Functional neuroanatomical correlates of hysterical sensorimotor loss

Institute of Pathology, University of Lausanne, Lausanne, Vaud, Switzerland
Brain (Impact Factor: 9.2). 07/2001; 124(Pt 6):1077-90. DOI: 10.1093/brain/124.6.1077
Source: PubMed


Hysterical conversion disorders refer to functional neurological deficits such as paralysis, anaesthesia or blindness not caused by organic damage but associated with emotional "psychogenic" disturbances. Symptoms are not intentionally feigned by the patients whose handicap often outweighs possible short-term gains. Neural concomitants of their altered experience of sensation and volition are still not known. We assessed brain functional activation in seven patients with unilateral hysterical sensorimotor loss during passive vibratory stimulation of both hands, when their deficit was present and 2-4 months later when they had recovered. Single photon emission computerized tomography using (99m)Tc-ECD revealed a consistent decrease of regional cerebral blood flow in the thalamus and basal ganglia contralateral to the deficit. Independent parametric mapping and principal component statistical analyses converged to show that such subcortical asymmetries were present in each subject. Importantly, contralateral basal ganglia and thalamic hypoactivation resolved after recovery. Furthermore, lower activation in contralateral caudate during hysterical conversion symptoms predicted poor recovery at follow-up. These results suggest that hysterical conversion deficits may entail a functional disorder in striatothalamocortical circuits controlling sensorimotor function and voluntary motor behaviour. Basal ganglia, especially the caudate nucleus, might be particularly well situated to modulate motor processes based on emotional and situational cues from the limbic system. Remarkably, the same subcortical premotor circuits are also involved in unilateral motor neglect after organic neurological damage, where voluntary limb use may fail despite a lack of true paralysis and intact primary sensorimotor pathways. These findings provide novel constraints for a modern psychobiological theory of hysteria.

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Available from: Fred Assal, Oct 07, 2015
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    • "Deeley, 2011; Cojan, Waber, Carruzzo, & Vuilleumier, 2009; Marshall, Halligan, Fink, Wade, & Frackowiak, 1997; Vuilleumier et al., 2001 "
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    Consciousness and Cognition 05/2015; 35:158–170. DOI:10.1016/j.concog.2015.05.010 · 2.31 Impact Factor
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    • "Patients with PNES have been noted to have abnormalities on structural brain imaging, [59] but no consistent lesion or localization has been identified [6]. In a related condition such as conversion disorder, abnormalities have been noted on functional MRI (fMRI) in striato-thalamo-cortical circuits [60] [61], frontal regions [62], and midline frontoparietal regions [63]. Other studies of conversion disorders have lead to different conjectures on the nature of focal dysfunction and conversion symptoms of tremor [64] [65]. "
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    Medical Hypotheses 01/2015; 84(4). DOI:10.1016/j.mehy.2015.01.034 · 1.07 Impact Factor
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    • "Numerous functional neuroimaging studies, using SPECT, fMRI, and FDG-PET, have implicated both hyper-and hypofunctioning of various brain regions during active FNSD symptoms. These include the left frontal–striatal circuits, the right frontal cortex, the thalamus (i.e., contralateral to symptom side), and the dorsolateral prefrontal cortex (DLPFC), among others [30] [31] [32] (for a thorough review, see [9]). "
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