Patients with traumatic brain injury (TBI) and significant cognitive deficits often fail to show abnormalities on standard magnetic resonance images (MRI). We describe Quantitative Automated Lesion Detection procedures using multiple MRI modalities (T1,...

Objective: Olfactory dysfunction is associated with Alzheimer’s Disease development. Our previous study revealed that odor identification tasks activated several olfactory brain regions more than odor memory tasks. In this study, we examined if apolipop...

Stereotactic placement of deep brain stimulation (DBS) leads for the treatment of movement disorders has traditionally been guided by microrecording and macrostimulation in awake patients, with subsequent confirmation by MRI after the lead’s stylet has been removed. When placement errors occur, the surgery must be repeated and the lead replaced. Visual guidance by concurrent MRI would improve placement accuracy and reduce the need for repeated surgeries. An MRI-compatible trajectory guidance system (IGN) has been developed to fix DBS leads in place without removing the stylet, and allow remote adjustment of the lead position as needed. In preparation for clinical applications, we performed safety tests of this device in a 1.5-Tesla Siemens Sonata MR system. We evaluated local temperature changes using clinically relevant and ¨worst-case¨ MRI sequences in a semi-solid, gel-filled phantom. The lead tip (Medtronic), with stylet in place, was immersed into the phantom using the trajectory guide and remote intr...

Background: Child neglect is a pervasive pediatric problem, frequently associated with disturbed mother-infant attachment. However, little is known about the neurobiological substrate underlying this relationship. This pilot study of healthy mother-infant dyads aims to examine brain regions activated in response to infant facial cues, and to explore the possible role of oxytocin in facilitating this interaction. Methods: Eight right-handed healthy mothers were enrolled, along with their infants aged between 3 and 8 months. Serum oxytocin levels levels were obtained sequentially during a standardized period of mother-infant interaction, during which the infant's facial expressions were videotaped. Functional MRI was then used to measure maternal brain activity in response to these facial images, compared with familiar and unknown facial images. Results: In comparing responses to the mothers’ own infants versus familiar but unknown infants, significantly increased brain responses (p<0.005) were seen in the v...

Prior MRI studies have shown cortical gray matter increases in bipolar patients treated with lithium, but it is unknown whether this is related to the disease process. We studied serial structural MRI brain scans (3D SPGR, 1.5 mm slices) from 13 healthy subjects (6F/7M; mean age: 25.5 yrs.+/-10.0SD, scan interval: 4 weeks) treated with 0.5-1.5 mEq/L lithium (a therapeutic dose). To map 3D patterns of local tissue changes over time, an intensity-based elastic registration algorithm deformed the follow-up to the baseline scan by maximizing the mutual information. A tissue change map (the Jacobian of the deformation), for each individual, was nonlinearly normalized to the anatomical space of a reference subject. Mean lithium effects were established by voxel-wise averaging the log-transformed Jacobian maps. Significant tissue hypertrophy was detected. A 2-4% average volume increase was detected in primary sensorimotor and superior frontal regions, consistent with tissue gains localized in prior cortical mappi...

MRI studies have shown dramatic age-associated changes in grey and white matter volume, but typically use univariate analyses that do not explicitly test the interrelationship among brain regions. The current study employed a multivariate approach to identify covariance patterns of grey and white matter tissue density to distinguish older from younger adults. A second aim was to examine whether the expression of these age-associated covariance topographies is related to performance on cognitive tests affected by normal aging. Methods: 84 young (M age=24.0) and 29 older (M age=73.1) participants were scanned with a 1.5 T MRI and assessed with a cognitive battery. Images were spatially normalized and segmented to produce grey and white matter density maps. A multivariate covariance technique, based on the Subprofile Scaling Model, was used to capture sources of between- and within-group variation and to produce a series of principal components (PCs). The analysis identified a linear combination of the PCs th...

Absence seizures are impairments of consciousness with 3 Hz spike-wave discharges (SWD) on EEG. To elucidate the neuroanatomy responsible for these behavioral and EEG effects, manganese enhanced MRI (MEMRI) was completed. Mn2+ is a Ca2+ analog and MR contrast agent that has been used to non-invasively visualize Ca2+-dependent neural activity. A unique property of Mn2+ is that once internalized it is transported transynaptically via functional connections of neurons. This study was designed to uncover the functional neuroanatomical circuit causing absence epilepsy. Rats were stereotaxically implanted with a cannula in the somatosensory cortex (peri-oral area). Rats were then given an i.p. injection of vehicle or γ-butyrolactone (GBL, used to induce the absence seizure). Five minutes after GBL/vehicle administration rats were microinjected with 100nl of 100mM MnCl2 into the somatosensory cortex. The SWDs characterizing the seizure were maintained for 8 hours by repeated injections of GBL to allow sufficient ...

Network analysis has provided new and important insights into the function of complex systems such as the brain by examining the topology of both structural and functional networks constructed from diffusion MRI, functional MRI (fMRI) and electro/magnet...

Continuous intrathecal (IT) delivery of morphine sulfate (MS) for 28 days can produce aseptic subdural inflammatory masses (granulomas) localized at the catheter tip. The rate at which these IT masses develop, and if they regress after MS infusions are terminated are unknown. To assess this, we performed serial MRI scans with gadolinium (Gd) enhancement in dogs. Beagle dogs were implanted with chronic IT lumbar catheters and were infused at 0.96 ml/day for 28 days. Dogs received a 100% granuloma inducing concentration of MS (12.5 mg/ml), the maximum tolerable concentration of fentanyl HCl (2 mg/ml) or the mu specific peptide DAMGO (2 mg/ml). Before MS infusions, MRI scans were obtained with a Siemens Symphony 1.5 Tesla system while dogs were anesthetized with propofol. Dogs had repeated MRI scans at intervals ranging from 3 to 14 days, for up to 45 days, with IV Gd (Optimark, 0.2 mmol/kg). One group of dogs had saline substituted for MS at the first appearance of a mass by MRI. A second group of dogs conti...

Combination therapies are being developed to improve memory in cases of mild cognitive impairment and early stage Alzheimer’s. To this end, we followed changes in brain activity caused by a serotonin receptor antagonist given alone or in combination wit...