Comparison of Form and Motion Coherence Processing in Autistic Spectrum Disorders and Dyslexia

A large body of research has reported visual perception deficits in both people with dyslexia and autistic spectrum disorders. In this study, we compared form and motion coherence detection between a group of adults with high-functioning autism, a group with Asperger's disorder, a group with dyslexia, and a matched control group. It was found that motion detection was intact in dyslexia and Asperger. Individuals with high-functioning autism showed a general impaired ability to detect coherent form and motion. Participants with Asperger's syndrome showed lower form coherence thresholds than the dyslexic and normally developing adults. The results are discussed with respect to the involvement of the dorsal and ventral pathways in developmental disorders.     

Extraction and localization of mesoscopic motor control signals for human ECoG neuroprosthetics

Electrocorticogram (ECoG) recordings for neuroprosthetics provide a mesoscopic level of abstraction of brain function between microwire single neuron recordings and the electroencephalogram (EEG). Single-trial ECoG neural interfaces require appropriate feature extraction and signal processing methods to identify and model in real-time signatures of motor events in spontaneous brain activity. Here, we develop the clinical experimental paradigm and analysis tools to record broadband (1Hz to 6kHz) ECoG from patients participating in a reaching and pointing task. Motivated by the significant role of amplitude modulated rate coding in extracellular spike based brain-machine interfaces (BMIs), we develop methods to quantify spatio-temporal intermittent increased ECoG voltages to determine if they provide viable control inputs for ECoG neural interfaces. This study seeks to explore preprocessing modalities that emphasize amplitude modulation across frequencies and channels in the ECoG above the level of noisy background fluctuations in order to derive the commands for complex, continuous control tasks. Preliminary experiments show that it is possible to derive online predictive models and spatially localize the generation of commands in the cortex for motor tasks using amplitude modulated ECoG.     

Reduced caudate gray matter volume in women with major depressive disorder

Previous brain-imaging studies have reported that major depressive disorder (MDD) is characterized by decreased volumes of several cortical and subcortical structures, including the hippocampus, amygdala, anterior cingulate cortex, and caudate nucleus. The purpose of the present study was to identify structural volumetric differences between MDD and healthy participants using a method that allows a comparison of gray and white matter volume across the whole brain. In addition, we explored the relation between symptom severity and brain regions with decreased volumes in MDD participants. The study group comprised 22 women diagnosed with MDD and 25 healthy women with no history of major psychiatric disorders. Magnetic resonance brain images were analyzed using optimized voxel-based morphometry to examine group differences in regional gray and white matter volume. Compared with healthy controls, MDD participants were found to have decreased gray matter volume in the bilateral caudate nucleus and the thalamus. No group differences were found for white matter volume, nor were there significant correlations between gray matter volumes and symptom severity within the MDD group. The present results suggest that smaller volume of the caudate nucleus may be related to the pathophysiology of MDD and may account for abnormalities of the cortico-striatal-pallido-thalamic loop in MDD.     

Screw orientation and plate type (variable- vs. fixed-angle) effect strength of fixation for in vitro biomechanical testing of the Synthes CSLP

BACKGROUND CONTEXT: Two common justifications for orienting cervical screws in an angled direction are to increase pullout strength and to allow use of longer screws. This concept is widely taught and has guided implant design. Fixed- versus variable-angle systems may offer strength advantages. Despite these teachings, there is a paucity of supporting biomechanical evidence. The purpose of our study is to test the influence of screw orientation and plate design on the maximum screw pullout force. PURPOSE: This study evaluates the effect of screw orientation and plate type (fixed- vs. variable-angle) on screw pullout strength. STUDY DESIGN: Anterior cervical plates of both a fixed- and variable-angle CSLP, were tested for peak pullout strength in a direct plate pullout model using polyurethane foam bone, which models osteoporotic bone. METHODS: Self-tapping, locking screws (4.0x14mm and 4.0x16mm) were used. Screws were oriented in the fixed-angle plate in the standard fashion. In the variable plate, screws were instrumented in three different orientations. Biomechanical testing was performed on an Instron DynaMight 8841 servohydraulic testing machine, measuring maximum pullout force under a displacement-controlled pullout rate of 1mm/min. Five samples were tested per group. RESULTS: When all screws were placed 90 degrees to the plate, there was a significantly increased peak pullout strength (412.8+/-22.2N) compared with when all screws were placed 12 degrees "up and in" (376.2+/-24.3N, p less than or equal to .03). When the 90 degrees construct was reproduced using 14-mm screws and compared with 16-mm screws oriented 12 degrees "all up and in," there was still significantly higher pullout strength with the all 90 degrees construct (434.2+/-28.7N vs. 376.2+/-24.3N, p less than or equal to .009). The fixed-angle plate had a significantly decreased peak pullout strength (288.2+/-15.7N) compared with the variable-angle plate (416.6+/-12.6N) (p less than .00001) when the screws were placed in the same orientation. Overall, the variable-angle plate, regardless of the orientation of screws, had a significantly greater pullout strength than the fixed-angle plate (p less than .001). CONCLUSIONS: In this system, a variable-angle plate has greater pullout strength than a fixed-angle plate, regardless of the orientation of screws. With the variable-angle plate, a construct of all screws 12 degrees "up and in" is the weakest configuration. We found that with the 90 degrees construct, both 16- and 14-mm screws performed significantly better than 16-mm convergent screws. These findings are remarkable because they contradict the current doctrine. This may be a function of plate-dependent factors and should not be applied universally to all plate systems. Further study of screw orientation in additional plating systems is warranted.     

An unusual case of spinal column metastasis after orthotopic transplantation for cardiac sarcoma

The authors describe a patient who underwent orthotopic cardiac transplantation after an undifferentiated cardiac sarcoma was diagnosed. While receiving immunosuppressive therapy, the patient developed spinal column metastases and cauda equina syndrome requiring surgical decompression and stabilization. This occurred despite an exhaustive search for metastatic disease prior to the transplantation. To the authors' knowledge, this represents the first reported case of an undifferentiated cardiac sarcoma metastasis to the spine. This previously healthy 18-year-old woman presented with a myocardial infarction. Investigations revealed a left atrial tumor, which was resected. Following local recurrence, the patient underwent extensive studies to rule out systemic disease. Orthotopic heart-lung transplantation was then performed. While receiving postoperative immunosuppressive therapy the patient presented with cauda equina syndrome secondary to metastatic tumor compression at the L-5 level. Despite a comprehensive screening process to exclude metastatic disease prior to transplantation, spinal metastases occurred while this patient was receiving immunosuppressive therapy. This represents a previously unreported and clinically significant complication for undifferentiated cardiac sarcoma.     

Distribution of in vivo and in vitro range of motion following 1-level arthroplasty with the CHARITE artificial disc compared with fusion

OBJECT: One of the goals of lumbar arthroplasty is to restore and maintain range of motion (ROM) and to protect adjacent levels from abnormal motion, which may be a factor in transition syndrome following arthrodesis. In this study, in vitro ROM results were compared with in vivo, 2-year postoperative radiographic ROM evaluations. METHODS: Radiographs of patients enrolled in the CHARITE investigational device exemption study were analyzed at baseline and at 2 years postoperatively. The ROM in flexion/extension at the implanted and adjacent levels was measured, normalized, and compared with ROM results obtained using cadaver (in vitro) evaluations. RESULTS: Preoperative ROM distributions in patients enrolled for arthroplasty or fusion at the L4-5 level was as follows: 28% motion was observed at L3-4, 35% at L4-5 and 37% at L5-S1. Following a one-level arthroplasty at L4-5, the in vivo ROM distribution from L-3 to S-1 at the 2-year time point was 36% at L3-4, 30% at L4-5 and 35% at L5-S1. Following a one-level fusion with BAK and pedicle screws at L4-5, the in vivo ROM distribution from L-3 to S-1 at the 2-year time point was 45% at L3-4, 9% at L4-5 and 46% at L5-S1. CONCLUSIONS: The baseline as well as the 2-year in vivo data confirmed previously published in vitro data. One-level arthroplasty was shown herein to replicate the normal distribution of motion of the intact spine.     

Validation of Surgical Intensive Care-Infection Registry: a medical informatics system for intensive care unit research, quality of care improvement, and daily patient care

BACKGROUND: We developed a prototype electronic clinical information system called the Surgical Intensive Care-Infection Registry (SIC-IR) to prospectively study infectious complications and monitor quality of care improvement programs in the surgical and trauma intensive care unit. The objective of this study was to validate SIC-IR as a successful health information technology with an accurate clinical data repository. STUDY DESIGN: Using the DeLone and McLean Model of Information Systems Success as a framework, we evaluated SIC-IR in a 3-month prospective crossover study of physician use in one of our two surgical and trauma intensive care units (SIC-IR unit versus non SIC-IR unit). Three simultaneous research methodologies were used: a user survey study, a pair of time-motion studies, and an accuracy study of SIC-IR's clinical data repository. RESULTS: The SIC-IR user survey results were positive for system reliability, graphic user interface, efficiency, and overall benefit to patient care. There was a significant decrease in prerounding time of nearly 4 minutes per patient on the SIC-IR unit compared with the non SIC-IR unit. The SIC-IR documentation and data archiving was accurate 74% to 100% of the time depending on the data entry method used. This accuracy was significantly improved compared with normal hand-written documentation on the non SIC-IR unit. CONCLUSIONS: SIC-IR proved to be a useful application both at individual user and organizational levels and will serve as an accurate tool to conduct prospective research and monitor quality of care improvement programs.     

Ductal prostate cancer: contemporary management and outcomes

OBJECTIVES: To evaluate contemporary management and outcomes of ductal prostate cancer (PCA). MATERIALS AND METHODS: We reviewed all patients with ductal PCA and at least 6 months of follow-up seen at UTMB from 1990 to 2005, which comprised 17 patients (mean age: 67.7 years, range 55-87). At time of diagnosis, 11 patients had localized disease (Group 1) and 6 patients had distant metastasis (Group 2). RESULTS: Treatment of Group 1 patients included radiation and endocrine treatment for at least 2 years (n = 7), radiation alone (n = 2), and radical surgery (n = 2). At a mean follow-up of 3.6 years (r = 1-12 years) 8 patients (67.7%) remained free of recurrence, 1 patient had biochemical recurrence alone, 1 patient had recurrence in the anterior urethra, and the other had progression with metastasis to the brain and subsequent death. In addition to metastasis to regional/distant lymph nodes and bone in Group 2, metastatic sites included brain (n = 1), peritoneum (n = 1), and lung (n = 1). Mean follow-up was 2.3 years (r = 8 months to 4 years). All patients received androgen deprivation. One patient had progression of disease despite lack of biochemical recurrence and is alive at 2.5 years. One patient died from other causes while the 4 remaining patients are in remission at last follow-up. CONCLUSIONS: Contemporary management of localized ductal PCA with radiation and endocrine therapy yields adequate disease-free survival. Metastatic sites include brain, lung, peritoneum, and anterior urethra, and most patients respond well to endocrine treatment.     

Metastatic adrenocortical oncocytoma: a case report

With only 51 cases reported in the literature to date, adrenocortical oncocytoma is an exceedingly rare pathological variant of adrenal neoplasms. The first case of metastatic adrenocortical oncocytoma is reported along with an update of the literature. A role for radiotherapy in the palliative setting is demonstrated.