Cortical evoked responses in hysterical hemianaesthesia

Lévy, Raymond; Behrman, Joan

doi:10.1016/0013-4694(70)90048-9

Cited by 31 publications

(14 citation statements)

References 2 publications

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“…Because Hernandez-Peon et al 53 had previously discovered in cats that stimulation of one sensory modality could suppress EPs in another sensory modality, they invoked an attentional mechanism to explain their findings from a patient with FND. Similar reports soon followed of reduced or absent SEPs over the somatosensory cortex corresponding to the affected side of patients with FND with unilateral 54,55 or bilateral 56 anesthesia, and it is commonly found that the diminished SEPs returned to normal after remission of clinical symptoms. An important aspect of this work was the finding that SEP reduction was seen with stimulation of the skin and with low-intensity stimuli near the perceptual threshold, but not with stimulation of the ulnar nerve, or with higher-intensity stimuli, suggesting that inhibitory corticofugal feedback suppressed the initial somatosensory transduction at the receptor level.…”

Section: Sensory and Visual Functionmentioning

confidence: 54%

“…Low intensities appear more likely to reveal abnormalities. 54,79 Or they might be attributable in part to the level at which the somatosensory system is stimulated. Earlier work found SEP abnormalities only when the skin receptors themselves were stimulated; stimulation of the ascending sensory (ulnar or tibial) nerve yielded normal SEPs 61 in the same patients.…”

Section: Sensory and Visual Functionmentioning

confidence: 99%

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

Voon¹,

Cavanna²,

Coburn³

et al. 2016

JNP

136

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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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Section: Sensory and Visual Functionmentioning

confidence: 54%

Section: Sensory and Visual Functionmentioning

confidence: 99%

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

Voon¹,

Cavanna²,

Coburn³

et al. 2016

JNP

136

View full text Add to dashboard Cite

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“…Ten studies [35–44] addressed the issue of whether WSs represent a nonorganic phenomenon and/or can be counted on to discriminate nonorganic from organic problems (Appendix 8). Four studies 25,35,39/40,42] addressed the issue of discrimination.…”

Section: Resultsmentioning

confidence: 99%

“…It is to be noted that some studies addressed more than one subject matter relevant to this review. These groups were the following: 1) Reliability (test‐retest) [1,18]; 2) Reliability (inter‐rater) [1,7,18– 20]; 3) Reliability (factor analysis) [22]; 4) Validity, the psychological distress concept [7,22–29]; 5) Validity, correlation with Minnesota Multiphasic Personality Inventory (MMPI) [1,21,22,30,31,55]; 6) Validity, correlation abnormal illness behavior [3,7,23,29]; 7) Validity, correlation other behavior [25,32,33]; 8) Validity, as a nonorganic phenomenon [25,35–44]; 9) Validity, correlation with pain drawing [46]; 10) Validity, functional performance [27,32,33,45,47–49]; 11) Validity, treatment outcome [5,22,30,31,50]; 12) Validity, predicting surgical outcome [1,2,16,30,31,51]; 13) Validity, outcome return to work [1,14,16,30,31,52– 59,68,71]; 14) Validity, secondary gain correlation [1,7,14,15,17,22,25,27,28,46,48,49,60–62]; 15) Validity, pain correlation [15,16,25,27,28,50,60,63– 67,69,70].…”

Section: Methodsmentioning

confidence: 99%

A Structured Evidence-Based Review on the Meaning of Nonorganic Physical Signs: Waddell Signs

Fishbain¹,

Cole

Cutler³

et al. 2003

Pain Medicine

119

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Based on the above results, the following conclusions were made: 1) WSs do not correlate with psychological distress; 2) WSs do not discriminate organic from nonorganic problems; 3) WSs may represent an organic phenomenon; 4) WSs are associated with poorer treatment outcome; 5) WSs are associated with greater pain levels; 6) WSs are not associated with secondary gain; and 7) As a group, WS studies demonstrate some methodological problems.

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“…Various changes in cortical blood flow and somatosensory evoked potentials have also been described in conversion patients with dominant sensory symptoms [10]–[13]. However to date, no data are available about direct time-dependent changes in cortical processing associated with preparation for movement in conversion paresis.…”

Section: Introductionmentioning

confidence: 99%

Distinct Modulation of Event-Related Potentials during Motor Preparation in Patients with Motor Conversion Disorder

et al. 2013

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ObjectiveConversion paresis patients and healthy people feigning weakness both exhibit weak voluntary movement without detectable neuropathology. Uniquely, conversion patients lack a sense of conscious awareness of the origin of their impairment. We investigated whether conversion paresis patients show distinct electroencephalographic (EEG) markers associated with their unconscious movement deficits.MethodsSix unilateral upper limb conversion paresis patients, 12 feigning participants asked to mimic weakness and 12 control participants performed a precued reaction time task, requiring movements of either hand, depending on precue information. Performance measures (force, reaction and movement time), and event-related EEG potentials (ERP) were compared, between groups and across hands or hemisphere, using linear mixed models.ResultsFeigners generated the same inter-hand difference in reaction and movement time as expressed by patients, even though no specific targets were set nor feedback given on these measures. We found novel ERP signatures specific to patients. When the symptomatic hand was precued, the P3 ERP component accompanying the precue was dramatically larger in patients than in feigning participants. Additionally, in patients the earlier N1 ERP component was diminished when the precue signalled either the symptomatic or asymptomatic hand.ConclusionsThese results are consistent with previous suggestions that lack of awareness of the origin of their symptoms in conversion disorder patients may result from suppression of brain activity normally related to self-agency. In patients the diminished N1 to all precues is consistent with a generalised reduction in cognitive processing of movement-related precues. The P3 enhancement in patients is unlikely to simply reflect changes required for generation of impaired movements, because it was not seen in feigners showing the same behavioural deficits. Rather, this P3 enhancement in patients may represent a neural biomarker of unconscious processes, including additional emotional loading, related to active suppression of brain circuits involved in the attribution of self-agency.

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Cortical evoked responses in hysterical hemianaesthesia

Cited by 31 publications

References 2 publications

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

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

A Structured Evidence-Based Review on the Meaning of Nonorganic Physical Signs: Waddell Signs

Distinct Modulation of Event-Related Potentials during Motor Preparation in Patients with Motor Conversion Disorder

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