Gliomas represent the most commonly occurring tumors in the central nervous system and account for approximately 80% of all malignant primary brain tumors. With a high malignancy and recurrence risk, the prognosis of high-grade gliomas is poor, with a mean survival time of 12-18 months. While contrast-enhanced MRI serves as the standard diagnostic imaging modality for gliomas, it faces limitations in the evaluation of recurrent gliomas, failing to distinguish between treatment-related changes and tumor progression, and offers no direct therapeutic options.
View Article and Find Full Text PDFObjective: Here, we demonstrate the first successful use of static neural stimulation patterns for specific information content. These static patterns were derived by a model that was applied to a subject's own hippocampal spatiotemporal neural codes for memory.
Approach: We constructed a new model of processes by which the hippocampus encodes specific memory items via spatiotemporal firing of neural ensembles that underlie the successful encoding of targeted content into short-term memory.
The noradrenaline (NA) system is one of the brain's major neuromodulatory systems; it originates in a small midbrain nucleus, the locus coeruleus (LC), and projects widely throughout the brain. The LC-NA system is believed to regulate arousal and attention and is a pharmacological target in multiple clinical conditions. Yet our understanding of its role in health and disease has been impeded by a lack of direct recordings in humans.
View Article and Find Full Text PDFBackground: The coexistence of meningioma and dural arteriovenous fistula (dAVF) is a rare, but highly complex condition. Various pathophysiological mechanisms underlie intracranial meningiomas with continuous or distant dAVFs. We describe a case of coexisting meningioma and dAVF with a systematic review of the literature.
View Article and Find Full Text PDFBackground: Adult spinal intradural arachnoid cysts are rare pathologic entities with an unclear etiopathogenesis. These lesions can be dichotomized into primary (idiopathic) or secondary (related to inflammation, intradural surgery, or trauma) etiologies. Limited series have depicted optimal management strategies and clinical outcomes.
View Article and Find Full Text PDFCortical ependymomas are currently not considered a subgroup of supratentorial ependymomas; however, there is a growing body of literature investigating the natural history of these lesions compared to supratentorial ependymomas. We performed a systematic literature review of cortical ependymomas with a focus on the natural history, clinical characteristics, and clinical outcomes of these lesions as compared to supratentorial ependymomas. Our search revealed 153 unique cases of cortical ependymomas.
View Article and Find Full Text PDFThe authors sought to evaluate whether immunologic counts on admission were associated with shunt-dependent hydrocephalus following aneurysmal subarachnoid hemorrhage. A retrospective analysis of 143 consecutive patients with aneurysmal subarachnoid hemorrhage over a 9-year period was performed. A stepwise algorithm was followed for external ventricular drain weaning and determining the necessity of shunt placement.
View Article and Find Full Text PDFIntroduction: Positron emission tomography (PET) imaging with prostate-specific membrane antigen- (PSMA-) binding tracers has been found incidentally to demonstrate uptake in CNS tumors. Following the encouraging findings of several such case reports, there is a growing interest in the potential application of PSMA-targeted PET imaging for diagnostics, theranostics, and monitoring of CNS tumors. This is a systematic literature review on PSMA-binding tracers in CNS tumors.
View Article and Find Full Text PDFCerebral amebic encephalitis due to Balamuthia mandrillaris is a rare yet typically fatal disease. As such, identification of the clinical characteristics, appropriate diagnostic workup and commencement of treatment is frequently delayed. Here, we present a case of a 4-year-old male with a B.
View Article and Find Full Text PDFObjective: To investigate the association between immunologic counts on admission and acute symptomatic hydrocephalus after aneurysmal subarachnoid hemorrhage (aSAH).
Methods: We conducted a retrospective analysis of 143 consecutive patients with aSAH. Patient demographics, clinical parameters, laboratory values, and radiographic imaging were obtained.
Pineal metastasis is an exceedingly rare finding in patients with systemic malignancies. Such lesions are typically the manifestation of a primary lung cancer; nonetheless, a variety of malignancies have been reported to disseminate to the pineal gland including gastrointestinal, endocrine, and skin cancers, among others. However, to our knowledge, pineal gland metastasis without a primary origin has yet to be described.
View Article and Find Full Text PDFBackground: Fourth ventricular outlet obstruction is an infrequent but well-established cause of tetraventricular hydrocephalus characterized by marked dilatation of the ventricular system with ballooning of the foramina of Monro, Magendie, and Luschka. Multiple processes including inflammation, infection, hemorrhage, neoplasms, or congenital malformations are known to cause this pathological obstruction. However, true idiopathic fourth ventricular outlet obstruction is a rare phenomenon with only a limited number of cases reported in the literature.
View Article and Find Full Text PDFObjective: Intracranial human brain recordings typically utilize recording systems that do not distinguish individual neuron action potentials. In such cases, individual neurons are not identified by location within functional circuits. In this paper, verified localization of singly recorded hippocampal neurons within the CA3 and CA1 cell fields is demonstrated.
View Article and Find Full Text PDFBackground: Recent studies have reported a gender and medical degree disparity for those receiving Research Project Grants in surgical specialties. The aim of the present study is to analyze factors among academics neurosurgeons that correlate to higher amounts of R01 grant monies awarded.
Materials And Methods: The National Institutes of Health Research Portfolio Online Reporting Tools Expenditures and Results database was queried for neurosurgery funding between 2008 and 2018.
We report a case of combined traumatic pseudoaneurysm and arteriovenous fistula of the middle meningeal artery, which presented clinically 1 year after initial head trauma. A 39-year-old male presented with seizure activity after a closed head injury from a fall. He was hospitalized for multiple intraparenchymal hemorrhages and ultimately discharged 2 weeks later without neurologic deficits.
View Article and Find Full Text PDFBackground: Epidermoid cysts in Meckel cave are exceedingly rare. Since 1971, only 17 cases have been reported in the literature, with most patients presenting with trigeminal hypesthesia. However, outgrowth of these lesions from Meckel cave can rarely lead to compression of the proximate cavernous sinus and the neurovascular structures contained within.
View Article and Find Full Text PDFObjective: We demonstrate here the first successful implementation in humans of a proof-of-concept system for restoring and improving memory function via facilitation of memory encoding using the patient's own hippocampal spatiotemporal neural codes for memory. Memory in humans is subject to disruption by drugs, disease and brain injury, yet previous attempts to restore or rescue memory function in humans typically involved only nonspecific, modulation of brain areas and neural systems related to memory retrieval.
Approach: We have constructed a model of processes by which the hippocampus encodes memory items via spatiotemporal firing of neural ensembles that underlie the successful encoding of short-term memory.
Neurostimulation is a promising therapy for abating epileptic seizures. However, it is extremely difficult to identify optimal stimulation patterns experimentally. In this study, human recordings are used to develop a functional 24 neuron network statistical model of hippocampal connectivity and dynamics.
View Article and Find Full Text PDFOper Neurosurg (Hagerstown)
December 2018
Introduction: The Responsive Neurostimulation System (RNS, Neuropace, Mountain View, California) has been proven to be effective at reducing seizures in patients with partial-onset epilepsy. The system incorporates a skull-mounted neurostimulator that requires a cranial incision for replacement. Although integral to the functioning of the system, in some circumstances, such as in the setting of infection, this can be disadvantageous.
View Article and Find Full Text PDFThe role of serotonin in human brain function remains elusive due, at least in part, to our inability to measure rapidly the local concentration of this neurotransmitter. We used fast-scan cyclic voltammetry to infer serotonergic signaling from the striatum of 14 brains of human patients with Parkinson's disease. Here we report these novel measurements and show that they correlate with outcomes and decisions in a sequential investment game.
View Article and Find Full Text PDFIn the mammalian brain, dopamine is a critical neuromodulator whose actions underlie learning, decision-making, and behavioral control. Degeneration of dopamine neurons causes Parkinson's disease, whereas dysregulation of dopamine signaling is believed to contribute to psychiatric conditions such as schizophrenia, addiction, and depression. Experiments in animal models suggest the hypothesis that dopamine release in human striatum encodes reward prediction errors (RPEs) (the difference between actual and expected outcomes) during ongoing decision-making.
View Article and Find Full Text PDFFront Comput Neurosci
September 2012
Epilepsy is a common chronic neurologic disorder affecting approximately 1% of the world population. More than one-third of all epilepsy patients have incompletely controlled seizures or debilitating medication side effects in spite of optimal medical management. Medically refractory epilepsy is associated with excess injury and mortality, psychosocial dysfunction, and significant cognitive impairment.
View Article and Find Full Text PDFPerisynaptic astroglia are critical for normal synaptic development and function. Little is known, however, about perisynaptic astroglia in the human hippocampus. When mesial temporal lobe epilepsy (MTLE) is refractory to medication, surgical removal is required for seizure quiescence.
View Article and Find Full Text PDFObject: Patients undergoing craniotomies have traditionally received opiates with acetaminophen for the management of their postoperative pain. The use of narcotic pain medications can be costly, decrease rates of early postoperative ambulation, lengthen hospital stays, and alter a patient's neurological examination. The use of alternative pain medications such as tramadol may benefit patients by resolving many of these issues.
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