Ramin Eskandari

Mapping the neuropsychological profile of temporal lobe epilepsy using cognitive network topology and graph theory

OBJECTIVE Normal cognitive function is defined by harmonious interaction among multiple neuropsychological domains. Epilepsy has a disruptive effect on cognition, but how diverse cognitive abilities differentially interact with one another compared with healthy controls (HC) is unclear. This study used graph theory to analyze the community structure of cognitive networks in adults with temporal lobe epilepsy (TLE) compared with that in HC. METHODS Neuropsychological assessment was performed in 100 patients with TLE and 82 HC. For each group, an adjacency matrix was constructed representing pair-wise correlation coefficients between raw scores obtained in each possible test combination. For each cognitive network, each node corresponded to a cognitive test; each link corresponded to the correlation coefficient between tests. Global network structure, community structure, and node-wise graph theory properties were qualitatively assessed. RESULTS The community structure in patients with TLE was composed of fewer, larger, more mixed modules, characterizing three main modules representing close relationships between the following: 1) aspects of executive function (EF), verbal and visual memory, 2) speed and fluency, and 3) speed, EF, perception, language, intelligence, and nonverbal memory. Conversely, controls exhibited a relative division between cognitive functions, segregating into more numerous, smaller modules consisting of the following: 1) verbal memory, 2) language, perception, and intelligence, 3) speed and fluency, and 4) visual memory and EF. Overall node-wise clustering coefficient and efficiency were increased in TLE. SIGNIFICANCE Adults with TLE demonstrate a less clear and poorly structured segregation between multiple cognitive domains. This panorama suggests a higher degree of interdependency across multiple cognitive domains in TLE, possibly indicating compensatory mechanisms to overcome functional impairments.

A novel technology to model pressure-induced cellular injuries in the brain

BACKGROUND Elevated intracranial pressure (ICP) accompanying a number of neurological emergencies is poorly understood, and lacks a model to determine cellular pathophysiology. This limits our ability to identify cellular and molecular biomarkers associated with the pathological progression from physiologic to pathologic ICP. NEW METHOD We developed an ex vivo model of pressure-induced brain injury, which combines 3D neural cell cultures and a newly developed Pressure Controlled Cell Culture Incubator (PC3I). Human astrocytes and neurons maintained in 3D peptide-conjugated alginate hydrogels were subjected to pressures that mimic both physiologic and pathologic levels of ICP for up to 48h to evaluate the earliest impacts of isolated pressure on cellular viability and quantify early indicators of pressure-induced cellular injury. RESULTS Compared to control cell cultures grown under physiologic pressure, sustained pathologic pressure exposure increased the release of intracellular ATP in a cell-specific manner. Eighteen hours of sustained pressure resulted in increased ATP release from neurons but not astrocytes. COMPARISON WITH EXISTING METHODS Cell culture incubators maintain cultures at normal atmospheric pressure. Based on multiple literature searches, we are not aware of any other cell culture incubator systems that modify the pressure at which primary CNS cells are maintained. CONCLUSION This model simulates the clinical features of elevated ICP encountered in patients with hydrocephalus, and provides a first estimate of the pathological signaling encountered during the earliest perid of progression in neonatal hydrocephalus. This model should provide a means to better understand the pathological biomarkers associated with the earliest stages of elevated ICP.

Pediatric Intraparenchymal Meningioma: Case Report and Comparative Review.

Intra-axial (intraparenchymal) meningiomas are an extremely rare pathology with only dozens of cases reported. In children, the unusual characteristics of intraparenchymal meningiomas can easily create an atypical preoperative differential. The authors present the case of an otherwise healthy 14-year-old girl presenting with new-onset seizures and an intracranial lesion upon investigation. CT and MRI revealed a lesion both cystic and calcified in nature, residing completely within the brain parenchyma. Upon operative examination, the mass was found to be completely surrounded by cortex and to be of two disparate consistencies. Pathological analysis revealed the mass to be a meningioma. Despite the rarity in children, meningiomas must be kept on the differential for cystic, calcified lesions. The differential diagnosis based on imaging as well as the operative strategy taken are further discussed. In addition, the authors review the current understanding of pediatric meningiomas as compared with adult meningiomas.

Surgical Management of Pediatric Epilepsy: Decision-Making and Outcomes.

First-line treatment for epilepsy is antiepileptic drug and requires an interdisciplinary approach and enduring commitment and adherence from the patient and family for successful outcome. Despite adherence to antiepileptic drugs, refractory epilepsy occurs in approximately 30% of children with epilepsy, and surgical treatment is an important intervention to consider. Surgical management of pediatric epilepsy is highly effective in selected patients with refractory epilepsy; however, an evidence-based protocol, including best methods of presurgical imaging assessments, and neurodevelopmental and/or behavioral health assessments, is not currently available for clinicians. Surgical treatment of epilepsy can be critical to avoid negative outcomes in functional, cognitive, and behavioral health status. Furthermore, it is often the only method to achieve seizure freedom in refractory epilepsy. Although a large literature base can be found for adults with refractory epilepsy undergoing surgical treatment, less is known about how surgical management affects outcomes in children with epilepsy. The purpose of the review was fourfold: (1) to evaluate the available literature regarding presurgical assessment and postsurgical outcomes in children with medically refractory epilepsy, (2) to identify gaps in our knowledge of surgical treatment and its outcomes in children with epilepsy, (3) to pose questions for further research, and (4) to advocate for a more unified presurgical evaluation protocol including earlier referral for surgical candidacy of pediatric patients with refractory epilepsy. Despite its effectiveness, epilepsy surgery remains an underutilized but evidence-based approach that could lead to positive short- and long-term outcomes for children with refractory epilepsy.

Basilar artery occlusion in a child treated successfully with mechanical thrombectomy using ADAPT

Acute ischemic stroke (AIS) in the pediatric population is rare. Furthermore, it is common for physicians to take significantly longer diagnosing a posterior circulation stroke in a child than in an adult. There are increasing case reports in the literature of treating AIS in children with intravenous tissue plasminogen activator, intra-arterial thrombolysis, and/or mechanical thrombectomy. We present the first case of pediatric AIS treated using a direct aspiration first pass technique (ADAPT) as a means of mechanical thrombectomy.

Primary repair of open neural tube defect in adulthood: case example and review of management strategies.

BACKGROUND CONTEXT Neural tube defects are congenital malformations that develop when the neural plate fails to close during embryogenesis. The most common open neural tube defect, myelomeningocele (MMC), is declining in frequency in North America. If identified, an MMC must be closed in the perinatal period to prevent lethal complications. Lesions presenting in older adults are, thus, very uncommon. PURPOSE The purpose of this study was to describe the surgical management of an adult with an unrepaired ulcerated lumbosacral MMC who presented with persistent cerebrospinal fluid (CSF) leakage and to review the management strategies for adult patients with unrepaired MMC. STUDY DESIGN A case report was used for this study. METHODS The patient was a 62-year-old woman with an unrepaired ulcerated lumbosacral MMC and associated lower extremity weakness. She sought medical care for persistent lumbar tenderness and ulceration after sustaining a fall 4 months before admission. Physical and radiological assessment revealed a lumbosacral MMC at the L5 and S1 levels and a tethered cord. Surgical resection of the placode and de-tethering were performed. RESULTS One week after repair of the lumbosacral MMC, the patient was readmitted for management of continued CSF leakage and hydrocephalus, requiring external ventricular drainage, wound revision, and placement of lumboperitoneal shunt. The patient experienced complete resolution of back pain without additional episodes of CSF leakage. CONCLUSIONS This rare case and review of management strategies suggests that proper surgical management of open MMC in adulthood can successfully be performed and improve patient symptoms and prevent further complications.

Transgenerational Inheritance of Familial Lipomyelomeningocele

Lipomyelomeningocele is a type of neural tube defect characterized by lipomatous tissue causing a defect in the vertebrae, infiltrating the dura, and tethering the spinal cord. Despite significant neurologic consequences, the underlying etiology remains poorly understood. We present a father and son with remarkably similar presentations of lipomyelomeningocele. Genetic testing did not reveal an underlying cause but whole exome sequencing identified variants in the ARHGAP29 and RADIL genes in the proband and his affected father. Genetic analyses of asymptomatic family members revealed several carriers of the ARHGAP29 or RADIL variants, but only the proband and his father carried both variants, suggesting a possible shared genetic mechanism. Rare cases of siblings affected with lipomyelomeningocele have suggested the possibility of autosomal recessive or germline mosaicism. We present the first documented cases of transgenerational lipomyelomeningocele with important implications for family counseling about the recurrence of lipomyelomeningocele.

Pediatric Hydrocephalus: Current State of Diagnosis and Treatment.

1. Zachary Wright, MD* 2. Thomas W. Larrew, MD* 3. Ramin Eskandari, MD, MS* 1. *Department of Neurosurgery, Medical University of South Carolina, Charleston, SC Hydrocephalus is a neurologic condition that requires lifelong vigilance by various health care professionals. Nonsurgical clinicians treating children with hydrocephalus, with or without shunts, often have questions about disease recognition, shunt infection, and shunt malfunction. Imaging modalities such as nonsedated magnetic resonance imaging and nonshunt endoscopic surgery have changed the landscape of the primary pediatric clinician’s interaction with this patient population. This article addresses the practice gap between pediatric outpatient and neurosurgical management of children with hydrocephalus in both the acute and chronic care settings. After completing this article, readers should be able to: 1. Understand basic pathophysiology related to hydrocephalus and available treatments. 2. Recognize presenting signs and symptoms of hydrocephalus. 3. Recognize when neurosurgical consultation is appropriate and manage hydrocephalus until a neurosurgeon is available. Hydrocephalus in the pediatric population is characterized by an initial increase in intraventricular pressure, resulting in pathologic dilation of the cerebral ventricles with an accumulation of cerebrospinal fluid (CSF). Although the pressure may be slight or severe, the balance between CSF production, flow, and absorption is lost in hydrocephalus. This condition is a significant cause of morbidity and mortality within the pediatric population, with a prevalence of approximately 6 in 10,000 live births and a neonatal mortality rate before initial hospital discharge of 13%. (1) The impact of this complex neurologic pathology on society is extremely large. According to nationally representative data sets, every year pediatric hydrocephalus accounts for 38,200 to 39,900 hospital admissions, 391,000 to 433,000 hospital days, and

Immunological low-dose radiation modulates the pediatric medulloblastoma antigens and enhances antibody-dependent cellular cytotoxicity

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IMMU-49. TARGETING CCR2 SIGNALING IN PEDIATRIC MEDULLOBLASTOMA

2.0 billion in total hospital charges in the United States. (2) In the healthy child, CSF is primarily produced in the choroid plexus, …