Scales for Assessing Nonmotor Symptom Severity Changes in Parkinson's Disease Patients With Symptom Fluctuations

Background: In Parkinson's disease (PD), the impact of nonmotor symptoms can outweigh the effect of worsening physical mobility on Health-Related Quality of Life (HRQoL). As PD progresses, patients may experience more severe changes in fluctuating nonmotor symptoms. Objective: This review summarizes nonmotor symptom assessments in patients with fluctuating symptoms, focusing on scales utilizing a daily-diary format for a broad spectrum of nonmotor symptoms. Methods: Medline on PubMed and EMBASE were searched for relevant articles published between January 2002 and October 2009. Results: Several nonmotor symptom scales were found, but no single scale with all desirable characteristics was identified. The Scales for Outcomes in Parkinson's Disease (SCOPA) battery of assessments, the Nonmotor Symptoms Scale (NMSS), and the Movement Disorder Society-sponsored revision of the Unified Parkinson's Disease Rating Scale (MDS-UPDRS) Part I offered a majority of the desirable characteristics, while practical, valid, and reliable. Conclusion: A single daily-diary instrument for assessing a broad spectrum of fluctuating nonmotor symptoms was not identified; however, the battery of SCOPA scales, the NMSS, and the MDS-UPDRS Part I provide useful nonmotor symptom severity assessment. The development of a diary assessment would be helpful in evaluating treatment interventions to improve HRQoL in patients with fluctuating symptoms.