Biomedical subjects
Publications and source records attributed to Richard E Latchaw.
Butane inhalation can cause serious medical complications and is particularly toxic to the nervous system. This is a report of an acutely encephalopathic youth with prominent abulia. MRI revealed severe bithalamic injury attributed to butane toxicity. Clinical issues, including particular radiologic findings, related to butane inhalation are reviewed.
BACKGROUND AND PURPOSE: To develop recommendations for the establishment of comprehensive stroke centers capable of delivering the full spectrum of care to seriously ill patients with stroke and cerebrovascular disease. Recommendations were developed by members of the Brain Attack Coalition (BAC), which is a multidisciplinary group of members from major professional organizations involved with the care of patients with stroke and cerebrovascular disease. SUMMARY OF REVIEW: A comprehensive literature search was conducted from 1966 through December 2004 using Medline and Pub Med. Articles with information about clinical trials, meta-analyses, care guidelines, scientific guidelines, and other relevant clinical and research reports were examined and graded using established evidence-based medicine approaches for therapeutic and diagnostic modalities. Evidence was also obtained from a questionnaire survey sent to leaders in cerebrovascular disease. Members of BAC reviewed literature related to their field and graded the scientific evidence on the various diagnostic and treatment modalities for stroke. Input was obtained from the organizations represented by BAC. BAC met on several occasions to review each specific recommendation and reach a consensus about its importance in light of other medical, logistical, and financial factors. CONCLUSIONS: There are a number of key areas supported by evidence-based medicine that are important for a comprehensive stroke center and its ability to deliver the wide variety of specialized care needed by patients with serious cerebrovascular disease. These areas include: (1) health care personnel with specific expertise in a number of disciplines, including neurosurgery and vascular neurology; (2) advanced neuroimaging capabilities such as MRI and various types of cerebral angiography; (3) surgical and endovascular techniques, including clipping and coiling of intracranial aneurysms, carotid endarterectomy, and intra-arterial thrombolytic therapy; and (4) other specific infrastructure and programmatic elements such as an intensive care unit and a stroke registry. Integration of these elements into a coordinated hospital-based program or system is likely to improve outcomes of patients with strokes and complex cerebrovascular disease who require the services of a comprehensive stroke center.
BACKGROUND AND PURPOSE: Percutaneous vertebroplasty is an effective tool for the relief of pain caused by osteoporotic spine fractures. Our purpose is to evaluate this technique and its effectiveness in restoring the height of such fractures. METHODS: Forty osteoporotic vertebral body fractures in 30 consecutive patients (24 female, six males; mean age, 70 years) were analyzed retrospectively, before and after percutaneous vertebroplasty, for changes in vertebral body height, kyphosis angle, and wedge angle. The ages of the fractures range from 1 to 5 months. RESULTS: Percutaneous vertebroplasty improved the pretreatment height of compression fractures in these patients by a mean of 47.6% (P < .001), with only 15% showing no improvement. These figures compare favorably with published results for kyphoplasty (47% mean improvement in height in 70% of fractures; no improvement in 30% of fractures). In addition, we achieved a mean improvement in kyphosis angle of 6 degrees and an improvement in the wedge angle of 3.5 degrees (as compared with published results for kyphoplasty of 7.4 and 4.3 degrees , respectively; P < .001). CONCLUSION: Percutaneous vertebroplasty should be viewed not only as a pain-relieving procedure, but also an effective method for improving vertebral body height, kyphosis angle, and wedge angle.
A case of symptomatic Rathke's cleft cyst and growth hormone (GH) secreting pituitary adenoma is described. A patient presented with a visual field deficit and a brain magnetic resonance imaging (MRI) study demonstrated compression of the optic chiasm by a large suprasellar cyst and a small lesion in the sellar consistent with a microadenoma. Preoperative clinical evaluation revealed mild acromegalic features, glucose intolerance, hypertension, hypercholesterolemia, and carpel tunnel syndrome, and blood testing confirmed an elevated insulin-like growth factor-1 (IGF-1). A modified transsphenoidal skull based approach was performed for selective transsphenoidal adenomectomy and decompression of the surprasellar cyst. The patient had an uneventful postoperative course with resolution of the visual field deficits and dysmenorrhea. Endocrine testing at two-month post procedure were normal. While there have been a small number of cases reported of concomitant pituitary adenomas and Rathke's cleft cysts, there is no report known to these authors of coexisting symptomatic lesions.
Herein, the author discusses four perfusion technologies, including the diffusible tracer methods-xenon-enhanced computed tomography (CT) and single photon emission CT with various radioisotopes-and the nondiffusible tracer techniques-CT perfusion and magnetic resonance (MR) perfusion and diffusion. The methods for and important issues in the performance of each technique are presented, along with the accuracy of the data acquired with each technique, as demonstrated with experimental studies. In addition, the use of each technique in the evaluation of patients with acute stroke and their relative advantages and disadvantages are presented.
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OBJECTIVE: The objective of our study was to determine whether a method could be found to reduce iatrogenic radicular pain during needle placement in lumbar diskography. MATERIALS AND METHODS: After obtaining permission from the institutional review board at the University of Pittsburgh Medical Center, we conducted a study using medical records and existing data that were recorded for quality control during lumbar diskography. A coaxial technique was being used for lumbar diskography. We evaluated data for 71 intervertebral disks in 26 patients in which the needle placement was randomly high (superior) or low (inferior), and the associated pain response during needle placement was recorded. In an attempt to minimize iatrogenic pain during needle placement, we identified a potentially "safe window" for needle placement on MRI of the lumbar spine. On oblique fluoroscopy of the lumbar spine, the safe window is a triangle formed by the superior articular facet medially, the superior endplate of the lower vertebra inferiorly, and an imaginary line joining the tip of the superior articular facet and the superolateral tip of the vertebral body. This safe window was then used for needle placement in another 73 intervertebral disks in 27 patients. Pain response to needle placement was recorded for quality control, and the medical records were retrospectively compared with the initial 71 intervertebral disks in which needle placement was random. RESULTS: In the initial group with random needle placement, lower extremity radicular pain occurred in 13 (18.3%) of 71 intervertebral disks with superior needle placement and in 23 (32.4%) of 71 intervertebral disks with inferior needle placement (total, 50.7%). The pain responses of the superior and inferior groups were not significantly different (p = 0.27). On MRI, the average distances between the nerve ganglion-fascicle-rami and the superior articular facets at the superior disk level were 1.1, 1.4, and 2.5 mm at L3-L4, L4-L5, and L5-S1, respectively. The average distances between the nerve ganglion-fascicle-rami and the superior articular facets at the inferior disk level were 3.0, 3.6, and 6.6 mm at L3-L4, L4-L5, and L5-S1, respectively. When the safe window was used, only five (6.8%) of 73 patients reported radicular pain. The decrease in radicular pain between the two groups was significant (p < 0.001). CONCLUSION: Iatrogenic lower extremity radicular pain is common during random needle placement at lumbar diskography. High or low needle placement in the intervertebral disk could not predict whether radicular pain would be averted. We identified a safe window that can be used for needle placement during lumbar diskography to minimize iatrogenic lower extremity radicular pain and thereby improve the reliability of the test.
BACKGROUND AND PURPOSE: MR imaging and contrast-enhanced MR angiography have been used to detect evidence of spinal dural arteriovenous fistulae (AVF); however, the sensitivity and specificity of these techniques have not been shown. The purpose of this study was to establish the sensitivity, specificity, and accuracy of MR imaging alone compared with MR imaging plus MR angiography in determining whether dural AVF are present and to establish the accuracy of MR angiography in predicting fistula level. METHODS: Twenty patients with surgically proven dural AVF (diagnosed with radiographic digital subtraction angiography) and 11 control patients who had normal digital subtraction angiography findings underwent routine MR imaging plus 3D contrast-enhanced MR angiography of the spine. Images were reviewed in two stages (stage I, MR images only; stage II, MR images plus MR angiograms) by three neuroradiologists who were blinded to the final diagnoses. RESULTS: The sensitivity, specificity, and accuracy of the three reviewers in detecting the presence of fistulae ranged from 85% to 90%, from 82% to 100%, and from 87% to 90%, respectively, for stage I, compared with values of 80% to 100%, 82%, and 81% to 94%, respectively, for stage II. For each reviewer, there was no significant difference between the values for stages I and II; however, among the reviewers, one of the more experienced neuroradiologists had significantly greater sensitivity than a less experienced neuroradiologist for stage II. On average, the percentage of true positive results for which the correct fistula level was predicted increased from 15% for stage I to 50% for stage II, and the correct level +/- one level was predicted in 73% for stage II. MR evidence of increased intradural vascularity was significantly greater in patients with dural AVF. CONCLUSION: The addition of MR angiography to standard MR imaging of the spine may improve sensitivity in the detection of spinal dural fistulae. The principal benefit of MR angiography is in the improved localization of the vertebral level of the fistula, which potentially expedites the subsequent digital subtraction angiography study.