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Dense sensor event-related brain potentials were measured in participants with spider phobia, high anxiety sensitive individuals and non-fearful controls during viewing of medical emergency, spider and standard emotional (pleasant, unpleasant, neutral) pictures. Compared to non-fearful controls spider phobia participants showed a significantly enlarged late positive potential (LPP) during the encoding of phobia-relevant pictures whereas high anxiety sensitive individuals showed a significantly greater Early Posterior Negativity (EPN) during the encoding of medical emergency pictures and a significantly greater Late Positive Potential (LPP) during the encoding of highly arousing unpleasant visual material. Moreover, within group comparisons of the spider phobia group revealed comparable LPP evoked by spider pictures and emotional (unpleasant and pleasant) picture contents indicating that at the level of early stimulus evaluation, the effects of selective attention seem to be related to emotional relevance of the stimulus rather than reflecting a fear-specific response.
The learning theory of panic disorder differs between panic attacks and anxious apprehension as distinct emotional states. Acute panic is accompanied by extreme fear, experience of strong body symptoms reflecting autonomic surge and flight tendencies. In contrast, anxious apprehension is associated with hypervigilance towards bodily sensations and increased distress when subtle somatic symptoms are identified. Following animal models, these clinical entities reflect different stages of defensive reactivity depending upon the imminence of interoceptive or exteroceptive threat cues with lowest distance to threat during panic attacks. We tested this model by investigating the dynamics of defensive reactivity in a large group of patients suffering from panic disorder and agoraphobia (PD/AG) prior to a multicenter controlled clinical trial. Three hundred forty-five patients participated in a standardized behavioral avoidance test (being entrapped in a small, dark chamber for 10 minutes). Defensive reactivity was assessed measuring avoidance and escape behavior, self reports of anxiety and panic symptoms, autonomic arousal (heart rate and skin conductance), and potentiation of the startle reflex before and during the exposure period of the behavioral avoidance test. While 125 patients showed strong anxious apprehension during the task (as indexed by increased reports of anxiety, elevated physiological arousal, and startle potentiation), 72 patients escaped from the test chamber. Active escape was initiated at the peak of the autonomic surge accompanied by an inhibition of the startle response as predicted by the animal model. These physiological responses were observed during 34 reported panic attacks as well. We found evidence that defensive reactivity in PD/AG patients is dynamically organized ranging from anxious apprehension to panic with increasing proximity of interoceptive threat. Importantly, the patients differed quite substantially according defensive reactivity during the behavioral avoidance test despite all patients received the same principal diagnosis. These differences can be explained in part by differences in the disposition according to two genetic variants previously associated with panic disorder. Patients carrying the risk variant of a polymorphism in the neuropeptide S receptor gene showed an overall increased heart rate during the whole behavioral avoidance test reflecting an enhanced sympathomimetic activation and consequently arousal level. During the entrapment situation in which heart rate further increased over an already elevated baseline level, risk variant carriers were prone to experience more panic symptoms. This is in line with the learning perspective of panic disorder, postulating that internal cues of elevated arousal increase the chance of experiencing another panic attack once they have been associated with aversive responses. Furthermore, the risk variant of a polymorphism in the monoamine oxidase A gene was observed to augment the occurrence of panic attacks and escape behavior preparation. In addition, we find evidence that suggest an enhanced resistance to corrective learning experiences as indicated by a lack of a reduction of avoiding and escaping behavior during repeated test chamber exposures in wait-list control patients carrying the risk gene variant. Both effects may strengthen the learning mechanism hypothesized to be involved in the pathogenesis of panic disorder. Exteroceptive and interoceptive cues previously associated with the initial panic attack might trigger subsequent attacks in risk allele carriers more rapidly while simultaneously the opportunity to dissolve once established associations due to contradictory experiences is limited. Now, differential dispositions regarding defensive reactivity in PD/AG patients has to be linked to mechanisms supposed to be involved in exposure based therapy. First outcome evaluations of the clinical trial indicated that a behavioral therapy variant suggested to be linked with higher fear activation during exposure exercises is more effective than another. Further analyses have to proof whether those patients showing a clear specific fear response during the behavioral avoidance test benefit more than others from exposure based therapy.
Das Teddybärkrankenhaus ist ein weltweites Projekt, welches bei Kindern die Angst vor dem Arzt reduzieren soll und einmal im Jahr durch Medizinstudenten in Greifswald durchgeführt wird. Da es deutschlandweit zuvor noch keine systematische Studien zu diesem Projekt gab, sollte mit dieser Arbeit herausgefunden werden, wie viel Angst die Kinder vor medizinischen Situationen zeigen und ob diese durch einen Besuch im Teddybärkrankenhaus reduziert werden kann. Außerdem wurde der Einfluss verschiedener Faktoren untersucht. Als Instrument wurde ein fünfteiliger Bilderfragebogen entwickelt, bei dem typische Situationen (Abhorchen, Zahnarzt, Kind mit Gipsbein, Spritze, Rettungswagen) dargestellt waren. Die Einschätzung durch die Kinder erfolgte auf einer dreistufigen Teddygesichtsskala. Einige Kinder wurden zusätzlich mit der etablierten „Hospital Fears Rating Scale“ (HFRS) befragt. Insgesamt 569 Kinder aus 18 Kindertagesstätten und einer Schule in Greifswald wurden zwei Wochen vor dem Besuch im Teddybärkrankenhaus interviewt. Unmittelbar nach der Intervention durch das Teddybärkrankenhaus wurden 481 der zuvor befragten Kinder erneut befragt. Die Probanden waren zwischen zwei und acht Jahren alt. „Viel Angst“ gaben die meisten Kinder (40%) beim Item „Spritze“ an. Die meisten Kinder gaben „keine Angst“ beim Item „Abhorchen“ an (82%). Die HFRS und der Bilderfragebogen korrelierten mäßig miteinander. Die Angstausprägung der Kinder wurde im Wesentlichen durch die innerstädtische Lage der Kindertagesstätte beeinflusst, sowie dem Geschlecht des Kindes und der Vorbereitung durch die Erzieher. Der Vergleich der beiden Testzeitpunkte ergab, dass die Angst bei 206 von 481 Kindern reduziert und nur bei 149 vergrößert wurde. Diese Tendenz ist für alle Items zu erkennen, für das Item „Abhorchen“ war die Reduktion der Angst nach dem Besuch im Teddybärkrankenhaus statistisch signifikant. Eine multivariate Regression wurde zur Untersuchung der simultanen Auswirkung aller Einflussfaktoren auf die Angstreduktion durchgeführt. Als wichtigster Einflussfaktor stellte sich die Stärke der angegebenen Angst bei der ersten Befragung heraus. Weitere Einflussfaktoren stellten sich dagegen im multivariaten Modell als nicht signifikant heraus. Die Ergebnisse zeigen, dass das Teddybärkrankenhaus die Angst der Kinder reduziert. Zudem bekommen die Kinder im Vorschulalter die Gelegenheit, sich mit den Themen Krankheit und Gesundheit auseinanderzusetzen. Die Ergebnisse sprechen insgesamt für eine Ausweitung des Projektes.
Body sensations play a crucial role in the etiology and maintenance of diverse anxiety and health problems (e.g., in panic disorder or respiratory diseases) as they may be perceived as threatening and consequently elicit anxious responses. The factors that may affect the perception of bodily sensations as a threat and thus modulate the anxious response to body sensations have so far rarely been studied. Therefore, the present thesis targeted at elucidating the effect of contextual (i.e., the predictability, expectation, and proximity of a threat) and dispositional factors (i.e., tendency to fear arousal sensations or trait fear of suffocation) on the defensive response to body sensations.
In study 1, it was investigated how a personality factor, that is, fear of suffocation, affects the acquisition of fear to body sensations (i.e., mild dyspnea induced by inspiratory resistive loads) and contexts when faced with a predictable and unpredictable respiratory threat (i.e., severe dyspnea). Study 2 aimed at examining the main and interactive effects of the tendency to fear arousal sensations, again a personality trait factor, and current arousal expectations as varied by situational variables on anxious responding to arousal sensations. In this study, expected and unexpected arousal sensations were induced by administering caffeine in coffee or bitter lemon soda, respectively. Moreover, in study 3, it was explored how subjective anxiety, bodily symptoms, and defensive respiratory responses change and might culminate into active defense behavior (i.e., escape/active avoidance) during increasing dyspnea that was evoked by inspiratory resistive loads increasing in intensity. For a detailed analysis of the factors that contribute to the initiation and maintenance of avoidance of or escape from increasing dyspnea, in study 4 changes in subjective, autonomic, somatic reflex and brain responses were analyzed during repeated avoidance of increasing dyspnea.
In study 1, it was demonstrated that only individuals who fear suffocation learned to fear mild dyspnea preceding the onset of severe dyspnea and developed anxiety during a context of unpredictable respiratory threat. Moreover, the data from study 2 indicate that individuals who fear arousal sensations show an increased attention allocation towards unexpected arousal sensations and higher threat appraisal when expecting arousal sensations. Increasing intensity of dyspnea as provoked in study 3 led to increased defensive respiratory responses that were associated with increased symptom reports in individuals with high compared to low fear of suffocation. Moreover, culminating dyspnea elicited repeated avoidance behavior preceded by increases in defensive respiratory mobilization. The analysis of repeated avoidance of increasing dyspnea in study 4 revealed that physiological fear responses might be involved in the initial initiation of this avoidance behavior while no indication of response preparation and physiological arousal was related to persistent avoidance.
Taken together, the present data suggest that the fear of suffocation, as well as the tendency to fear arousal sensations along with the predictability, expectation, or proximity of interoceptive threat, may increase the perceived threat and thus the anxious response to body sensations. Therefore, contextual and dispositional factors may set the stage for the culmination of body sensations into defensive action and might contribute to the development of pathological anxiety and fear of body sensations. The present findings are integrated into the current literature and discussed in relation to the development and maintenance of pathological anxiety and fear of body sensations.
Recently, there was a debate about whether borderline dysplastic hips should be treated surgically with hip arthroscopy or periacetabular osteotomy (PAO). Current studies recommend a classification into stable and unstable hips. Therefore, radiological scores have been described in recent years. Likewise, a new clinical stability test with the Prone Apprehension Relocation Test (PART) has been described. However, there has been no correlation between the modern radiological scores and the PART. We prospectively studied a consecutive group of patients who presented to our clinic. The PART and radiological scores were assessed in these patients. We divided the patients into a PART-positive and a PART-negative group and analyzed the associated clinical and radiological findings. Out of 126 patients (126 hips) included, 36 hips (29%) were evaluated as PART positive. There were significantly more females in the PART positive group (P = 0.005). Comparing the PART groups, significant differences (P < 0.0001) were found for the lateral center edge angle (LCEA), Femoro-Epiphyseal Acetabular Roof (FEAR) index, Gothic arch angle (GAA), anterior wall index (AWI), the occurrence of the upsloping lateral sourcil (ULS) and signs of acetabular retroversion. The correlation analysis showed an association between LCEA, FEAR index, GAA, AWI, ULS and the PART. A chi-square automatic interaction detection algorithm revealed that the strongest predictor of positive PART was the GAA. In conclusion, a high correlation between the PART and known radiological instability parameters was found. Consequently, a combination of clinical instability testing and radiological instability parameters should be applied to detect unstable hips.