NCT05943652

Observational Study on "Functional Overlay" in Patients With Movement Disorders

Prevalence and Clinical Presentation of Functional Neurological Disorders in Patients With Movement Disorders - A Cross-sectional Study in the Movement Disorders Clinic of the Department of Neurology, Medical University of Graz

• Status: Recruiting
• Phase: —
• Study type: Observational
• Enrollment: 216 (estimated)
• Sponsor: Medical University of Graz · Academic / Other
• Sex: All
• Age: 18 Years – 18 Years
• Healthy volunteers: —

Summary

The goal of this observational study is to learn about functional neurological disorders in patients with common non-functional movement disorders ("functional overlay"). The main questions it aims to answer are: * What is the frequency of functional neurological disorders in patients with non-functional movement disorders (functional overlay)? * What are the characteristics of functional neurological disorders in patients with non-functional movement disorders? Participants will be examined clinically and electrophysiologically, the examinations consist of: * a neurological examination * neuropsychological testing * electrophysiological tremor diagnostic * questionnaires about psychological, biological and social risk factors Researchers will compare patients with functional motor disorders to patients wit non-functional movement disorders to see if they differ from each other regarding the functional symptoms.

Detailed description

Functional neurological disorders (FND) are common neurological disorders that are present in up to 16% of patients in neurological outpatient clinics. They are associated with a significant reduction in quality of life, can lead to permanent impairment, and have a poor prognosis, especially if the diagnosis is delayed. FND have multifactorial causes and risk factors, including psychological stressors, childhood trauma, female gender, psychiatric disorders such as depression, anxiety disorder, or post-traumatic stress disorder, and other functional disorders such as irritable bowel syndrome or chronic pain syndrome. Patients with FND often report additional cognitive complaints ("cognitive fog"). A mismatch of various regulatory mechanisms, a disruption of sensory processing and motor output is assumed to be a central part of the pathogenesis. A characteristic feature of FND is a variability of symptoms according to attention. FND can be intensified by increased attention and weakened by distraction. Positive diagnostic criteria for FND have been established recently, so that by definition FND are no longer a diagnosis of exclusion. The clinical presentations of FND are diverse and include impaired limb movement control, disturbances in vigilance that may be associated with seizures, and non-motor symptoms. FND often coincide and often coexist with pain, fatigue, sleep disorders, and cognitive disorders. Particularly non-motor functional symptoms are highly debilitating for patients. The coincidence of "organic" neurological disorders and FND in the same patients ("functional overlay") is probably not uncommon, but has been investigated primarily in patients with Parkinson's Disease and epilepsy, so far. However, it is important to recognize FND in patients with movement disorders in order to treat them adequately and to protect them from incorrect treatment (surgery, unnecessary medication, etc.). However, the basic prerequisite for this is an exploration of the frequency and characteristics of the functional symptoms in movement disorders.

Conditions

• Conversion Disorder
• Parkinson Disease
• Tremor
• Dystonia

Interventions

Type	Name	Description
DIAGNOSTIC_TEST	Neurological examination	A neurological examination following a protocol to detect positive signs of functional neurological disorders.
DIAGNOSTIC_TEST	Anamnesis	A standardized question about the patient´s history. The response time is measured. Question: "Could you tell me about the problems with the movement disorder you are experiencing?"
DIAGNOSTIC_TEST	Neuropsychological testing	Neuropsychological cognitive testing including: * Montreal Cognitive Assessment (MOCA) * Rey-Osterrieth Complex Figure Test (ROCFT) * Wechsler Memory Scale IV * Comprehensive Trail Making Test (CTMT) * semantic and phonematic fluency tests
DIAGNOSTIC_TEST	Questionnaires	* Short Form 36 (SF 36) * Somatic Symptom Disorder - B Criteria Scale (SSD 12) * Patient Health Questionnaire 9 (PHQ 9) * Patient Health Questionnaire 15 (PHQ 15) * Generalized Anxiety Disorder 7 (GAD 7) * Fatigue Severity Scale (FSS) * Psychosomatic Competence Inventory (PSCI) * Work Ability Index (WAI) * Level of Personality Functioning Scale * Toronto Alexithymia Scale * Levels of Emotional Awareness Scale (short version) * Certainty About Mental States Questionnaire * Somatosensoric Amplification Scale * Personality Inventory for DSM-5 short version (PID5BF+M) * Childhood Trauma Questionnaire * European Quality of Life 5 Dimensions 5 Level Version (EQ5D5L)
DIAGNOSTIC_TEST	Tremor recording	Accelerometry following a standardized protocol, using a triaxial accelerometer transducer (Biometrics ACL300, Sensitivity 6 100 mV/G, Biometrics Ltd, UK)

Timeline

• Start date: 2023-01-01
• Primary completion: 2025-12-31
• Completion: 2026-06-30
• First posted: 2023-07-13
• Last updated: 2025-09-29

Locations

1 site across 1 country: Austria