Time Taken for and Causes of a Decline to Hoehn and Yahr Stage 5 in Patients with Parkinson's Disease.

Objective Prediction of time until and causes of becoming bedridden may help patients with Parkinson's disease (PD) plan their productive lives. This study assessed the relationship between the age at the PD onset and time taken to reach Hoehn and Yahr stage (HY) 5 as well as the causes of motor decline to HY5 in Japanese patients with PD. Patients We enrolled patients with PD who visited our institute between April 2015 and December 2020, met the UK brain bank criteria, had medical records from the early PD stage, and had had HY5 for over three months. The relationship between the age at the PD onset and the disease duration was evaluated. Data on the possible causes of motor decline to HY5 were obtained from patients, caregivers or medical records. Results In total, 123 patients with PD (mean age at the PD onset was 69.3 years old; 80 women and 43 men) were included. The age at the PD onset was significantly and negatively correlated with the time until the decline to HY5. Among the 123 patients, 49 reported that the natural course of PD caused the decline to HY5. Possible events that accelerated the motor decline to HY5 included traumatic injury, pneumonia, and other medical or social conditions that might have resulted in reduced daily activities. Conclusion The time until the decline to HY5 can be estimated based on the age at the PD onset. In addition to natural PD progression, medical or social conditions that reduce physical activity may accelerate motor decline to HY5.