MRI-based methodology to monitor the impact of positional changes on the airway caliber in obstructive sleep apnea patients.

Purpose: To develop a non-invasive MRI-based methodology to visually and quantitatively assess the impact of head and chest rotations on the airway caliber.

Methods: An MRI table set-up was developed for independent rotations of the head and chest along B field and tested for feasibility using phantom scans. The accuracy of the head and chest rotations was validated with ten volunteer scans.

Spinal Cord Stimulation (SCS) and Functional Magnetic Resonance Imaging (fMRI): Modulation of Cortical Connectivity With Therapeutic SCS.

Introduction: The neurophysiological basis of pain relief due to spinal cord stimulation (SCS) and the related cortical processing of sensory information are not completely understood. The aim of this study was to use resting state functional magnetic resonance imaging (rs-fMRI) to detect changes in cortical networks and cortical processing related to the stimulator-induced pain relief.

Methods: Ten patients with complex regional pain syndrome (CRPS) or neuropathic leg pain underwent thoracic epidural spinal cord stimulator implantation.

Subclinical albuminuria is linked to gray matter atrophy in type 2 diabetes mellitus.

Objective: Microalbuminuria (MA), a marker of renal microvascular disease, is associated with brain atrophy and neurovascular changes in older adults with type 2 diabetes mellitus (DM). We evaluated the relationship between urine albumin-to-creatinine ratio (UACR) and regional brain volumes to determine whether subclinical albuminuria may indicate early structural brain changes in type 2 DM.

Materials/methods: We studied UACR and brain volumes in 85 type 2 DM patients (64.

Multi-scale glycemic variability: a link to gray matter atrophy and cognitive decline in type 2 diabetes.

Objective: Type 2 diabetes mellitus (DM) accelerates brain aging and cognitive decline. Complex interactions between hyperglycemia, glycemic variability and brain aging remain unresolved. This study investigated the relationship between glycemic variability at multiple time scales, brain volumes and cognition in type 2 DM.

Enhancement of vasoreactivity and cognition by intranasal insulin in type 2 diabetes.

Objective: To determine acute effects of intranasal insulin on regional cerebral perfusion and cognition in older adults with type 2 diabetes mellitus (DM).

Research Design And Methods: This was a proof-of-concept, randomized, double-blind, placebo-controlled intervention evaluating the effects of a single 40-IU dose of insulin or saline on vasoreactivity and cognition in 15 DM and 14 control subjects. Measurements included regional perfusion, vasodilatation to hypercapnia with 3-Tesla MRI, and neuropsychological evaluation.

Resting-state functional connectivity in multiple sclerosis: an examination of group differences and individual differences.

Multiple sclerosis (MS) is a neurodegenerative, inflammatory disease of the central nervous system, resulting in physical and cognitive disturbances. The goal of the current study was to examine the association between network integrity and composite measures of cognition and disease severity in individuals with relapsing-remitting MS (RRMS), relative to healthy controls. All participants underwent a neuropsychological and neuroimaging session, where resting-state data was collected.

Treatment of multiple system atrophy using intravenous immunoglobulin.

Background: Multiple system atrophy (MSA) is a progressive neurodegenerative disorder of unknown etiology, manifesting as combination of parkinsonism, cerebellar syndrome and dysautonomia. Disease-modifying therapies are unavailable. Activation of microglia and production of toxic cytokines suggest a role of neuroinflammation in MSA pathogenesis.

The relationship between brain volume and walking outcomes in older adults with and without diabetic peripheral neuropathy.

Objective: Diabetic peripheral neuropathy (DPN) alters walking. Yet, the compensatory role of central locomotor circuits remains unclear. We hypothesized that walking outcomes would be more closely related to regional gray matter volumes in older adults with DPN as compared with nonneuropathic diabetic patients and nondiabetic control subjects.

"Tumoral pseudoblush" identified within gliomas at high-spatial-resolution ultrahigh-field-strength gradient-echo MR imaging corresponds to microvascularity at stereotactic biopsy.

Purpose: To use directed biopsy sampling to determine whether microvascular assessment within gliomas, by means of ultrahigh-field-strength high-spatial-resolution gradient-echo (GRE) magnetic resonance (MR) imaging at 8 T, correlates with histopathologic assessment of microvascularity.

Materials And Methods: The study was institutional review board approved and HIPAA compliant. Informed consent was obtained.

Functional connectivity during language processing in acute cocaine withdrawal: a pilot study.

Recent research revealed decreased access to semantic and associative networks in acute cocaine withdrawal. In autism, such behavioral outcomes are associated with decreased functional connectivity using functional magnetic resonance imaging. Therefore, we wished to determine whether connectivity is also decreased in acute cocaine withdrawal.

Physical activity associated with increased resting-state functional connectivity in multiple sclerosis.

Multiple sclerosis (MS) is an inflammatory disease of the central nervous system, resulting in physical, cognitive and affective disturbances, with notable declines in the ability to learn and retain new information. In this study, we examined if higher levels of physical activity in MS individuals were associated with an increased resting-state connectivity of the hippocampus and cortex, resulting in better performance on a task of episodic memory. Forty-five individuals with a clinically definite diagnosis of MS were recruited for the study.

The value of success: acquiring gains, avoiding losses, and simply being successful.

A large network of spatially contiguous, yet anatomically distinct regions in medial frontal cortex is involved in reward processing. Although it is clear these regions play a role in critical aspects of reward-related learning and decision-making, the individual contributions of each component remains unclear. We explored dissociations in reward processing throughout several key regions in the reward system and aimed to clarify the nature of previously observed outcome-related activity in a portion of anterior medial orbitofrontal cortex (mOFC).

Adhesion molecules, altered vasoreactivity, and brain atrophy in type 2 diabetes.

Objective: To investigate the effects of inflammation on perfusion regulation and brain volumes in type 2 diabetes.

Research Design And Methods: A total of 147 subjects (71 diabetic and 76 nondiabetic, aged 65.2 ± 8 years) were studied using 3T anatomical and continuous arterial spin labeling magnetic resonance imaging.

Tocotrienol vitamin E protects against preclinical canine ischemic stroke by inducing arteriogenesis.

Vitamin E consists of tocopherols and tocotrienols, in which α-tocotrienol is the most potent neuroprotective form that is also effective in protecting against stroke in rodents. As neuroprotective agents alone are insufficient to protect against stroke, we sought to test the effects of tocotrienol on the cerebrovascular circulation during ischemic stroke using a preclinical model that enables fluoroscopy-guided angiography. Mongrel canines (mean weight=26.

Reprint of: Aspects of neuroticism and the amygdala: chronic tuning from motivational styles.

Recent research and theory has highlighted the dynamic nature of amygdala activation. Rather than simply being sensitive to a few limited stimulus categories, amygdala activation appears to be dependent on the goals of the perceiver. In this study, we extend this line of work by demonstrating that the means by which a person seeks to accomplish a goal also modulates the amygdala response.

An endovascular canine middle cerebral artery occlusion model for the study of leptomeningeal collateral recruitment.

Objectives: This work aimed to refine a large animal in minimally invasive reversible middle cerebral artery (MCA) occlusion (MCAO) model to account for leptomeningeal collateral formation.

Materials And Methods: An angiographically based methodology allowed for transient MCA and carotid terminus occlusion in 12 mongrel dogs and assessment of pial collateral recruitment. Outcome measures included 1- and 24-hour magnetic resonance imaging-based infarct volume calculation, a behavioral scale and histopathologic sections.

Aspects of neuroticism and the amygdala: chronic tuning from motivational styles.

Recent research and theory has highlighted the dynamic nature of amygdala activation. Rather than simply being sensitive to a few limited stimulus categories, amygdala activation appears to be dependent on the goals of the perceiver. In this study, we extend this line of work by demonstrating that the means by which a person seeks to accomplish a goal also modulates the amygdala response.

Effect of propranolol on functional connectivity in autism spectrum disorder--a pilot study.

A decrease in interaction between brain regions is observed in individuals with autism spectrum disorder (ASD), which is believed to be related to restricted neural network access in ASD. Propranolol, a beta-adrenergic antagonist, has revealed benefit during performance of tasks involving flexibility of access to networks, a benefit also seen in ASD. Our goal was to determine the effect of propranolol on functional connectivity in ASD during a verbal decision making task as compared to nadolol, thereby accounting for the potential spurious fMRI effects due to peripheral hemodynamic effects of propranolol.

7 Tesla MR imaging of the human eye in vivo.

Purpose: To develop a protocol which optimizes contrast, resolution and scan time for three-dimensional (3D) imaging of the human eye in vivo using a 7 Tesla (T) scanner and custom radio frequency (RF) coil.

Materials And Methods: Initial testing was conducted to reduce motion and susceptibility artifacts. Three-dimensional FFE and IR-TFE images were obtained with variable flip angles and TI times.

Association of blood pressure elevation and nocturnal dipping with brain atrophy, perfusion and functional measures in stroke and nonstroke individuals.

Background: Although both blood pressure elevation and lower nocturnal dipping increase vascular risk, it is not known whether either or both are also associated with brain atrophy, cerebral perfusion, and functional status.

Methods: We investigated the association of elevated blood pressure and nocturnal dipping based on 24-h ambulatory recordings with brain atrophy and perfusion and functional status in 80 older adults with and without stroke (age 66.4 +/- 0.

High resolution ultra high field magnetic resonance imaging of glioma microvascularity and hypoxia using ultra-small particles of iron oxide.

Objectives: This study assessed whether ultra-small particles of iron oxide (USPIO) intravascular contrast agent could enhance visualization of tumor microvascularity in F98 glioma bearing rats by means of ultra high field (UHF) high-resolution gradient echo (GRE) magnetic resonance imaging (MRI). In an effort to explain differences in visualization of microvascularity before and after USPIO administration, hypoxia and vessel diameters were assessed on corresponding histopathologic sections.

Materials And Methods: F98 glioma cells were implanted stereotactically into the brains of syngeneic Fischer rats.

White matter hyperintensities and dynamics of postural control.

Background: White matter hyperintensities (WMHs) on MRI have been associated with age, cardiovascular risk factors and falls in the elderly. This study evaluated the relationship between WMHs and dynamics of postural control in older adults without history of falls.

Methods: We studied 76 community-living subjects without history of falls (age 64.

Minimally invasive neuroradiologic model of preclinical transient middle cerebral artery occlusion in canines.

Stroke is currently the third leading cause of death in the United States, with approximately 780,000 Americans affected by a new or recurring stroke each year. Although a variety of therapeutic approaches have shown promise in small-animal models of stroke, the vast majority of clinical trials to test the efficacy of such modalities have failed. To bridge the translational gap between laboratory and clinical research, we developed a preclinical model of acute ischemic stroke in dogs.

Characterization of water distribution in bread during storage using magnetic resonance imaging.

A soy bread of fully acceptable quality and containing 49% soy ingredients (with or without 5% almond powder) has been recently developed in our laboratory. An investigation on water distribution and mobility, as probed by proton signal intensity and T2 magnetic resonance images, during storage was designed to examine possible relations between water states and hindered staling rate upon soy or soy-almond addition. Water proton distribution throughout soy-containing loaves was found to be very homogeneous in fresh breads with and without almond, with minimal water migration occurring during prolonged storage.

Global and regional effects of type 2 diabetes on brain tissue volumes and cerebral vasoreactivity.

Objective: The aim of this study was to evaluate the regional effects of type 2 diabetes and associated conditions on cerebral tissue volumes and cerebral blood flow (CBF) regulation.

Research Design And Methods: CBF was examined in 26 diabetic (aged 61.6 +/- 6.