Utility of Routine Surveillance Head Computed Tomography After Receiving Therapeutic Anticoagulation in Patients with Acute Traumatic Intracranial Hemorrhage

INTRODUCTION

Patients with traumatic intracranial hemorrhage (tICH) are at increased risk of venous thromboembolism and may require anticoagulation. We evaluated the utility of surveillance computed tomography (CT) in patients with tICH who required therapeutic anticoagulation.

METHODS

This single institution, retrospective study included adult patients with tICH who required anticoagulation within 4 weeks and had a surveillance head CT within 24 hours of reaching therapeutic anticoagulation levels. The primary outcome was hematoma expansion (HE) detected by the surveillance CT. Secondary outcomes included 1) changes in management in patients with HE on the surveillance head CT, 2) HE in the absence of clinical changes, and 3) mortality due to HE. We also compared mortality between patients who did and did not have a surveillance CT.

RESULTS

Of 175 patients, 5 (2.9%) were found to have HE. Most (n = 4, 80%) had changes in management including anticoagulation discontinuation (n = 4), reversal (n = 1), and operative management (n = 1). Two patients developed symptoms or exam changes prior to the head CT. Of the 3 patients (1.7%) without preceding exam changes, each had only very minor HE and did not require operative management. No patient experienced mortality directly attributed to HE. There was no difference in mortality between patients who did and those who did not have a surveillance scan.

CONCLUSIONS

Our findings suggest that most patients with tICH who are started on anticoagulation could be followed clinically, and providers may reserve CT imaging for patients with changes in exam/symptoms or those who have a poor clinical examination to follow.

Toward a brighter constellation: multiorgan neuroimaging of neural and vascular dynamics in the spinal cord and brain

Significance

Pain comprises a complex interaction between motor action and somatosensation that is dependent on dynamic interactions between the brain and spinal cord. This makes understanding pain particularly challenging as it involves rich interactions between many circuits (e.g., neural and vascular) and signaling cascades throughout the body. As such, experimentation on a single region may lead to an incomplete and potentially incorrect understanding of crucial underlying mechanisms.

Aim

We aimed to develop and validate tools to enable detailed and extended observation of neural and vascular activity in the brain and spinal cord. The first key set of innovations was targeted to developing novel imaging hardware that addresses the many challenges of multisite imaging. The second key set of innovations was targeted to enabling bioluminescent (BL) imaging, as this approach can address limitations of fluorescent microscopy including photobleaching, phototoxicity, and decreased resolution due to scattering of excitation signals.

Approach

We designed 3D-printed brain and spinal cord implants to enable effective surgical implantations and optical access with wearable miniscopes or an open window (e.g., for one- or two-photon microscopy or optogenetic stimulation). We also tested the viability for BL imaging and developed a novel modified miniscope optimized for these signals (BLmini).

Results

We describe "universal" implants for acute and chronic simultaneous brain-spinal cord imaging and optical stimulation. We further describe successful imaging of BL signals in both foci and a new miniscope, the "BLmini," which has reduced weight, cost, and form-factor relative to standard wearable miniscopes.

Conclusions

The combination of 3D-printed implants, advanced imaging tools, and bioluminescence imaging techniques offers a coalition of methods for understanding spinal cord-brain interactions. Our work has the potential for use in future research into neuropathic pain and other sensory disorders and motor behavior.

Towards a Brighter Constellation: Multi-Organ Neuroimaging of Neural and Vascular Dynamics in the Spinal Cord and Brain

Significance

Pain is comprised of a complex interaction between motor action and somatosensation that is dependent on dynamic interactions between the brain and spinal cord. This makes understanding pain particularly challenging as it involves rich interactions between many circuits (e.g., neural and vascular) and signaling cascades throughout the body. As such, experimentation on a single region may lead to an incomplete and potentially incorrect understanding of crucial underlying mechanisms.

Aim

Here, we aimed to develop and validate new tools to enable detailed and extended observation of neural and vascular activity in the brain and spinal cord. The first key set of innovations were targeted to developing novel imaging hardware that addresses the many challenges of multi-site imaging. The second key set of innovations were targeted to enabling bioluminescent imaging, as this approach can address limitations of fluorescent microscopy including photobleaching, phototoxicity and decreased resolution due to scattering of excitation signals.

Approach

We designed 3D-printed brain and spinal cord implants to enable effective surgical implantations and optical access with wearable miniscopes or an open window (e.g., for one- or two-photon microscopy or optogenetic stimulation). We also tested the viability for bioluminescent imaging, and developed a novel modified miniscope optimized for these signals (BLmini).

Results

Here, we describe novel 'universal' implants for acute and chronic simultaneous brain-spinal cord imaging and optical stimulation. We further describe successful imaging of bioluminescent signals in both foci, and a new miniscope, the 'BLmini,' which has reduced weight, cost and form-factor relative to standard wearable miniscopes.

Conclusions

The combination of 3D printed implants, advanced imaging tools, and bioluminescence imaging techniques offers a new coalition of methods for understanding spinal cord-brain interactions. This work has the potential for use in future research into neuropathic pain and other sensory disorders and motor behavior.

Locoregional CAR T cells for children with CNS tumors: Clinical procedure and catheter safety

Central nervous system (CNS) tumors are the most common solid malignancy in the pediatric population. Based on adoptive cellular therapy's clinical success against childhood leukemia and the preclinical efficacy against pediatric CNS tumors, chimeric antigen receptor (CAR) T cells offer hope of improving outcomes for recurrent tumors and universally fatal diseases such as diffuse intrinsic pontine glioma (DIPG). However, a major obstacle for tumors of the brain and spine is ineffective T cell chemotaxis to disease sites. Locoregional CAR T cell delivery via infusion through an intracranial catheter is currently under study in multiple early phase clinical trials. Here, we describe the Seattle Children's single-institution experience including the multidisciplinary process for the preparation of successful, repetitive intracranial T cell infusion for children and the catheter-related safety of our 307 intracranial CAR T cell doses.

Long-Term Motor versus Sensory Lumbar Plexopathy After Lateral Lumbar Interbody Fusion: Single-Center Experience, Intraoperative Neuromonitoring Results, and Multivariate Analysis of Patient-Level Predictors

BACKGROUND

Although lateral lumbar interbody fusion (LLIF) is an effective surgical option for lumbar arthrodesis, postoperative plexopathies are a common complication. We characterized post-LLIF plexopathies in a large cohort and analyzed potential risk factors for each.

METHODS

A single-institutional cohort who underwent LLIF between May 2015 and December 2019 was retrospectively reviewed for postoperative lumbar plexopathies. Plexopathies were divided based on sensory and motor symptoms and duration, as well as by laterality relative to the surgical approach. We assessed these subgroups for associations with patient and surgical characteristics as well as psoas dimensions. We then evaluated risk of developing plexopathies after intraoperative neuromonitoring observations.

RESULTS

A total of 127 patients were included. The overall rate of LLIF-induced sensory or motor lumbar plexopathy was 37.8% (48/127). Of all cases, 42 were ipsilateral to the surgical approach (33.1%); conversely, 6 patients developed contralateral plexopathies (4.7%). Most (31/48; 64.6%) resolved with a follow-up interval of 402 days in the plexopathy group. Of ipsilateral cases, 24 patients experienced persistent (>90 days) postoperative sensory symptoms (18.9%), whereas 20 experienced persistent weakness (15.7%). More levels fused predicted persistent sensory symptoms (odds ratio, 1.714 [1.246-2.359]; P = 0.0085), whereas surgical duration predicted persistent weakness (odds ratio, 1.004 [1.002-1.006]; P = 0.0382). Psoas anatomic variables were not significantly associated with plexopathy. Nonresolution of intraoperative evoked motor potential alerts was a significant risk factor for developing plexopathies (relative risk, 2.29 [1.17-4.45]).

CONCLUSIONS

Post-LLIF plexopathies are common but usually resolve. Surgical complexity and unresolved neuromonitoring alerts are possible risk factors for persistent plexopathy.

Radiographic analysis of neuroforaminal and central canal decompression following lateral lumbar interbody fusion

Background

Lateral lumbar interbody fusion (LLIF) is a minimally invasive surgical option for treating symptomatic degenerative lumbar spinal stenosis (DLSS) in select patients. However, the efficacy of LLIF for indirectly decompressing the lumbar spine in DLSS, as well as the best radiographic metrics for evaluating such changes, are incompletely understood.

Methods

A single-institutional cohort of patients who underwent LLIF for DLSS between 5/2015 – 12/2019 was retrospectively reviewed. Diameter, area, and stenosis grades were measured for the central canal (CC) and neural foramina (NF) at each LLIF level based on preoperative and postoperative T2-weighted MRI. Baseline facet joint (FJ) space, degree of FJ osteoarthritis, presence of spondylolisthesis, interbody graft position, and posterior disc height were analyzed as potential predictors of radiographic outcomes. Changes to all metrics after LLIF were analyzed and compared across lumbar levels. Preoperative and intraoperative predictors of decompression were then assessed using multivariate linear regression.

Results

A total of 102 patients comprising 153 fused levels were analyzed. Pairwise linear regression of stenosis grade to diameter and area revealed significant correlations for both the CC and NF. All metrics except CC area were significantly improved after LLIF (p < 0.05, 2-tailed t-test). Worse FJ osteoarthritis ipsilateral to the surgical approach was predictive of greater post-operative CC and NF stenosis grade (p < 0.05, univariate and multivariate ordinary least squares linear regression). Lumbar levels L3-5 had significantly higher absolute postoperative CC stenosis grades while relative change in CC stenosis at the L2-3 was significantly greater than other lumbar levels (p < 0.05, one-way ANOVA). There were no baseline or postoperative differences in NF stenosis grade across lumbar levels.

Conclusions

Radiographically, LLIF is effective at indirect compression of the CC and NF at all lumbar levels, though worse FJ osteoarthritis predicted higher degrees of post-operative stenosis.

Inter-alpha Inhibitor Proteins Ameliorate Brain Injury and Improve Behavioral Outcomes in a Sex-Dependent Manner After Exposure to Neonatal Hypoxia Ischemia in Newborn and Young Adult Rats

Hypoxic-ischemic (HI) brain injury is a major contributor to neurodevelopmental morbidities. Inter-alpha inhibitor proteins (IAIPs) have neuroprotective effects on HI-related brain injury in neonatal rats. However, the effects of treatment with IAIPs on sequential behavioral, MRI, and histopathological abnormalities in the young adult brain after treatment with IAIPs in neonates remain to be determined. The objective of this study was to examine the neuroprotective effects of IAIPs at different neurodevelopmental stages from newborn to young adults after exposure of neonates to HI injury. IAIPs were given as 11-sequential 30-mg/kg doses to postnatal (P) day 7-21 rats after right common carotid artery ligation and exposure to 90 min of 8% oxygen. The resulting brain edema and injury were examined by T2-weighted magnetic resonance imaging (MRI) and cresyl violet staining, respectively. The mean T2 values of the ipsilateral hemisphere from MRI slices 6 to 10 were reduced in IAIP-treated HI males + females on P8, P9, and P10 and females on P8, P9, P10, and P14. IAIP treatment reduced hemispheric volume atrophy by 44.5 ± 29.7% in adult male + female P42 rats and improved general locomotor abilities measured by the righting reflex over time at P7.5, P8, and P9 in males + females and males and muscle strength/endurance measured by wire hang on P16 in males + females and females. IAIPs provided beneficial effects during the learning phase of the Morris water maze with females exhibiting beneficial effects. IAIPs confer neuroprotection from HI-related brain injury in neonates and even in adult rats and beneficial MRI and behavioral benefits in a sex-dependent manner.

The Patient Lived-Experience of Ventral Capsulotomy for Obsessive-Compulsive Disorder: An Interpretive Phenomenological Analysis of Neuroablative Psychiatric Neurosurgery

Ventral Capsulotomy (VC) is a surgical intervention for treatment-resistant Obsessive-Compulsive Disorder (OCD). Despite clinical studies, little is known about patient perception and lived experience after neurosurgery for severe OCD. To examine the lived experiences of patients who have undergone VC for severe, treatment-resistant OCD through qualitative analysis. We conducted semi-structured interviews with six participants treated with VC for OCD. Interviews were analyzed using Interpretive Phenomenological Analysis. The following themes emerged: (1) After years of conventional treatments, patients felt neurosurgery was their “last hope” and described themselves as “desperate,” (2) While some described the surgery as a “supernatural experience,” patients also demonstrated understanding of the scientific procedure, its risks and potential benefits, (3) The surgical experience itself was positive or neutral, which was linked to trust in the clinical team, (4) Post-surgery, participants described months of heightened fear as they awaited lesion formation and functional improvement. (5) Patients consistently contextualized outcome in the context of their own life goals. Patients undergoing VC have positive views of this neurosurgical intervention, but psychiatric neurosurgical teams should anticipate patient discomfort with the time needed to achieve behavioral improvement following surgery and emphasize the importance of post-operative psychiatric care.

Long-term ecological assessment of intracranial electrophysiology synchronized to behavioral markers in obsessive-compulsive disorder

Detection of neural signatures related to pathological behavioral states could enable adaptive deep brain stimulation (DBS), a potential strategy for improving efficacy of DBS for neurological and psychiatric disorders. This approach requires identifying neural biomarkers of relevant behavioral states, a task best performed in ecologically valid environments. Here, in human participants with obsessive-compulsive disorder (OCD) implanted with recording-capable DBS devices, we synchronized chronic ventral striatum local field potentials with relevant, disease-specific behaviors. We captured over 1,000 h of local field potentials in the clinic and at home during unstructured activity, as well as during DBS and exposure therapy. The wide range of symptom severity over which the data were captured allowed us to identify candidate neural biomarkers of OCD symptom intensity. This work demonstrates the feasibility and utility of capturing chronic intracranial electrophysiology during daily symptom fluctuations to enable neural biomarker identification, a prerequisite for future development of adaptive DBS for OCD and other psychiatric disorders.

A survey study examining the motivations, concerns, and perspectives of medical students engaging in neurosurgical research

Background

In a competitive landscape for neurosurgical residency admission, research productivity is increasingly important. Medical school applicants to neurosurgery report high numbers of "scholarly products" as published by the National Residency Match Program. Despite increased student involvement in research and productivity, to the best of our knowledge, no previous reported studies have examined student perspectives on their involvement in neurosurgical research.

Methods

For 2 consecutive years (February 2019 and February 2020), medical students (n = 55) from around the United States presented original research at the Student Neurosurgical Research Conference. Participants were administered a mixed-method survey designed to assess experiences and perspectives on engaging in neurosurgical research. Survey responses were analyzed independently by two researchers to assess for common themes and perspectives.

Results

Medical students engaged in all types of research work across nearly every neurosurgical subfield with "Basic/Bench Lab work" (38.5%) and "Chart Review" (23.1%) representing the majority of projects. Students commonly cited "curiosity/interest," and "residency application competitiveness" as main reasons for participation in research. About 66% of respondents reported experiencing anxiety/concern about research productivity "often" or "very often." Thematic analysis revealed that sources of research-related stress were (1) having enough publications to match into residency, and (2) having enough time in medical school to engage in research.

Conclusion

Medical students engaging in neurosurgical research are highly motivated students driven by scientific curiosity and pressure to prepare for competitive residency applications. Students experience anxiety due to time constraints in medical curricula and increasing demands for scholarly productivity.

Magnetic Resonance Imaging-Guided Laser Thermal Ventral Capsulotomy for Intractable Obsessive-Compulsive Disorder

BACKGROUND

Obsessive-compulsive disorder (OCD) is a disabling condition characterized by intrusive thoughts and repetitive behaviors. A subset of individuals have severe, treatment-resistant illness and are nonresponsive to medication or behavioral therapies. Without response to conventional therapeutic options, surgical intervention becomes an appropriate consideration.

OBJECTIVE

To report clinical outcomes and the safety profile of bilateral ventral anterior capsulotomy for OCD using magnetic resonance (MR)-guided laser interstitial thermal therapy (LITT) in 10 patients followed for 6 to 24 mo.

METHODS

A total of 10 patients underwent LITT for severe OCD; 1 patient withdrew prior to follow-up. LITT is a minimally invasive ablative technique performed with precise targeting and use of thermography under MR guidance. Lesions of the ventral anterior limb of the internal capsule by other techniques have been shown to be efficacious in prior studies.

RESULTS

A total of 7 of the 9 patients were considered full responders (77.8%; Yale-Brown Obsessive-Compulsive Scale change ≥35%). Adverse effects included transient apathy/amotivation postsurgery (2 patients). One patient had a small tract hemorrhage where the laser fiber traversed the cerebral cortex as well as persistent insomnia postsurgery. One individual died after a drug overdose 7 mo postsurgery, which was judged unrelated to the surgery.

CONCLUSION

LITT ventral capsulotomy was generally well tolerated, with promising evidence of effectiveness in the largest such series to date. Results were comparable to those after gamma knife ventral capsulotomy, as well as ventral anterior limb deep brain stimulation.

Paraspinal radiation recall myositis after gemcitabine for pancreatic adenocarcinoma

Radiation recall (RR) is a chemotherapy-induced reaction that leads to inflammation and necrosis in previously irradiated tissue. Gemcitabine is a cytidine analogue that is often used in conjunction with nab-paclitaxel in the treatment of pancreatic cancer. Herein, we present a case of a 56-year-old woman with stage III pancreatic adenocarcinoma diagnosed with gemcitabine-induced RR when she presented with lower back pain and new rim-enhancing collections within the right and left paraspinal musculature 5 months after radiation therapy to the pancreas. A PubMed search was performed for 'Radiation Recall Myositis' and a complete literature review performed. This case and review of the literature of published cases of RR myositis highlight the clinical course and presentation of RR myositis. This review highlights the importance of considering RR in the differential diagnosis when patients who are undergoing chemotherapy and radiation present with inflammatory changes in previously irradiated areas.

Ossification of the Posterior Longitudinal Ligament in the Cervical, Thoracic, and Lumbar Spine

Ossification of the posterior longitudinal ligament (OPLL) is a relatively rare disorder characterized by elongation of the posterior longitudinal ligament followed by the progressive development of ectopic osseous tissue along the ligament. OPLL is most commonly reported in the cervical spine, with fewer reported cases of thoracic or lumbar OPLL. The incidence of OPLL is high in east Asian populations with a much lower incidence in the United States. In this case report and review, we present the case of a 44-year-old female who was admitted to the hospital with a one-year history of progressive bilateral lower extremity weakness. Her lower extremity weakness had worsened over months and precipitated a gait disturbance that left her wheelchair-bound at the time of presentation. Additional presenting symptoms included lower back pain, stool incontinence, neck pain, and upper extremity paresthesias. Computed tomography of the spine revealed multiple areas of osteophyte formation and OPLL in the cervical spine from C2-5, thoracic spine from T6-10, and in the lumbar and sacral spine from L1-S1. There were notable areas of accompanying neural foraminal stenosis and central canal stenosis with visible spinal cord compression present in various locations. The patient did not undergo surgical intervention given the significant risk of multilevel surgery, and her symptoms were managed with medication. OPLL, particularly when not considered in lower-risk populations, can be a significant cause for progressive debilitating neurological abnormality. We report a rare case of OPLL occurring throughout the cervical, thoracic, lumbar, and sacral spine.

The National Student Neurosurgical Research Conference: A Research Conference for Medical Students

OBJECTIVE

Medical students interested in neurosurgery are increasingly involved in research, and research conferences have proven valuable for developing medical research experience and exposure. A research conference was designed for medical students interested in neurosurgery to present research.

METHODS

Our team designed an annual research conference at the Warren Alpert Medical School of Brown University in conjunction with the Neurosurgery and Neurology Departments. In February 2019, we hosted the first Student Neurosurgical and Neurological Research Conference (SNRC), the first national research conference, to our knowledge, designed for medical students to present neurosurgical research in the United States. The conference consisted of student poster/oral presentations, keynote speeches from clinical faculty, and surgical skills workstations. In February 2020, we hosted the second SNRC. After each conference, participants (n = 55) completed a survey to assess student perspectives of the conference.

RESULTS

Fifty-five medical students from around the nation attended the conferences to present their research. One hundred percent of participants affirmed that the conference fulfilled their primary reason for attending, which for most (54.5%) was the opportunity to present research. Thematic analysis revealed that students especially appreciated the "lower stress environment" and "opportunity to get feedback on their research." Notably, 97.6% of students felt the conference strengthened or increased their interest in neurosurgery.

CONCLUSIONS

Participants felt that the SNRC was a valuable opportunity to present research in an environment conducive for practice and improvement. Research conferences primarily for medical students may support the development of young researchers while increasing and strengthening interest in the field of neurosurgery.

Inter-alpha Inhibitor Proteins Modulate Neuroinflammatory Biomarkers After Hypoxia-Ischemia in Neonatal Rats

Neuroinflammation contributes to hypoxic-ischemic (HI) brain injury. Inter-alpha inhibitor proteins (IAIPs) have important immunomodulatory properties. Human (h) plasma-derived IAIPs reduce brain injury and improve neurobehavioral outcomes after HI. However, the effects of hIAIPs on neuroinflammatory biomarkers after HI have not been examined. We determined whether hIAIPs attenuated HI-related neuroinflammation. Postnatal day-7 rats exposed to sham-placebo, or right carotid ligation and 8% oxygen for 90 minutes with placebo, and hIAIP treatment were studied. hIAIPs (30 mg/kg) or PL was injected intraperitoneally immediately, 24, and 48 hours after HI. Rat complete blood counts and sex were determined. Brain tissue and peripheral blood were prepared for analysis 72 hours after HI. The effects of hIAIPs on HI-induced neuroinflammation were quantified by image analysis of positively stained astrocytic (glial fibrillary acid protein [GFAP]), microglial (ionized calcium binding adaptor molecule-1 [Iba-1]), neutrophilic (myeloperoxidase [MPO]), matrix metalloproteinase-9 (MMP9), and MMP9-MPO cellular markers in brain regions. hIAIPs reduced quantities of cortical GFAP, hippocampal Iba-1-positive microglia, corpus callosum MPO, and cortical MMP9-MPO cells and the percent of neutrophils in peripheral blood after HI in male, but not female rats. hIAIPs modulate neuroinflammatory biomarkers in the neonatal brain after HI and may exhibit sex-related differential effects.

The Case for Adaptive Neuromodulation to Treat Severe Intractable Mental Disorders

Mental disorders are a leading cause of disability worldwide, and available treatments have limited efficacy for severe cases unresponsive to conventional therapies. Neurosurgical interventions, such as lesioning procedures, have shown success in treating refractory cases of mental illness, but may have irreversible side effects. Neuromodulation therapies, specifically Deep Brain Stimulation (DBS), may offer similar therapeutic benefits using a reversible (explantable) and adjustable platform. Early DBS trials have been promising, however, pivotal clinical trials have failed to date. These failures may be attributed to targeting, patient selection, or the “open-loop” nature of DBS, where stimulation parameters are chosen ad hoc during infrequent visits to the clinician’s office that take place weeks to months apart. Further, the tonic continuous stimulation fails to address the dynamic nature of mental illness; symptoms often fluctuate over minutes to days. Additionally, stimulation-based interventions can cause undesirable effects if applied when not needed. A responsive, adaptive DBS (aDBS) system may improve efficacy by titrating stimulation parameters in response to neural signatures (i.e., biomarkers) related to symptoms and side effects. Here, we present rationale for the development of a responsive DBS system for treatment of refractory mental illness, detail a strategic approach for identification of electrophysiological and behavioral biomarkers of mental illness, and discuss opportunities for future technological developments that may harness aDBS to deliver improved therapy.

Abstract WP353: Inter-alpha Inhibitor Proteins (IAIPs) Reduce Astrocyte Activation and Gliosis in the Neonatal Brain After Hypoxic-ischemic (HI) Brain Injury

Background: IAIPs are serine protease inhibitors that exert anti-inflammatory effects after HI brain injury. We have previously shown that IAIP administration after HI attenuates histopathological brain injury, apoptosis, and microglial activation and improves neurobehavioral outcomes in neonatal rats. Astrocytes are known to form glial scars, increase neuroinflammation, and exacerbate brain injury after stroke.

Objective: To determine the effect of IAIPs on astrocytic GFAP expression in the neonatal rat brain after HI.

Methods: HI was induced using the Rice-Vannucci method with right carotid ligation and exposure to 8% O 2 for 90 min. Post-natal day 7 rats were assigned to one of three groups: non-ischemic sham-control (Sham, n=12), HI exposed placebo-treated (HI-PL, n=13), or HI exposed IAIP-treated (HI-IAIP, n=14). Intraperitoneal injections of 30 mg/kg of IAIP or saline were given at 15 min, 24, and 48 h after HI. We recorded the sex of the rats. 72 h after HI, brains were collected, paraffin embedded, and sectioned. We performed immunohistochemical analysis by staining slides with GFAP, a marker of astrocyte activation. We performed stereological analysis by capturing images of the whole damaged hemisphere, cerebral cortex, hippocampus, and corpus callosum with the StereoInvestgator 10.0 Probe. We quantified GFAP expression levels using Image J software without knowledge of the group assignments.

Results: Sham rats had significantly lower GFAP expression compared with the HI-PL group in the hemisphere (P<0.001), cortex (P<0.005), and hippocampus (P<0.005). IAIP treatment significantly reduced GFAP expression after HI in the hemisphere (P<0.05) compared with the HI-PL group. We also examined GFAP expression separately in male and female rats and found no differences in GFAP expression among the groups in females. However, we found that the Sham males had significantly lower GFAP expression compared to HI-PL in the hemisphere (P<0.005), cortex (P<0.005), and hippocampus (P<0.005), and that the IAIP treated HI exposed males had lower GFAP expression compared with the HI-PL group in the hemisphere (P<0.05) and cortex (P<0.05).

Conclusion: IAIPs attenuate HI related astrogliosis in some brain regions particularly in male neonatal rats.

Abstract WP288: Inter-Alpha Inhibitor Proteins Reduce the Presence of Neutrophils and Matrix Metalloproteinase-9 Positive Neutrophils in Damaged Brain Regions of Neonates with Hypoxic-Ischemic (HI) Brain Injury

Introduction: Inter-alpha inhibitor proteins (IAIPs) are immunomodulatory proteins that play a significant anti-inflammatory role in hypoxic ischemic (HI) brain injury. We have shown that administering IAIPs after HI improves histopathological brain injury, brain weight, and behavioral outcomes in neonatal rats. Neutrophils are specialized leukocytes known to infiltrate the brain parenchyma and exacerbate neuronal injury after HI. One molecular mechanism by which neutrophils exert damage on the blood-brain barrier (BBB) and brain tissue after ischemia is by the release of matrix metalloproteinase-9 (MMP9), an enzyme that breaks down the extracellular matrices of surrounding cells.

Objective: To determine the effect of IAIPs on neutrophil infiltration and release of MMP9 in neonatal rats after HI.

Methods: The Vannucci model was used to induce neonatal HI in postnatal day 7 rats that were assigned to a Non-ischemic sham-control group (Sham, n=12), right-sided carotid ligation with exposure to hypoxia (8% oxygen for 90 min) treated with placebo group (PL-HI, n=17), or an IAIP treated group (IAIP-HI, n=17). Rat sex was recorded. IAIP (30 mg/kg) or PL was given intraperitoneally at 0, 24 and 48 h after HI. We removed the rat brain after 72h and performed immunohistochemistry using MPO (neutrophil selective) and MMP9 fluorescent markers. We performed stereological analyses with the StereoInvestigator 10.0 Fractionator probe without knowledge of group assignment to quantify neutrophils and MMP9 positive cells present within the right hemisphere, cortex, corpus callosum, and hippocampus.

Results: MPO positive cells were significantly reduced in male IAIP treated rats compared with PL-HI in the overall damaged hemisphere (p<0.01) and the corpus callosum (p<0.05). Further, we observed MPO and MMP9 co-localization, and IAIP treatment reduced the presence of MMP9 positive neutrophils in the cortex of male rats compared to placebo (P<0.05).

Abstract 60: Inter-alpha Inhibitor Proteins Reduce the Quantity of Microglia in the Hippocampus After Hypoxic-ischemic Brain Injury in the Neonate

Background: Inter-alpha inhibitor proteins (IAIPs) are immunomodulatory proteins that act as anti-inflammatory agents in hypoxic-ischemic (HI) injury. We have recently shown that administering IAIP after HI improves histopathological brain injury, and behavioral outcomes in neonatal rats. Microglia are glial cells that act as macrophages in the brain and are important constituents in the neuroinflammatory response.

Objective: To determine the effect of IAIP treatment on microglial expression in specific brain regions of neonatal rats after HI brain related injury.

Methods: The Vannucci model was used to induce neonatal HI brain injury. Postnatal day 7 rats were assigned to a non-ischemic sham-control group (Sham, n=11), a right carotid ligation and hypoxia exposed (8% oxygen for 90 min) placebo-treated group (IschPL, n=12), or a right carotid ligation and hypoxia IAIP-treated group (Isch-IAIP, n=12). The sex of the rats was recorded. IAIP (30 mg/kg) or PL was given intraperitoneally at 0, 24 and 48 h after HI. 72 h after HI, brains were collected, sectioned, and prepared for slides. We performed immunohistochemistry by staining with Iba-1 (selective for microglia) and DAPI. Stereological analyses were then performed with the StereoInvestigator 10.0 Fractionator probe without knowledge of group assignment to quantify microglia present in the whole hemisphere, cortex, corpus callosum, and hippocampus.

Results: The number of Iba-1 positive microglial cells per area of tissue was lower in Sham than in the Isch-PL animals in the cortex, hippocampus, and hemisphere of female and in the hippocampus and corpus callosum of male rats (P <0.05). IAIP treatment appears to reduce the number of Iba-1 positive cells across all brain regions compared with the PL treated HI in the male but not female neonatal rats. Post hoc analysis showed that IAIP treatment significantly reduced the number of positive Iba-1 cells in the hippocampus of the male rats (P<0.01).

Abstract TP342: Central Origin of Fever Should not be Assumed in Stroke Patients

Introduction: Fever worsens outcomes in patients with ischemic and hemorrhagic stroke. Fever can be infectious or non-infectious (central) in etiology. Previous literature suggests 32% of patients with ICH and 31% of ischemic stroke patients have noninfectious fever.

Hypothesis: Central fever is rare in stroke patients undergoing a rigorous evaluation for infection.

Methods: We retrospectively reviewed the electronic medical records of 419 patients with ICH (n=199), ischemic stroke (n=107) and subdural hemorrhage (SDH, n=113) from January 2011 to February 2014. We collected data on the following diagnostic measures: fever (temperature ≥ 100.4°F), Leukocytosis (white blood cell ≥ 11X109 cells/L), positive blood culture, positive urinalysis, positive chest X-ray, and use of non-prophylactic antibiotics. We identified patients who had evidence of fever without any other positives out of the above mentioned measures. These patients were identified as having noninfectious or central origin of their fever.

Results: Of the 419 patients studied, 45 (22.6% of ICH), 27(25.2% of ischemic stroke) and 29(25.7% of SDH) patients with ICH, ischemic stroke and SDH respectively had fever at least once during the first 72 hours of their hospital stay. Of these patients with early fever, 8(4.02%), 3(2.8%) and 0 patients, respectively, had noninfectious fever. Out of 419 patients studied, 101(24.1%) patients had fever and 11(2.6%) of those were noninfectious in origin. Also, significantly higher number of patients with ICH had noninfectious fever as compared to patients with ischemic stroke (P=0.042). Additional analysis of the ICH population revealed that IVH was directly correlated with early fever incidence (p<0.001).

Conclusion: Even though fever was commonly observed in about 25% of stroke patients, central fever was rare, occurring in fewer than 3%. Among stroke patients, those with intraventricular hemorrhage were most likely to have central origin of fever. Our data suggest that overall, infections etiologies of fever outnumber central fever approximately 10 to 1.

Abstract NS5: Early Infection Worsens ICH

Background: Intracerebral hemorrhage (ICH) is a dynamic disease in which coagulopathy, early re-bleeds, and tissue ischemia account for potential decline. Infection is known to contribute to coagulopathy and ischemia and may be a significant source of early decline and worse initial clinical presentation.

Hypothesis: Infection within 72 hours is an independent marker of early decline in hemorrhagic stroke.

Methods: To validate our hypothesis, we retrospectively analyzed infection and ICH presentation in 53 ICH patients at Houston Methodist Hospital from 2011-2013. We used the Glasgow Coma Score (GCS) on admission and the ICH Score as the primary outcome data on the severity of the initial clinical presentation of ICH patients. We considered the following diagnostic measures to determine infection within 72 hours: fever, leukocytosis, positive blood culture, positive urinalysis, positive chest X-ray, and use of non-prophylactic antibiotics. If any one of the diagnostic measures was positive then we counted the patient as having an infection within 72 hours. Additionally, we developed an Infection on Admission Score as the sum of each measure to establish a scale for the certainty and possible severity of infection with higher scores suggesting greater certainty and severity.

Results: Any marker of infection within 72 hours was independently associated with lower GCS on admission ( P =0.0259). Using the Infection on Admission Score , we found that a higher score was also independently associated with higher (or more severe) ICH score ( P = .0025) and with lower GCS ( P = .0070).

Conclusions: Any sign of infection within 72 hours correlates with a worse initial clinical presentation of hemorrhagic stroke. Furthermore, these data suggest a physiological influence, as the severity of ICH rose in relationship to the severity of infection. We suggest further studies into this relationship to determine if infection itself causes decline or is simply a marker of overall decline.