Experimental evidence for a robust, transdiagnostic marker in functional disorders: Erroneous sensorimotor processing
Franziska Regnath1, Katharina Biersack1, Lena Schröder2
1Department of Psychosomatic Medicine and Psychotherapy, University Hospital Rechts der Isar, Technical University of Munich, Munich, Germany; TUM Graduate School, Graduate Center of Medicine and Health (GC MH), Technical University of Munich, Munich, Germany.
Journal of Psychosomatic Research
|May 11, 2024
Summary
Patients with functional movement disorder and functional dizziness exhibit impaired sensorimotor processing during eye-head movements. This finding suggests a shared mechanism across functional disorders, aiding diagnosis and treatment.
Area of Science:
- Neuroscience
- Psychiatry
- Movement Disorders
Background:
- Recent neuroscientific models propose perceptual dysregulation in the central nervous system underlies functional bodily symptoms.
- Patients with functional dizziness show sensorimotor processing deficits in eye-head movement planning and execution.
- Similar deficits in irritable bowel syndrome suggest a shared, transdiagnostic mechanism for functional disorders.
Purpose of the Study:
- To investigate whether erroneous sensorimotor processing is implicated in functional movement disorder.
- To examine sensorimotor processing during eye-head movements in patients with functional movement disorder.
Main Methods:
- 10 patients with functional movement disorder, 10 with functional dizziness, and 10 healthy controls participated.
- Head movements were measured during an eye-head experiment with varying head inertia.
- Head oscillations post-gaze shift were analyzed as a marker of sensorimotor processing deficits.
Main Results:
- Patients with functional movement disorder and functional dizziness demonstrated increased head oscillations compared to controls.
- These findings indicate marked deficits in the planning and execution of movement in both patient groups.
- Bayesian statistics provided substantial to strong evidence for these differences.
Conclusions:
- The study replicates findings of erroneous sensorimotor processing in functional dizziness.
- Patients with functional movement disorder exhibit similar sensorimotor processing impairments during gaze shifts.
- This provides an objective, transdiagnostic marker for functional disorders, with implications for diagnosis, treatment, and de-stigmatization.
