Balance problems with Parkinson's disease: are they anxiety-dependent?

Area of Science:

• Neuroscience
• Human Physiology
• Movement Disorders

Background:

• Non-motor symptoms like anxiety and fear of falling are common in Parkinson's disease (PD).
• Anxiety and fear are known to affect balance control in healthy individuals.
• The direct impact of these emotional states on balance deficits in PD remains unclear.

Purpose of the Study:

• To investigate if Parkinson's disease patients and healthy controls exhibit similar or different responses to experimentally induced anxiety.
• To explore the direct contribution of fear of falling and anxiety to balance deficits in PD.

Main Methods:

• 14 PD patients (ON state) and 16 healthy controls underwent three postural threat conditions: normal, medium (80 cm), and high (160 cm).
• Center of Pressure (COP) displacements (anterior-posterior and medial-lateral) were measured using mean position, MPF, and RMS.
• Physiological and psychosocial measures of fear and anxiety were recorded.

Main Results:

• Increased postural threat similarly affected balance in both PD patients and controls.
• Mean Power of Frequency (MPF) of COP in AP and ML directions increased, and mean COP position shifted backward in both groups.
• Correlations between COP changes and fear/anxiety measures suggest neural links between emotion and postural control.

Conclusions:

• Static balance in PD patients (ON state) and controls is equally susceptible to anxiety.
• Emotional states like anxiety and fear of falling may directly contribute to balance impairments in Parkinson's disease.
• Future research should examine more severe PD, medication effects, anxious populations, and dynamic balance.