Abstract TP364: Developing a Pediatric Ischemic Stroke Code Protocol at a Comprehensive Stroke Center: The Georgetown Experience

Background/ Issue: Epidemiologically, pediatric strokes are rare; therefore, index of suspicion is low and many cases are not recognized early enough to qualify for acute treatment. With this small patient population, many regions have yet to develop protocols and policies for acute pediatric stroke response. In the District of Columbia, MedStar Georgetown University Hospital (MGUH) is the only Joint Commission Accredited Comprehensive Stroke Center with a pediatric intensive care unit.

Purpose: The purpose of our program was to develop institutional protocols for pediatric stroke patients who are candidates for hyper-acute treatment. Protocols focused on pediatric patients who presented through our emergency department or were transferred from other facilities within the time window for acute treatment. The protocols were established to ensure a clear process for physicians and staff to follow.

Methods: An interdisciplinary group met to discuss modification of our current Adult Ischemic Stroke Code Protocol needed for a coordinated approach to pediatric stroke patients. The team members included the Stroke Coordinator, Stroke Nurse Navigator, Stroke Nurse Practitioner, Pediatric Neurologist, Medical Director of the Pediatric ICU, Manager of the Pediatric ICU, Pediatric Anesthesia, Medical Director of the Stroke Program, and the Emergency Department Team.

Results: The interdisciplinary team was able to adapt a protocol using the Adult Ischemic Stroke Code Protocol. Key differences between the adult and pediatric stroke code work-flow consisted of including pediatric neurologists early in the decision process, pediatric nurses to assist with monitoring children, and pediatric anesthesia for assistance with imaging and/or endovascular intervention. The order sets were adjusted to include weight- based calculations for medications, age-based monitoring parameters, and specific pediatric needs.

Conclusion: It is possible to develop a Pediatric Stroke Code Protocol based on the Adult Ischemic Stroke Code Protocol to include all modifications appropriate for pediatric care and still maintain the rapid work-flow that everyone is familiar with. It is essential to include all key stakeholders to ensure a smooth and safe process.

Survey of practice patterns and preparedness for endovascular therapy in acute pediatric stroke

PURPOSE

Endovascular therapy benefits selected adults with acute stroke while data are lacking for children. The purpose of this study was to assess physician practice and institutional preparedness for endovascular therapy in pediatric stroke.

METHODS

A link to an anonymous online survey was sent to members of the International Pediatric Stroke Study (IPSS) group about physician experience with endovascular therapy, likelihood of treatment for provided clinical vignettes, and institutional readiness for the delivery of endovascular therapy to children.

RESULTS

Thirty-one pediatric physicians with a mean of 11 years (SD 7.1) of experience responded. All but two would consider endovascular therapy in a child, and 20 (64.5%) had recommended endovascular therapy for a child in the preceding year. Most (n = 19, 67.9%) did not commit to an age minimum for endovascular therapy. Sixteen (57.1%) would consider treatment up to 24 h after symptom onset with 19 (67.9%) respondents reporting that their practice changed after the 2018 American Heart Association guidelines extended the time window for endovascular therapy in adults. Seventeen (60.7%) preferred imaging that included perfusion in children presenting beyond 6 h. Nineteen (70.4%) had institutional endovascular therapy criteria. Physicians in larger pediatric groups had more "likely to treat" responses on the clinical vignettes than physicians working in smaller groups (11.7 vs. 6.1, p < 0.05).

CONCLUSION

Pediatric stroke physicians are largely willing to consider endovascular therapy with most changing their practice according to adult guidelines, though experience and selection criteria varied. These findings may help to inform consensus guidelines and clinical trial development.

Acute Pontine Ischemic Stroke in a Healthy Child With Intracranial Vasculopathy

Here we report the case of a previously healthy 8-year-old boy who presented with altered mental status, right facial droop and right-sided hemiplegia the day after playing in an inflatable bouncer. No head trauma was reported by the patient nor witnessed by the parents. Urgent magnetic resonance imaging (MRI) demonstrated acute ischemic infarction in the left pons; computed tomographic angiography excluded arterial dissection but identified a small hyperdense filling defect in the basilar artery, later confirmed to be a calcification at the origin of a perforating artery. Pediatric National Institutes of Health (PedNIH) Stroke Scale score was 15. Infectious, inflammatory, hypercoagulable and additional vascular causes were excluded. Although the cause of the calcification remains obscure, we speculate that, similarly to mineralizing microangiopathy, a minor trauma led to stroke in this child. To our knowledge, mineralizing microangiopathy, the well-described entity affecting perforating arteries of the anterior circulation in young children leading to basal ganglia stroke following minor head traumas has not been described in the posterior circulation or in previously healthy school-age children.

Characteristics and Outcome in Children With Craniectomy Following Acute Ischemic Stroke in the International Pediatric Stroke Study

The outcome of children with acute ischemic stroke treated with craniectomy has not been thoroughly examined. In adults, hemicraniectomy after middle cerebral artery territory stroke and posterior decompression after posterior circulation stroke has been shown to improve outcome. Pediatric cases of hemicraniectomy for middle cerebral artery stroke and posterior decompression following posterior circulation stroke suggest relatively good outcome. There are no published data in adults or children with craniectomy after cerebral sinovenous thrombosis. Our aim was to determine the outcome of children with acute ischemic stroke treated with craniectomy in the International Pediatric Stroke Study (IPSS). We included children enrolled who had a craniectomy following stroke presentation. Of 4294 patients in IPSS, 38 children (1%) were found to have craniectomy following an ischemic stroke. Of 38 craniectomy cases, 29 had anterior circulation strokes, 5 had posterior circulation strokes, and 4 had cerebral sinovenous thromboses. The mortality rate was 8%. Overall, children who have craniectomies have significant neurologic deficits. Prospective studies are needed to examine long-term morbidity following craniectomy.

Abstract NS5: Is the Extended Time Window Approach Safe in Pediatric AIS? Lessons Learned From 3 Cases

Background: Pediatric stroke is a rare but important cause of mortality and morbidity in this population. Endovascular therapy up to 24 hours after symptoms onset is beneficial in adults LVO acute ischemic stroke (AIS), but no safety or efficacy data of this approach is available for patients <18.

Methods and Results: We present three pediatric AIS cases (age 15-17) treated at GUH and WVU with endovascular techniques using extended time-window with selection based on perfusion criteria. Case 1 : 17 year old patient with history of Ebstein’s anomaly presented the day after a cardiac catheterization procedure with right hemiparesis and aphasia (NIHSS = 22). CTP identified left proximal ICA occlusion (ASPECTS score 7). Using the Penumbra device successful clot retrieval was achieved at 9:19 hours from onset. She was found to have a venous clot and right-to-left shunt from an atrial septal defect. 3 months mRS was 1. Case 2 : 17 y.o. female with 2 weeks history of intermittent right arm numbness presented with left hemiparesis and hemi-sensory loss (NIHSS 12). ER arrival time was 18:43 hours from the onset of sensory symptoms. CTP demonstrated complete right M1 occlusion secondary to right sub-clavian thrombus (ASPECTS score 8). Using the Solitaire stent retriever, recanalization was obtained at 20:05 hours after clinical onset. 3 months mRS was 1. Case 3 : 15 y.o female with Down syndrome, recently started on BCP woke up with right hemiparesis and aphasia (NIHSS = 22). MR perfusion demonstrated a distal M1/M2 clot with a large mismatch in the left MCA territory. Using a stent retriever device complete recanalization was obtained at 14:46 hours from the last time she was well. On the day of discharge her NIHSS was 7. Complete recanalization (TICI 3) was obtained in all three patients. No complications were observed during or following the procedure. NIHSS before and after the procedure improved by 11-to-17 points.

Conclusions: A controlled study regarding endovascular approach in pediatric stroke is unlikely to occur. Therefore, case series must be reported in order to understand the safety of this approach. Strict patient selection and a team approach involving multiple pediatric and adult expertise are needed for a pediatric AIS response that includes endovascular intervention.

Abstract TP504: Development of a Smart-phone App for Fast and Accurate Pediatric NIHSS Administration

Background: The NIH stroke scale (NIHSS) is a standardized scale for evaluation of severity in stroke patient, and is utilized in adults with acute stroke to select patients for urgent intervention. A modified NIHSS has been validated for use in children (PedNIHSS). As pediatric stroke is rare, the PedNIHSS is not used frequently, and physicians are less familiar with the administration. Hence, this scale is used inconsistently, scoring can be less accurate, and important information is lost. We developed a smart-phone app for facilitated administration and recording of PedNIHSS in pediatrics.

Methods: The PedNIHSS-App was built using the cross-platform software-developed environment Xamarin. Throughout development] validation and testing was performed with neurology colleagues. Feedbacks were collected from six pediatric neurologists for optimization. A web-based testing version was available during development.

Results: Administration of the NIHSS stroke scale involves scoring 11 items of neurologic function. Administration of the PedNIHSS in children requires specific age-appropriate modification for testing and scoring. In the newly-developed PedNIHSSApp each item appears on a single page with clear explanations for administration and immediate scoring. Cartoons have been developed for visual instruction. Anonymously-recorded scoring -with no concerns for violation of confidentiality and/or dissemination of protected medical information- can be saved with a time stamp or sent via password-protected email.

Conclusion: The user friendly, easy-to-use PedNIHSS App will facilitate accurate acquisition of PedNIHSS in children with acute stroke, particularly in situations when time is critical and standardized tools can support decision-making. Additionally, the easy to use PedNIHSS App will support increased data acquisition and therefore facilitate future outcome studies in pediatric stroke.

Socioeconomic determinants of outcome after childhood arterial ischemic stroke

OBJECTIVE

To determine whether lower socioeconomic status (SES) is associated with worse 1-year neurologic outcomes and reduced access to rehabilitation services in children with arterial ischemic stroke (AIS).

METHODS

From 2010 to 2014, the Vascular effects of Infection in Pediatric Stroke (VIPS) observational study prospectively enrolled and confirmed 355 children (age 29 days-18 years) with AIS at 37 international centers. SES markers measured via parental interview included annual household income (US dollars) at the time of enrollment, maternal education level, and rural/suburban/urban residence. Receipt of rehabilitation services was measured by parental report. Pediatric Stroke Outcome Measure scores were categorized as 0 to 1, 1.5 to 3, 3.5 to 6, and 6.5 to 10. Univariate and multivariable ordinal logistic regression models examined potential predictors of outcome.

RESULTS

At 12 ± 3 months after stroke, 320 children had documented outcome measurements, including 15 who had died. In univariate analysis, very low income (<US $10,000), but not other markers of SES, was associated with worse outcomes (odds ratio [OR] 3.13, 95% confidence interval [CI] 1.43-6.88, p = 0.004). In multivariable analysis, including adjustment for stroke etiology, this association persisted (OR 3.17, 95% CI 1.18-8.47, p = 0.02). Income did not correlate with receiving rehabilitation services at 1 year after stroke; however, quality and quantity of services were not assessed.

CONCLUSIONS

In a large, multinational, prospective cohort of children with AIS, low income was associated with worse neurologic outcomes compared to higher income levels. This difference was not explained by stroke type, neurologic comorbidities, or reported use of rehabilitation services. The root causes of this disparity are not clear and warrant further investigation.

Abstract 197: Practice and Preparedness for Endovascular Therapy in Acute Pediatric Stroke

Introduction: Endovascular therapy (ET) for pediatric stroke has been described through case reports and series.

Hypothesis: We aimed to determine how pediatric stroke neurologists practice regarding ET, and institutional readiness for this therapy.

Methods: A link to a REDCap survey was emailed to the members of the International Pediatric Stroke Study (IPSS), which includes 58 centers and approximately 150 investigators, requesting responses from physicians who manage acute stroke.

Results: We received 42 responses, with 12 countries represented. Most respondents were pediatric neurologists (n=33), with a median 10 years of experience treating pediatric stroke (SD 6.8). Fourteen (33%) had never recommended/performed ET, 10 (24%) had treated 1-2 patients, and 17 (40%) had treated 3-10 patients. All but one respondent would consider ET in a child. The mean minimum age for consideration of ET was 3 years (range 2-12 years), however most (n=27) had no set minimum age. Most used a time-window of 6 (33%) or 8 (24%) hours for anterior circulation stroke, though 38% had no set time window. Only 7 respondents reported a minimum NIHSS (median NIHSS 6, range 4-15), with the remainder reporting that deficits needed to be significant or the decision would dependent on the clinical scenario. The institutional analyses included only the responses of the 25 IPSS principal investigators to ensure just one response per institution. Fifty-six percent reported that ET would be performed at a children’s hospitals, 36% at an adjacent hospital, and 4% reported that ET would be performed off-site, with 67% responding that patients would need to travel > 10 miles. Only 3 reported working with interventional neuroradiologists who primarily or exclusively treated children, however 22 (88%) worked with adult interventional neuroradiologists comfortable treating children. Twenty (80%) reported having institutional ET guidelines in place or in development.

Conclusions: Pediatric stroke neurologists were largely willing to consider ET, though many had limited experience. With varied clinician expertise and hospital settings, consensus-based guidelines would need to include minimum requirements for institutions to perform ET.

Absolute lymphocyte and neutrophil counts in neonatal ischemic brain injury

Objectives:

This study aimed to identify differences in absolute neutrophils, lymphocytes, and neutrophil-to-lymphocyte ratio between neonates with two forms of ischemic brain injury, hypoxic-ischemic encephalopathy, and acute ischemic stroke, compared to controls. We also aimed to determine whether this neutrophil/lymphocyte response pattern is associated with disease severity or is a consequence of the effects of total-body cooling, an approved treatment for moderate-to-severe hypoxic-ischemic encephalopathy.

Methods:

A retrospective chart review of 101 neonates with hypoxic-ischemic encephalopathy + total-body cooling (n = 26), hypoxic-ischemic encephalopathy (n = 12), acute ischemic stroke (n = 15), and transient tachypnea of the newborn (n = 48) was conducted; transient tachypnea of the newborn neonates were used as the control group. Absolute neutrophil count and absolute lymphocyte count at three time-intervals (0–12, 12–36, and 36–60 h after birth) were collected, and neutrophil-to-lymphocyte ratio was calculated.

Results:

Hypoxic-ischemic encephalopathy + total-body cooling neonates demonstrated significant time-interval-dependent changes in absolute lymphocyte count and neutrophil-to-lymphocyte ratio levels compared to transient tachypnea of the newborn and acute ischemic stroke patients. Pooled analysis of absolute lymphocyte count for neonates with acute ischemic stroke and hypoxic-ischemic encephalopathy (not hypoxic-ischemic encephalopathy + total-body cooling) revealed that absolute lymphocyte count changes occurring at 0–12 h are likely due to disease progression, rather than total-body cooling treatment.

Conclusion:

These data suggest that the neutrophil/lymphocyte response is modulated following neonatal ischemic brain injury, representing a possible target for therapeutic intervention. However, initial severity of hypoxic-ischemic encephalopathy among these patients could also account for the observed changes in the immune response to injury. Thus, additional work to clarify the contributions of cooling therapy and disease severity to neutrophil/lymphocyte response following hypoxic-ischemic encephalopathy in neonates is warranted.

Classification of Normal and Pathological Gait in Young Children Based on Foot Pressure Data

Human gait recognition, an active research topic in computer vision, is generally based on data obtained from images/videos. We applied computer vision technology to classify pathology-related changes in gait in young children using a foot-pressure database collected using the GAITRite walkway system. As foot positioning changes with children's development, we also investigated the possibility of age estimation based on this data. Our results demonstrate that the data collected by the GAITRite system can be used for normal/pathological gait classification. Combining age information and normal/pathological gait classification increases the accuracy of the classifier. This novel approach could support the development of an accurate, real-time, and economic measure of gait abnormalities in children, able to provide important feedback to clinicians regarding the effect of rehabilitation interventions, and to support targeted treatment modifications.

Effects of monoaminergic drugs on training-induced motor cortex plasticity in older adults

Primary motor cortex (M1) plasticity is involved in motor learning and stroke motor recovery, and enhanced by increasing monoaminergic transmission. Age impacts these processes but there is a paucity of systematic studies on the effects of monoaminergic drugs in older adults. Here, in ten older adults (age 61+4years, 4 males), we determine the effects of a single oral dose of carbidopa/levodopa (DOPA), d-amphetamine (AMPH), methylphenidate (MEPH) and placebo (PLAC) on M1 excitability and motor training-induced M1 plasticity. M1 plasticity is defined as training related long lasting changes in M1 excitability and kinematics of the trained movement. At peak plasma level of the drugs, subjects trained wrist extension movements for 30min. Outcome measures were motor evoked potentials (MEPs) elicited by transcranial magnetic stimulation at increasing intensity (stimulus response curve, SRC) and peak acceleration of the trained wrist extension movements. Measures were obtained before and after completion of training. The curve parameters plateau (MEPmax), inflection point, and slope were extracted from SRC. At baseline drugs had a differential effect on curve parameters, while kinematics remained unchanged. Training alone (PLAC) increased MEPmax but did not improve kinematics. Drugs affected training-related changes of the curve parameters differently, but did not enhance them or kinematics when compared to PLAC. The results demonstrate that in the older adults, MEPH, DOPA, or AMPH have differential effects on baseline M1 excitability and training-related M1 plasticity but fail to enhance them above the naïve level.

Abstract WMP111: Socioeconomic Determinants of Outcome After Childhood Arterial Ischemic Stroke

Introduction: Lower socioeconomic status (SES) is associated with poorer outcome after adult stroke. In a large cohort of children with arterial ischemic stroke (AIS), we determined 12-month neurological outcome and tested the hypothesis that SES is a determinant of outcome in children.

Methods: From 2009-2014, the Vascular Effects of Infection in Pediatric Stroke (VIPS) study enrolled 355 children with AIS (29 days-18 years) at 37 international centers, including 3 in lower and middle income (LAMI) countries. Outcome was assessed at 12 months via the recurrence and recovery questionnaire (RRQ) parental report of the pediatric stroke outcome measure (PSOM). Poor outcome was defined as a PSOM of ≥1.

Results: Of 355 children, outcome was available for 310 (87%) at a median of 12 months (IQR 11-13). Ten children died prior to hospital discharge and 4 by 12 months. Outcomes improved from discharge to 12 months (Figure). Of 23 cases in LAMI countries, 88% had an income <USD$10,000, compared to 11% of 287 cases in non-LAMI countries. Overall, only 39% LAMI cases had a good outcome, versus 61% of non-LAMI cases (p=0.052). There were too few cases to analyze outcome predictors in LAMI countries. However, in non-LAMI countries, income did not independently predict poor outcome (OR 1.7, 95% CI 0.57, 4.8, for income <$10,000 vs. >$100,000). Other markers of SES (maternal education level and rural/suburban/urban residence) also did not predict outcome. Independent predictors of poor outcome included moderate (OR 4.6, 95% CI 2.0, 11) or severe (OR 21, 95% CI 7.1, 60) neurological deficits at discharge (compared to no deficits) and recurrent stroke (OR 3.5, 95% CI 1.5, 8.3).

Conclusion: Outcomes after childhood stroke may be worse in LAMI countries, although we were underpowered to study this subgroup. Within non-LAMI countries, SES does not appear to impact outcome in children, unlike reports in adults, perhaps reflecting better access to rehabilitation services in the pediatric population.

Prolonged or recurrent acute seizures after pediatric arterial ischemic stroke are associated with increasing epilepsy risk

AIM

To determine epilepsy risk factors after pediatric stroke.

METHOD

A cohort of children with arterial ischemic stroke (birth-18y) was enrolled at 21 centers and followed for 1 year. Acute seizures (≤7d after stroke) and active epilepsy (at least one unprovoked remote seizure plus maintenance anticonvulsant at 1y) were identified. Predictors were determined using logistic regression.

RESULTS

Among 114 patients (28 neonates and 86 children) enrolled, 26 neonates (93%) and 32 children (37%) had an acute seizure. Acute seizures lasted longer than 5 minutes in 23 patients (40%) and were frequently recurrent: 33 (57%) had 2 to 10 seizures and 11 (19%) had more than 10. Among 109 patients with 1-year follow-up, 11 (10%) had active epilepsy. For each year younger, active epilepsy was 20% more likely (odds ratio [OR] 0.8, 95% confidence interval [CI] 0.6-0.99, p=0.041). Prolonged or recurrent acute seizures also increased epilepsy risk. Each additional 10 minutes of the longest acute seizure increased epilepsy risk fivefold (OR 4.7, 95% CI 1.7-13). Patients with more than 10 acute seizures had a 30-fold increased epilepsy risk (OR 30, 95% CI 2.9-305).

INTERPRETATION

Pediatric stroke survivors, especially younger children, have a high risk of epilepsy 1 year after stroke. Prolonged or recurrent acute seizures increase epilepsy risk in a dose-dependent manner.

Gait parameters associated with balance in healthy 2- to 4-year-old children

The use of validated measurements of gait and balance are crucial to establish baseline function and assess effectiveness of therapeutic interventions. Gait in children changes with motor development requiring frequent observations to effectively track progress. Standardized baseline spatiotemporal measurements and a greater understanding of the relationship between gait and balance would provide important feedback to clinicians regarding the effectiveness of rehabilitation and guide treatment modifications. 84 subjects (2.0-4.9 years) walked along the GAITRite(®), a walkway that records spatiotemporal parameters. The Pediatric Balance Scale (PBS) was administered to assess balance. Comparison of spatiotemporal parameter means between age groups showed trends associated with motor development similar to the ones described in the literature such as decreased cadence and increased step/stride length with increasing age. However, no significant differences in normalized spatiotemporal parameters were found between age groups. Age, leg length, cadence, step/stride length, step/stance time, and single/double support time showed significant correlation with balance scores. When the parameters were grouped into spatial, temporal, and age-related components using principal components analysis and included in a multiple regression model, they significantly predicted 51% of the balance score variance. Age-related components most strongly predicted balance outcomes. We suggest that balance can potentially be evaluated by assessment of spatial, temporal, and age-related characteristics of gait such as step length, cadence, and leg length. This suggests the possibility of developing new gait measurement technology that could provide functional assessment and track improvements during rehabilitation regimens. If the same model can be applied to monitor treatment efficacy in children with gait abnormalities remains to be addressed.

Can We Predict Functional Outcome in Neonates with Hypoxic Ischemic Encephalopathy by the Combination of Neuroimaging and Electroencephalography?

BACKGROUND

Neonatal hypoxic ischemic encephalopathy (HIE) is a major cause of mortality, morbidity, and long-term neurological deficits. Despite the availability of neuroimaging and neurophysiological testing, tools for accurate early diagnosis and prediction of developmental outcome are still lacking. The goal of this study was to determine if combined use of magnetic resonance imaging (MRI) and electroencephalography (EEG) findings could support outcome prediction.

METHODS

We retrospectively reviewed records of 17 HIE neonates, classified brain MRI and EEG findings based on severity, and assessed clinical outcome up to 48 months. We determined the relation between MRI/EEG findings and clinical outcome.

RESULTS

We demonstrated a significant relationship between MRI findings and clinical outcome (Fisher's exact test, p = 0.017). EEG provided no additional information about the outcome beyond that contained in the MRI score. The statistical model for outcome prediction based on random forests suggested that EEG readings at 24 hours and 72 hours could be important variables for outcome prediction, but this needs to be investigated further.

CONCLUSION

Caution should be used when discussing prognosis for neonates with mild-to-moderate HIE based on early MR imaging and EEG findings. A robust, quantitative marker of HIE severity that allows for accurate prediction of long-term outcome, particularly for mild-to-moderate cases, is still needed.

Comparing tract-based spatial statistics and manual region-of-Interest labeling as diffusion analysis methods to detect white matter abnormalities in infants with hypoxic-Ischemic encephalopathy

PURPOSE

To compare manual region of interest (ROI) labeling and tract-based spatial statistics (TBSS) by their ability to detect group-wise differences in fractional anisotropy (FA) in the neonatal brain.

MATERIALS AND METHODS

Diffusion-weighted data were obtained for nine infants with hypoxic-ischemic encephalopathy (HIE) (six males, three females; gestational age [GA] range, 36-40 weeks; mean GA, 37.8 weeks) and 11 healthy-control infants (10 males, 1 female; GA range, 36-40 weeks; mean GA, 38.4 weeks) at 3T. For manual ROI labeling, ROIs were drawn freehand for each subject in eight, clinically relevant brain regions. For TBSS, all FA data underwent an optimized, automated protocol for neonates. Each method was evaluated for detection of decreased FA in HIE infants, sensitivity, specificity, and variability.

RESULTS

FA values from manual ROI and TBSS were strongly correlated (r = 0.94, P < 0.0001). Both methods found decreased FA in most ROIs for HIE infants. There was no significant interaction between method and group, indicating a similar ability to detect FA differences (F(1,19) = 0.599, P = 0.449). Sensitivity (manual: 0.709, TBSS: 0.694, 95% CI [-0.136, 0.163], P = 0.856), specificity (manual and TBSS: 0.716, 95% CI [-0.133, 0.133], P = 1), and standard error (manual: 0.009, TBSS: 0.007) were comparable.

CONCLUSION

Manual ROI labeling and TBSS are comparable methods of diffusion analysis to detect group differences in FA in the neonatal brain.

Abstract T P372: Comparing Methods for Detecting White Matter Abnormalities in Neonates With Hypoxic-Ischemic Encephalopathy

Purpose: To compare manual region of interest (ROI) labeling and tract-based spatial statistics (TBSS) by their ability to detect group-wise differences in fractional anisotropy (FA) in the neonatal brain.

Materials and Methods: Diffusion weighted data were obtained for nine infants with hypoxic-ischemic encephalopathy (HIE) (6 males, 3 females; gestational age range, 36-40 weeks; mean gestational age, 37.8 weeks) and eleven healthy-born infants (10 males, 1 female; gestational age range, 36-40 weeks; mean gestational age, 38.4 weeks) on a 3T scanner. For manual ROI labeling, eight ROIs were drawn freehand for each subject. For TBSS, all FA data underwent an optimized, automated protocol for neonates. Each method was evaluated for detection of decreased FA in HIE infants, sensitivity, specificity, and variability.

Results: FA values from manual ROI and TBSS were strongly correlated. Both methods found decreased FA in most ROIs for HIE infants. There was no significant interaction between method and group, indicating a similar ability to detect FA differences. Sensitivity (manual: 0.71, TBSS: 0.69), specificity (manual and TBSS: 0.72), and standard error (manual: 0.009, TBSS: 0.007) were comparable.

Conclusions: Manual ROI labeling and TBSS are comparable methods of diffusion analysis to detect group differences in FA in the neonatal brain

Abstract T P112: The Effect of Monoaminergic Drugs on Motor Cortex Excitability, Motor Performance and Psychophysics

INTRODUCTION: The benefit of pharmacologic augmentation of stroke recovery remains unclear. As post-stroke motor recovery depends on training-dependent plasticity, we wanted to test the effect of these drugs on the excitability of primary motor cortex (M1), kinematic and psychophysical measures.

METHODS: Nine able-bodied individuals (4 males) participated in 4 test sessions at least 1 week apart during which they were administered one oral dose of 4 different medications: placebo (P), amphetamine 10mg (A), methylphenidate 20mg (M), carbidopa/levodopa 25/100mg (D). We used transcranial magnetic stimulation (TMS) to measure the effects of the different drugs on M1 excitability. Motor evoked potentials (MEP) were elicited using TMS at intensities of 35-80% of maximum stimulator output. The Boltzmann function was calculated for MEP amplitudes and compared across the 4 drug conditions. The effects of the drugs on psychophysics and movement kinematics were captured by a 2d accelerometer mounted on the dorsum of the hand. We measured the reaction time and the peak acceleration and dispersion of directions of auditory paced ballistic wrist extension movements.

RESULTS: Comparison of the 4 different equations for the Boltzmann sigmoid curve where R max represents the maximum MEP amplitude; k, the slope of the curve; and S50, the intensity that produced half of the maximum MEP amplitude revealed significant differences between drug conditions. Compared to P, A led to a significant decrease in the maximum MEP amplitude (p= 0.00015), while D increased it (p=0.013). The other two parameters were similar to placebo. M had no effect on any of the three parameters. The different drugs had no statistically significant effect on the kinematic measures or reaction time.

CONCLUSIONS: These results indicate that the neuromodulatory effect of drugs on M1 excitability differs, which may point to different mechanisms mediating the beneficial effects of these drugs on functional recovery after stroke. It would also support the notion that the beneficial effect of the drugs on recovery is likely due to improved kinematics or psychophysics of executions during training.

West Virginia University pediatric stroke registry: clinical description and risk factors identification in patients from a rural area

PURPOSE

To develop an institutional pediatric stroke database at West Virginia University to support the classification and description of clinical and radiographic characteristics of pediatric stroke in children living in rural areas.

METHODS

A custom-made database was developed using Microsoft Access to include specific query forms for data retrieval. Data were collected retrospectively from electronic medical record of pediatric patients with ischemic and hemorrhagic stroke, with emphasis on clinical presentation, risk factors, and neuroimaging studies between 2000 and 2012.

RESULTS

In the children group, vasculitis and hypercoagulable disorders were identified less frequently than reported. In the neonate group, only extremely sick, symptomatic patents were acutely diagnosed with stroke.

CONCLUSION

Patients with the most common risk factors for stroke (cardiac disease) were overrepresented. This suggests that in children receiving medical attention in rural areas less common risk factors for stroke might not be identified, increasing the risk recurrence. Increased index of suspicion is needed about pediatric stroke in rural areas, and early transfer to a tertiary care center for identification of risk factors is mandatory.

Conditions for enhancing the encoding of an elementary motor memory by rTMS

OBJECTIVE

Motor learning results in changes of movement representation in primary motor cortex (M1) a process involving long-term potentiation (LTP). Pairing motor training with repetitive transcranial magnetic stimulation (rTMS) of M1 enhances the formation of a motor memory. Here we determined the effect of pairing M1 stimulation and the execution of training movements at different times and frequencies on the formation of a motor memory.

METHODS

Formation of a motor memory was defined as increases in motor evoked potentials (MEP) of the training agonist (extensor carpi ulnaris muscle, ECU) and increases in peak acceleration of the trained movements that last more than 60min. Training consisted of auditory-paced ballistic wrist extension movements (30min, 0.5Hz) paired with 0.1, 0.25 or 0.5Hz subthreshold rTMS. The rTMS pulse was applied at either the onset, 100ms prior to or 300ms after the onset of training movement related increases in electromyographic (EMG) activity of ECU. This was compared to a Sham condition.

RESULTS

Only 0.1Hz rTMS applied at the onset of the training related increase in ECU-EMG activity resulted in increases in MEP amplitudes and peak acceleration when compared to the Sham.

CONCLUSIONS

The formation of motor memory is enhanced above the naïve level by co-administration of low frequency rTMS at the time of execution of training movements.

SIGNIFICANCE

These results indicate the importance of time and frequency of rTMS in these settings and should be considered in the design of rehabilitation treatment strategies using rTMS.

Nocturnal headaches and pulsatile cranial mass: the tip of an iceberg

BACKGROUND

Capillary malformation-arteriovenous malformation (CM-AVM) disorder is a newly defined hereditary disorder of the vasculature with typical defining features that include cutaneous capillary malformations associated with high-flow lesions in various other organ systems. Mutations on the RASA1 gene are reported to be associated with a variety of vascular malformations and present with a widely varying phenotype.

PATIENT

A healthy 3 year old presented with acute onset of severe nocturnal headaches, nausea, and vomiting associated with a 2-cm pulsatile mass and prominent superficial veins on her forehead. Neuroimaging demonstrated a complex vascular malformation with multiple arteriovenous fistulae and cavernous angiomas present in multiple locations in the brain, but not in any other organ system.

RESULTS

The patient was found to have a mutation of the RASA1 gene, which has not been previously described in the literature.

CONCLUSIONS

This case describes a new RASA1 mutation with a phenotype that has not been previously described with a combination of pial fistulae and intracranial AV fistula in the absence of arteriovenous malformations.

Teaching Neuroimages: a pediatric patient with headache and neck stiffness

A 14-year-old right-handed boy presented with sudden onset of severe headache and neck stiffness. Physical examination showed arm asymmetry with smaller size and muscle bulk (present since childhood) and increased deep tendon reflexes on the right, but normal strength. Brain CT and lumbar puncture ruled out subarachnoid hemorrhage or infection. MRI and angiography (figure) identified an unruptured type III spinal arteriovenous malformation at the C3-C4 level, supplied by the right vertebral artery.(1) Subtle physical examination findings can indicate underlying pathology and should not be overlooked in the proper context. Vascular studies should be considered for severe headache with negative initial workup.(2.)

Validation of a computer application as a test of motor function in healthy children and adults

We recently developed a computer-based test that uses a pointing task with multiple levels of difficulty to evaluate upper extremity motor function. The purpose of this study is to report performance data in adults and children, to determine test reliability, and to validate this test against well established scales of motor function (Purdue Pegboard and 9-hole Pegboard tests). We examined 40 healthy right-handed subjects (18 children and 22 adults) to determine the correlation among computer-based test and validated measures. The test is quick to administer, engaging for adults and children, with a steep learning curve to stable performance, and can be finely tuned to baseline ability. Test-retest reliability was confirmed for all levels of difficulty. The computer-based test demonstrated moderate correlation in healthy adults and children with the Purdue Pegboard test (Spearman, r = 0.52, p = 0.0005; Pearson, r = 0.55, p = 0.0002).

IMPLICATIONS

The test is a valid measure of motor skills and could be use for periodic evaluation and monitoring in the clinic setting. Further development of a user-friendly version for self-administration would allow for home based monitoring of treatment/interventions.

Stroke in children: need for increased awareness

An 11-year old pediatric patient, who suffered a stroke is presented. She experienced a new-onset, severe, and persistent headache. Despite identification of a subacute ischemic lesion on CT scan, a delay in transfer to specialized care occurred. Laboratory investigations revealed hypercoagulability, which prompted treatment initiation. Stroke in children is a rare but significant cause of death and long-term disability. With increased understanding, improved guidelines, and emerging treatment options for children's stroke, increased awareness about this disease is necessary for prompt identification and treatment in this population.

Motor demand-dependent improvement in accuracy following low-frequency transcranial magnetic stimulation of left motor cortex

The role of primary motor cortex (M1) in the control of voluntary movements is still unclear. In brain functional imaging studies of unilateral hand performance, bilateral M1 activation is inconsistently observed, and disruptions of M1 using repetitive transcranial magnetic stimulation (rTMS) lead to variable results in the hand motor performance. As the motor tasks differed qualitatively in these studies, it is conceivable that M1 contribution differs depending on the level of skillfulness. The objective of the present study was to determine whether M1 contribution to hand motor performance differed depending on the level of precision of the motor task. Here, we used low-frequency rTMS of left M1 to determine its effect on the performance of a pointing task that allows the parametric increase of the level of precision and thereby increase the level of required precision quantitatively. We found that low-frequency rTMS improved performance in both hands for the task with the highest demand on precision, whereas performance remained unchanged for the tasks with lower demands. These results suggest that the functional relevance of M1 activity for motor performance changes as a function of motor demand. The bilateral effect of rTMS to left M1 would also support the notion of M1 functions at a higher level in motor control by integrating afferent input from nonprimary motor areas.

Impact of anticoagulation on the short-term outcome in a population of neonates with cerebral sinovenous thrombosis: a retrospective study

To investigate the impact of anticoagulation on short-term outcome (1 month) in neonates with cerebral sinovenous thrombosis, the authors conducted a retrospective chart review of neonates admitted to 2 tertiary hospitals over a 5- and 8-year period, respectively. Neonates with confirmed radiographic evidence of cerebral sinovenous thrombosis were included. Eighteen total patients treated with hydration only were identified. Approximately 50% of these neonates showed clot extension or other complications on follow-up imaging that were obtained within 72 hours with either magnetic resonance imaging or computed topography. Five neonates were treated with anticoagulation, and none of these patients developed new infarcts or hemorrhages. The results of this retrospective study suggest that anticoagulation is safe in neonates with cerebral sinovenous thrombosis. Early follow-up scans can help treatment decision. Larger studies are needed to develop standardized guidelines for the evaluation and treatment of neonatal cerebral sinovenous thrombosis.

Infective proteins: the prion puzzle

According to the Koch postulates an infectious organism is the one that can be isolated from an host suffering from a disorder, can be propagated in laboratory, can cause the same disease when introduced in another host, and finally, can be re-isolated from the host itself. If we change the word "organism" with the word "protein" we have a quite exact description of prions. Prion related disorders are a very unique category of infectious diseases. The ethiology of the so-called prionoses is related to the conversion of a normal protein (PrP(C), the cellular isoform of the prion protein) into a pathological form (the scrapie isoform of the prion protein, PrP(Sc)) which is able to propagate. The striking difference between the two forms seems to consist in a conformational modification of a mainly alpha-helix structured PrP(C) into a mainly beta-sheet PrP(Sc). The latter forms amyloid-like fibrils which precipitate into insoluble aggregates leading to the neurodegenerative changes specific of Spongiform Encephalopathies. This review will focus on the structure of the prion proteins and on PrP(C) cellular cycle, and it will discuss some hypothesis about the protein biochemical function. Finally, the various molecular mechanisms proposed for the development of conformational modifications will be reviewed, i.e. how a protein can become infectious by simply changing its structure.

Dejerine's syndrome or Spiller's syndrome?

We report the difference existing between two clinical syndromes: Spiller's syndrome is caused by a complete involvement of the medial hemimedulla, while Déjérine's syndrome is determined by lesions restricted to the anterior portion of the medial hemimedulla and is characterized by hypoglossal nerve palsy and contralateral hemiparesis.

Structural dependence of the cellular isoform of prion protein on solvent: spectroscopic characterization of an intermediate conformation

Using circular dichroism, fluorescence, and infrared spectroscopies, we studied the secondary structure of purified hamster PrP(C) in the presence of the mild, nonionic detergent octylglucoside. Under these native conditions, PrP(C) displayed an unexpectedly high beta-sheet component, intermediate between the values previously reported for PrP(Sc) and an isoform of PrP(C) isolated in a zwitterionic detergent. The structure of PrP(C) appeared to depend strongly on the detergent and/or phase. Switching from octylglucoside to zwitterion 3-14 drastically modified PrP secondary structure by increasing the alpha-helix while abolishing the beta-sheet component. In contrast, the conformation of PrP(C) in zwitterion was highly stable, since reverting to octylglucoside did not restore the original native structure. These and other results show that native PrP(C) in octylglucoside has some of the conformational characteristics that make the protein susceptible to conversion into PrP(Sc). Most importantly, this is the first study to demonstrate the intrinsic plasticity of the full-length native PrP(C) isolated from animal brains.

Early induction of protein nexin-I in scrapie

We used RNA fingerprinting by arbitrary primed PCR to identify genes whose expression is up-regulated in the brain of hamsters affected by prion disease. One gene implicated by RNA fingerprinting encoded the hamster homologue of protein nexin-I (PN-I), a serine proteinase inhibitor, and was further investigated by Northern blot analysis. PN-I mRNA levels were increased at pre-clinical stages (19 days after inoculation) and remained elevated when the spongiform encephalopathy was anatomopathologically and clinically evident (at 50 and 80 days). Future RNA screening conducted as illustrated may help to reveal a spectrum of genes relevant for the etiopathogenesis and/or diagnosis of prion disease.

Use of CD and FT-IR to determine the secondary structure of purified proteins in the low-microgram range

The spectroscopic characterization of protein secondary structure is often partially unreliable when samples are not extremely pure and abundant. This problem may be overcome by the combination of circular dichroism (CD) and Fourier transform infrared spectroscopy (FT-IR). We used these methods to characterize the secondary structure of two proteins of neurobiological interest, calexcitin (CE) and the cellular isoform of prion protein (PrPC). Both proteins were purified with multiple chromatographic steps and were obtained in buffer with high purity (> 95%) and in low amount (approximately 2 micrograms). The samples were analyzed by circular dichroism (down to 184 or 182 nm), recovered, and deposited on films for infrared analysis. The spectral deconvolution from the two methods yielded secondary structures in good agreement with each other as well as with theoretical predictions based on amino acid sequence. The conformation of CE was found to be dependent on its concentration and on calcium binding. The secondary structure of cellular native PrP varied dramatically with the detergent used. In conclusion, the combination of CD and FT-IR analysis is suitable for the characterization of the conformational changes induced by ligand binding and/or by different solvent conditions when the protein of interest is only scarcely available. The methods used here provide valuable insights into the putative correlation between protein structure and activity.

Semipreparative chromatographic method to purify the normal cellular isoform of the prion protein in nondenatured form

A fundamental step in the pathogenesis of spongiform encephalopathies (prion diseases) is the conversion of the cellular isoform of prion protein (PrPC) into the infectious form (scrapie isoform, PrPSc), apparently by a conformational mechanism. Comparison of the native secondary and tertiary structures of both proteins is essential to elucidate the molecular basis of this transformation. To obtain sufficient quantities of native-like PrPC, we have developed a semipreparative method to purify PrPC from hamster brains. PrPC was solubilized from purified synaptosomal and microsomal membranes by the nonionic detergent n-octyl- beta-glucopyranoside; the soluble fraction was loaded at pH 7.5 onto a semipreparative cation-exchange TSK-SP-5PW (HPLC) column. The fractions eluted by linear NaCl gradient and enriched for PrPC were sequentially purified using an immobilized ion-affinity HPLC column charged by Co2+, followed by wheat germ agglutinin (WGA)-affinity HPLC or size-exclusion HPLC (SE-HPLC) using a TSK G3000SW column. More than 95% purity was achieved after SE-HPLC as estimated by quantitative densitometry of the silver-stained SDS-PAGE gel; the recovery of total brain PrPC was >/=8%. The purified PrPC was a monomer with an intact N-terminus, and with a Stoke's radius of 26 A, corresponding to that expected from the molecular weight for a native protein. The presence of the native-like conformation was further verified by peptide mapping after limited trypsin proteolysis, and by the apparent unfolding in guanidine hydrochloride, as detected by SE-HPLC.

Disseminated encephalitis following streptococcal infection

Various neurological disorders have been related to Streptococcus pyogenes infection. Only recently, and for the first time, it has been suggested that acute disseminated encephalitis may also complicate a streptococcal infection. The case reported in this paper seems to confirm this hypothesis.

[Encephalitis lethargica]

We report the case of a 34-year old patient who first complained of fever, confusion and transient ophthalmoplegia and then developed akinetic mutism, frontal lobe, pyramidal tract and extrapyramidal signs. Clinical and electrophysiological data support a diagnosis of encephalitis lethargica. Magnetic resonance imaging showed hyperintensive lesions in various brain regions. The patient responded to corticosteroid treatment. Two years after the onset of the first clinical signs he had recovered completely and today, after 5 years, he shows no sign of disease.

Elongated styloid process and Eagle's syndrome

A controversial entity, Eagle's syndrome, is reviewed. After an anatomical description of the maxillo-vertebro-pharyngeal region we summarize the causative, diagnostic and therapeutic aspects of the syndrome. Two different conditions are often reported as Eagle's syndrome: one characterized by dysphagia and unilateral pharyngeal pain radiating to the ear and worsened by swallowing; the other characterized by pain in the head and neck region due to compression of the neurovascular structure by an elongated styloid process. The latter also includes typical cranial neuralgias (such as glossopharyngeal neuralgia) and carotidynia. We believe that the term "Eagle's syndrome" is legitimate only in the first case and in those "atypical" painful head and neck conditions related to an elongated styloid process and relieved by styloidectomy. We believe Eagle's syndrome deserves consideration in the International Headache Classification.

High incidence of gastrointestinal cancer in a family with ataxia-telangiectasia

Literature suggests that not only homozygotes but also heterozygotes for ataxia-telangiectasia have a high incidence of cancer, probably due to an impairment in DNA repair. The most frequent associations are with breast, lung, bladder, prostate and stomach tumors, while no correlation with colorectal cancer has been demonstrated. The affected family reported in this paper seems to have a high incidence of gastrointestinal tract tumors, including the colorectal ones.