN. Measures of autonomic nervous system activity, including saliva α-amylase and cortisol, electrodermal activity, and heart rate variability, were collected from six participants. RESULTS: Self-rated and caretaker-rated measures of anxiety were significantly improved with TEN treatment as compared to the sham, with effect sizes ranging from medium to large depending on the rating scale. Sleep scores from caretaker questionnaires also improved, but not significantly. Performance on two of the three anxiety-provoking cognitive tasks and heart rate variability significantly improved with TEN stimulation as compared to the sham. Four of the seven (57%) participants were responders, defined as a ≥ 30% improvement in self-reported anxiety. Salivary α-amylase decreased with more TEN sessions and decreased from the beginning to the end of the session on TEN days for responders. TEN was well-tolerated without significant adverse events. CONCLUSIONS: This study provides preliminary evidence that TEN is well-tolerated in individuals with ASD and can improve anxiety.

Association of Outcomes with Model-Based Indices of Cerebral Autoregulation After Pediatric Traumatic Brain Injury.

BACKGROUND: We investigated whether model-based indices of cerebral autoregulation (CA) are associated with outcomes after pediatric traumatic brain injury. METHODS: This was a retrospective analysis of a prospective clinical database of 56 pediatric patients with traumatic brain injury undergoing intracranial pressure monitoring. CA indices were calculated, including pressure reactivity index (PRx), wavelet pressure reactivity index (wPRx), pulse amplitude index (PAx), and correlation coefficient between intracranial pressure pulse amplitude and cerebral perfusion pressure (RAC). Each CA index was used to compute optimal cerebral perfusion pressure (CPP). Time of CPP below lower limit of autoregulation (LLA) or above upper limit of autoregulation (ULA) were computed for each index. Demographic, physiologic, and neuroimaging data were collected. Primary outcome was determined using Pediatric Glasgow Outcome Scale Extended (GOSE-Peds) at 12 months, with higher scores being suggestive of unfavorable outcome. Univariate and multiple linear regression with guided stepwise variable selection was used to find combinations of risk factors that can best explain the variability of GOSE-Peds scores, and the best fit model was applied to the age strata. We hypothesized that higher GOSE-Peds scores were associated with higher CA values and more time below LLA or above ULA for each index. RESULTS: At the univariate level, CPP, dose of intracranial hypertension, PRx, PAx, wPRx, RAC, percent time more than ULA derived for PAx, and percent time less than LLA derived for PRx, PAx, wPRx, and RAC were all associated with GOSE-Peds scores. The best subset model selection on all pediatric patients identified that when accounting for CPP, increased dose of intracranial hypertension and percent time less than LLA derived for wPRx were independently associated with higher GOSE-Peds scores. Age stratification of the best fit model identified that in children less than 2 years of age or 8 years of age or more, percent time less than LLA derived for wPRx represented the sole independent predictor of higher GOSE-Peds scores when accounting for CPP and dose of intracranial hypertension. For children 2 years or younger to less than 8 years of age, dose of intracranial hypertension was identified as the sole independent predictor of higher GOSE-Peds scores when accounting for CPP and percent time less than LLA derived for wPRx. CONCLUSIONS: Increased dose of intracranial hypertension, PRx, wPRx, PAx, and RAC values and increased percentage time less than LLA based on PRx, wPRx, PAx, and RAC are associated with higher GOSE-Peds scores, suggestive of unfavorable outcome. Reducing intracranial hypertension and maintaining CPP more than LLA based on wPRx may improve outcomes and warrants prospective investigation.

Multimodal Assessment of Cerebral Autoregulation and Autonomic Function After Pediatric Cerebral Arteriovenous Malformation Rupture.

BACKGROUND: Management after cerebral arteriovenous malformation (AVM) rupture aims toward preventing hemorrhagic expansion while maintaining cerebral perfusion to avoid secondary injury. We investigated associations of model-based indices of cerebral autoregulation (CA) and autonomic function (AF) with outcomes after pediatric cerebral AVM rupture. METHODS: Multimodal neurologic monitoring data from the initial 3 days after cerebral AVM rupture were retrospectively analyzed in children (< 18 years). AF indices included standard deviation of heart rate (HRsd), root-mean-square of successive differences in heart rate (HRrmssd), low-high frequency ratio (LHF), and baroreflex sensitivity (BRS). CA indices include pressure reactivity index (PRx), wavelet pressure reactivity indices (wPRx and wPRx-thr), pulse amplitude index (PAx), and correlation coefficient between intracranial pressure pulse amplitude and cerebral perfusion pressure (RAC). Percent time of cerebral perfusion pressure (CPP) below lower limits of autoregulation (LLA) was also computed for each CA index. Primary outcomes were determined using Pediatric Glasgow Outcome Score Extended-Pediatrics (GOSE-PEDs) at 12 months and acquired epilepsy. Association of biomarkers with outcomes was investigated using linear regression, Wilcoxon signed-rank, or Chi-square. RESULTS: Fourteen children were analyzed. Lower AF indices were associated with poor outcomes (BRS [p = 0.04], HRsd [p = 0.04], and HRrmssd [p = 0.00]; and acquired epilepsy (LHF [p = 0.027]). Higher CA indices were associated with poor outcomes (PRx [p = 0.00], wPRx [p = 0.00], and wPRx-thr [p = 0.01]), and acquired epilepsy (PRx [p = 0.02] and wPRx [p = 0.00]). Increased time below LLA was associated with poor outcome (percent time below LLA based on PRx [p = 0.00], PAx [p = 0.04], wPRx-thr [p = 0.03], and RAC [p = 0.01]; and acquired epilepsy (PRx [p = 0.00], PAx [p = 0.00], wPRx-thr [p = 0.03], and RAC [p = 0.01]). CONCLUSIONS: After pediatric cerebral AVM rupture, poor outcomes are associated with AF and CA when applying various neurophysiologic model-based indices. Prospective work is needed to assess these indices of CA and AF in clinical decision support.

Intracranial Electroencephalography in Pediatric Severe Traumatic Brain Injury.

OBJECTIVES: Electroencephalography is used in neurocritical care for detection of seizures and assessment of cortical function. Due to limited resolution from scalp electroencephalography, important abnormalities may not be readily detectable. We aimed to identify whether intracranial electroencephalography allows for improved methods of monitoring cortical function in children with severe traumatic brain injury. DESIGN: This is a retrospective cohort study from a prospectively collected clinical database. We investigated the occurrence rate of epileptiform abnormalities detected on intracranial electroencephalography when compared with scalp electroencephalography. We also investigated the strength of association of quantitative electroencephalographic parameters and cerebral perfusion pressure between both intracranial and scalp electroencephalography. SETTING: This is a single-institution study performed in the Phoenix Children's Hospital PICU. PATIENTS: Eleven children with severe traumatic brain injury requiring invasive neuromonitoring underwent implantation of a six-contact intracranial electrode as well as continuous surface electroencephalography. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Visual detection of epileptiform abnormalities was performed by pediatric epileptologists. Association of intracranial and scalp electroencephalography total power, alpha percentage, and alpha-delta power ratio to cerebral perfusion pressure was performed using univariate dynamic structural equations modeling. Demographic data were assessed by retrospective analysis. Intracranial and scalp electroencephalography was performed in 11 children. Three of 11 children had observed epileptiform abnormalities on intracranial electroencephalography. Two patients had epileptiform abnormalities identified exclusively on intracranial electroencephalography, and one patient had seizures initiating on intracranial electroencephalography before arising on scalp electroencephalography. Identification of epileptiform abnormalities was associated with subsequent identification of stroke or malignant cerebral edema. We observed statistically significant positive associations between intracranial alpha-delta power ratio to cerebral perfusion pressure in nine of 11 patients with increased strength of association on intracranial compared with scalp recordings. CONCLUSIONS: These findings suggest that intracranial electroencephalography may be useful for detection of secondary insult development in children with traumatic brain injury.