Journal of neurology, neurosurgery, and psychiatry
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J. Neurol. Neurosurg. Psychiatr. · Feb 2014
ReviewNeurophysiological correlates of dissociative symptoms.
Dissociation is a mental process with psychological and somatoform manifestations, which is closely related to hypnotic suggestibility and essentially shows the ability to obtain distance from reality. An increased tendency to dissociate is a frequently reported characteristic of patients with functional neurological symptoms and syndromes (FNSS), which account for a substantial part of all neurological admissions. This review aims to investigate what heart rate variability (HRV), EEG and neuroimaging data (MRI) reveal about the nature of dissociation and related conditions. ⋯ HRV, EEG and (functional) MRI are sensitive methods to detect physiological changes related to dissociation and dissociative disorders such as FNSS, and can possibly provide more information about their aetiology. The use of such measures could eventually provide biomarkers for earlier identification of patients at risk and appropriate treatment of dissociative conditions.
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J. Neurol. Neurosurg. Psychiatr. · Feb 2014
ReviewA systematic review of transcranial magnetic stimulation in the treatment of functional (conversion) neurological symptoms.
Functional (conversion) neurological symptoms (FNS) are commonly encountered in neurological and psychiatric clinical settings and represent a considerable burden on healthcare systems. There is a conspicuous paucity of evidence-based treatments for FNS. Transcranial magnetic stimulation (TMS) offers a safe, non-invasive method of probing changes in cortical excitability and/or connectivity. ⋯ No studies were placebo controlled. Despite the majority of studies claiming success for the technique, there is insufficient good quality evidence to establish TMS as an effective treatment modality for FNS. We outline the methodological considerations that should be taken into account in future studies of the efficacy of TMS in treating FNS and discuss mechanisms by which TMS, if efficacious, may exert a therapeutic effect, including: (a) via genuine neuromodulation, (b) via non-specific placebo effects and (c) by demonstrating, through its immediate effects on the motor system (eg, movement in a 'paretic' limb), that symptom improvement is possible, thus directly changing higher level beliefs that may be responsible for the maintenance of the disorder.
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J. Neurol. Neurosurg. Psychiatr. · Feb 2014
The elbow flex-ex: a new sign to detect unilateral upper extremity non-organic paresis.
To examine a new neurological sign that uses synergistic oppositional movements of the arms to evaluate for non-organic upper extremity weakness. ⋯ The elbow flex-ex sign is useful in differentiating between functional and organic arm paresis.