M. Brus-ramer

Neurogenic thoracic outlet syndrome (nTOS) is caused by compression of the brachial plexus as it traverses from the thoracic outlet to the axilla. Diagnosing nTOS can be difficult because of overlap with other complex pain and entrapment syndromes. An nTOS diagnosis is made based on patient history, physical exam, electrodiagnostic studies, and, more recently, interpretation of MR neurograms with tractography. Advances in high-resolution MRI and tractography can confirm an nTOS diagnosis and identify the location of nerve compression, allowing tailored surgical decompression. In this report, the authors review the current diagnostic criteria, present an update on advances in MRI, and provide case examples demonstrating how MR neurography (MRN) can aid in diagnosing nTOS. The authors conclude that improved high-resolution MRN and tractography are valuable tools for identifying the source of nerve compression in patients with nTOS and can augment current diagnostic modalities for this...

Increasing in number and complexity, interventional neuroradiology (INR) procedures are becoming an important source of radiation exposure for patients. In accordance with the ALARA principle, radiation exposure during INR procedures should be curtailed as much as possible while reaching successful treatment outcomes. Moreover, the extent of radiation exposure should be one outcome measure used to assess new technologies and procedural efficacy, and training programs should include techniques for exposure limitation. This study provides a methodology and preliminary data to assess radiation exposure during different INR procedure types. All patients undergoing endovascular procedures in two biplanar dedicated neuroangiography suites at a major academic medical center were monitored according to procedure type, pathological indication, fluoroscopy time and machine-generated patient dose estimates between April 2006 and July 2008. 1678 patients underwent cerebral arteriography during ...

Injury to the brain or spinal cord usually preserves some corticospinal (CS) connections. These residual circuits sprout spontaneously and in response to activity-based treatments. We hypothesized that augmenting activity in spared CS circuits would restore the skilled motor control lost after injury and augment outgrowth of CS terminations in the spinal cord. After selective injury of one half of the CS tract (CST) in the rat, we applied 10 d of electrical stimulation to the forelimb area of motor cortex of the spared half and tested motor performance for 30 d. Rats with injury and CST stimulation showed substantial improvements in skilled paw placement while walking over a horizontal ladder. By the end of the testing period, the walking errors of the previously impaired forelimb in rats with injury and stimulation returned to baseline, while the errors remained elevated in rats with injury only. Whereas the time to perform the task returned to normal in all animals, the pattern of...

tSCH in the absence of spinal trauma or surgery is a rare disorder for which numerous mechanisms have been proposed. Here, we have conducted an analysis of images in all published reports of idiopathic tSCH and identified evidence supporting a pathogenesis in which anterior dural erosion at thoracic levels generates a CSF leak that pushes adjacent spinal tissue to tamponade the dural defect, causing progressive myelopathy. Additionally, we describe a case of tSCH in which postural headache was a significant symptom before myelopathy. This finding suggests that tSCH pathogenesis may be related to spontaneous intracranial hypotension. Published imaging from all available prior case reports in the scientific literature was reviewed to determine whether tSCH occurred at the disk or bone level. The presence of EDF, HNP, or an osteophyte in the spinal canal was determined from review of published images. Additionally, 3 previously unreported cases from the teaching files of our department...

Hyperperfusion is a rare but serious complication following cerebrovascular angioplasty and stent placement. Radiographically identifying hyperperfusion before the development of severe sequelae is difficult, as few diagnostic criteria have been established. A 50-year-old woman, initially presenting with 6 weeks of right-sided hemiparesis and dysarthria, was treated for severe stenosis of the left internal carotid and middle cerebral arteries with intracranial angioplasty and placement of a balloon mounted Wingspan Stent (Boston Scientific, Fremont, CA). Continuous transcranial Doppler monitoring after stent placement indicated developing cerebral hyperperfusion. Concurrent angiography revealed markings consistent with dilatations of small arteries in the vascular territory of the stented arteries. Aggressive blood pressure management started in the procedure and continued postprocedure led to an approximately 40% reduction in systolic blood pressure. The patient had an uneventful p...

To evaluate the occurrence of alterations to diagnostic information from radiological studies, which are altered by person-to-person communication and/or faulty recall, and whether they affect patient management A structured telephone survey was conducted at a large tertiary care medical centre of house staff managing inpatients who had undergone chest, abdominal, or pelvic computed tomography (CT) or magnetic resonance imaging (MRI) and remained in the hospital at least 2 days later. Fifty-six physicians were surveyed regarding 98 patient cases. Each physician was asked how he or she first became aware of the results of the study. Each was then asked to recall the substance of radiological interpretation and to compare it with the radiology report. Each was then asked to assess the level of difference between the interpretations and whether management was affected. Results were correlated with the route by which interviewees became aware of the report, the report length, and whether the managing service was medical or surgical. In nearly 15% (14/98) of cases, differences between the recalled and official results were such that patient management could have been (11.2%) or had already been affected (3.1%). There was no significant correlation between errors and either the route of report communication or the report length. There was a substantial rate of error in the recall and/or transmission of diagnostic radiological information, which was sufficiently severe to affect patient management.

Activity-dependent competition shapes corticospinal (CS) axon outgrowth in the spinal cord during development. An important question in neural repair is whether activity can be used to promote outgrowth of CS axons in maturity. After injury, spared CS axons sprout and make new connections, but often not enough to restore function. We propose that electrically stimulating spared axons after injury will enhance sprouting and strengthen connections with spinal motor circuits. To study the effects of activity, we electrically stimulated CS tract axons in the medullary pyramid. To study the effects of injury, one pyramid was lesioned. We studied sparse ipsilateral CS projections of the intact pyramid as a model of the sparse connections preserved after CNS injury. We determined the capacity of CS axons to activate ipsilateral spinal motor circuits and traced their spinal projections. To understand the separate and combined contributions of injury and activity, we examined animals receivi...

Tissue processing and analysis require good preservation of both the shape and content of cells. Lowicryl resin is one of the few embedding media that allow good preservation of both tissue architecture and cellular contents. Therefore, different histochemical and immunohistochemical reactions can be applied to semithin sister sections from one biopsy. Further examination of a zone of interest can be carried out under the electron microscope. The hydrophilic property of Lowicryl resins makes possible different histochemical reactions; however, the technique used for paraf?n sections must be adapted for each reaction. Antigenic preservation of cells by low temperature embedding allows immunolabeling on either semithin sections or in the zone of interest on ultrathin sections. We have shown the application and adaptation of different histochemical and immunohistochemical reactions on semithin and ultrathin sections from hepatic biopsies that were large, but thin. The variety of techni...