Deficit in late-stage contingent negative variation provides evidence for disrupted movement preparation in patients with conversion paresis

Blakemore, Rebekah L.; Hyland, Brian I.; Hammond-Tooke, Graeme; Anson, J. Greg

doi:10.1016/j.biopsycho.2015.04.009

Cited by 15 publications

(13 citation statements)

References 54 publications

(86 reference statements)

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“…Moreover, maximum force and force immediately prior to image onset was not different between groups. In agreement with previous reports (Kanaan, et al, 2007;Seignourel, et al, 2007), a decoupling between affective experience and behavioural reactivity may reflect the non-volitional nature of FND, where modulation of emotion and motor processing occur outside conscious awareness (Blakemore, et al, 2013(Blakemore, et al, , 2015. A dissociation between affective experience and emotion-motor Fig.…”

Section: Discussionsupporting

confidence: 91%

Aversive stimuli exacerbate defensive motor behaviour in motor conversion disorder

et al. 2016

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A B S T R A C TConversion disorder or functional neurological symptom disorder (FND) can affect the voluntary motor system, without an organic cause. Functional symptoms are thought to be generated unconsciously, arising from underlying psychological stressors. However, attempts to demonstrate a direct relationship between the limbic system and disrupted motor function in FND are lacking. We tested whether negative affect would exacerbate alterations of motor control and corresponding brain activations in individuals with FND. Ten patients and ten healthy controls produced an isometric precision-grip contraction at 10% of maximum force while either viewing visual feedback of their force output, or unpleasant or pleasant emotional images (without feedback). Force magnitude was continuously recorded together with change in brain activity using fMRI. For controls, force output decayed from the target level while viewing pleasant and unpleasant images. Patients however, maintained force at the target level without decay while viewing unpleasant images, indicating a pronounced effect of negative affect on force output in FND. This emotional modulation of force control was associated with different brain activation patterns between groups. Contrasting the unpleasant with the pleasant condition, controls showed increased activity in the inferior frontal cortex and pre-supplementary motor area, whereas patients had greater activity in the cerebellum (vermis), posterior cingulate cortex, and hippocampus. Engagement of a cerebellar-limbic network in patients is consistent with heightened processing of emotional salience, and supports the role of the cerebellum in freezing responses in the presence of aversive events. These data highlight a possible neural circuit through which psychological stressors elicit defensive behaviour and modulate motor function in FND.

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Section: Discussionsupporting

confidence: 91%

Aversive stimuli exacerbate defensive motor behaviour in motor conversion disorder

et al. 2016

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“…These findings (Liepert, et al, 2008(Liepert, et al, , 2009(Liepert, et al, , 2011 (Blakemore, et al, 2015). Patients showed longer premotor (the central component of reaction time) and motor times (the peripheral component of reaction time) in both their symptomatic and asymptomatic limbs compared to healthy controls.…”

Section: Motor Imagery and Motor Conversion Disordermentioning

confidence: 78%

“…The findings of Liepert, et al (2008Liepert, et al ( , 2009Liepert, et al ( , 2011 and Blakemore, et al (2015) indicate that imagery related movement suppression may be involved in motor CD. Normally a presumed inhibitory mechanism prevents overt movement during kinaesthetic MI.…”

Section: Motor Imagery and Motor Conversion Disordermentioning

confidence: 88%

“…Individuals feigning weakness showed a similar pattern of impairment to motor CD patients (Blakemore, et al, 2015). These participants were instructed "to imagine that their left arm, hand and fingers had become so weak, such as following a severe injury to the limb, that their muscles would be unable to exert a lot of force", or "to imagine that their left fingers were moving against a resistance that, however hard they tried, they would find difficult".…”

Section: Motor Imagery and Motor Conversion Disordermentioning

confidence: 99%

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Can motor imagery and hypnotic susceptibility explain Conversion Disorder with motor symptoms?

et al. 2016

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“…Firstly, in terms of feigning, while it is not possible to give a unifying account of the difference, all studies concurred that there is a difference from feigning–which, despite the caveats above, is hard to find via other means, except perhaps electrophysiology. 55 This is crucial for the status of the disorder.…”

Section: Discussionmentioning

confidence: 99%

Uncovering the etiology of conversion disorder: insights from functional neuroimaging

Dar¹,

Kanaan²

2016

NDT

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Conversion disorder (CD) is a syndrome of neurological symptoms arising without organic cause, arguably in response to emotional stress, but the exact neural substrates of these symptoms and the underlying mechanisms remain poorly understood with the hunt for a biological basis afoot for centuries. In the past 15 years, novel insights have been gained with the advent of functional neuroimaging studies in patients suffering from CDs in both motor and nonmotor domains. This review summarizes recent functional neuroimaging studies including functional magnetic resonance imaging (fMRI), single photon emission computerized tomography (SPECT), and positron emission tomography (PET) to see whether they bring us closer to understanding the etiology of CD. Convergent functional neuroimaging findings suggest alterations in brain circuits that could point to different mechanisms for manifesting functional neurological symptoms, in contrast with feigning or healthy controls. Abnormalities in emotion processing and in emotion-motor processing suggest a diathesis, while differential reactions to certain stressors implicate a specific response to trauma. No comprehensive theory emerges from these clues, and all results remain preliminary, but functional neuroimaging has at least given grounds for hope that a model for CD may soon be found.

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Deficit in late-stage contingent negative variation provides evidence for disrupted movement preparation in patients with conversion paresis

Cited by 15 publications

References 54 publications

Aversive stimuli exacerbate defensive motor behaviour in motor conversion disorder

Aversive stimuli exacerbate defensive motor behaviour in motor conversion disorder

Can motor imagery and hypnotic susceptibility explain Conversion Disorder with motor symptoms?

Uncovering the etiology of conversion disorder: insights from functional neuroimaging

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