Pupillary unrest correlates with arousal symptoms and motor signs in Parkinson disease.

BACKGROUND: Arousal symptoms (e.g., sleepiness) are common in Parkinson's disease, and pupillary unrest (spontaneous changes in pupil diameter) is positively associated with sleepiness. We explored pupillary unrest in Parkinson's disease.
METHODS: Arousal symptoms (Epworth sleepiness scale and sleep/fatigue domain of the nonmotor symptoms scale for Parkinson's disease) and pupillary unrest were assessed in 31 participants (14 patients with Parkinson's disease, 17 controls). Effect sizes and t tests compared patients with Parkinson's disease with control participants. Correlation coefficients were calculated among arousal symptoms, pupillary unrest, and Unified Parkinson Disease Rating Scale Part III. Linear regression was performed with arousal symptoms or pupillary unrest as outcome.
RESULTS: Participants with Parkinson's disease reported more arousal symptoms than controls. Pupillary unrest, arousal symptoms, and Unified Parkinson Disease Rating Scale Part III were positively correlated. The association between nonmotor symptoms scale-sleep score and pupillary unrest was higher in participants with Parkinson's disease than controls and higher in those with more Parkinsonian motor signs. Unified Parkinson Disease Rating Scale Part III was positively associated with pupillary unrest.
CONCLUSIONS: Pupillary unrest correlates with motor and nonmotor features associated with Lewy-related pathology, suggesting it may be a nonmotor marker of progression in Parkinson's disease. © 2011 Movement Disorder Society.