Unraveling the Relationship between Motor Symptoms, Affective States and Contextual Factors in Parkinson's Disease: A Feasibility Study of the Experience Sampling Method

Abstract

Background: In Parkinson's disease (PD), the complex relationship between motor symptoms, affective states, and contextual factors remains to be elucidated. The Experience Sampling Method provides (ESM) a novel approach to this issue. Using a mobile device with a special purpose application (app), motor symptoms, affective states and contextual factors are assessed repeatedly at random moments in the flow of daily life, yielding an intensive time series of symptoms and experience. The aim of this study was to study the feasibility of this method.

Method: We studied the feasibility of a five-day period of ESM in PD and its ability to objectify diurnal fluctuations in motor symptom severity and their relation with affect and contextual factors in five PD patients with motor fluctuations.

Results: Participants achieved a high compliance, with 84% of assessment moments completed without disturbance of daily activities. The utility of the device was rated 8 on a 10-point scale. We were able to capture extensive diurnal fluctuations that were not revealed by routine clinical assessment. In addition, we were able to detect clinically relevant associations between motor symptoms, emotional fluctuations and contextual factors at an intra-individual level.

Conclusions: ESM represents a viable and novel approach to elucidate relationships between motor symptoms, affective states and contextual factors at the level of individual subjects. ESM holds promise for clinical practice and scientific research.

Conflict of interest statement

Competing Interests: M. Broen, V. Marsman, M. Kuijf and R. Van Oostenbrugge have nothing to disclose. J. van Os has potential financial competing interests since he received unrestricted investigator-led research grants or recompense for presenting research at meetings from Eli Lilly, Bristol-Myers Squibb, Lundbeck, Organon, Takeda, Janssen-Cilag, GlaxoSmithKline, AstraZeneca, Pfizer and Servier. This does not alter the authors' adherence to PLOS ONE policies on sharing data and materials. A.F.G. Leentjens has potential financial competing interests since he received research grants from the Michael J Fox Foundation and the Stichting Internationaal Parkinson Fonds, as well as royalties from Reed-Elsevier, de Tijdstroom and Van Gorcum publishers. In addition he receives payment from Elsevier Inc as Editor-in-Chief of the Journal of Psychosomatic Research. This does not alter the authors' adherence to PLOS ONE policies on sharing data and materials.

Figures

Fig 1. Screenshot of the question “Ik voel me opgewekt”(“I feel cheerful”) on a 7 point Likert scale.

A score of 1 indicates “niet” (“not at all”), a score of 4 “matig” (“moderate”) and a score of 7 “Zeer” (“Very much so”).

Fig 2

a and b. Cross-sectional overall daily assessment (Fig 2a) versus real-time measurements (Fig 2b) of motor symptoms in subject 4. Legend: Y-axis: item score (1 = not all, 7 = very much); X-axis: time. Blue solid line: Tremor; Orange line: Dyskinesia; Red line: Trouble Walking; Green line: Rigidity.

Fig 3. Example of real time assessment of tremor and positive affect in subject 1.

Fig 4. Example of real time assessment of tremor and positive affect in subject 4.

Fig 5. Clustered column diagram of motor symptom severity in subject 1.

Legend: Y-axis: item score (1 = not all, 7 = very much); X-axis: motor symptoms.