Publications by authors named "John Tsiouris"

Background And Purpose: Traumatic brain injury (TBI) is a major source of health loss and disability worldwide. Accurate and timely diagnosis of TBI is critical for appropriate treatment and management of the condition. Neuroimaging plays a crucial role in the diagnosis and characterization of TBI.

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Introduction: Cyclic adenosine monophosphate (cAMP) levels in the lymphoblasts and leukocytes of patients with major depressive disorder (MDD) have been reported to be downregulated compared to in controls. cAMP is a derivative of adenosine triphosphate (ATP), and low ATP turnover has been reported in the state of hypometabolism associated with human MDD and with mammalian hibernation due to suppression of mitochondrial metabolism. Similarities have been noted between many state-dependent neurobiological changes associated with MDD in humans and with mammalian hibernation.

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Background: Safe posterior cervical spine surgery requires in-depth understanding of the surgical anatomy and common variations. The cervical pedicle attachment site to the vertebral body (VB) affects the location of exiting nerve roots and warrants preoperative evaluation. The relative site of attachment of the cervical pedicle has not been previously described.

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Objective: Symptomatic lumbar spinal stenosis (LSS) is a common indication for surgery in the elderly. Preoperative radiographic evaluation of patients with LSS often reveals redundant nerve roots (RNRs). The clinical significance of RNRs is uncertain.

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Head trauma (ie, head injury) is a significant public health concern and is a leading cause of morbidity and mortality in children and young adults. Neuroimaging plays an important role in the management of head and brain injury, which can be separated into acute (0-7 days), subacute (<3 months), then chronic (>3 months) phases. Over 75% of acute head trauma is classified as mild, of which over 75% have a normal Glasgow Coma Scale score of 15, therefore clinical practice guidelines universally recommend selective CT scanning in this patient population, which is often based on clinical decision rules.

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Aggressive behaviors in those with intellectual disability (ID) and autism (ASD) have been linked to a variety of factors including ID level, age, sex, psychiatric disorders, and medical conditions but these factors have not been studied, in large samples, in terms of how they affect the stimuli that trigger aggression. In this survey of 2243 adults, four triggers of aggression associated with frustration, discomfort, change in the physical/social environment, and defensive reactions were analyzed for their relation to ID level, ASD, age, sex, number of psychiatric diagnoses, sleeping problems, seizures, visual impairment, ear infections and gastrointestinal problems. All four triggers were associated with increasing number of psychiatric disorders, with frustration, discomfort, and change intolerance commonly linked to sleeping problems and ASD.

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The use of magnetic resonance imaging (MRI) during pregnancy is on the rise due its ability to provide detailed cross-sectional anatomy without ionizing radiation. Despite the favorable radiation profile, theoretically concerns regarding the safety of MRI and gadolinium-based contrast agent (GBCA) administration have been raised. Currently there are no studies that have shown any attributable harms of MRI during any trimester of pregnancy although prospective and longitudinal studies are lacking.

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While the diagnosis of traumatic brain injury (TBI) is a clinical decision, neuroimaging remains vital for guiding management on the basis of identification of intracranial pathologic conditions. CT is the mainstay of imaging of acute TBI for both initial triage and follow-up, as it is fast and accurate in detecting both primary and secondary injuries that require neurosurgical intervention. MRI is more sensitive for the detection of certain intracranial injuries (eg, axonal injuries) and blood products 24-48 hours after injury, but it has limitations (eg, speed, accessibility, sensitivity to motion, and cost).

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Mild traumatic brain injury (mTBI) affects about 42 million people worldwide. It is often associated with headache, cognitive deficits, and balance difficulties but rarely shows any abnormalities on conventional computed tomography (CT) or magnetic resonance imaging (MRI). Although in most mTBI patients the symptoms resolve within 3 months, 10-15% of patients continue to exhibit symptoms beyond a year.

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Tension pneumocephalus can lead to rapid neurologic deterioration. We report for the first time its association with aseptic systemic inflammatory response syndrome mimicking septic shock and the efficacy of prompt neurosurgical intervention and critical care support in treating this condition. A 64-year-old man underwent 2-stage olfactory groove meningioma resection.

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Purpose: Superselective intra-arterial cerebral infusion (SIACI) of bevacizumab (BV) has emerged as a novel therapy in the treatment of recurrent glioblastoma (GB). This study assessed the use of apparent diffusion coefficient (ADC) in predicting length of survival after SIACI BV and overall survival in patients with recurrent GB.

Methods: Sixty-five patients from a cohort enrolled in a phase I/II trial of SIACI BV for treatment of recurrent GB were retrospectively included in this analysis.

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The response assessment in neuro-oncology (RANO) working group recently proposed standardized response criteria for brain metastases (RANO-BM). We sought to compare RANO-BM to other criteria in an ongoing brain metastasis trial. The first 36 patients enrolled on NCT02085070, an ongoing trial of pembrolizumab for patients with untreated brain metastases, were included in this analysis.

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Melanoma central nervous system metastases are increasing, and the challenges presented by this patient population remain complex. In December 2015, the Melanoma Research Foundation and the Wistar Institute hosted the First Summit on Melanoma Central Nervous System (CNS) Metastases in Philadelphia, Pennsylvania. Here, we provide a review of the current status of the field of melanoma brain metastasis research; identify key challenges and opportunities for improving the outcomes in patients with melanoma brain metastases; and set a framework to optimize future research in this critical area.

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Background: Distinction between tumor and treatment related changes is crucial for clinical management of patients with high-grade gliomas. Our purpose was to evaluate whether dynamic susceptibility contrast-enhanced (DSC) and dynamic contrast enhanced (DCE) perfusion-weighted imaging (PWI) metrics can effectively differentiate between recurrent tumor and posttreatment changes within the enhancing signal abnormality on conventional MRI.

Methods: A comprehensive literature search was performed for studies evaluating PWI-based differentiation of recurrent tumor and posttreatment changes in patients with high-grade gliomas (World Health Organization grades III and IV).

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Objective To establish a maximum tolerated dose of superselective intraarterial cerebral infusion (SIACI) of Cetuximab after osmotic disruption of the blood-brain barrier (BBB) with mannitol, and examine safety of the procedure in patients with recurrent malignant glioma. Methods A total of 15 patients with recurrent malignant glioma were included in the current study. The starting dose of Cetuximab was 100 mg/m(2) and dose escalation was done to 250 mg/m(2).

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Neurotoxicity following paradichlorobenzene (PDCB) exposure is rare and can occur in patients with pica and mothball or toilet cake ingestion. We present a rare case of toxic encephalopathy due to PDCB mothball inhalation and ingestion and describe the rapidly progressive leukoencephalopathy seen on computed tomography, magnetic resonance, and magnetic resonance spectroscopy. Given the nonspecificity of clinical and imaging findings, it is important for radiologists to maintain a high index of suspicion for toxic encephalopathy.

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Objective: The diagnosis of amyotrophic lateral sclerosis (ALS) and primary lateral sclerosis (PLS) is often difficult because of a lack of disease biomarkers. The purpose of this study was to investigate quantitative susceptibility mapping (QSM) of the motor cortex as a potential quantitative biomarker for the diagnosis of ALS and PLS.

Materials And Methods: From a retrospective database, QSM images of 16 patients with upper motor neuron disease (nine men [56%], seven women; mean age, 56.

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Imaging plays an essential role in identifying intracranial injury in patients with traumatic brain injury (TBI). The goals of imaging include (1) detecting injuries that may require immediate surgical or procedural intervention, (2) detecting injuries that may benefit from early medical therapy or vigilant neurologic supervision, and (3) determining the prognosis of patients to tailor rehabilitative therapy or help with family counseling and discharge planning. In this article, the authors perform a review of the evidence on the utility of various imaging techniques in patients presenting with TBI to provide guidance for evidence-based, clinical imaging protocols.

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Objective: To investigate the effects of antidepressants on longevity, age at dementia onset, and survival after onset among adults with Down syndrome, controlling for late-onset seizures, trisomy 21 mosaicism, and cholinesterase inhibitor use.

Method: The charts of 357 adults with Down syndrome (mean age at first visit = 46.3 years, SD = 9.

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Objective: Suprasellar meningiomas have been resected via various open cranial approaches. During the past 2 decades, the endoscopic endonasal approach has been shown to be an option in selected patients. We wished to examine the learning curve for parameters such as extent of resection, visual outcome, and complications.

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Although a certain degree of arteriovenous shunting may be expected in glioblastoma, to our knowledge, the coexistence of a glioblastoma and arteriovenous fistula has not been previously reported. In this case report, we present such a lesion and discuss its diagnosis with a multimodal imaging approach. Additionally, we discuss treatment considerations for such a lesion.

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Various regularization methods have been proposed for single-orientation quantitative susceptibility mapping (QSM), which is an ill-posed magnetic field to susceptibility source inverse problem. Noise amplification, a major issue in inverse problems, manifests as streaking artifacts and quantification errors in QSM and has not been comparatively evaluated in these algorithms. In this paper, various QSM methods were systematically categorized for noise analysis.

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