Faculty Bibliography

Research Objectives: Processing speed (PS) deficits are among the most common neuropsychological (NP) deficits following traumatic brain injury (TBI). These objective deficits may lead to subjective feelings of being flooded and overwhelmed or that things happen too quickly that one can no longer keep up with cognitive demands made by external events. This subjective experience of slowed PS has been proposed to underlie symptoms of emotional reactivity (ER), such as, tension, frustration, and irritability, which in turn may exacerbate cognitive complaints. The aim of this study was to evaluate the role of objective PS deficits in ER and cognitive/somatic postconcussive symptoms (PCS) following mild TBI (mTBI). Design: Correlational/regression analyses examining objective PS measures, ER, and somatic/cognitive PCS. Setting: Large academic medical center. Participants: Adults with mTBI (n = 31), 52% female, primarily White (74%), average age of 35.8, with 16.1 years of education. Interventions: N/A. Main Outcome Measure(s): Standard TBI outcome battery, 6,7 addressing (a) objective NP impairments, (b) psychological status, and (c) PCS. ER was assessed using z-score composite of relevant self-report items. Results: Objective PS measures were significantly related to ER. ER explained a significant 33% of variance in somatic/cognitive PCS, Beta = -.62, t (29) = -3.15, p =.004, over and above variance explained directly by PS, Beta = -.07, t (29) = -.38, ns. Conclusions: ER is directly related to objective PS deficits. In addition, ER is a significant predictor of somatic/cognitive PCS, whereas objective PS measures are not directly related to PCS. Emotional reactions to the experience of objective cognitive slowing warrant further investigation as a predictor of those at risk for prolonged PCS. Further examination of ER as a predictor of PCS may lead to more accurate assessment/prognosis following mTBI

Hip pain is a common complaint that can have both intra-articular and extra-articular origins. Three common causes of hip pain are hip osteoarthritis, iliopsoas tendinopathy, and gluteus medius tendinopathy. Current treatment plans range from conservative measures to surgical replacement. Traditionally, minimally invasive approaches with the use of corticosteroid and local anesthetic injections have served to manage symptoms of pain without altering disease progression. In addition, these agents have been associated with deleterious effects on bone, tendon, and cartilage health. Emerging regenerative medicine techniques are becoming increasingly popular for the management of hip pain, as they have been shown to improve clinical outcomes and potentially alter disease progression. Some of these techniques, such as injection of platelet-rich plasma, mesenchymal stem cells, and percutaneous needle fenestration, have been shown to promote healing of damaged tissue. These techniques are often augmented by the use of ultrasound imaging, which greatly increases ease and accuracy. This article reviews ultrasound-guided regenerative orthopedic injections specifically for hip joint osteoarthritis, gluteus medius tendinopathy, and iliopsoas tendinopathy.

Schemas are abstract nonverbal representations that parsimoniously depict spatial relations. Despite their ubiquitous use in maps and diagrams, little is known about their neural instantiation. We sought to determine the extent to which schematic representations are neurally distinguished from language on the one hand, and from rich perceptual representations on the other. In patients with either left hemisphere damage or right hemisphere damage, a battery of matching tasks depicting categorical spatial relations was used to probe for the comprehension of basic spatial concepts across distinct representational formats (words, pictures, and schemas). Left hemisphere patients underperformed right hemisphere patients across all tasks. However, focused residual analyses using voxel-based lesion-symptom mapping (VLSM) suggest that (1) left hemisphere deficits in the representation of categorical spatial relations are difficult to distinguish from deficits in naming these relations and (2) the right hemisphere plays a special role in extracting schematic representations from richly textured pictures.

Studies in semantics traditionally focus on knowledge of objects. By contrast, less is known about how objects relate to each other. In an fMRI study, we tested the hypothesis that the neural processing of categorical spatial relations between objects is distinct from the processing of the identity of objects. Attending to the categorical spatial relations compared with attending to the identity of objects resulted in greater activity in superior and inferior parietal cortices (especially on the left) and posterior middle frontal cortices bilaterally. In an accompanying lesion study, we tested the hypothesis that comparable areas would be necessary to represent categorical spatial relations and that the hemispheres differ in their biases to process categorical or coordinate spatial relations. Voxel-based lesion symptom mapping results were consistent with the fMRI observations. Damage to a network comprising left inferior frontal, supramarginal, and angular gyri resulted in behavioral impairment on categorical spatial judgments. Homologous right brain damage also produced such deficits, albeit less severely. The reverse pattern was observed for coordinate spatial processing. Right brain damage to the middle temporal gyrus produced more severe deficits than left hemisphere damage. Additional analyses suggested that some areas process both kinds of spatial relations conjointly and others distinctly. The left angular and inferior frontal gyrus processes coordinate spatial information over and above the categorical processing. The anterior superior temporal gyrus appears to process categorical spatial information uniquely. No areas within the right hemisphere processed categorical spatial information uniquely. Taken together, these findings suggest that the functional neuroanatomy of categorical and coordinate processing is more nuanced than implied by a simple hemispheric dichotomy.

Artists with neurological diseases sometimes produce remarkably appealing art. Here we present the art of a patient with Parkinson's disease, who demonstrated remarkable creativity and productivity well into the course of his disease. Despite his manifest motor impairments, he produced paintings and drawings with fluid sinuous movements. He also became preoccupied with his art in an unprecedented way, raising the possibility that his disease and medications were contributing to his creative drive.

It is well established that the amygdala plays an essential role in Pavlovian fear conditioning, with the lateral nucleus serving as the interface with sensory systems that transmit the conditioned stimulus and the central nucleus as the link with motor regions that control conditioned fear responses. The lateral nucleus connects with the central nucleus directly and by way of several other amygdala regions, including the basal, accessory basal, and medial nuclei. To determine which of these regions is necessary, and thus whether conditioning requires the direct or one of the indirect intra-amygdala pathways, we made lesions in rats of the lateral, central, basal, accessory basal, and medial nuclei, as well as combined lesions of the basal and accessory basal nuclei and of the entire amygdala. Animals subsequently underwent fear conditioning trials in which an auditory conditioned stimulus was paired with a footshock unconditioned stimulus. Animals that received lesions of the lateral or central nucleus, or of the entire amygdala, were dramatically impaired, whereas the other lesions had little effect. These findings show that only the lateral and central nuclei are necessary for the acquisition of conditioned fear response to an auditory conditioned stimulus

It is commonly assumed that suppression of an ongoing behavior is an indirect measure of freezing behavior. We tested whether conditioned suppression and freezing are the same or distinct conditioned responses. Rats were trained to press a bar for food and then given fear-conditioning sessions in which a tone was paired with a foot shock (two pairings a day for 2 days). They then received either sham or electrolytic lesions of the periaqueductal gray (PAG). Post-training PAG lesions blocked freezing to the conditioned stimulus (CS), but had no effect on the suppression of operant behavior to the same CS. Thus, conditioned suppression and freezing, which both cause a cessation in activity, appear to be mediated by separate processes