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PubMed1997

Anatomical variability in the cortical representation of first and second language.

Functional magnetic resonance imaging was used to assess inter-subject variability in the cortical representation of language comprehension processes. Moderately fluent French-English bilinguals were scanned while they listened to stories in their first language (L1 = French) or in a second language (L2 = English) acquired at school after the age of seven. In all subjects, listening to L1 always activated a similar set of areas in the left temporal lobe, clustered along the left superior temporal sulcus. Listening to L2, however, activated a highly variable network of left and right temporal and frontal areas, sometimes restricted only to right-hemispheric regions. These results support the hypothesis that first language acquisition relies on a dedicated left-hemispheric cerebral network, while late second language acquisition is not necessarily associated with a reproducible biological substrate. The postulated contribution of the right hemisphere to L2 comprehension is found to hold only on average, individual subjects varying from complete right lateralization to standard left lateralization for L2.

Adult↗

PubMed1983

Intracoronary thrombolysis in evolving myocardial infarction. Sequential angiographic analysis of left ventricular performance.

Since November 1979 left ventricular angiography and coronary arteriography have been performed in 80 patients with evolving acute myocardial infarction in order to attempt coronary recanalisation by local streptokinase infusion. The average delay between the onset of symptoms and streptokinase infusion was 3.6 hours. Thrombolysis was successful in 64% of cases. No serious complications related to the procedure were noted. Of the 12 patients in cardiogenic shock, recanalisation was achieved in only four, of whom two survived. To evaluate the left ventricular salvage resulting from early recanalisation the last 58 patients had a second left ventricular angiogram and further coronary arteriograms 21 +/- 10 days later and 16 patients had a third study three months later. From the left ventricular angiogram in the right anterior oblique projection the ejection fraction and two graphic variables of regional wall motion were computed quantifying the hypokinetic zone. Patients were divided into two groups, according to the patency of the infarct related artery at the second control: group 1 consisted of 28 patients with successful recanalisation confirmed, and group 2 of 30 patients in whom no recanalisation was achieved or secondary reocclusion had occurred. At the second study the ejection fraction was unchanged in group 1 but had significantly decreased in group 2. Regional wall motion improved in group 1 and worsened in group 2, more so in patients without recanalisation than in those in whom secondary reocclusion had occurred. The third study showed a further decrease in ejection fraction in group 2. A progressive decrease in percentage residual stenosis was observed in group 1. This sequential angiographic study confirms the partial myocardial salvage resulting from early coronary recanalisation during acute myocardial infarction.

Adult↗

PubMed2004

Repeatability of motor and working-memory tasks in healthy older volunteers: assessment at functional MR imaging.

PURPOSE: To prospectively determine the repeatability of functional magnetic resonance (MR) imaging brain activation tasks in a group of healthy older male volunteers. MATERIALS AND METHODS: Local research ethics committee approval and informed consent were obtained. Sixteen men with a mean age of 69 years +/- 3 (standard deviation) performed finger-tapping and N-back (number of screens back) working-memory tasks. Each subject underwent MR imaging three times in weekly intervals. Within-subject task repeatability was analyzed in terms of the number of voxels classified as activated (activation extent), the mean activation amplitude, and (for finger tapping) the center of the mass of the activated region. A repeatability index was calculated to compare test-retest repeatability between subjects and between functional MR imaging tasks. Within-session, between-session, and between-subject variability was assessed by using analysis of variance testing of activation amplitude and extent. RESULTS: Nine of the 16 subjects generated useful data at all three MR imaging-functional task sessions. At single-subject, single-session analysis, cortical activation was identified in most subjects and at most sessions. The centers of the masses of motor cortex activation were highly reproducible (within 3 mm). Patterns of activation were qualitatively repeatable, but there was substantial variability in the amplitudes and extents of activated regions. Within-session coefficients of variation (CVs) for left- versus right-hand and right- versus left-hand finger tapping were, respectively, 65% and 43% for activation amplitude and 75% and 121% for activation extent. The between-session CVs for activation amplitude were similar to the within-session values, whereas between-session CVs for activation extent were much greater than within-session values, up to 206%. CONCLUSION: The generally poor quantitative task repeatability highlights the need for further methodologic developments before much reliance can be placed on functional MR imaging results of single-session experiments.

Aged↗

PubMed1994

Pressure recovery in aortic valve stenosis.

BACKGROUND: Pressure recovery is the variable increase in lateral pressure downstream from a stenotic orifice. The magnitude and clinical significance of pressure recovery in aortic valve stenosis are poorly defined. METHODS AND RESULTS: We obtained high-fidelity pressure and velocity recordings in 11 patients with isolated significant aortic valve stenosis at the time of diagnostic cardiac catheterization. Systematic catheter pullback from the left ventricular cavity revealed a consistent although variable subvalvular gradient. Further pullback across and distal to the region of the stenosed aortic valve revealed a consistent and progressive increase in the ascending aortic pressure. This increase in lateral pressure occurred pari passu with a diminution in amplitude of the velocity pulse. The extent of pressure recovery was directly related to systemic blood flow and transvalvular flow but inversely related to the Gorlin-derived aortic valve area. CONCLUSIONS: These findings have potentially important implications for the hemodynamic evaluation of mild to moderately severe aortic valve stenosis. The extent of pressure recovery may be of additional utility in the assessment of aortic valve stenosis under varying physiological states.

Aorta↗

PubMed1987

The distribution of ventilation-perfusion ratios in the lungs of newborn foals.

The distributions of ventilation-perfusion ratios, and the effects of 100% oxygen administration on the distributions, were studied in 3 foals from 4h to 9 days of age, using the multiple inert gas elimination technique. The distributions were calculated from the pulmonary clearance of 6 inert gases following infusion into a peripheral vein of a solution containing the inert gases. The results from a total of 8 studies showed several consistent features. The major findings were (i) the absence of low ventilation-perfusion ratios, i.e. regions where blood flow was greatly in excess of ventilation; (ii) the presence of variable right to left shunt; (iii) a reduction in this shunt with increasing post-natal age; (iv) the presence of a separate high mode of ventilation-perfusion ratios where ventilation was greatly in excess of blood flow and; (v) the observation that breathing enriched oxygen mixtures for 40 min did not increase the right to left shunt in any foal at any age studied. These studies indicate that hypoxaemia in the neonatal foal is attributable to right to left shunt which may be intrapulmonary or intracardiac, or both, rather than overperfusion of poorly ventilated lungs.

Age Factors↗

PubMed2000

Echocardiographic determinants of left ventricular ejection fraction after acute myocardial infarction.

OBJECTIVE: This study was performed to determine if factors other than the size of regional dysfunction influence the global left ventricular ejection fraction after acute myocardial infarction. BACKGROUND: Left ventricular ejection fraction is an important prognostic variable after acute myocardial infarction. Although infarct size is known to affect the subsequent global left ventricular ejection fraction, it remains unclear whether other factors such as site or severity of the wall motion abnormality influence the ejection fraction after acute myocardial infarction. METHODS: Sixty-nine consecutive patients (mean age 61 +/- 14 years, 46 [67%] male) who did not receive thrombolytic therapy or undergo early revascularization were studied by echocardiography 1 week after Q-wave myocardial infarction. The absolute size of the region of abnormal wall motion (AWM) and the percentage of the endocardium involved (%AWM) were quantitated along with the wall motion score. A severity index was then derived as the mean wall motion score within the region of AWM. Site of myocardial infarction was classified as either anterior or inferior from the endocardial map. Left ventricular ejection fraction was measured by Simpson's method with 2 apical views. RESULTS: Twenty-nine (42%) patients had anterior and 40 had inferior myocardial infarction. The mean left ventricular ejection fraction was significantly lower in anterior than in inferior myocardial infarction (44.8% +/- 11.5% vs 53% +/- 8.6%; P =. 001). The mean %AWM was greater in anterior than in inferior myocardial infarction (32.1 +/- 15.5 vs 22.4 +/- 14.1; P =.01). The mean wall motion score was greater in anterior than in inferior myocardial infarction (9.8 +/- 6.4 vs 6.4 +/- 4.4; P =.01). The mean severity index did not differ by site. Multiple regression analysis demonstrated that, in descending order of importance, %AWM, extent of apical involvement, and site of myocardial infarction were independent determinants of global left ventricular ejection fraction. CONCLUSIONS: For myocardial infarctions of similar size, left ventricular ejection fraction is lower when apical involvement is extensive and the site of infarction is anterior. This site-dependent difference may be related to characteristics specific to the apex.

Adult↗

PubMed1992

Quantitative gated blood pool tomographic assessment of regional ejection fraction: definition of normal limits.

OBJECTIVE: Our aim was to select a method of analysis for gated blood pool tomography that reduced variability in a group of normal subjects, allowed comparison with normal limit files and displayed results in the bull's-eye format. BACKGROUND: Abnormalities in left ventricular function may not be accurately detected by measures of global function because hyperkinesia in normal regions may compensate for abnormal regional function. Gated blood pool tomography acquires three-dimensional data and offers advantages over other noninvasive modalities for quantitative assessment of global and regional function. METHODS: Alternative methods for selecting the ventricular axis, calculating regional ejection fraction and choosing the number of ventricular divisions were studied in 15 normal volunteers to select the combination of parameters that produced the lowest variability in quantitative regional ejection fraction. Methods for quantitative comparison of regional ejection fraction with normal limit files and for display in the bull's-eye format were also examined. RESULTS: A fixed axis (the geometric center of the ventricle defined for end-diastole and used for end-systole) gave ejection fractions that were significantly higher in the lateral wall versus in the septum, 82 +/- 8 (mean +/- 1 SD) versus 39 +/- 17 (p less than 0.001) at the midcavity and 66 +/- 11 versus 21 +/- 20 (p less than 0.001) at the base. A floating axis system (axis defined individually for end-diastole and end-systole and realigned at the center) gave more uniform regional ejection fraction: 63 +/- 6 versus 64 +/- 8 (p = NS) at the midcavity and 44 +/- 16 versus 45 +/- 15 (p = NS) at the base. The coefficient of variability for regional ejection fraction was consistently lower using a floating axis. Calculating regional ejection fraction by dividing the regional stroke volume by the end-diastolic volume of the region gave a lower coefficient of variability and a more easily understood value than dividing the regional stroke volume by the total end-diastolic volume of the ventricle. Although the variability was lower using five versus nine ventricular divisions, nine regions offer greater spatial resolution. Comparison of regional ejection fraction with normal data identified regions greater than 2.5 SD below the mean as abnormal. We described the two-dimensional bull's-eye format as a method for displaying the regional three-dimensional data and illustrated abnormalities in patients with prior myocardial infarction. CONCLUSIONS: Gated blood pool tomography performed using a floating axis system, regional stroke volume calculation of ejection fraction and nine regions uses all the three-dimensional blood pool data to calculate regional ejection fraction, allow quantitative comparison with normal limit files, display the functional data in the two-dimensional bull's-eye format and demonstrate abnormalities in patients with myocardial infarction.

Adult↗

PubMed1982

Assessment of left ventricular function using an angiographic method.

Angiographic methods are by far the most frequently used for calculation of left ventricular volume, mass, forces acting within the ventricular wall or for analysis of contractile performance and diastolic property of the overall ventricle, as well as regional myocardial function in the presence of ischemia. A critical review of the theoretical basis and practical methods of calculation of these variables is presented. The left ventricular pressure-volume diagram is constructed which allows for an assessment of the inotropic state of the ventricle from the similar tension-length framework as obtained in the isolated papillary muscle. Computer technology of digital filtering and subtraction provides for an enhancement of the contrast of the ventricular image obtained with minimal doses of contrast medium. On-line methods for edge tracing and subsequent data processing are alleviating much of the tedious and laborious work of manual analysis of angiograms and accuracy of the calculation has been enhanced. Left ventriculography is most useful in diagnosing the presence of abnormal wall motion. Methods of assessing the magnitude and extent of the relative area of localized myocardial dysfunction are discussed. Quantitative information is crucial for evaluating prognosis and determining the application of therapeutic interventions.

Angiocardiography↗

PubMed1993

Extension of hypokinesia into angiographically perfused myocardium in patients with acute infarction.

OBJECTIVE: This study was performed to determine whether left ventricular hypokinesia due to acute myocardial infarction lies between the site of coronary artery occlusion and the end of the infarct-related artery in patients. BACKGROUND: Normalizing for the size of the risk region reduces variability in measuring infarct size in experimental studies. The ability to gauge the size of the region at risk of becoming dysfunctional may help reduce variability in measuring regional hypokinesia due to acute myocardial infarction. METHODS: Angiograms of 84 patients with acute infarction due to isolated stenosis of the right coronary artery (n = 40) or the left anterior descending coronary artery (n = 44) were analyzed. The location and length of the segment with hypokinesia more severe than -1 or -2 SD below the normal mean were determined by the centerline method. The risk region was defined as the left ventricular contour between the site of the occlusion and the end of the infarct-related artery on the angiogram. RESULTS: The segment with hypokinesia below -1 SD was longer than the risk region in 52% of patients with occlusion of the left anterior descending coronary artery, more frequently (p < 0.01) than in right coronary artery occlusion (22%), owing to extension of hypokinesia beyond the distal end of the artery. Extension of severe hypokinesia (below -2 SD) beyond the risk region occurred in 33% of patients with an anterior infarct and in 9% of patients with an inferior infarct. CONCLUSIONS: The size of the risk region cannot be assessed accurately from coronary angiography.

Bias↗

PubMed1994

ALCAPA syndrome: an example of chronic myocardial hypoperfusion?

OBJECTIVES: The purpose of this study was to evaluate functional variables and morphologic correlates of chronically hypoperfused myocardium before and after revascularization. BACKGROUND: Neonates with congenital anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA syndrome) develop some myocardial necrosis shortly after birth. The survivors of this event are left with a localized infarction and an almost entirely collateral circulation-dependent perfusion of the left ventricle that results in poor global left ventricular function. Survival beyond infancy is uncommon because of severe left heart failure. Revascularization, however, brings about functional recovery with good clinical outcome. The ALCAPA syndrome is thus characterized by chronic collateral circulation-dependent low perfusion, low contraction matching and potential revivability. METHODS: Five patients with ALCAPA syndrome are presented, with preoperative and postoperative clinical findings and histologic data obtained from intraoperative transmural biopsy specimens. RESULTS: The angiographically assessed preoperative ejection fraction was 33 +/- 19% (mean +/- SD). Postoperative echocardiographic follow-up revealed normal left ventricular function in all patients. Histologic study of the biopsy specimens taken from the region perfused by the anomalous artery showed a variable degree of fibrosis (51 +/- 32%). The ultrastructure of the remaining myocytes revealed viable characteristics, but a substantial percent (46 +/- 26%) showed a markedly reduced fraction of contractile material. CONCLUSIONS: These ultrastructural studies suggest delayed subcellular adaptive responses in the chronically hypoperfused myocardium of patients with ALCAPA syndrome.

Adolescent↗

PubMed1996

Modeling of mechanical dysfunction in regional stunned myocardium of the left ventricle.

Reversible mechanical dysfunction of the myocardium after a single or multiple episode(s) of coronary artery occlusion has been observed in previous studies and is termed myocardial stunning. The hypothesis that stunning could be represented by a decrease in maximum available muscle force in the stunned region was examined by means of a mathematical model that incorporates series viscoelastic elements. A canine experimental model was also employed to demonstrate depressed contractility and a consistent delay of shortening in the stunned region. The mechanical model of the left ventricle was designed to include a normal and stunned region, for which the stunned region was allowed to have variable size. Each region consisted of a volume and time dependent force generator in parallel with a passive elastic force element. The passive elastic element was placed in series with a constant viscosity component and a series elastic component. The model was solved by means of a computer. Passive and active properties of each region could be altered independently. The typical regional measures of muscle performance such as percent shortening, percent bulge, percent thickening, delay of shortening, percent increase in end-diastolic length and other hemodynamic measures were computed. These results were similar to those observed in animal models of stunning. In addition, a nearly linear relationship with end-diastolic length and delay of shortening was predicted by the model. It was concluded that a decrease in the peak isovolumic elastance and augmentation of viscosity effect of creep during stunning can explain mechanical abnormalities of stunned myocardium.

Analysis of Variance↗

PubMed1989

Variability and reproducibility of quantitative left ventricular angiography.

To evaluate the reproducibility of left ventricular angiography for the assessment of left ventricular (LV) function and regional wall motion, two ventriculographies were performed in the 30 degrees right anterior oblique (RAO) projection, at 15-minute intervals, in 19 patients undergoing coronary angiography. Heart rate, left ventricular systolic pressure, and end-diastolic pressure were measured 15 minutes after the first angiography returned to the baseline values (71.0 +/- 14.1 vs. 72.2 +/- 15.5 beats/minute, 153.6 +/- 18.0 vs. 152.8 +/- 19.9 mm Hg, 21.7 +/- 8.6 vs. 20.9 +/- 7.3 mm Hg, respectively). Global and regional LV performance was analyzed by two observers with a computer-assisted technique. Intraobserver mean variation of end-diastolic volume and ejection fraction was less than 3% of the control value. Interobserver mean variations for the same parameters were less than 4% of control values. For both observers, there was no significant variation of LV end-diastolic volume and ejection fraction from one study to the other. Under stable hemodynamic conditions, the mean observed variations were, depending on the observer, 5-6% of the control value for LV end-diastolic volume and 5% for ejection fraction. Analysis of segmental wall motion was also highly reproducible. The mean intraobserver variation (% of control value) of wall motion ranged from 4.4% to 9.2%, depending on the sectors studied. The mean interobserver variation, whatever the sector, ranged from 6.9% to 13.5%.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1998

Normal Values in Children for Myocardial Ultrasonic Tissue Characterization by Integrated Backscatter.

Normal values in adults for ultrasonic tissue characterization by integrated backscatter have been reported previously and subsequently applied to patients with specific diseases. Factors influencing integrated backscatter values in a pediatric population are not clearly defined. To obtain normal values for myocardial ultrasonic integrated backscatter in a pediatric population, we studied 72 children with normal cardiac anatomy using an ultrasonic integrated backscatter imaging system. The parameters measured were at peak, nadir, and end-diastole in eight different regions with two different settings: fixed and variable. We subsequently calculated cyclic variation, the ratios of cyclic variation to end-diastole and to peak. Age ranged from 1 day to 17.4 years (median 4.4 years). More than 90% of data curves from the two regions in the left ventricular posterior wall in long-axis view had normal patterns, whereas more than 50% of curves for the other regions had abnormal patterns. Comparing the two posterior wall positions, there were no differences in cyclic variation between the two regions, with little effect of setting. Less effect of regions and settings was noted for the ratios of cyclic variation to end-diastole or peak. There was no relation between backscatter variables and age, gender, or height, and some variables correlated weakly with body surface area. The assessment of integrated backscatter in children is optimal with interrogation of the left ventricular posterior wall imaged in the long-axis view. More stable estimates are obtained when the cyclic variation is related to the peak or end-diastolic value.

Journal Article↗

PubMed2005

Semiparametric analysis of survival data with left truncation and dependent right censoring.

Studies of chronic life-threatening diseases often involve both mortality and morbidity. In observational studies, the data may also be subject to administrative left truncation and right censoring. Because mortality and morbidity may be correlated and mortality may censor morbidity, the Lynden-Bell estimator for left-truncated and right-censored data may be biased for estimating the marginal survival function of the non-terminal event. We propose a semiparametric estimator for this survival function based on a joint model for the two time-to-event variables, which utilizes the gamma frailty specification in the region of the observable data. First, we develop a novel estimator for the gamma frailty parameter under left truncation. Using this estimator, we then derive a closed-form estimator for the marginal distribution of the non-terminal event. The large sample properties of the estimators are established via asymptotic theory. The methodology performs well with moderate sample sizes, both in simulations and in an analysis of data from a diabetes registry.

Analysis of Variance↗

PubMed1991

No evidence for blood flow redistribution with isoflurane or halothane during acute coronary artery occlusion in fentanyl-anesthetized dogs.

The present study examines the postulate that isoflurane, in contrast to halothane, causes redistribution of blood flow away from an ischemic myocardial region through vasodilation of adjacent normally perfused myocardium. The study was performed in open-chest dogs anesthetized with fentanyl; ischemia was induced by occlusion of the left anterior descending coronary artery. At 0.6% alveolar concentration, isoflurane increased transmural blood flow to 125% of control values (P less than 0.05) in the normal region without concomitant changes in blood flow to the ischemic region or in the endocardial/epicardial flow ratio in the ischemic region. The evidence excludes either transmural steal or regional redistribution phenomena. Myocardial blood flow variables returned to control values at 1.8% isoflurane, and no blood flow redistribution effects were evident. In contrast, whereas halothane 0.4% caused no significant effect on myocardial blood flows, an alveolar concentration of 1.2% decreased transmural blood flow to normally perfused left ventricle to 70% of control (P less than 0.05). Regional myocardial oxygen consumption in the normal and ischemic areas decreased at higher alveolar concentrations and was unchanged at the lower concentrations for both agents. Myocardial lactate production from the ischemic region was unchanged with either agent, suggesting that, in terms of metabolic changes, neither agent worsened ischemia during sustained occlusion of the left anterior descending coronary artery. The present data show no evidence for worsening of myocardial ischemia with either isoflurane or halothane. Isoflurane causes a relatively greater increase in perfusion compared to myocardial oxygen consumption of normally perfused myocardium; nevertheless, sufficient coronary vascular reserve remains in the native collateral circulation so that myocardial metabolic supply-and-demand relationships during ischemia are not further compromised.

Animals↗

PubMed1998

Hippocampal volume reduction in schizophrenia as assessed by magnetic resonance imaging: a meta-analytic study.

BACKGROUND: Although many quantitative magnetic resonance imaging studies have found significant volume reductions in the hippocampi of patients with schizophrenia compared with those of normal control subjects, others have not. Therefore, the issue of hippocampal volume differences associated with schizophrenia remains in question. METHODS: Two meta-analyses were conducted to reduce the potential effects of sampling error and methodological differences in data acquisition and analysis. Eighteen studies with a total patient number of 522 and a total control number of 426 met the initial selection criteria. RESULTS: Meta-analysis 1 yielded mean effect sizes of 0.37 (P<.001) for the left hippocampus and 0.39 (P<.001) for the right, corresponding to a bilateral reduction of 4%. Meta-analysis 2 indicated that the inclusion of the amygdala in the region of interest significantly increased effect sizes across studies (effect size for the left hippocampus and amygdala, 0.67; for the right, 0.72), whereas variables such as illness duration, total slice width, magnet strength, the use of the intracranial volume as a covariate, measurement reliability, and study quality did not. No laterality differences were observed in these data. CONCLUSIONS: Schizophrenia is associated with a bilateral volumetric reduction of the hippocampus and probably of the amygdala as well. These findings reinforce the importance of the medial temporal region in schizophrenia and are consistent with frequently reported memory deficits in these patients. Future quantitative magnetic resonance imaging studies evaluating the hippocampal volume should measure the hippocampus and amygdala separately and compare the volumetric reduction in these structures to that observed in other gray matter areas.

Adult↗

PubMed1998

[Quantification of myocardial ischemia in regions dependent on occluded coronary arteries in patients without previous infarction].

INTRODUCTION AND OBJECTIVES: The aim of this study is to assess myocardial ischemia in regions with no infarction dependent occluded coronary arteries. PATIENTS AND METHODS: 149 patients with proved coronary artery disease and without previous myocardial infarction were studied by 99mTc-MIBI SPECT (long protocol) and coronary angiography. The extent of the uptake reversibility was quantified in 3 regions (antero-septal, inferior and lateral) of the polar maps, assessing the percentage of each region that had a > 10% difference resulting from the rest uptake minus the stress uptake. The regions dependent on one occluded artery were compared to those dependent on non-occluded arteries. In the regions dependent on one occluded artery a comparison was also made between those which had a good collateral circulation and those which did not. RESULTS: Fifty-four out of 149 patients (36%) had at least one occluded coronary artery (20 anterior descending, 22 right and 27 circumflex coronary arteries). In the visual analysis, reversible defects were observed in all patients with occlusion of the anterior descending and the right coronary artery, but only in half of the occlusions of the circumflex coronary artery. The extent of this reversibility was significantly higher in the regions dependent on occluded arteries and was highly variable, though lower when good collateral circulation was present. CONCLUSIONS: Reversible defects were always observed in the occlusions of the left anterior descending and right coronary arteries, but only in half of those of the circumflex artery. The extent of the ischemia was higher in the regions dependent on one occluded coronary artery, mainly when there was an absence of good collateral circulation.

Aged↗

PubMed2002

Characterization of tissue components in the temporomandibular joint disc and posterior disc attachment region: internal derangement and control autopsy specimens compared by morphometry.

PURPOSE: Our aim was to morphologically investigate the occurrence of fibroblasts, chondrocytes, and blood vessels in the tissue of the temporomandibular joint (TMJ) disc, the intermediate zone, and the posterior disc attachment region in control autopsy specimens and to compare the results with those observed in corresponding tissues from patients with TMJ internal derangement. PATIENTS AND METHODS: First, 20 bilateral TMJ disc specimens from selected autopsy cases were analyzed by conventional morphometry. Thus, the volume density of fibroblasts, chondrocytes, and blood vessels was determined. Second, the obtained results from the right joint of the autopsy disc specimens were compared with 12 TMJ disc specimens obtained at surgery from patients with internal derangement. RESULTS: The tissue compartments of interest (disc, intermediate zone, and posterior disc attachment region) were identified unequivocally in all specimens. None of the autopsy cases showed any significant difference between the right and left joints or related to gender. The only variable that differed between autopsy and patient specimens was volume density of blood vessels, which was higher in patient specimens. CONCLUSIONS: We found that the volume density of blood vessels was significantly higher in the posterior disc attachment region in patient specimens than in autopsy controls. Whether this reflects a role for vessels in the pathogenesis of TMJ internal derangement or merely is a reaction to another type of injury remains to be settled. In both the autopsy control and patient specimens, chondrocytes and fibroblasts were characteristic for disc respective posterior disc attachment region. Thus it appears that the occurrence of these cells can be used to distinguish TMJ disc from posterior disc attachment in small biopsy specimens.

Adolescent↗