Abnormal motor excitability in patients with psychogenic paresis

Liepert, Joachim; Hassa, Thomas; Tüscher, Oliver; Schmidt, Roger

doi:10.1007/s00415-009-0090-4

Cited by 28 publications

(30 citation statements)

References 38 publications

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“…In line with this, we observed a stronger modulatory influence of dlPFC during the generation of action plans of the affected limb that was positive in sign for the PMd and negative in sign for S1. The stronger inhibitory coupling between dlPFC and S1 during motor imagery of the affected hand could also provide an explanation for the decreased excitability of the primary motor cortex that has previously been observed in CP (Liepert et al, 2009). Activity in S1 can strongly contribute to the excitability of the motor system as measured by motor evoked potentials (Avenanti, Bolognini, Maravita, & Aglioti, 2007).…”

Section: Increased Negative Coupling Between Dlpfc and S1 During Imagmentioning

confidence: 81%

“…For instance, a recent study that directly probed the excitability of the motor cortex using transcranial magnetic stimulation observed striking excitability changes in the motor system during motor imagery of the affected hand in CP (Liepert, Hassa, Tüscher, & Schmidt, 2009). While motor imagery of the unaffected hand resulted in higher motor excitability, as it is normally observed in the healthy population (Abbruzzese, Trompetto, & Schieppati, 1996), motor imagery of the affected hand led to a paradoxical decrease of motor excitability.…”

Section: Introductionmentioning

confidence: 97%

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Altered connectivity between prefrontal and sensorimotor cortex in conversion paralysis

2010

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a b s t r a c tConversion paralysis (CP) is a frequent and impairing psychiatric disorder, affecting voluntary motor function. Yet, we have previously shown that the motor system of CP patients with a unilateral conversion paresis is recruited to a similar degree during imagined movements of the affected and unaffected limb. In contrast, imagery of movements with the affected limb results in larger prefrontal activation. It remains unclear how this hand-specific increased prefrontal activity relates to the reduced responsiveness of motor and somatosensory areas, a consistent and important feature of CP patients.In the current study, we investigated changes in the inter-regional coupling between prefrontal cortex (PFC) and sensorimotor regions when CP patients imagined movements involving either the affected or the unaffected hand. We found that there were distinct connectivity patterns for different parts of the PFC. While ventromedial PFC was not functionally connected to the motor system, we observed strong functional coupling between the dorsolateral PFC and various sensorimotor areas. Furthermore, this coupling was modulated by whether patients imagined movements of their affected or unaffected hand. Together, these results suggest that the reduced motor responsitivity observed in CP may be linked to altered dorsolateral prefrontal-motor connectivity.

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Section: Increased Negative Coupling Between Dlpfc and S1 During Imagmentioning

confidence: 81%

Section: Introductionmentioning

confidence: 97%

Altered connectivity between prefrontal and sensorimotor cortex in conversion paralysis

2010

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“…In another experiment, the authors described a specific slowing of motor initiation but not a general slowing involving motor execution [30]. Recent TMS studies with patients suffering from psychogenic upper limb paresis demonstrated that MI of finger movements with the affected limb induced a decrease of motor excitability, suggesting an inhibition of the motor system during that task [31,32]. The present study explored if a similar phenomenon can also be found in psychogenic lower limb paresis and if abnormalities occur to a comparable degree in MI and AO, respectively.…”

Section: Introductionmentioning

confidence: 97%

Motor excitability during movement imagination and movement observation in psychogenic lower limb paresis

Liepert

Hassa

Tüscher

et al. 2011

Journal of Psychosomatic Research

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“…Liepert et al 32 showed that in response to motor imagery, patients with unilateral functional paralysis (N=5) or fixed dystonia (N=3) had a decrease in MEP of the affected hand by 37%, compared with rest with an increase in MEP by 63% of the unaffected side These findings were specific to MEPs because motor threshold, short intracortical inhibition, and intracortical facilitation were shown to be unremarkable among individuals with functional paralysis. 33,34 In healthy individuals, motor imagery commonly increases MEPs to a level comparable to that observed during executed movements. In a study by Liepert et al, 34 subjects…”

mentioning

confidence: 99%

“…33,34 In healthy individuals, motor imagery commonly increases MEPs to a level comparable to that observed during executed movements. In a study by Liepert et al, 34 subjects…”

mentioning

confidence: 99%

Functional Neuroanatomy and Neurophysiology of Functional Neurological Disorders (Conversion Disorder)

Voon¹,

Cavanna²,

Coburn³

et al. 2016

JNP

131

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Much is known regarding the physical characteristics, comorbid symptoms, psychological makeup, and neuropsychological performance of patients with functional neurological disorders (FNDs)/conversion disorders. Gross neurostructural deficits do not account for the patients' deficits or symptoms. This review describes the literature focusing on potential neurobiological (i.e. functional neuroanatomic/neurophysiological) findings among individuals with FND, examining neuroimaging and neurophysiological studies of patients with the various forms of motor and sensory FND. In summary, neural networks and neurophysiologic mechanisms may mediate "functional" symptoms, reflecting neurobiological and intrapsychic processes. J Neuropsychiatry Clin Neurosci 2016; 28:168-190; doi: 10.1176/appi.neuropsych.14090217 Functional neurological disorders (FNDs; or psychogenic neurological symptoms), also known as conversion disorder, are a classic neuropsychiatric disorder, existing in the border between neurology and psychiatry. Unexplained neurological symptoms are common, occurring in up to one-third of patients in neurological outpatient clinics.1 Relative to disorders such as Parkinson's disease, FND is associated with similar levels of disability and physical quality of life with poorer mental health quality of life. 2 The prognosis is poor, with a recent reviewshowing that up to 40% of patients with FND report similar or worse outcomes at 7-year follow-up. 3 Given the frequency, consequences, prognosis, and burden, FND has been called a "crisis for neurology." 4 Despite this, FND is poorly understood. In the last decade, an increasing number of studies have focused on underlying neurobiological mechanisms. FND is defined in DSM-5 as the presence of one or more symptoms of altered voluntary or sensory function, with clinical findings providing evidence of incompatibility between the symptom and recognized neurological or medical conditions.5 The DSM-5 diagnosis differs from that of the DSM-IV diagnosis of conversion disorder by adding the criterion of incorporating physical diagnostic features and by relegating to the accompanying text the criteria requiring (a) an association with psychological stressors and (b) the exclusion of malingering or factitious disorder to make the diagnosis. DSM-5 FND diagnosis criteria now allow for potential greater interrater reliability, making them appropriate for research studies and greater compatibility with specialtyspecific diagnoses including psychogenic movement disorder (PMD) and psychogenic nonepileptic seizures (PNES). 6The putative biopsychosocial mechanisms underlying FND are complex and have been extensively reviewed.7 Our review focuses on the physiological mechanisms that may underlie FND and does not specifically focus on the extensive literature on the antecedents of early childhood experiences and temperament (Figure 1). At the outset, regarding the proposed model, we acknowledge that predisposing factors for functional neurological symptoms are not limited to genetics, te...

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Abnormal motor excitability in patients with psychogenic paresis

Cited by 28 publications

References 38 publications

Altered connectivity between prefrontal and sensorimotor cortex in conversion paralysis

Altered connectivity between prefrontal and sensorimotor cortex in conversion paralysis

Motor excitability during movement imagination and movement observation in psychogenic lower limb paresis

Functional Neuroanatomy and Neurophysiology of Functional Neurological Disorders (Conversion Disorder)

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