Which Parkinson Disease Symptoms Appear Earliest?

Sleep disturbances, autonomic dysfunction, and emotional changes may emerge more than a decade before a Parkinson disease (PD) diagnosis, according to findings from a large survey-based study presented at the 7^th World Parkinson Congress. Investigators analyzed responses from 5797 participants with PD enrolled in the Fox Insight study to better characterize the chronology of early self-reported symptoms preceding diagnosis.

Motor symptoms remained the most commonly reported changes overall (91%), followed by autonomic (70%), sleep (65%), emotional (51%), cognitive (47%), and smell or taste changes (45%). Frequently endorsed symptoms included tremor (50%), reduced sense of smell (42%), smaller handwriting (37%), nocturia (37%), and difficulty maintaining sleep (36%).

What Nonmotor Symptoms Were Reported Before a Parkinson Disease Diagnosis?

However, nonmotor symptoms were most likely to begin years before diagnosis. Sleep, autonomic, and emotional symptoms showed the highest proportions of participants reporting onset at least 4 years before diagnosis and remained common more than 10 years before diagnosis. Among the earliest reported symptoms were persistent sadness, claustrophobia, frightening dreams, constipation, sleep talking, hopelessness, and anxiety.

The findings reinforce growing evidence that PD develops gradually over many years before motor manifestations prompt clinical recognition. Researchers suggest that defining the sequence and timing of prodromal symptoms could improve screening strategies and support earlier intervention efforts once disease-modifying therapies become available.

Sources

Trinh E, Harrison K, Brown E, et al. Chronology of early changes in Parkinson’s disease. Presented at 7th World Parkinson Congress; May 24-27, 2026; Phoenix, AZ.