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Neurofunktionelle Aspekte von experimentell induzierter Angst bei Patienten mit phobischem Schwankschwindel
Neurofunktionelle Aspekte von experimentell induzierter Angst bei Patienten mit phobischem Schwankschwindel
INTRODUCTION Vertigo and anxiety are frequent symptoms in both psychiatric and vertigo patients, especially in those with phobic postural vertigo (PPV). Vertigo is one of the most common causes for a visit in a neurological practice. Furthermore, PPV has one of the highest incidence rates among all types of vertigo. Patients suffering from PPV show many symptoms similar to anxiety disorders. On account of this, functional magnetic resonance and cholecystokinin tetrapeptide (CCK-4) were used as a valid model to experimentally induce anxiety symptoms, in order to investigate the neuronal correlates of anxiety in PPV patients in comparison to healthy controls (HC). This was done by addressing, among other things, the question to which extent the underlying fear-networks differ between those two groups. METHODS 15 PPV patients (average age: 43 years, 6 f, 9 m) and 15 gender and age (± 2 years) matched healthy controls underwent challenges with 50 µg bolus CCK-4 injections, not knowing the exact time point of the injection, for the purpose of distinguishing between anticipatory and CCK-4 induced anxiety. Simultaneously a functional MRI (3T Verio Siemens; echo-planar EPI sequence [TR = 3s; 36 slices; slice thickness: 3mm; interslice-gap: 0.75mm]) was recorded. The panic symptom scale was used before (PSS pre) and after (PSS post) the injection. In addition, psychiatric symptoms (e.g. depression, anxiety) as well as somatic symptoms (e.g. heart rate) were assessed. BrainVoyager™ and FSL Software were used to examine the functional MRI data (Independent Component Analysis and Region of Interest analysis). RESULTS During anticipatory anxiety, healthy controls showed functional responses mainly in fronto-temporal regions. In comparison to HC, patients suffering from PPV revealed pronounced BOLD responses e.g. in the insula, the amygdala, the inferior frontal gyrus (BA 13), the superior and medial temporal gyrus as well as the cuneus. CCK-4 induced anxiety (PPV vs. HC) was accompanied by activations, for example in the anterior cingulate gyrus (ACC), the amygdala, the putamen, the insula as well as the superior, medial, inferior frontal and temporal gyrus. In addition, a region of interest analysis demonstrated an increased number of activated voxels in the parietal, temporal and occipital lobe in patients after CCK-4 injection compared to healthy controls; the differences regarding amygdala and orbitofrontal cortex reached a trend level.With respect to the psychiatric symptoms, significantly increased scores were demonstrated in patients regarding depression and anxiety ratings (especially somatic symptoms), vertigo symptoms (VSS-D) and PSS values before the injection (PSS pre). The injection of CCK-4 led to an increase of heart rate in all subjects. CONCLUSIONS In patients suffering from phobic postural vertigo the application of CCK-4 led to pronounced BOLD responses in brain regions playing a central role in anxiety and cognition as seen in fear-related processes. These neuronal responses were more pronounced than in healthy subjects. Given this fact, these findings could provide evidence for common aspects of phobic postural vertigo and anxiety disorders.
phobischer Schwankschwindel, fMRT, CCK-4, Angst- und somatoforme Störungen
Chrobok, Agnieszka Ilona
2017
German
Universitätsbibliothek der Ludwig-Maximilians-Universität München
Chrobok, Agnieszka Ilona (2017): Neurofunktionelle Aspekte von experimentell induzierter Angst bei Patienten mit phobischem Schwankschwindel. Dissertation, LMU München: Faculty of Medicine
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Abstract

INTRODUCTION Vertigo and anxiety are frequent symptoms in both psychiatric and vertigo patients, especially in those with phobic postural vertigo (PPV). Vertigo is one of the most common causes for a visit in a neurological practice. Furthermore, PPV has one of the highest incidence rates among all types of vertigo. Patients suffering from PPV show many symptoms similar to anxiety disorders. On account of this, functional magnetic resonance and cholecystokinin tetrapeptide (CCK-4) were used as a valid model to experimentally induce anxiety symptoms, in order to investigate the neuronal correlates of anxiety in PPV patients in comparison to healthy controls (HC). This was done by addressing, among other things, the question to which extent the underlying fear-networks differ between those two groups. METHODS 15 PPV patients (average age: 43 years, 6 f, 9 m) and 15 gender and age (± 2 years) matched healthy controls underwent challenges with 50 µg bolus CCK-4 injections, not knowing the exact time point of the injection, for the purpose of distinguishing between anticipatory and CCK-4 induced anxiety. Simultaneously a functional MRI (3T Verio Siemens; echo-planar EPI sequence [TR = 3s; 36 slices; slice thickness: 3mm; interslice-gap: 0.75mm]) was recorded. The panic symptom scale was used before (PSS pre) and after (PSS post) the injection. In addition, psychiatric symptoms (e.g. depression, anxiety) as well as somatic symptoms (e.g. heart rate) were assessed. BrainVoyager™ and FSL Software were used to examine the functional MRI data (Independent Component Analysis and Region of Interest analysis). RESULTS During anticipatory anxiety, healthy controls showed functional responses mainly in fronto-temporal regions. In comparison to HC, patients suffering from PPV revealed pronounced BOLD responses e.g. in the insula, the amygdala, the inferior frontal gyrus (BA 13), the superior and medial temporal gyrus as well as the cuneus. CCK-4 induced anxiety (PPV vs. HC) was accompanied by activations, for example in the anterior cingulate gyrus (ACC), the amygdala, the putamen, the insula as well as the superior, medial, inferior frontal and temporal gyrus. In addition, a region of interest analysis demonstrated an increased number of activated voxels in the parietal, temporal and occipital lobe in patients after CCK-4 injection compared to healthy controls; the differences regarding amygdala and orbitofrontal cortex reached a trend level.With respect to the psychiatric symptoms, significantly increased scores were demonstrated in patients regarding depression and anxiety ratings (especially somatic symptoms), vertigo symptoms (VSS-D) and PSS values before the injection (PSS pre). The injection of CCK-4 led to an increase of heart rate in all subjects. CONCLUSIONS In patients suffering from phobic postural vertigo the application of CCK-4 led to pronounced BOLD responses in brain regions playing a central role in anxiety and cognition as seen in fear-related processes. These neuronal responses were more pronounced than in healthy subjects. Given this fact, these findings could provide evidence for common aspects of phobic postural vertigo and anxiety disorders.