Uncovering the etiology of conversion disorder: insights from functional neuroimaging

ASTASIA-ABASIA, PSYCHOGENIC OR ORGANIC? IT ́S NOT EASY

Astasia-abasia was described by Paul Blocq as a psychogenic condition; later, several brain injuries have been described for its explanation too.

A dimensional approach to functional movement disorders: Heresy or opportunity

Functional movement disorders (FMD) are a common and disabling neuropsychiatric condition, part of the spectrum of functional neurological/conversion disorder. FMD represent one of the most enigmatic disorders in the history of medicine. However, in the twenty years after the first report of distinctive abnormal brain activity associated with functional motor symptoms, there have been tremendous advances in the pathophysiologic understanding of these disorders. FMD can be characterized as a disorder of aberrant neurocircuitry interacting with environmental and genetic factors. These developments suggest that research on FMD could be better served by an integrative, neuroscience-based approach focused on functional domains and their neurobiological substrates. This approach has been developed in 'Research Domain Criteria' (RDoC) project, which promotes a dimensional approach to psychiatric disorders. Here, we use the RDoC conceptualization to review recent neuroscience research on FMD, focusing on the domains most relevant to these disorders. We discuss how the adoption of a similar integrative framework may facilitate the identification of the mechanisms underlying FMD and could also have potential clinical applicability.

Postoperative hemiparesis due to conversion disorder after moderate sedation: a case report

Peri-operative conversion disorder that manifests as postoperative muscle weakness is an uncommon diagnosis made through exclusion of neurological, metabolic or iatrogenic aetiologies. We present a case where a patient with a considerable history of physical and psychological trauma suffered from prolonged right-sided hemiparesis following a breast biopsy under moderate-to-deep sedation. Conversion disorder following moderate-to-deep sedation has yet to be discussed in the literature, as all previous cases have described postoperative conversion disorder in the setting of general or central neuraxial anaesthesia. Our recommendation is for practitioners to keep conversion disorder on the list of differential diagnoses, despite the depth of sedation or type of anaesthetic utilised, and perform the same detailed neurological, metabolic and psychiatric assessment when considering postoperative weakness.

A Case Series from Rantauprapat, La Belle Indifference: A Coping Mechanism or Is There Something Organic Behind?

BACKGROUND

La belle indifference, a term that is inexhaustible to discuss, albeit there is no single definition that best describes the condition. To date, la belle indifference has gotten no place in the DSM-5 criteria for being a distinct entity of mental health issue.

CASE REPORTS

We reported 3 cases with la belle indifference. These patients include a stroke patient with right-sided hemiparesis, a patient suffering from neuropathic pain because of diabetic neuropathy, and a patient with cardiac dyspnea due to chronic heart failure - these three cases presented with a similar clinical profile that is the trigger for developing la belle indifference.

CONCLUSIONS

La belle indifference has varying symptom spectrum, and there is always something called "trigger" to induce it.

Widespread cortical PET abnormalities in an adolescent related to a PNES dissociative state, PTSD, ADHD, and domestic violence exposure

BACKGROUND

Accumulated evidence indicates that exposure to trauma is associated with the development of cognitive impairments and psychiatric symptoms in children and adolescents.

OBJECTIVE

In this case study of a female adolescent of 17 years, we aimed to evaluate how cortical positron emission tomography (PET) abnormalities relate to psychogenic non-epileptic seizure (PNES) dissociative state, post-traumatic stress disorder (PTSD), attention-deficit/hyperactivity disorder (ADHD), and domestic violence exposure.

METHODS

Detailed psychiatric and neuropsychological assessment was performed initially, followed by a PET study. The PET imaging was carried out in the resting-state and in the dissociative-state.

RESULTS

The adolescent was suffering from multiple episodes of unconsciousness, all found to be psychogenic; thus, PNES was diagnosed. However, at the psychopathology symptom level, the adolescent had heightened impulsivity, hyperactivity, hyperarousal, anxiety, somatic, and dissociative/ functional neurological symptoms present separately or concurrently at some point during her life; thus, the criteria for PTSD and ADHD were also fulfilled. In the resting state, significant hypometabolism was observed in the occipital, occipitotemporal, polar, and mesial parts of the temporal regions bilaterally, fronto-parietal medial and lateral pericental regions, and fronto-temporal and insular region on the left. The most intense metabolism was observed in the posterior cingulate gyrus and the medial parts of the posterior parietal lobe. In the dissociative state, there was a slight increase in the metabolism of the brain globally compared with the resting state, but with identical distribution of the regional changes observed.

CONCLUSIONS

Widespread cortical PET abnormalities were found, possibly indicating alterations in large-scale brain networks, in a patient with PNES and a dissociative state, PTSD, and ADHD, who was exposed to chronic domestic violence.

Prosopagnosia as a Type of Conversion Disorder

Background

Conversion disorder is a common and debilitating condition that remains poorly understood. We present a previously undescribed form of conversion disorder to highlight the complexity of the condition and consider the interplay of factors that produce conversion symptoms.

Case

A 50-year-old male presented with acquired prosopagnosia and language impairment. Neuropsychological testing indicated right temporal lobe dysfunction. Extensive work-up outruled an organic aetiology. Reactivation of childhood trauma coincided with the onset of his symptoms. Childhood trauma is known to have adverse effects on the developing brain which may affect an individual's emotional behaviour and coping style. Functional neuroimaging techniques suggest that conversion symptoms may be linked to the disruption of higher order neural circuitry involved in the integration of emotional processing and cortical functioning.

Conclusions

We propose that our patient's adverse childhood experiences led to the development of a particular personality and coping style that “primed” him for a later abnormal emotional and behavioural response when confronted with reminders of his traumatic background. Further interdisciplinary studies are required to further elucidate the neurobiological basis for this condition.

Conversion Disorder, Functional Neurological Symptom Disorder, and Chronic Pain: Comorbidity, Assessment, and Treatment

PURPOSE OF REVIEW

This paper examines the overlap of conversion disorder with chronic pain conditions, describes ways to assess for conversion disorder, and provides an overview of evidence-based treatments for conversion disorder and chronic pain, with a focus on conversion symptoms.

RECENT FINDINGS

Conversion disorder is a significant problem that warrants further study, given that there are not many well-established guidelines. Accurate and timely assessment should help move treatment in a more fruitful direction and avoid unnecessary medical interventions. Advances in neuroimaging may also help further our understanding of conversion disorder. Creating a supportive environment and a collaborative treatment relationship and improving understanding of conversion symptoms appear to help individuals diagnosed with conversion disorder engage in appropriate treatments. Novel uses of earlier treatments, such as hypnosis and psychodynamic approaches, could potentially be beneficial and require a more vigorous and systematic study. There are treatments that produce significant improvements in functioning and reduction of physical symptoms from conversion disorder even for very severe cases. Hypnotherapy, cognitive behavioral therapy, and inpatient multidisciplinary treatment with intensive physiotherapy for severe cases have the most evidence to support reduction of symptoms. Components of treatment for conversion disorder overlap with treatments for chronic pain and can be used together to produce therapeutic effects for both conditions. Treatment needs to be tailored for each individual's specific symptoms.

5-HT2A Agonists: A Novel Therapy for Functional Neurological Disorders?

Functional neurological disorders are frequently encountered in clinical practice. They have a poor prognosis and treatment options are limited. Their etiology is unknown, but leading theories propose a disturbance of somatic self-representation: the mind perceives dysfunction of a body region despite intact motor and sensory pathways. Central to this model is the concept of an abnormal top-down cognitive influence upon sensorimotor function. There is growing interest in the use of 5-HT2A agonists in the management of neuropsychiatric conditions. Recent studies have shown that these agents induce changes in neural activity that disrupt hierarchical brain dynamics and modulate networks subserving self-related processing. Converging evidence suggests they may hold unique therapeutic potential in functional neurological disorders. This is of importance given the considerable personal and societal burden of this condition and we argue a clinical trial to test this hypothesis is warranted.

Non-Invasive Brain Stimulation in Conversion (Functional) Weakness and Paralysis: A Systematic Review and Future Perspectives

Conversion (functional) limb weakness or paralysis (FW) can be a debilitating condition, and often causes significant distress or impairment in social, occupational, or other important areas of functioning. Most treatment concepts are multi-disciplinary, containing a behavioral approach combined with a motor learning program. Non-invasive brain stimulation (NIBS) methods, such as electroconvulsive therapy (ECT), and transcranial magnetic stimulation (TMS) have been used in the past few decades to treat FW. In order to identify all published studies that used NIBS methods such as ECT, TMS and transcranial direct current stimulation (tDCS) for treating FW patients a systematic review of the literature was conducted in PubMed and Web of Science. In a second step, narratives were used to retrospectively determine nominal CGI-I (Clinical Global Impression scale–Improvement) scores to describe approximate changes of FW symptoms. We identified two articles (case reports) with ECT used for treatment of FW, five with TMS with a total of 86 patients, and none with tDCS. In 75 out of 86 patients treated with repetitive (r)TMS a nominal CGI-I score could be estimated, showing a satisfactory short-term improvement. Fifty-four out of seventy-five identified patients (72%) had a CGI-I score of 1 (very much improved), 13 (17%) a score of 2 (much improved), 5 (7%) a score of 3 (minimally improved), and 3 (5%) remained unchanged (CGI-I = 4). In no case did patients worsen after rTMS treatment, and no severe adverse effects were reported. At follow-up, symptom improvement was not quantifiable in terms of CGI-I for the majority of the cases. Patients treated with ECT showed a satisfactory short-term response (CGI-I = 2), but deterioration of FW symptoms at follow-up. Despite the predominantly positive results presented in the identified studies and satisfactory levels of efficacy measured with retrospectively calculated nominal CGI-I scores, any assumption of a beneficial effect of NIBS in FW has to be seen with caution, as only few articles could be retrieved and their quality was mostly poor. This article elucidates how NIBS might help in FW and gives recommendations for future study designs using NIBS in this condition.