roselight wrote:2.Research on CD:
Conversion disorder is characterized by neurological signs and symptoms related to an underlying psychological issue. Amygdala activity to affective stimuli is well characterized in healthy volunteers with greater amygdala activity to both negative and positive stimuli relative to neutral stimuli, and greater activity to negative relative to positive stimuli. We investigated the relationship between conversion disorder and affect by assessing amygdala activity to affective stimuli. We conducted a functional magnetic resonance imaging study using a block design incidental affective task with fearful, happy and neutral face stimuli and compared valence contrasts between 16 patients with conversion disorder and 16 age- and gender-matched healthy volunteers. The patients with conversion disorder had positive movements such as tremor, dystonia or gait abnormalities. We also assessed functional connectivity between the amygdala and regions associated with motor preparation. A group by affect valence interaction was observed. Post hoc analyses revealed that whereas healthy volunteers had greater right amygdala activity to fearful versus neutral compared with happy versus neutral as expected, there were no valence differences in patients with conversion disorder. There were no group differences observed. The time course analysis also revealed greater right amygdala activity in patients with conversion disorder for happy stimuli (t 2.96, P 0.006) (with a trend for fearful stimuli, t 1.81, P 0.08) compared with healthy volunteers, with a pattern suggestive of impaired amygdala habituation even when controlling for depressive and anxiety symptoms. Using psychophysiological interaction analysis, patients with conversion disorder had greater functional connectivity between the right amygdala and the right supplementary motor area during both fearful versus neutral, and happy versus neutral stimuli compared with healthy volunteers. These results were confirmed with Granger Causality Modelling analysis indicating a directional influence from the right amygdala to the right supplementary motor area to happy stimuli (P < 0.05) with a similar trend observed to fearful stimuli (P 0.07). Our data provide a potential neural mechanism that may explain why psychological or physiological stressors can trigger or exacerbate conversion disorder symptoms in some patients. Greater functional connectivity of limbic regions influencing motor preparatory regions during states of arousal may underlie the pathophysiology of motor conversion symptoms.
Psychological or organic or both? The line is becoming ever more blurred & Freud's "hysteria" theory should be largely dismissed. Especially in cases where CD becomes a permanent disability.
I've always thought that CD lasting longer than a brief period of time must be pathphysiological. Research in the 21st century is proving it to be so. Much more research is needed in order to work towards a possible cure. Naturally it requires funding as well as Med professionals pushing for that funding. Maybe that could be part of the campaign because way too many Neuro's & Psych's still hold fast to the old, outdated theory that it's all in the mind. This attitude won't change without a push in the right direction & that has to come from people with CD and/or affected by it. No-one else will do it for us.From American Journal of Neuropsychiatry:
A growing body of neuroimaging studies is beginning to propose possible biological explanations for hysteria. The mapping of the brain in conversion disorder has implications for the conscious experience of self and the disruption of selfhood in dissociative identity disorder and schizophrenia.44 Performing larger studies that control for comorbidities such as depression,1 incorporating broader deficits (e.g., blindness), imaging limbic brain areas (e.g., the insula and amygdala), using novel techniques such as MEG,22 and studying patients at different phases of their illness1 are all necessary in order to develop a more detailed understanding of this biology./quote]
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