Ruptured true posterior communicating artery aneurysm and cystic craniopharyngioma.
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Biomedical subjects
Publications and source records attributed to M B Pritz.
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Caiman crocodilus, as a representative of the order Crocodilia, was used in immunohistochemical studies. Immunohistochemical procedures were performed on free-floating sections using a monoclonal antibody against porcine glial fibrillary acidic protein (GFAP) and employing standard avidin-biotin complex methodology. The astroglia of Caiman exhibited robust immunoreactivity to the antibodies raised against mammalian GFAP. In Caiman, the predominant GFAP-immunopositive elements are the radial ependymoglia, similar to other reptiles. The regional variability of glial architecture in Caiman, however, seems greater than in other reptiles so far examined, although it is less compared with chickens. We suggest that this finding corresponds to a more advanced "regional adaptation" of the glial structure in Caiman compared with other reptiles. The main feature that distinguishes the astroglia of Caiman from those of other reptiles is the widespread occurrence of GFAP-immunopositive astrocytes. These cells are limited in lizards and snakes, are not present in turtles, but are found in every major brain area in Caiman. However, even in Caiman, astrocytes are only intermingled with radial glia and are not the predominant glial element of any brain area. The occurrence of astrocytes does not correlate with brain wall thickness. Despite their origin from different ancestral groups of stem reptiles (synapsid or diapsid), mammals and birds exhibit some common general features in their glial architecture and GFAP distribution: 1) predominance of astrocytes and 2) absent or limited GFAP immunopositivity of several brain areas. The present study demonstrates that, even in Caiman, a representative of the reptilian group most closely related to birds, these features are present only in part, suggesting that, in mammals and birds, they have evolved independently.
BACKGROUND: Moyamoya usually presents with cerebral ischemia in children and intracranial hemorrhage in adults. Treatment remains controversial. DESIGN AND OBJECTIVE: We reviewed our experience from June 1995 to August 1999 of 20 adult and pediatric angiographically diagnosed patients with moyamoya to report their clinical presentation, radiological findings, management, and clinical outcomes. RESULTS: The mean age of patients at symptom onset was 17 years (range, 2-54 years). Patients were divided into 2 age groups (group 1, <18 years; group 2, > or =18 years). There were 13 patients in group 1 and 7 patients in group 2. Ischemic strokes or transient ischemic attacks were the predominant initial presentations in both groups. One patient in group 2 had an intraparenchymal brain hemorrhage. Five patients received medical treatment, and 15 had surgical revascularization. The mean time from symptom onset to surgical procedure was significantly longer for patients in group 1 than for those in group 2 (P =.03). The mean follow-up time was 36 months. One patient in group 1 had an ischemic stroke. There was no difference in stroke recurrence, mortality, or modified Rankin scale score among medically or surgically treated patients. CONCLUSIONS: Moyamoya disease may have a different presentation and more benign natural history in our population than in Asian populations. Our findings emphasize the need to better understand the natural history of patients with moyamoya as well as the clinical benefit of different treatment modalities. Structured multicenter randomized clinical trials are needed to further assess the best treatment modalities for patients with moyamoya in the United States.
BACKGROUND: Although subarachnoid hemorrhage (SAH) is often associated with electrocardiographic abnormalities, profound effects on cardiac performance are rare. CASE DESCRIPTION: A 57-year-old woman who developed loss of consciousness, respiratory distress, severe hypotension, and left ventricular hypokinesis with minimal coronary artery disease is described. Despite normal appearance of the coronary arteries on angiography, left ventricle function was so severely depressed that she required intra-aortic balloon pump support for 24 hours. Mental status changes prompted a head computed tomographic (CT) scan, which showed severe SAH and an intraventricular hemorrhage (IVH). Cerebral angiography demonstrated a basilar apex aneurysm. An echocardiogram done on hospital day 6 was normal. A left frontal ventriculostomy catheter was placed. This was later changed to a lumbar subarachnoid (SA) drain. The patient underwent an orbito-zygomatic craniotomy and aneurysm clipping. Although several serious medical problems occurred during her hospitalization, at follow-up, her sole neurological impairment was a minimal and resolving oculomotor paresis. CONCLUSION: This patient's respiratory failure and severe hypotension were initially thought to be due to a chemical pneumonitis or a cardiomyopathy. However, her symptoms ultimately proved to be secondary to a ruptured basilar apex aneurysm. The complex relationship of SAH to myocardial stunning, as illustrated by this patient, is discussed.
BACKGROUND: While rupture of a cerebral aneurysm into the subdural space is rare, aneurysmal subarachnoid hemorrhage in the presence of subdural hematoma(s) is much more uncommon. Such a patient requires changes in routine perioperative management. CASE DESCRIPTION: A patient with a ruptured middle cerebral artery bifurcation aneurysm and bilateral subdural hematomas is presented. He underwent successful aneurysm clipping and subdural hematoma evacuations. At the time of surgery, measures commonly used to obtain brain relaxation were avoided. The patient was kept normovolemic, normocarbic, and normotensive. He recovered completely and resumed his prior occupation. CONCLUSIONS: Changes in standard techniques for a patient undergoing a pterional craniotomy for a ruptured cerebral aneurysm are required when bilateral extra-axial mass lesions are present.
BACKGROUND: While color Doppler ultrasonography and microvascular Doppler recordings have been used intraoperatively for spinal cord vascular malformations, they have not been employed for similar spinal cord lesions preoperatively. CASE DESCRIPTION: We report the usefulness of color Doppler ultrasonography through a lumbar laminectomy defect in the management of a spinal arteriovenous fistula. CONCLUSION: Color Doppler ultrasonography should be considered for spinal lesions in which a laminectomy defect is present.
The reconstruction of the external carotid artery (ECA) and obliteration of an occluded stump or atretic internal carotid artery (ICA) are described. In this method the occluded ICA is used as an autologous patch graft. Satisfactory ICA obliteration and expanded, smooth common carotid artery-ECA contour were obtained in three patients. Advantages of this procedure include ICA obliteration and precise patch placement by using an ideal, autologous, arterial graft.
STUDY DESIGN: A technique for posterior cervical hemilaminectomy reconstruction is described. OBJECTIVE: To describe a technique for reconstruction of cervical hemilaminae in an adult that resulted in osseous fusion and to suggest modifications for use in children. SUMMARY OF BACKGROUND DATA: Although uncommon, cervical hemilaminectomy can result in spine deformity. Re-establishment of the osseous and ligamentous structures should minimize this problem. METHOD: After excision of an intraspinal neurenteric cyst, removed cervical hemilaminae at C2 and C3 were reconstructed with metal plates, and posterior ligaments were reapproximated with suture. RESULTS: Radiologic evidence of osseous fusion was present at 1 year after surgery. CONCLUSIONS: The advantages of this technique are restoration of normal anatomy, technical ease, and simplicity. A modification of this technique in children by using absorbable rather than metal plates should allow for normal spine growth.
Rhombomere development was investigated in a reptile, Alligator mississippiensis, using a variety of methodologies: cytoarchitecture (cresyl violet), histochemistry (peanut agglutinin), immunocytochemistry (antibodies to acetylated tubulin, vimentin, calretinin, and acetylcholinesterase), and external and internal morphology of wholemount embryos. Rhombomere boundaries form sequentially until 8 rhombomeres are present at stage 8. From stage 11 onwards, rhombomere borders fade. When present, boundaries of rhombomeres 2 through 5 were distinct. In all embryos, except the earliest stages, neural tissue was divided between the caudal end of the mesencephalon and the rostral end of the rhombencephalon. This area of transection was designated as the isthmus. For these technical reasons, a distinct border between the midbrain and the first rhombomere was not seen and the isthmic rhombomere could not be identified. The interrhombomeric boundary between rhombomere 7 and rhombomere 8 and between the most caudal rhombomere and the spinal cord was not nearly as clear as were the boundaries of rhombomeres 2 through 5. Development of rhombomeres 2 through 5 was investigated in wholemount preparations between stages 5/6 and 11. Qualitative and quantitative observations were made. In these rhombomeres, r2 through r5, rostrocaudal caudal expansion occurs at a slower rate than mediolateral development. This differential growth sculpts the morphology of rhombomeres 2 through 5. Rhombomere development in Alligator shares several features in common with hindbrain segmentation in chick. The identification of rhombomeres in a multitude of vertebrates from a variety of classes suggests that segmentation is a feature common to hindbrain development in all vertebrates.
When several independent groups have conducted studies to estimate a procedure's success rate, it is often of interest to combine the results of these studies in the hopes of obtaining a better estimate for the true unknown success rate of the procedure. In this paper we present two hierarchical methods for estimating the overall rate of success. Both methods take into account the within-study and between-study variation and assume in the first stage that the number of successes within each study follows a binomial distribution given each study's own success rate. They differ, however, in their second stage assumptions. The first method assumes in the second stage that the rates of success from individual studies form a random sample having a constant expected value and variance. Generalized estimating equations (GEE) are then used to estimate the overall rate of success and its variance. The second method assumes in the second stage that the success rates from different studies follow a beta distribution. Both methods use the maximum likelihood approach to derive an estimate for the overall success rate and to construct the corresponding confidence intervals. We also present a two-stage bootstrap approach to estimating a confidence interval for the success rate when the number of studies is small. We then perform a simulation study to compare the two methods. Finally, we illustrate these two methods and obtain bootstrap confidence intervals in a medical example analysing the effectiveness of hyperdynamic therapy for cerebral vasospasm.
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BACKGROUND: Many reports indicate that acoustic neuromas greater than 2.0 cm should be removed without hearing preservation attempted, even if hearing is present preoperatively. These studies advocate a translabyrinthine approach because the likelihood of hearing preservation is low. Medial acoustic neuromas, unlike the more common lateral tumors that involve the internal auditory canal, originate medial to that portion of the eighth nerve complex where the cochlear and vestibular nerves are fused. This anatomical feature suggests that these tumors may be amenable to resection with hearing preservation. METHODS: A patient with a 3.5 cm medial acoustic neuroma and useful preoperative hearing is presented. RESULTS: Gross total tumor removal with functional hearing was achieved after a two-stage procedure using a suboccipital approach. CONCLUSION: Based on the anatomico-pathologic features in this case, we believe that, if a patient has reasonable preoperative hearing (speech discrimination score > 70%) and a medial acoustic neuroma, an approach to preserve hearing should be considered regardless of tumor size.
BACKGROUND: Chondrosarcoma of the nasal septum is a rare, malignant neoplasm. A case is presented that illustrates the evaluation and treatment of this malignancy, reviews the relevant literature, discusses surgical approaches, and assesses adjuvant, nonsurgical therapy. METHODS: A craniofacial approach using an extended, bifrontal craniotomy and lateral rhinotomy with medial maxillectomy resulted in gross total resection at surgery. Because permanent sections of bone margins after decalcification were positive, conformal external beam radiation was used. RESULTS: The patient made a complete recovery, returned to work, and is disease-free 26 months after treatment. CONCLUSIONS: Surgical therapy using an anterior craniofacial resection is the preferred approach. External beam radiation therapy is potentially indicated for the following: positive or close surgical margins on permanent histopathology, extensive tumor with known residual at operation, or local recurrence not amenable to resection. Because of late local recurrence, lifelong follow-up is required.
We describe a retroauricular approach, adjacent to the mastoid tip, in two patients that allowed successful biopsy of posterior skull base lesions. Diagnoses were central giant cell granuloma, an unusual tumor rarely reported in the skull base, and meningioma. In both patients, the needle biopsy accurately identified the pathology found at surgery. The described approach may allow biopsy of posterior lesions that are inaccessible with other methods.
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Carotid endarterectomy is an established surgical procedure to prevent stroke. The indications, preoperative evaluation, surgical timing, technical details, complications, and special circumstances for the use of this operation are reviewed. Future developments in the surgical reconstruction of the extracranial carotid artery are also discussed.
A 37-year-old woman had visual changes. Magnetic resonance imaging showed an extraaxial mass in the anterior clinoid region that was presumed to be meningioma. There was no evidence of systemic or leptomeningeal disease. Pathologic findings were consistent with sarcoidosis. Isolated mass-like neurosarcoidosis, without systemic or leptomeningeal disease is difficult to diagnose preoperatively.
The morphology of nucleus rotundus, a visual thalamic nucleus, was investigated in one species of reptiles. Caiman crocodilus, using Nisst stained material in transverse, sagittal, and horizontal planes. The topographical location of nucleus rotundus and its relationship to surrounding thalamic nuclear groups are described. Nucleus rotundus in Caiman can be subdivided into three areas: (1) an outer shell; (2) an inner core; and (3) a cell poor zone located between the shell and core. Most rotundal core neurons were round, fusiform, triangular, pear-shaped, or elliptical. Core neurons were not distributed evenly throughout the nucleus but, in many instances, were arranged in clusters composed of two to ten neurons. Quantitative measurements of area, perimeter, and eccentricity (greatest width/greatest length), which served as an index of cell roundness, were made on rotundal core neuron profiles in transverse, sagittal, and horizontal planes of section. Qualitative and quantitative observations were not appreciably different regardless of the plane of orientation. Both qualitative and quantitative data suggest that relay cells located in the core of nucleus rotundus are not a homogeneous population of neurons but comprise several subtypes.