Topic
Functional weakness
About: Functional weakness is a research topic. Over the lifetime, 51 publications have been published within this topic receiving 1384 citations.
Papers published on a yearly basis
Papers
TL;DR: Patients with this symptom are as disabled as patients with weakness of similar duration due to neurological disease, and there is a paradox between the frequency of depression and anxiety diagnoses and the patient's willingness to accept these as potentially relevant to their symptoms.
Abstract: Functional weakness describes weakness which is both internally inconsistent and incongruent with any recognizable neurological disease. It may be diagnosed as a manifestation of conversion disorder or dissociative motor disorder. Other names include psychogenic or 'non-organic' paralysis. We aimed to describe the incidence, demographic and clinical characteristics of cases with functional weakness of less than 2 years duration, and to compare these with controls with weakness attributable to neurological disease. Both cases and controls were recruited from consultant neurologists in South East Scotland. Participating patients underwent detailed assessments which included: physical examination, structured psychiatric interview (Structured Clinical Interview for the Diagnostic and Statistical Manual of Mental Disorders), measures of symptoms, disability and distress [Short Form (36) Health Survey, Hospital and Anxiety Depression Scale], and assessment of their illness beliefs using an augmented version of the Illness Perception Questionnaire. In total, 107 cases (79% female, mean age 39 years, median duration of illness 9 months) were recruited. This number suggests a minimum annual incidence of 3.9/100 000. Forty-six controls (83% female, median age 39 years, duration 11 months) were also recruited. Compared to controls, cases had similar levels of disability but more physical symptoms, especially pain. They had a higher frequency of psychiatric disorders, especially current major depression (32 versus 7%, P < 0.0001), generalized anxiety disorder (21 versus 2%, P < 0.005), panic disorder (36 versus 13%, P < 0.001) and somatization disorder (27 versus 0%, P < 0001). There was no difference in median self-rated anxiety and depression scores. Paradoxically, they were less likely than controls to agree that stress was a possible cause of their illness (24 versus 56%, P < 0.001). Cases were twice as likely as controls to report that they were not working because of their symptoms (65 versus 33%, P < 0.0005). Functional weakness is a commonly encountered clinical problem. Patients with this symptom are as disabled as patients with weakness of similar duration due to neurological disease. There is a paradox between the frequency of depression and anxiety diagnoses and the patient's willingness to accept these as potentially relevant to their symptoms. We discuss the theoretical and practical implications of these findings for the concept of conversion disorder.
269 citations
TL;DR: The overall pattern suggests more complex mental activity in patients with conversion disorder than in controls, and is associated with a distinctive pattern of activation, which overlaps with but is different from the activation pattern associated with simulated weakness.
Abstract: Background Conversion disorder (motor type) describes weakness that is not due to recognized disease or conscious simulation but instead is thought to be a "psychogenic" phenomenon. It is a common clinical problem in neurology but its neural correlates remain poorly understood. Objective To compare the neural correlates of unilateral functional weakness in conversion disorder with those in healthy controls asked to simulate unilateral weakness. Methods Functional magnetic resonance imaging (fMRI) was used to examine whole brain activations during ankle plantarflexion in four patients with unilateral ankle weakness due to conversion disorder and four healthy controls simulating unilateral weakness. Group data were analyzed separately for patients and controls. Results Both patients and controls activated the motor cortex (paracentral lobule) contralateral to the "weak" limb less strongly and more diffusely than the motor cortex contralateral to the normally moving leg. Patients with conversion disorder activated a network of areas including the putamen and lingual gyri bilaterally, left inferior frontal gyrus, left insula, and deactivated right middle frontal and orbitofrontal cortices. Controls simulating weakness, but not cases, activated the contralateral supplementary motor area. Conclusions Unilateral weakness in established conversion disorder is associated with a distinctive pattern of activation, which overlaps with but is different from the activation pattern associated with simulated weakness. The overall pattern suggests more complex mental activity in patients with conversion disorder than in controls.
173 citations
TL;DR: A previously assembled cohort of 60 patients seen as inpatients by consultant neurologists in Edinburgh between 1985 and 1992 and diagnosed as having unilateral functional weakness or sensory disturbance found that patients who had sensory symptoms had better functioning at follow up than those who had weakness.
Abstract: Background: Although the symptoms of unilateral "medically unexplained" or "functional" weakness and sensory disturbance present commonly to neurologists, little is known about their long term prognosis.
Objective: To determine the long term outcome of functional weakness and sensory disturbance.
Patients: A previously assembled cohort of 60 patients seen as inpatients by consultant neurologists in Edinburgh between 1985 and 1992 and diagnosed as having unilateral functional weakness or sensory disturbance.
Methods: Current symptoms, disability, and distress were assessed by postal questionnaire to the patients and their family doctors.
Results: Follow up data relating to mortality were obtained in 56 patients (93%) and to current diagnosis in 48 patients (80%). Patient questionnaire data were obtained in 42 patients (70%). The median duration of follow up was 12.5 years (range 9 to 16). Thirty five of the 42 patients (83%) still reported weakness or sensory symptoms, and the majority reported limitation of physical function, distress, and multiple other somatic symptoms. Twenty nine per cent had taken medical retirement. An examination of baseline predictors indicated that patients who had sensory symptoms had better functioning at follow up than those who had weakness. Only one patient had developed a neurological disorder which, in hindsight, explained the original presentation. Another patient had died of unrelated causes.
Conclusions: Many patients assessed by neurologists with unilateral functional weakness and sensory symptoms as inpatients remain symptomatic, distressed, and disabled as long as 12 years after the original diagnosis. These symptoms are only rarely explained by the subsequent development of a recognisable neurological disorder in the long term.
162 citations
TL;DR: This study reveals distinct cingulo-insular alterations for FND and PTSD symptoms and may advance the understanding of FND.
Abstract: Objective Adverse early-life events are predisposing factors for functional neurological disorder (FND) and post-traumatic stress disorder (PTSD). Cingulo-insular regions are implicated in the biology of both conditions and are sites of stress-mediated neuroplasticity. We hypothesised that functional neurological symptoms and the magnitude of childhood abuse would be associated with overlapping anterior cingulate cortex (ACC) and insular volumetric reductions, and that FND and PTSD symptoms would map onto distinct cingulo-insular areas. Methods This within-group voxel-based morphometry study probes volumetric associations with self-report measures of functional neurological symptoms, adverse life events and PTSD symptoms in 23 mixed-gender FND patients. Separate secondary analyses were also performed in the subset of 18 women with FND to account for gender-specific effects. Results Across the entire cohort, there were no statistically significant volumetric associations with self-report measures of functional neurological symptom severity or childhood abuse. In women with FND, however, parallel inverse associations were observed between left anterior insular volume and functional neurological symptoms as measured by the Patient Health Questionnaire-15 and the Screening for Somatoform Symptoms Conversion Disorder subscale. Similar inverse relationships were also appreciated between childhood abuse burden and left anterior insular volume. Across all subjects, PTSD symptom severity was inversely associated with dorsal ACC volume, and the magnitude of lifetime adverse events was inversely associated with left hippocampal volume. Conclusions This study reveals distinct cingulo-insular alterations for FND and PTSD symptoms and may advance our understanding of FND. Potential biological convergence between stress-related neuroplasticity, functional neurological symptoms and reduced insular volume was identified.
105 citations
TL;DR: Examining symptoms and circumstances associated closely with the onset suggests hypotheses for the mechanism of onset of weakness in vulnerable individuals.
Abstract: Background Functional weakness describes weakness which is inconsistent and incongruent with disease. It is also referred to as motor conversion disorder (DSM-IV), dissociative motor disorder (ICD-10) and ‘psychogenic’ paralysis. Studies of aetiology have focused on risk factors such as childhood adversity and life events; information on the nature and circumstance of symptom onset may shed light on the mechanism of symptom formation. Aim To describe the mode of onset, associated symptoms and circumstances at the onset of functional weakness. Methods Retrospective interviews administered to 107 adults with functional weakness of Results The sample was 79% female, mean age 39 years and median duration of weakness 9 months. Three distinct modes of onset were discerned. These were: sudden (n=49, 46%), present on waking (or from general anaesthesia) (n=16, 13%) or gradual (n=42, 39%). In ‘sudden onset’ cases, panic (n=29, 59%), dissociative symptoms (n=19, 39%) and injury to the relevant limb (n=10, 20%) were commonly associated with onset. Other associated symptoms were non-epileptic attacks, migraine, fatigue and sleep paralysis. In six patients the weakness was noticed first by a health professional. In 16% of all patients, no potentially relevant factors could be discerned. Conclusions The onset of functional weakness is commonly sudden. Examining symptoms and circumstances associated closely with the onset suggests hypotheses for the mechanism of onset of weakness in vulnerable individuals.
104 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 3 |
| 2020 | 4 |
| 2019 | 3 |
| 2018 | 3 |
| 2017 | 3 |
| 2016 | 2 |