Revised Rating Scale May Be Useful for Tracking Parkinson Disease Progression

Assessing patient-reported emergent symptoms on the Movement Disorder Society-sponsored revision of the Unified Parkinson Disease Rating Scale (MDS-UPDRS) may be useful for tracking the progression of early Parkinson disease, according to study findings published in the Journal of Parkinson’s Disease.

“The results of our study demonstrated that Parts IB and II of the MDS-UPDRS, taken together as a single patient-reported outcome measure, can function as a record of milestone attainment in the form of appearance of new disease manifestations,” wrote researchers. “Arguably, especially early in disease, appearance of a new symptom, as occurred in 87% of our participants within the first year of observation, could be interpreted to represent a significant milestone for most persons suffering from Parkinson disease.”

Because summary scores of current clinical rating scales may lack the sensitivity to quantify early Parkinson disease progression for clinical trials of interventions, researchers explored the potential use of patient-reported emergent symptoms on the MDS-UPDRS.

Specifically, the study assessed the number of emergent symptoms reported on the MDS-UPDRS Parts IB (nonmotor) and II (motor) Experiences of Daily Living scales over 2 years from the Safety, Tolerability, and Efficacy Assessment of Isradipine for PD (STEADY-PD) study.

Among 331 participants, 87% developed emergent symptoms and 55% started symptomatic treatment during the first year.

When researchers looked at patients who started symptomatic treatment and patients who did not, they found the median number of emergent Part IB, or nonmotor, symptoms did not significantly differ between the groups, but new motor symptoms in Part II were significantly more frequent in the group that started symptomatic treatment.

Among 148 participants who did not start symptomatic treatment into year 2, 77% developed symptoms and 42% started symptomatic treatment. The study again showed that Part II, but not Part IB, emergent symptoms were more frequent in the treatment group.

Based on the findings, researchers believe a sample size of about 90 patients per group would be necessary to detect a 30% decrease in combined Part IB and II emergent symptoms over 12 months.

“The accrual of emergent symptoms may have a particular advantage as an efficient outcome in proof-of-concept clinical trials which, by their nature, require relatively small sample sizes,” reported researchers. “The concept of tracking emergent symptoms as a milestone-based clinical trial outcome measure is worthy of exploration in future studies and alternative datasets.”

Reference:
Tosin MHS, Simuni T, Stebbins GT, Cedarbaum JM. Tracking emergence of new motor and non-motor symptoms using the MDS-UPDRS: a novel outcome measure for early Parkinson’s disease? J Parkinsons Dis. Published online April 18, 2022. doi: 10.3233/JPD-223170.