Internal Versus External Frame of Reference in Functional Movement Disorders

Area of Science:

• Neurology
• Psychology

Background:

• Functional movement disorders (FMDs) are complex neurological conditions.
• Understanding the psychological factors, such as locus of control (LOC), is crucial for managing FMDs.
• Comparing LOC in FMD patients with other neurological conditions like Parkinson's disease and focal dystonia provides valuable insights.

Purpose of the Study:

• To investigate differences in internal versus external locus of control (LOC) between patients with functional movement disorders (FMDs) and control groups.
• To determine if LOC influences disease severity, quality of life, and functional impairment in FMD patients.

Main Methods:

• 156 patients (45 FMD, 64 Parkinson's disease, 47 focal dystonia) were recruited.
• Levenson Multidimensional LOC (LOC-G) and Health LOC (LOC-H) scales were administered.
• Statistical analyses included ANOVA and logistic regressions to compare LOC and its effects.

Main Results:

• FMD patients showed lower external chance LOC-G scores than Parkinson's disease patients.
• FMD patients had higher internal and lower external doctor LOC-H scores compared to focal dystonia patients.
• External powerful others LOC-G score correlated with functional impairment, but LOC did not affect quality of life or disease severity.

Conclusions:

• Patients with FMD demonstrate a predominantly internal locus of control.
• Locus of control was found to have no significant impact on quality of life or disease severity in this FMD cohort.