ORCID Profile
0000-0002-8013-0424
Current Organisation
Chiba University
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Publisher: Wiley
Date: 2007
DOI: 10.1002/ANA.21024
Abstract: This study aimed to identify persistent morphological changes subsequent to an acute single-time exposure to sarin, a highly poisonous organophosphate, and the neurobiological basis of long-lasting somatic and cognitive symptoms in victims exposed to sarin. Thirty-eight victims of the 1995 Tokyo subway sarin attack, all of whom had been treated in an emergency department for sarin intoxication, and 76 matched healthy control subjects underwent T1-weighted and diffusion tensor magnetic resonance imaging (DTI) in 2000 to 2001. Serum cholinesterase (ChE) levels measured immediately and longitudinally after the exposure and the current severity of chronic reports in the victims were also evaluated. The voxel-based morphometry exhibited smaller than normal regional brain volumes in the insular cortex and neighboring white matter, as well as in the hippoc us in the victims. The reduced regional white matter volume correlated with decreased serum cholinesterase levels and with the severity of chronic somatic complaints related to interoceptive awareness. Voxel-based analysis of diffusion tensor magnetic resonance imaging further demonstrated an extensively lower than normal fractional anisotropy in the victims. All these findings were statistically significant (corrected p < 0.05). Sarin intoxication might be associated with structural changes in specific regions of the human brain, including those surrounding the insular cortex, which might be related to elevated subjective awareness of internal bodily status in exposed in iduals.
Publisher: Elsevier BV
Date: 12-2009
DOI: 10.1016/J.PSCYCHRESNS.2009.06.001
Abstract: Although post-traumatic stress disorder (PTSD) may be seen to represent a failure to extinguish learned fear, significant aspects of the pathophysiology relevant to this hypothesis remain unknown. Both the amygdala and hippoc us are necessary for fear extinction occur, and thus both regions may be abnormal in PTSD. Twenty-five people who experienced the Tokyo subway sarin attack in 1995, nine who later developed PTSD and 16 who did not, underwent magnetic resonance imaging (MRI) with manual tracing to determine bilateral amygdala and hippoc us volumes. At the time of scanning, one had PTSD and eight had a history of PTSD. Results indicated that the group with a history of PTSD had significantly smaller mean bilateral amygdala volume than did the group that did not develop PTSD. Furthermore, left amygdala volume showed a significant negative correlation with severity of PTSD symptomatology as well as reduced gray matter density in the left anterior cingulate cortex. To our knowledge, this is the first observation of an association between PTSD and amygdala volume. Furthermore the apparent interplay between amygdala and anterior cingulate cortex represents support at the level of gross brain morphology for the theory of PTSD as a failure of fear extinction.
Publisher: Wiley
Date: 25-07-2013
DOI: 10.1111/PCN.12069
Abstract: The present study examined the effect of irritable bowel syndrome (IBS), cognitive appraisal of IBS, and anxiety sensitivity on anticipatory anxiety (AA) and agoraphobia (AG) in patients with panic disorder (PD). We examined 244 PD patients who completed a set of questionnaires that included the Rome II Modular Questionnaire to assess the presence of IBS, the Anxiety Sensitivity Index (ASI), the Cognitive Appraisal Rating Scale (CARS assessing the cognitive appraisal of abdominal symptoms in four dimensions: commitment, appraisal of effect, appraisal of threat, and controllability), and items about the severity of AA and AG. The Mini International Neuropsychiatric Interview was used to diagnose AG and PD. After excluding in iduals with possible organic gastrointestinal diseases by using 'red flag items,' valid data were obtained from 174 participants, including 110 PD patients without IBS (PD/IBS[-]) and 64 with IBS (PD/IBS[+]). The PD/IBS[+] group had higher AA and higher comorbidity with AG than the PD/IBS[-] group. In the PD/IBS[+] group, the controllability score of CARS was significantly correlated with AA and ASI. Multiple regression analysis showed a significant effect of ASI but not of controllability on AA in PD/IBS[+] subjects. This study suggested that the presence of IBS may be related to agoraphobia and anticipatory anxiety in PD patients. Cognitive appraisal could be partly related to anticipatory anxiety in PD patients with IBS with anxiety sensitivity mediating this correlation.
No related grants have been discovered for Toshiyuki Ohtani.