Après un traumatisme de la moelle épinière (TM), l’ischémieest un facteur d’aggravation des lésions. Cette ischémie peut être aggravée par l’augmentation depression du liquide cérébro-spinal (LCS) par le biais d’un effet tamponnade. Or chez l’homme,après un TM avec préservation de l’intégrité de la dure-mère, la pression de LCS augmentesignificativement. On suppose donc que le maintien d’une pression de LCS à des valeursphysiologique pourrait être une méthode de limitation de l’ischémie post-traumatique et doncd’amélioration du pronostic fonctionnel. Afin de pouvoir réaliser une étude expérimentale de cesphénomènes, nous avons consacré la première partie expérimentale de cette thèse à la mise au pointd’un modèle de TM à dure-mère intacte chez le rat permettant la mesure simultanée de la pressionde LCS et de la perfusion médullaire. Nous avons confirmé expérimentalement que la pression deLCS augmente après TM. Dans la seconde partie expérimentale, nous avons mis au point unetechnique expérimentale de quantification spatiale et temporelle de la perfusion médullaire grâce àl’échographie de contraste. Cette technique permettait aussi un suivi en temps réel de l’évolution dusaignement intra-parenchymateux induit par le TM. Dans la troisième partie expérimentale, nousavons utilisé notre modèle couplé avec l’échographie de contraste et le laser Doppler pour évaluerles effets de la noradrénaline injectée à la phase aigüe d’un TM sur la perfusion médullaire et lesaignement intra-parenchymateux. Nous avons montré que la noradrénaline augmentait trèslégèrement le flux sanguin superficiel mais pas le flux sanguin profond et qu’elle augmentait lataille du saignement. / After spinal cord injury (SCI), ischaemia aggravates lesions.Increase in cerebrospinal fluid (CSF) pressure can worsens ischaemia through a tamponnade effect.In humans, it has been shown that after SCI with intact dura mater, CSF pressure significantlyincreases. Therefore, preserving CSF pressure within a physiological range may limit post-traumaischaemia and improve neurological outcome. In order to experimentally study these phenomenon,we have dedicated the first part of that work to create a model of SCI in rats preserving dura’sintegrity and allowing simultaneous measurement of spinal cord blood flow (SCBF) and CSFpressure. We have confirmed that CSF pressure increases after SCI with intact dura. In the secondexperimental part, we have developed a technique allowing to perform spatial and temporalmeasurement of SCBF thanks to contrast enhanced ultrasonography (CEU). Moreover, thistechnique allows real-time measurement of the size of the parenchymal hemorrhage. In the thirdexperimental part, we have used our experimental model in association with CEU and LaserDoppler to assess the effects of early injection of norepinephrine on SCBF and parenchymalhemorrhage. We found that norepinephrine induces a slight increase in superficial SCBF while itdoesn’t modify deep SCBF and significantly increases the size of parenchymal hemorrhage.

La compression nerveuse chronique (CNC) est un modèle d’étude expérimental définit pour l’examen du syndrome du canal carpien. Notre travail consistait à étudier chez le rat sain, l’effet d’une CNC de courte ou de longue durée sur la microcirculation cutanée, ainsi que la capacité de récupération fonctionnelle du nerf suite à une décompression, et les mécanismes moléculaires impliqués dans la régénération nerveuse. L’originalité de l’équipe de recherche est d’avoir montré un mécanisme physiologique original permettant d’étudier l’interaction neurovasculaire cutanée qui peut être observée sur le nerf. La PIV (Pressure‐Induced Vasodilation) est un outil original de commande de la vasomotricité par les fibres C. Les dysfonctions neurovasculaires cutanées et nerveuses induites par une CNC de courte durée sont associés à l’altération des fibres C et, à des mécanismes angiogéniques et inflammatoires du nerf lésé. Ces atteintes sont réversibles après une décompression nerveuse, malgré une modification de la balance des facteurs angiogéniques, une augmentation de l’expression de facteurs inflammatoires et l’activité de protéines à profil apoptotique. La CNC de longue durée provoque des traumatismes plus importants auxquels s’ajoutent des atteintes vasculaires. Par conséquent la décompression du nerf sciatique n’a pas permis de rétablir les fonctions nerveuses périphériques. La PIV fournit un diagnostic précoce de l’atteinte nerveuse suivant sa réduction, synonyme d’une CNC de courte durée, ou de son abolition, synonyme d’une CNC longue durée. Ces niveaux d’atteintes nerveuses et inflammatoires pourraient être responsables ou non de la récupération fonctionnelle nerveuse / Chronic nerve compression (CNC) is an experimental study model for the examination of the carpal tunnel syndrome. Our work aimed to study the effect of short or long‐term CNC on the cutaneous blood flow, on the nerve ability to recover following to nerve release, and the molecular mechanisms involved in the nervous regeneration. For that purpose, our laboratory established an original physiological mechanism in the study of the relationship between vessel and nerve in the sciatic nerve but also at the periphery, in the cutaneous tissue. Therefore, PIV (Pressure‐Induced Vasodilation) is an original tool of vasomotion linked to C‐fibers. Cutaneous and nervous neurovascular dysfunctions induced by a shortterm CNC were associated to cutaneous C‐fibers impairment and, angiogenic and inflammatory mechanisms of the injured nerve. These achievements are reversible after nerve release, even though the nerve showed a modification of the balance of angiogenic factors, an increase of the expression of inflammatory factors and the activity of proteins with apoptotic type. The long‐term CNC induced more important trauma that further affected the vascular function. Consequently the decompression of the sciatic nerve did not allow restoring the peripheral nervous function. PIV allows to early diagnosing nerve damage with a reduction referring to a short‐term CNC or an abolition referring to a long‐term CNC. Activation of the inflammatory pathway during CNC could compromise nerve recovery following nerve decompression

No campo da medicina diagnóstica através de imagens, o baixo custo e a característica não-invasiva da ultrassonografia modo-B favoreceram as pesquisas que analisam a relação entre a espessura íntima-média (EIM) da artéria carótida e o desenvolvimento de doenças cardiovasculares. Outra técnica de ultrassonografia, baseada no efeito Doppler, também tem sido extensivamente empregada em ambientes clínicos para a medição da velocidade e do fluxo de sangue das artérias periféricas, oferecendo uma abordagem distinta para estudar as doenças cardiovasculares. Neste trabalho, métodos computacionais foram implementados e analisados para extrair informações quantitativas de artérias a partir de imagens 2D. Os ensaios com imagens em modo-B contemplaram a combinação de técnicas de filtragem e algoritmos de contornos ativos para a detecção das interfaces das paredes arteriais e medições da EIM e do diâmetro da luz (DL). Um modelo matemático e 7 imagens reais da artéria carótida comum foram utilizados neste estudo que, dentre as diversas combinações de filtros e algoritmos, apresentou resultados quantitativos similares no cálculo do DL. Para a EIM, porém, a reduzida dimensão da camada íntima-média proporcionou variações indesejadas dos cálculos. Para medir a velocidade do sangue utilizando o modo Doppler, um método semiautomático foi incorporado a um aplicativo computacional para a detecção da envoltória do espectro do gráfico de velocidades. Uma análise comparativa entre sistemas de ultrassonografia comerciais operados por especialistas e este aplicativo incluiu a velocidade de pico sistólico e a integral de velocidade e tempo (VTI) das artérias carótida comum e braquial e de exames ecocardiográficos. A análise de Bland-Altman e o coeficiente de correlação validaram esta metodologia que, complementada pela interface gráfica amigável do aplicativo, pode auxiliar os clínicos em seus estudos de larga escala, baseados nas imagens Doppler ultrassonográficas, com as seguintes vantagens: redução do tempo operacional e de resultados subjetivos e aumento do grau de reprodutibilidade dos resultados. / In the field of image-based diagnostic medicine, low cost and noninvasive B-mode ultrasound technique have supported the researches which investigates the relation between the carotid intima-media thickness (IMT) and the development of cardiovascular diseases. Other ultrasound technique, that offers a different approach to study these diseases, is based on Doppler effect and has also been extensively used in clinical sites to measure blood velocity and flow in peripheral arteries. In this work, computational methods were implemented and analyzed to extract quantitative data from 2D images of arteries. Tests with B-mode images covered the combination of filtering techniques and active contour algorithms, in order to detect the arterial wall interfaces and to measure IMT and lumen diameter (LD). One mathematical model and seven real images of the common carotid artery were used in this study which, among several filters and algorithms combinations, showed similar quantitative results for DL measurements. However, for IMT, the small thickness of intima-media layer led to undesirable variation results. To measure blood velocity by using Doppler mode, a semi-automatic methodology was implemented in a computational tool to detect the spectrum envelope of the velocity graphic. A comparative analysis between commercial ultrasound systems operated by specialists and this tool included systolic peak velocities and velocity-time integral (VTI) of the common carotid and brachial arteries and of echocardiographic exams. Bland-Altmans analysis and the correlation coefficient validated this methodology which, besides the user friendly graphical interface of the tool, may help the clinicians for their large-scale studies based on Doppler ultrasound images, with the following advantages: to save operational time, to lower subjective results, and to support measurement reproducibility.

The peripheral skin microcirculation reflects the overall health status of the cardiovascular system and can be examined non-invasively by laser methods to assess early cardiovascular disease (CVD) risk factors, i.e. oxidative stress and endothelial dysfunction. Examples of methods used for this task are the laser Doppler flowmetry (LDF) and laser fluorescence spectroscopy (LFS), which respectively allow tracing blood flow and the amounts of the coenzyme NAD(P)H (nicotamide adenine dinucleotide) that is involved in the cellular production of ATP (adenosine triphosphate) energy. In this work, these methods were combined with iontophoresis and PORH (post-occlusive reactive hyperaemia) reactive tests to assess skin microvascular function and oxidative stress in mice and human subjects. The main focus of the research was exploring the nonlinear dynamics of skin LDF and NAD(P)H time series by processing the signals with the wavelet transform analysis. The study of nonlinear fluctuations of the microcirculation and cell energy metabolism allows detecting dynamic oscillators reflecting the activity of microvascular factors (i.e. endothelial cells, smooth muscle cells, sympathetic nerves) and specific patterns of mitochondrial or glycolytic ATP production. Monitoring these dynamic factors is powerful for the prediction of general vascular/metabolic health conditions, and can help the study of the mechanisms at the basis of the rhythmic fluctuations of micro-vessels diameter (vasomotion). In this thesis, the microvascular and metabolic dynamic biomarkers were characterised <i>in-vivo</i> in a mouse model affected by oxidative stress and a human cohort of smokers. Data comparison, respectively, with results from control mice and non-smokers, revealed significant differences suggesting the eligibility of these markers as predictors of risk associated with oxidative stress and smoke. Moreover, a relevant link between microvascular and metabolic oscillators was observed during vasomotion induced by α-adrenergic (in mice) or PORH (in humans) stimulations, suggesting a possible role of cellular Ca²⁺oscillations of metabolic origin as drivers of vasomotion which is a theory poorly explored in literature. As future perspective, further exploration of these promising nonlinear biomarkers is required in the presence of risk factors different from smoke or oxidative stress and during vasomotion induced by stimuli different from PORH or α-adrenergic reactive challenges, to obtain a full picture on the use of these factors as predictors of risk and their role in the regulation of vasomotion.

L'échographie est largement utilisée pour l'imagerie du flux sanguin pour ses nombreux avantages tels que son inocuité, son cout réduit, sa facilité d'utilisation et ses performances. Cette thèse a pour objectif de proposer de nouvelles méthodes ultrasonores d'imagerie du flux sanguin. Après une étude bibliographique, plusieurs approches ont été étudiées en détail jusqu'à leur implémentation sur l'échographe de recherche ULA-OP développé au sein du laboratoire et ont été validées en laboratoire et en clinique. La transmission d'ondes planes a été proposée pour améliorer la technique d'imagerie utilisant les oscillations transverses. Des champs de pression ultrasonores présentant des oscillations transverses sont générés dans de larges régions et exploités pour l'estimation vectorielle du flux sanguin à une haute cadence d'imagerie. Des cartes du flux sanguin sont obtenues grâce à une technique s'appuyant sur la transmission d'ondes planes couplées à un nouvel algorithme d'estimation de la vitesse dans le domaine fréquentiel. Les méthodes vectorielles implémentées en temps réel dans le ULA-OP ont été comparées à la méthode Doppler classique lors d'une étude clinique. Les résultats ont montré le bénéfice des méthodes vectorielles en termes de précision et de répétabilité. La nouvelle méthode proposée a démontré sa grande précision ainsi que son gain en termes de temps de calcul aussi bien en simulations qu'en acquisitions en laboratoire ou lors d'essais in vivo. Une solution logicielle temps réel implémentée sur une carte GPU a été proposée et testée afin de réduire encore le temps de calcul et permettre l'emploi de la méthode en clinique / Ultrasound is widely used for blood flow imaging because of the considerable advantages for the clinician, in terms of performance, costs, portability, and ease of use, and for the patient, in terms of safety and rapid checkup. The undesired limitations of conventional methods (1-D estimations and low frame-rate) are widely overtaken by new vector approaches that offer detailed descriptions of the flow for a more accurate diagnosis of cardiovascular system diseases. This PhD project concerns the development of novel methods for blood flow imaging. After studying the state-of-the-art in the field, a few approaches have been examined in depth up to their experimental validation, both in technical and clinical environments, on a powerful ultrasound research platform (ULA-OP). Real-time novel vector methods implemented on ULA-OP were compared to standard Doppler methods in a clinical study. The results attest the benefits of the vector methods in terms of accuracy and repeatability. Plane-wave transmissions were exploited to improve the transverse oscillation imaging method. Double oscillating fields were produced in large regions and exploited for the vectorial description of blood flow at high frame rates. Blood flow maps were obtained by plane waves coupled to a novel velocity estimation algorithm operating in the frequency domain. The new method was demonstrated capable of high accuracy and reduced computational load by simulations and experiments (also in vivo). The investigation of blood flow inside the common carotid artery has revealed the hemodynamic details with unprecedented quality. A software solution implemented on a graphic processing unit (GPU) board was suggested and tested to reduce the computational time and support the clinical employment of the method

La thérapie par compression médicale est reconnue comme une composante essentielle dans le traitement des pathologies veineuses et demeure incontournable dans la prise en charge des affections veineuses aux différents stades de la pathologie (jambes lourdes, œdèmes, ulcères). Si le bénéfice est reconnu par les patients eux-mêmes ainsi que par les médecins, il n’existe à l’heure actuelle que peu d’éléments permettant de quantifier ce bénéfice. Dans ce contexte, l’objectif de ces travaux de thèse est d’apporter des éléments de compréhension et d’objectiver les effets bénéfiques des bas médicaux de compression (BMC) aux niveaux physiologique, neurophysiologique et comportemental. Trois axes de recherche ont été dégagés. Le premier axe de recherche est l’étude de l’effet de la compression sur l’activité microcirculatoire cutanée dans les membres inférieurs en utilisant le dispositif Hématron, dispositif ambulatoire exclusif d’évaluation de l’activité microcirculatoire cutanée. Les résultats ont montré une amélioration de l’activité microcirculatoire pour différentes classes de BMC et pour différentes positions. Ces résultats tendraient à mettre en cause l’hypothèse, largement admise, que les BMC améliorent le retour veineux principalement en diminuant la section des veines (superficielles voire profondes). La deuxième piste de recherche concerne l’objectivation de l’amélioration de la qualité de vie liée au port des BMC, généralement exprimée subjectivement par les personnes atteintes de pathologie veineuse. Les résultats préliminaires montrent que l’analyse de la variabilité cardiaque permet de mettre en évidence une relation entre le paramètre indicateur de l’activité de la balance sympatho-vagale et le port de la compression médicale au cours d’une journée. Compte tenu de la grande dispersion des résultats, cette étude serait à poursuivre sur une population plus large pour aboutir à des conclusions fiables. Le dernier axe de recherche est lié à l’impact du port des BMC sur le comportement du sujet et plus précisément sur sa déambulation. Les patients déclarent une fatigue physique dans les membres inférieurs moins intense en fin de journée grâce à la compression médicale. Notre hypothèse est que le port des BMC impacterait directement la dynamique de la déambulation. Pour évaluer la cinétique de la marche, nous avons conçu, développé et validé une instrumentation intégrant des capteurs accéléromètres. Des tests préliminaires ont permis de dégager des paramètres pertinents caractéristiques de la déambulation. La prochaine étape sera de conduire une campagne d’expérimentation destinée à objectiver la fatigue comportementale en fin d’après-midi mesurée avec ou sans compression médicale portée au cours de la journée. / Medical compression therapy is recognized as an essential component in the treatment of venous diseases and is indispensable in the treatment of venous diseases at different stages of the disease (heavy legs, edema and ulcers). Although the benefit is recognized by the patients themselves and by physicians, there is at present little evidence to quantify this benefit. Against this background, the aim of this thesis is to provide more understanding and objectify the benefits of compression stockings (MCS) on in terms of physiology, neurophysiology and gait dynamics. Three areas of research were identified and studied. The first line of research is the study of the effect of compression on skin microcirculatory activity in the lower limbs using the Hematron ambulatory device. The results showed an improvement in skin blood flow activity for different classes of MCS and at different positions. These results would tend to challenge the widely accepted assumption that MCS improve venous return primarily by decreasing the cross-sectional area of (superficial or deep) veins. The second line of research involves the objectification of the improvement in the quality of life resulting from the wearing of MCS, usually this is expressed subjectively by people with venous disease. Preliminary results show that the analysis of heart rate variability highlights a relationship between the indicators of sympathovagal balance activity and the use of medical compression during the day. Given the wide dispersion in the results, this study should be carried out on a larger population to draw more reliable conclusions. The last line of research relates to the impact of MCS on the behavior and, in particular, the gait of the subject. Patients report that physical fatigue in the lower limbs is less prevalent at the end of the day with compression therapy. Our hypothesis is that the wearing of MCS has a direct impact on gait. To evaluate the kinetics of walking, we have designed, developed and validated an instrumentation involving accelerometers sensors. Preliminary tests have yielded relevant parameters characteristic of gait dynamics. The next step is to conduct an experimental campaign to objectify behavioral fatigue, with or without the wearing of medical compression, at the end of the afternoon.

Centers for Disease Control and Prevention (CDC) estimate that more than 11.2 million people require critical and emergency care in the United States per year. Optimizing and improving patient morbidity and mortality outcomes are the primary objectives of monitoring in critical and emergency care. Patients in need of critical or emergency care in general are at a risk of single or multiple organ failures occurring due to a traumatic injury, a surgical event, or an underlying pathology that results in severe patient hemodynamic instability. Hence, continuous monitoring of fundamental cardiovascular hemodynamic parameters, such as heart rate, respiratory rate, blood pressure, blood oxygenation and core temperature, is essential to accomplish diagnostics in critical and emergency care. Today’s standard of care measures these critical parameters using multiple monitoring technologies. Though it is possible to measure all the fundamental cardiovascular hemodynamic parameters using the blood flow dynamics, its use is currently only limited to measuring continuous blood pressure. No other comparable studies in the literature were successful in quantifying other critical parameters from the blood flow dynamics for a few reasons. First, the blood flow dynamics exhibit a complicated and sensitive dynamic pressure field. Existing blood flow based data acquisition systems are unable to detect these sensitive variations in the pressure field. Further, the pressure field is also influenced by the presence of background acoustic interference, resulting in a noisy pressure profile. Thus in order to extract critical parameters from this dynamic pressure field with fidelity, there is need for an integrated framework that is composed of a highly sensitive data acquisition system and advanced signal processing. In addition, existing state-of-the-art technologies require expensive instrumentation and complex infrastructure. The information sensed using these multiple monitoring technologies is integrated and visualized using a clinical information system. This process of integration and visualization creates the need for functional interoperability within the multiple monitoring technologies. Limited functional interoperability not only results in diagnostic errors but also their complexity makes it impossible to use such technologies to accomplish monitoring in low resource settings. These multiple monitoring technologies are neither portable nor scalable, in addition to inducing extreme patient discomfort. For these reasons, existing monitoring technologies do not efficiently meet the monitoring and diagnostic requirements of critical and emergency care. In order to address the challenges presented by existing blood flow based data acquisition systems and other monitoring systems, a point of care monitoring device was developed to provide multiple critical parameters by means of uniquely measuring a physiological process. To demonstrate the usability of this novel catheter multiscope, a feasibility study was performed using an animal model. The corresponding results are presented in this dissertation. The developed measurement system first acquires the dynamics of blood flow through a minimally invasive catheter. Then, a signal processing framework is developed to characterize the blood flow dynamics and to provide critical parameters such as heart rate, respiratory rate, and blood pressure. The framework used to extract the physiological data corresponding to the acoustic field of the blood flow consisted of a noise cancellation technique and a wavelet based source separation. The preliminary results of the acoustic field of the blood flow revealed the presence of acoustic heart and respiratory pulses. A unique and novel framework was also developed to extract continuous blood pressure from the pressure field of the blood flow. Finally, the computed heart and respiratory rates, systolic and diastolic pressures were benchmarked with actual values measured using conventional devices to validate the measurements of the catheter multiscope. In summary, the results of the feasibility study showed that the novel catheter multiscope can provide critical parameters such as heart rate, respiratory rate and blood pressure with clinical accuracy. In addition, this dissertation also highlights the diagnostic potential of the developed catheter multiscope by presenting preliminary results of proof of concept studies performed for application case studies such as sinus rhythm pattern recognition and fetal monitoring through phonocardiography.

Abstract not available

<p>The gastrointestinal mucus gel layer and blood flow are two important mechanisms for protection at the pre-epithelial and sub-epithelial levels, respectively. <i>Helicobacter pylori</i> might circumvent these mechanisms and elicit a chronic inflammatory response with consequent ulcers in the stomach and duodenum. In this thesis, the physical state and properties of the adherent mucus gel layer was studied from the stomach to colon. Furthermore, the acute and chronic effects of <i>H. pylori</i> on the integrity of the mucus gel layer and mucosal blood flow were studied in the anesthetized rat.</p><p>A translucent mucus gel covers all studied segments of the gastrointestinal tract during fasting conditions, with the thickest layers in the colon and ileum. Carefully applied suction revealed that the mucus gel was a multi-layered structure comprising a firmly adherent layer covering the mucosa, impossible to remove, and a loosely adherent upper layer. The firmly adherent layer was thick and continuous in the corpus (80μm), antrum (154μm) and colon (116μm), but thin (<20μm) and discontinuous in the small intestine.</p><p>Following mucus removal, a rapid renewal of the loosely adherent layer ensued. The highest rate was observed in the colon with intermediate values in the small intestine. Mucus renewal in the stomach was attenuated on acute luminal application of water extracts from <i>H. pylori</i> (HPE). In animals with a chronic <i>H. pylori</i> infection the mucus renewal rate was unaffected, but the total gastric mucus gel thickness was reduced and the mucus secretory response to luminal acid (pH1) attenuated in the antrum. </p><p>HPE from type I strains acutely reduced corporal mucosal blood flow, measured with laser-Doppler flowmetry, by approximately 15%. The reduction in blood flow was mediated by a heat stable factor other than VacA and CagA. Inhibition of endogenous nitric oxide production with Nω-nitro-l-arginine augmented the decrease. However, ketotifen, a mast cell stabilizer, completely attenuated the effect of the extract as did the platelet activating factor (PAF) receptor-antagonist, WEB2086, thus depicting a detrimental role for the microvascular actions of PAF.</p>

<p>This thesis explored the epidemiology of Posttraumatic Stress Disorder (PTSD) and different aspects of the disorder. Firstly, we investigated the lifetime prevalence of traumatic experiences and PTSD in the general adult population in Sweden and evaluated the impact of different trauma types, trauma frequency, and perceived distress. The results show that traumatic experiences are common and PTSD is not rare; roughly one out of ten traumatic events results in PTSD, with a 5.6% lifetime prevalence. The female/male ratio is 2:1. The risk for PTSD increases considerably with a high trauma-associated emotional impact. The distressing impact of a given trauma appears to be higher in women than in men, indicating an increased vulnerability in women. Secondly, we hypothesized that traffic road accidents (TRA’s) are one of the most prevalent types of traumatic events in Swedish society; therefore, we examined the impact of event and response characteristics associated with TRA’s on PTSD development. The data demonstrate that of those who had experienced a TRA (n=1074, 58.9%), 6.1% reported lifetime PTSD. TRA’s associated with fatal accidents and injury to oneself and related to high distress more than double the risk for PTSD. Thirdly, we compared the relative merits of the DSM-IV’s three-factor solution for PTSD symptoms to alternative models. We found that the symptomatology is equally well accounted for using all factor analytic models as yet presented in the literature; the DSM-IV, we found, provides as good a fit to data as other models. Fourthly, we examined the neurofunctional correlates of PTSD symptoms and whether a treatment-induced (serotonin reuptake inhibitor - SSRI) reduction of PTSD symptoms is associated with altered rCBF during symptom provocation. Our results indicate that PTSD symptoms correlates with areas involved in memory, emotion, attention, and motor control and that SSRI treatment normalizes provocation-induced rCBF in these areas.</p>