Motion sickness susceptibility and visually induced motion sickness as diagnostic signs in Parkinson's disease

Area of Science:

• Neuroscience
• Human Physiology
• Clinical Neurology

Background:

• Parkinson's Disease (PD) is characterized by postural instability and reduced vestibular and somatosensory acuity.
• PD patients often exhibit increased visual dependency, altering sensory input hierarchy.
• Altered sensory processing in PD can predict susceptibility to motion sickness (MS).

Purpose of the Study:

• To assess motion sickness (MS) susceptibility in Parkinson's Disease (PD) patients.
• To evaluate the effects of experimentally induced MS on posture in PD patients.
• To investigate the relationship between levodopa medication, visual dependency, and MS in PD.

Main Methods:

• Evaluated 63 PD patients (varying levodopa levels) and 27 healthy controls using an MS questionnaire.
• Assessed postural stability via posturography in virtual reality for 9 PD patients and 43 controls.
• Correlated drug dosage with MS susceptibility and postural responses.

Main Results:

• Higher levodopa dosage predicted susceptibility to visually induced MS (p=0.01) but not real-induced MS.
• PD patients did not show postural instability in virtual reality, unlike healthy controls.
• PD patients experienced visually induced MS more with increased levodopa, suggesting enhanced visual dependency.

Conclusions:

• PD patients may rely less on vestibular and somatosensory inputs during vestibular stimulation, potentially explaining reduced MS.
• Increased levodopa dosage in PD correlates with heightened visual dependency and susceptibility to visual MS.
• Further research into MS predictors in PD is crucial for understanding visual and vestibular stimulation effects.