T Kraus

Publications (3)10.24 Total impact

• Article: Ghrelin and eating disturbances in psychiatric disorders.

  A Schanze, U Reulbach, M Scheuchenzuber, M Groschl, J Kornhuber, T Kraus
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  ABSTRACT: Appetite and eating behavior are frequently altered in psychiatric patients. The newly discovered gut-derived neuropeptide ghrelin simulates hunger and weight gain. Therefore, it might be involved in appetite regulation during psychiatric disorders. In 83 depressed, 42 schizophrenic patients and 46 healthy controls plasma ghrelin levels were measured, and the psychometric scores on the Three-Factor Eating Questionnaire (TFEQ) were assessed. Neither ghrelin levels nor TFEQ scores differed between both patient groups and healthy subjects. However, TFEQ subscale 2 (disinhibition) was predicted by BMI-corrected ghrelin levels, while age, sex, smoking, and medication did not show any influence. Ghrelin correlates with factors of eating behavior, specifically with subscale 2 on the TFEQ. Ghrelin might be involved in appetite-regulating pathways during psychiatric disorders. However, its influence is not likely to be displayed as a difference between diagnostic groups. Rather, ghrelin is associated with eating behavior in psychiatric patients meaning susceptibility to eating problems.
  Neuropsychobiology 07/2008; 57(3):126-30. · 2.67 Impact Factor
• Article: BOLD fMRI deactivation of limbic and temporal brain structures and mood enhancing effect by transcutaneous vagus nerve stimulation.

  T Kraus, K Hösl, O Kiess, A Schanze, J Kornhuber, C Forster
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  ABSTRACT: Direct vagus nerve stimulation (VNS) has proved to be an effective treatment for seizure disorder and major depression. However, since this invasive technique implies surgery, with its side-effects and relatively high financial costs, a non-invasive method to stimulate vagal afferences would be a great step forward. We studied effects of non-invasive electrical stimulation of the nerves in the left outer auditory canal in healthy subjects (n = 22), aiming to activate vagal afferences transcutaneously (t-VNS). Short-term changes in brain activation and subjective well-being induced by t-VNS were investigated by functional magnetic resonance imaging (fMRI) and psychometric assessment using the Adjective Mood Scale (AMS), a self-rating scale for current subjective feeling. Stimulation of the ear lobe served as a sham control. fMRI showed that robust t-VNS induced BOLD-signal decreases in limbic brain areas, including the amygdala, hippocampus, parahippocampal gyrus and the middle and superior temporal gyrus. Increased activation was seen in the insula, precentral gyrus and the thalamus. Psychometric assessment revealed significant improvement of well-being after t-VNS. Ear lobe stimulation as a sham control intervention did not show similar effects in either fMRI or psychometric assessment. No significant effects on heart rate, blood pressure or peripheral microcirculation could be detected during the stimulation procedure. CONCLUSIONS: Our study shows the feasibility and beneficial effects of transcutaneous nerve stimulation in the left auditory canal of healthy subjects. Brain activation patterns clearly share features with changes observed during invasive vagus nerve stimulation.
  Acta Neurovegetativa 02/2007; 114(11):1485-93. · 2.73 Impact Factor
• Article: Leptin is associated with craving in females with alcoholism.

  T Kraus, U Reulbach, K Bayerlein, B Mugele, T Hillemacher, W Sperling, J Kornhuber, S Bleich
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  ABSTRACT: The appetite and weight regulating peptide leptin was associated recently with alcohol craving during withdrawal. Nevertheless, correlations were only significant with craving displayed on the visual analogue scale for maximum craving during the previous week (VAS), and not if assessed with the highly validated Obsessive Compulsive Drinking Scale (OCDS). The objective of the following study, therefore, is to elucidate further the associations between the leptin system and craving concepts during alcohol withdrawal. A sufficiently large sample size should allow multiple statistical subgroup and confounder analyses. We prospectively investigated 102 chronic alcoholic inpatients (23 females, 79 males) during withdrawal on days 0 (admission), 1, 2 and days 7-10. In addition to the statistical analysis of the total sample, females and males were to be analysed separately. For detecting associations between leptin levels and craving scores multiple regression analysis was performed. Plasma leptin levels were determined, and craving for ethanol was assessed by both the OCDS and the VAS. Leptin plasma levels significantly increased during alcohol withdrawal compared to day 0, while all craving scores decreased. Body mass corrected leptin plasma levels predicted craving on day 0 in the OCDS total score (R=0.55, F=7.91, df=1.19, p<0.05) and in the OCDS obsessive subscore (R=0.57, F>=8.48, df=1.19, p<0.05) in females. Neither in males nor in the total population did multiple regression analysis reveal any significant results. Leptin levels seem to change during inpatient alcohol withdrawal. In a multivariate model, correlations between leptin levels and the highly validated craving scores of the OCDS can only be assumed in females. Hence, gender differences have to be taken into account when searching for neurobiological models of alcohol craving.
  Addiction Biology 9(3-4):213-9. · 4.83 Impact Factor