Showing papers by "Sunnybrook Health Sciences Centre published in 2000"

Advances in ultrasound biomicroscopy

Abstract: The visualisation of living tissues at microscopic resolution is attracting attention in several fields. In medicine, the goals are to image healthy and diseased tissue with the aim of providing information previously only available from biopsy samples. In basic biology, the goal may be to image biological models of human disease or to conduct longitudinal studies of small-animal development. High-frequency ultrasonic imaging (ultrasound biomicroscopy) offers unique advantages for these applications. In this paper, the development of ultrasound biomicroscopy is reviewed. Aspects of transducer development, systems design and tissue properties are pre- sented to provide a foundation for medical and biological applications. The majority of applications appear to be developing in the 40 - 60-MHz frequency range, where resolution on the order of 50 mm can be achieved. Doppler processing in this frequency range is beginning to emerge and some examples of current achievements will be highlighted. The current state of the art is reviewed for medical applications in ophthalmology, intravascular ultrasound, dermatology, and cartilage imaging. Ultrasound biomicroscopic studies of mouse embryonic devel- opment and tumour biology are presented. Speculation on the continuing evolution of ultrasound biomicroscopy will be discussed. © 2000 World Federation for Ultrasound in Medicine & Biology.

The role of the cerebellum in cognition and behavior: A selective review

Abstract: The cerebellum has traditionally been seen primarily to coordinate voluntary movement, but evidence is accumulating that it may play a role in cognition and behavior as well. This is a selective review of studies assessing potential cognitive deficits and personality changes associated with cerebellar disease. Preliminary studies of the role of the cerebellum in schizophrenia, dementia, and other psychiatric disorders are also discussed. Efforts to understand the neurological substrates of behavior should consider the role of the cerebellum.

Oncogenes and Tumor Angiogenesis: Differential Modes of Vascular Endothelial Growth Factor Up-Regulation in ras-transformed Epithelial Cells and Fibroblasts

Abstract: A possible link between oncogenes and tumor angiogenesis has been implicated by the finding that expression of various oncogenes, particularly mutant ras, can lead to a marked induction of a potent paracrine stimulator of angiogenesis, vascular endothelial growth factor (VEGF). We sought to determine how oncogenic ras induction of VEGF is mediated at the molecular level and whether the mechanisms involved differ fundamentally between transformed epithelial cells and fibroblasts. Our results suggest that in a subline (called RAS-3) of immortalized nontumorigenic rat intestinal epithelial cells (IEC-18) that acquired a tumorigenic phenotype upon transfection of mutant ras, up-regulation of VEGF occurs in the absence of an autocrine growth factor circuit. The expression of VEGF mRNA and protein by RAS-3 cells was strongly suppressed in the presence of LY294002, an inhibitor of phosphatidylinositol 3'-kinase, but remained largely unaffected in the same cells treated with an inhibitor (PD98059) of mitogen-activated protein/extracellular signal-regulated kinase kinase 1 (MKK/MEK-1). This is consistent with the observation that overexpression of a constitutively activated mutant of MEK-1 (AN3/ S222D) in the parental IEC-18 cells did not result in up-regulation of VEGF production. The impact of mutant ras on VEGF expression was also significantly amplified at high cell density, conditions under which RAS-3 cells became less sensitive to LY294002-induced VEGF down-regulation. In marked contrast to cells of epithelial origin, ras-transformed murine fibroblasts (3T3RAS) up-regulated VEGF in a manner that was strongly inhibitable by MEK-1 blockade (ie. treatment with PD98059), whereas these cells were relatively unaffected by treatment with the phosphatidylinositol 3'-kinase inhibitor LY294002. In addition, VEGF was up-regulated by 2-3-fold in NIH3T3 cells overexpressing mutant MEK-1. Collectively, the data suggest that the stimulatory effect of mutant ras on VEGF expression is executed in a nonautocrine and cell type-dependent manner and that it can be significantly exacerbated by physiological/ environmental influences such as high cell density.

432 Somali women's birth experiences in Canada after earlier female genital mutilation.

Abstract: Background:Women with previous female genital mutilation (sometimes referred to as circumcision) are migrating, with increasing frequency, to countries where this practice is uncommon. Many health care professionals in these countries lack experience in assisting women with female genital mutilation during pregnancy and birth, and they are usually untrained in this aspect of care. Somali women who customarily practice the most extensive form of female mutilation, who were resident in Ontario and had recently given birth to a baby in Canada, were surveyed to explore their perceptions of perinatal care and their earlier genital mutilation experiences.Method:Interviews of 432 Somali women with previous female genital mutilation, who had given birth to a baby in Canada in the past five years, were conducted at their homes by a Somali woman interviewer.Results:Findings suggested that women's needs are not always adequately met during their pregnancy and birth care. Women reported unhappiness with both clinical practice and quality of care.Conclusions:Changes in clinical obstetric practice are necessary to incorporate women's perceptions and needs, to use fewer interventions, and to demonstrate greater sensitivity for cross-cultural practices and more respectful treatment than is currently available in the present system of care.

Randomized, Controlled Trial of an Interactive Videodisc Decision Aid for Patients with Ischemic Heart Disease

Abstract: OBJECTIVE: To determine the effect of the Ischemic Heart Disease Shared Decision-Making Program (IHD SDP) an interactive videodisc designed to assist patients in the decision-making process involving treatment choices for ischemic heart disease, on patient decision-making.

Targeted insertion of Cre recombinase into the TNAP gene: excision in primordial germ cells.

Abstract: system are a powerful approach to study thefunction of genes in particular cell lineages and forwhich generalized null mutations result in early lethalphenotypes (Lobe and Nagy, 1998). Here we report thecreation of a primarily PGC (primordial germ cell) spe-cific Cre recombinase transgenic line, designated TNAP-Cre. In this strain, the Cre recombinase has beenknocked into the locus of the TNAP (Tissue Non-SpecificAlkaline Phosphatase) gene.The structure of the TNAP-Cre targeting construct isdepicted in Figure 1a. After electroporation into R1 ES(Nagy

Expression of GPC3, an X-linked recessive overgrowth gene, is silenced in malignant mesothelioma.

Abstract: Gene expression changes in rat asbestos-induced malignant mesothelioma (MM) cells were investigated by differential mRNA display. A mRNA transcript identified by this approach was abundant in normal rat mesothelial cells but not expressed in rat MM cell lines. Northern blot analysis confirmed that this transcript is uniformly silenced in rat MM cell lines and primary tumors. Nucleotide sequence analysis revealed that this transcript is encoded by the rat glypican 3 gene (GPC3), whose human homolog is mutated in the Simpson-Golabi-Behmel overgrowth syndrome. Allelic loss at the GPC3 locus was infrequent (6.9%) in MM cell lines, and no mutations were found. GPC3 transcript levels were markedly decreased in 16 of 18 primary tumors and 17 of 22 human MM cell lines. Most of the cell lines were shown to have aberrant methylation of the GPC3 promoter region. In two of four human MM cell lines tested, GPC3 expression was restored after 2-deoxy 5-azacytidine (DAC)-mediated demethylation of its promoter region. Ectopic expression of GPC3 inhibited in vitro colony formation of human MM cells. Collectively, these data suggest that down-regulation of GPC3 is a common occurrence in MM and that GPC3, an X-linked recessive overgrowth gene, may encode a negative regulator of mesothelial cell growth.

Functional outcome after open supracondylar fractures of the humerus. The effect of the surgical approach.

Abstract: We reviewed 26 patients who had had internal fixation of an open intra-articular supracondylar fracture of the humerus. All operations were performed using a posterior approach, 13 with a triceps split and 13 with an olecranon osteotomy. The outcome was assessed by means of the Mayo Elbow score, the Disability of the Arm, Shoulder and Hand (DASH) score and the SF-36 Physical Function score. Patients with an olecranon osteotomy had less good results.

Death in two Canadian intensive care units: institutional difference and changes over time.

Abstract: Objective: To study and compare the mode of death in two different institutions' intensive care units (ICUs) for the two time periods, 1988 and 1993. Design: Retrospective chart review. Setting: Medical/surgical/trauma ICUs in two tertiary care teaching hospitals. Patients: Patients dying in the medical/surgical/trauma ICUs between January 1, 1988 and December 31, 1988; and January 1, 1993 and December 31, 1993. Data collection included demographics, origin of admission, date of ICU admission, date of death, Acute Physiology and Chronic Health Evaluation (APACHE) III diagnostic categories, APACHE II physiologic variables, organ system failures present at the time of admission and 24 hrs before death, and mode of dying. APACHE II scores and mortality risk were calculated. Data analysis included a multiple analysis of variance to assess overall effect, with subsequent analyses of variance to assess the effect of institution and year on each individual dependent variable. All results are reported as mean ± SEM values. Results: A total of 439 charts were reviewed. Gender, age, and origin of admission were not different between the 2 yrs or the two institutions. Mean APACHE II scores and organ system failures were lower at Hospital A in 1998 vs. Hospital B, as was predicted mortality. These factors increased at Hospital A in 1993 and were similar to those at Hospital B. Withdrawal of support was much more common in 1993 than 1988 at both institutions (43% at Hospital A and 46% at Hospital B in 1988 vs. 66% at A and 80% at B in 1993), increasing to a greater extent in 1993 at Hospital B (p <.05). Length of stay in the ICU was significantly longer at Hospital A than at Hospital B in 1988 (9.4 ± 1.4 vs. 4.3 ± 0.6 days; p <.05) and in 1993 (8.2 ± 2.9 vs. 3.8 ± 0.5 days; p <.05). Conclusions: There has been an increase in withdrawal of life support, in recent years, at both the institutions studied. Differences exist between institutions with respect to end-of-life decisions in the ICU. These differences are likely representative of widely prevalent regional differences and are the result of many factors.

Paraneoplastic rheumatic syndromes.

Abstract: Malignant neoplasms are associated with a wide variety of paraneoplastic rheumatological syndromes. Among these, hypertrophic osteoarthropathy, carcinoma polyarthritis, dermatomyositis/polymyositis, and paraneoplastic vasculitis are the most frequently recognized. Other less known associations are based upon a smaller number of reported patients, and include fasciitis, panniculitis, erythema nodosum, Raynaud's syndrome, digital gangrene, erythromelalgia and lupus-like syndromes. Musculoskeletal manifestations of malignancy may coincide, follow or antedate the diagnosis of cancer, or herald its recurrence. The clinical course generally parallels that of the primary tumour, and treatment of the underlying malignancy often results in regression of the rheumatic disorder. Awareness that cancer can cause certain non-metastatic symptoms is important for early diagnosis and treatment of an occult neoplasm. Rheumatic manifestations suggesting a hidden cancer include: rapid onset of an unusual inflammatory arthritis clubbing or diffuse bone pains in a patient 50 years of age or older, chronic unexplained vasculitis, refractory fasciitis, Raynaud's syndrome unresponsive to vasodilator therapy, rapidly progressive digital gangrene or Lambert-Eaton myasthenic syndrome. Management consists of control of the underlying cancer and symptomatic treatment of the rheumatic syndrome with non-steroidal anti-inflammatory drugs or corticosteroids.

Estimated prevalence of the seasonal subtype of major depression in a Canadian community sample.

Abstract: Objective:To examine estimates of lifetime prevalence of seasonal affective disorder (SAD) in Toronto, Ontario.MethodRandom telephone numbers were generated for the city of Toronto, and 781 respond...

Enterohemorrhagic Escherichia coli induces apoptosis which augments bacterial binding and phosphatidylethanolamine exposure on the plasma membrane outer leaflet.

Abstract: Enterohemorrhagic Escherichia coli (EHEC) is a gastrointestinal pathogen that causes watery diarrhea and hemorrhagic colitis and can lead to serious and even fatal complications such as hemolytic uremic syndrome. We investigated the ability of EHEC to kill host cells using three human epithelial cell lines. Analysis of phosphatidylserine expression, internucleosomal cleavage of host cell DNA and morphological changes detected by electron microscopy changes revealed evidence of apoptotic cell death. The rates and extents of cell death were similar for both verotoxin-producing and nonproducing strains of EHEC as well as for a related gastrointestinal pathogen, enteropathogenic E. coli (EPEC). The induction of apoptosis by bacterial attachment was independent of verotoxin production and greater than that produced by a similar treatment with verotoxin alone. Expression of phosphatidylethanolamine, previously reported to bind EHEC and EPEC, was also increased on apoptotic cells but with little correlation to phosphatidylserine expression. Phosphatidylethanolamine levels but not phosphatidylserine levels on dying cells correlated with EHEC binding. Cells treated with phosphatidylethanolamine-containing liposomes also showed increased EHEC binding. These results suggest that bacterial induction of apoptosis offers an advantage for bacterial attachment by augmenting outer leaflet levels of the phosphatidylethanolamine receptor.

Evaluation of medical students' performance using the anaesthesia simulator.

Abstract: Objectives A pilot project assessing clinical performance was undertaken using the Anaesthesia Simulation Centre at the University of Toronto. The purpose of this study was to determine the reliability of assessments of medical students’ performance using the simulator as an evaluation tool, to compare these assessments to written and clinical evaluations and to elicit student opinion. Simulator assessments were performed at the completion of the anaesthesia rotation. Design Twenty-four of 177 University of Toronto medical students participated in a videotaped simulator session with an attending faculty. These 24 students were based at Sunnybrook Health Science Centre. During the session, each student worked through one of six predetermined cases involving discrete patient problems based on the list of core objectives. Five evaluators independently assessed each student’s videotaped performance using standardized performance evaluation criteria and data were examined for inter-rater reliability. Clinical and written examination marks were compared to simulator assessments. A student questionnaire was administered and descriptive data obtained. Setting The University of Toronto. Subjects Medical students. Results The intraclass correlation coefficient (ICC) of inter-rater reliability was 0·87. There was poor correlation between the simulator and written examination marks (r=0·19, P=0·38) and between the simulator and clinical marks (r=0·04, P=0·87). The simulator experience was highly rated by students: learning experience 4·6 ± 0·51, appropriate content 4·4 ± 0·74, use as evaluation tool, 4·1 ± 0·92 (1=poor, 5=excellent). Conclusions Our pilot data suggest that the simulator is a reliable assessment method for medical students’ performance. Further work may justify the inclusion of the simulator as an evaluation and education tool and expanded to incorporate learning objectives of other medical disciplines.

Dopamine D1 receptor protein is elevated in nucleus accumbens of human, chronic methamphetamine users.

Abstract: Animal data have long suggested that an adaptive upregulation of nucleus accumbens dopamine D1 receptor function might underlie part of the dependency on drugs of abuse. We measured by quantitative immunoblotting protein levels of dopamine D1 and, for comparison, D2 receptors in brain of chronic users of methamphetamine, cocaine, and heroin. As compared with the controls, brain dopamine D1 receptor concentrations were selectively increased (by 44%) in the nucleus accumbens of the methamphetamine users, whereas a trend was observed in this brain area for reduced protein levels of the dopamine D2 receptor in all three drug groups (-25 to -37%; P < 0.05 for heroin group only). Our data support the hypothesis that aspects of the drug-dependent state in human methamphetamine users might be related to increased dopamine D1 receptor function in limbic brain.

Molecular Mechanism of Ultraviolet-Induced Keratinocyte Apoptosis

Abstract: This article reviews advances in the study of the molecular mechanisms for ultraviolet (UV)-induced keratinocyte apoptosis, with particular reference to the cytokines tumor necrosis factor-alpha (TNF-alpha) and Fas ligand (FasL) TNF-alpha and FasL induce their respective receptors and then activate caspase enzymes that are critically involved in the apoptotic process This activation is further amplified by intracellular mitochondria-associated mechanisms Using gene-targeted knockout mice lacking either the TNF-Rp55 or the TNF-Rp75, we have shown that TNF-alpha plays an important role in UV-induced keratinocyte apoptosis via TNF-Rp55 TNF-Rp55 shares homology with Fas and contains an intracellular death domain UV seems to directly stimulate cross-linking of Fas, resulting in the engagement of the death machinery Fas-associated death domain protein (FADD) acts as an adapter protein in both the TNF-Rp55 and Fas death-inducing cascades and is responsible for downstream signal transduction by recruiting caspases Moreover, signaling of p53 contributes to the induction of apoptosis by regulating Bcl-2 family expression and increasing surface Fas expression In addition to induction mechanisms of apoptosis, there are numerous inhibitory molecules that play a role in restricting the apoptotic pathway Thus, the ultimate determination of whether or not a cell undergoes apoptosis after UV radiation is based on the balance between agonist and antagonist pathways

Effect of premedication guidelines and leukoreduction on the rate of febrile nonhaemolytic platelet transfusion reactions.

Abstract: Platelet transfusion reactions were prospectively studied in haematology/oncology patients at five university teaching hospitals over three consecutive summers. The initial summer study provided baseline information on the use of premedications and the rate of platelet transfusion reactions (fever, chills, rigors and hives). Most (73%) platelet recipients were premedicated and 30% (95% CI 28-33%) of transfusions were complicated by reactions. The second study followed implementation of guidelines for premedicating platelet transfusions. Despite a marked reduction in premedication (50%), there was little change in the platelet transfusion reaction rate, 26% (95% CI 24-29%), or the type of reactions. The third study followed implementation of prestorage platelet leukoreduction while maintaining the premedication guidelines. The reaction rate decreased to 19% (95% CI 17-22%). For nonleukoreduced platelets, there was a statistically significant association between the platelet age and reaction rate (P = 0.04). For leukoreduced platelets, there was no statistically significant association between platelet age and reaction rate (P = 0.5). Plasma reduction of nonleukoreduced platelet products also reduced the reaction rate. These prospective studies document a high rate of platelet transfusion reactions in haematology/oncology patients and indicate premedication use can be reduced without increasing the reaction rate. Prestorage leukoreduction and/or plasma reduction of platelet products reduces but does not eliminate febrile nonhemolytic platelet transfusion reactions.

Skeletal muscle infarction in diabetes mellitus.

Abstract: Objective. To analyze the risk factors, clinical features, and methods of diagnosis of diabetic muscle infarction (DMI). Methods. Three patients with diabetes mellitus (DM) and skeletal muscle infarction were studied, and 49 additional cases reported in the English literature (Medline database search) were reviewed. Results. Review of all 52 patients with DMI revealed a number of typical features: equal sex distribution; mean age 41.5 years (range 19-81 yrs); a number of risk factors long duration of DM (mean 15.2 yrs), poor control and microvascular diabetic complications (neuropathy, retinopathy. nephropathy) (94%), and insulin dependent type I DM (77%)]; a characteristic clinical presentation with painful diffuse muscle swelling (100%); and sometimes a muscle mass (44%), predilection for quadriceps (62% ), hip adductors (13%) and leg muscles (13% ), elevated serum creatine phosphokinase (47%), abnormal sonograms (81%), abnormal magnetic resonance image (MRI) findings (100%), typical histopathologic findings of a muscle infarct (100%) (ultrastructural evidence of microangiography in one patient); and a tendency toward spontaneous resolution although recurrences are common (51%), Conclusion. Skeletal muscle infarction is a rare complication of long standing, poorly controlled DM associated with multiple end organ microvascular sequelae. Increased clinical awareness is important for early recognition, particularly in a diabetic patient presenting with a painful thigh or leg swelling. MR imaging is the diagnostic study of choice, and in the appropriate clinical setting, may obviate the need for a muscle biopsy.

Regional distribution of cocaine in postmortem brain of chronic human cocaine users.

Abstract: We measured concentrations of cocaine and its major metabolites (benzoylecgonine, ecgonine methylester, norcocaine, and cocaethylene) in 15 autopsied brain regions of 14 human chronic cocaine users. Only slight differences were observed in concentrations of cocaine and its metabolites amongst the examined brain areas. Although it is likely that some postmortem redistribution of the drug must have occurred, our data are consistent with the possibility that behaviorally relevant doses of cocaine are widely distributed throughout the brain of humans who use the drug on a chronic basis. Consideration should therefore be given to the possible pharmacological and toxicological actions of cocaine in both striatal and extra-striatal brain areas in human users of the drug.

Properties of a-Se for use in flat panel X-ray image detectors

Abstract: The present paper examines why a-Se has become the key photoconductor material in flat panel direct conversion X-ray image detectors. We critically examine the X-ray sensitivity of stabilized a-Se layers as a function of electric field and mean photon energy. The radiation energy W± absorbed per free electron–hole pair liberated for photoconduction in both a-Se and a-Si:H seem to follow the Que–Rowlands rule of W ± ≈2.2 E g +E phonon for amorphous semiconductors.

Primary cutaneous B cell lymphoma during methotrexate therapy for rheumatoid arthritis.

Abstract: A patient with rheumatoid arthritis developed a reversible, primary cutaneous, large B cell lymphoma during prolonged methotrexate (MTX) treatment. Regression of the skin lesions after discontinuation of the drug suggested a close relationship to MTX. Increased clinical awareness, discontinuation of MTX, and close observation are important in the initial management of this rare lymphoproliferative disorder.

Anger expression, gender, and ambulatory blood pressure in mild, unmedicated adults with hypertension.

Abstract: The suppression of anger has been associated with the development of hypertension. This study evaluated the association between anger management style (anger-in and anger-out) and ambulatory blood pressure (ABP) in patients with repeated clinic diastolic blood pressures (DBPs) between 90–105 mmHg, unmedicated and with no known coronary artery disease. A total of 128 men (46.0 years) and 66 women (46.6 years) participated. Fourteen percent of men and 35% of women were classified as having “white coat” hypertension (daytime DBP<85 mmHg). Mean awake and sleep DBP and systolic blood pressure (SBP) were evaluated in a repeated measures analysis of variance (ANOVA). Anger-in and anger-out scores were categorized into low, medium, and hight-scores (<50, 50–59, ≥60). Results indicated that in women, increasing anger-in is associated with greater SBPs while awake and sleeping, whereas no effect was found for DBP, nor any effect in men. No significant association was found between gender, anger-out, and ABP. The clinical diagnostic status of white coat hypertension was not differentially associated with anger-in or anger-out in men and women. In conclusion, in a sample of mild unmedicated adults with hypertension, suppression of anger is associated with greater ambulatory SBP in women, but not in men.

Dose-response evaluation of the interaction between sertraline and alprazolam in vivo.

Abstract: In vitro data show the inhibition of alprazolam metabolism by sertraline via CYP3A4; therefore, using a randomized, double-blind, placebo-controlled design, the authors conducted this study to assess the potential for similar in vivo inhibition in humans Ten healthy volunteers participated in two test sessions (placebo/alprazolam 1 mg orally) before the initiation of sertraline treatment Blood samples were obtained over a 32-hour period and pharmacodynamic measures (sedation, psychomotor performance, memory function) were obtained over an 8-hour period After a minimum of 2 weeks of daily sertraline self-administration (50, 100, or 150 mg/day), test sessions were repeated Alprazolam concentrations (N = 6, 4, and 6 at sertraline doses of 50, 100, and 150 mg/day, respectively) showed no significant changes based on peak concentration (Cmax), time to maximum concentration (Tmax), elimination half-life (t1/2[beta]), and area under the concentration-time curve (AUC(0-8)), with the exception of a reduced Cmax in the 50 mg/day group Similarly, dynamic data showed no significant variations based on peak effect, Tmax, and AUC(0-infinity), with the exception of increased peak impairment in one measure of psychomotor performance No differences were detected between placebo alone and placebo plus sertraline These findings suggest that sertraline (50-150 mg/day) does not alter the single-dose kinetics or dynamics of alprazolam; therefore, the combination may be prescribed without an increased risk of alprazolam toxicity

Does intratympanic gentamicin treatment for Meniere's disease cause complete vestibular ablation?

Abstract: Objectif: Determiner les changements dans la fonction vestibulaire a la suite d'un protocole de gentamycine intratympanique dans le traitement du syndrome de Meniere et de correler ces changements avec les besoins de retraitement. Devis: Serie de cas prospective. Patients: Cent trois patients avec Meniere unilateral incapacitant et resistant a au moins 6 mois de traitement medical. Mesures: La fonction vestibulaire a ete mesuree par ENG avec stimulation calorique avant et de facon seriee apres le traitement. La reponse calorique est classee en quatre groupes: normale (Difference d'excitabilite (DE) 25%), reponse positive a l'eau glacee seulement et absence de reponse. Resultats: Vingt-et-un pourcent des patients presentaient une reponse bithermique, 17% avaient une reponse a l'eau glacee seulement et 62% avaient une absence de reponse un mois apres le traitement. Quatorze patients ont eu besoin d'une autre serie d'injections a cause d'une recidive du vertige. Trente-huit pourcent de ceux-ci avaient une recuperation de la fonction calorique. Les patients qui avaient une fonction calorique normale avant le traitement initial etaient significativement plus a risque d'avoir besoin d'un autre traitement que ceux dont la fonction etait deja anormale (p <.05). A l'oppose, le risque d'avoir besoin d'un traitement supplementaire etait moins eleve chez les patients qui ont developpe une absence de reponse (p <.001). Conclusion: Une absence de reponse a l'eau froide est fortement predictive d'un controle adequat du vertige. Nous recommandons donc les protocoles de traitement qui visent a eradiquer completement la fonction vestibulaire.

Temporal bone necrosis: diagnosis, classification, and management.

Abstract: OBJECTIVE: The goal of this study was to analyze temporal bone necrosis and classify its diagnosis and treatment according to extent of necrosis and cause.METHODS AND MATERIAL: Twenty-six cases of temporal bone necrosis were retrospectively reviewed between 1988 and 1997 at the University of British Columbia.RESULTS: Patients were classified on the basis of disease extent restricted to the tympanic bone or extension beyond the tympanic bone, as well as on the basis of the cause of disease; treatment based on classification. Patients with localized disease of the tympanic bone had minimal symptoms. Those with radiation-induced localized necrosis were less likely to respond to conservative medical management. Patients with diffuse disease were more likely to require surgical intervention.CONCLUSIONS: Temporal bone necrosis comprises a spectrum of disease from idiopathic tympanic bone necrosis, which rarely requires surgery, to the more severe forms of radiation-induced diffuse temporal bone necrosis that ma...