Objective: To investigate the reporting of changes observed by Knowledgeable Informants (KIs) and people with Parkinson’s disease (PwPD) prior to a Parkinson’s disease (PD) diagnosis.

Background: Early detection of PD is crucial for timely diagnosis and intervention. This study aims to explore the temporal onset of early PD features and examine the role of KIs in recognizing prodromal indicators of the disease.

Method: We invited PwPD and KIs, individuals who reported knowing a PwPD prior to their diagnosis, to complete a survey through the Fox Insight online platform. The survey was designed to capture changes reported by PwPD and observed by KIs, including temporal relationship to clinical diagnosis. We subsequently selected a subset of respondents to take part in semi-structured interviews, which were analyzed using inductive qualitative methodology.

Results: 1860 KIs and 5549 PwPD completed the survey [Table 1], with 63 KIs participating in interviews. KIs reported certain prodromal features more frequently than PwPD and reported them emerging four or more years before diagnosis: difficulty using new gadgets or machines (KI: 45%, PwPD: 33%), trouble keeping track of time (KI: 41%, PwPD: 33%), and reduced task persistence (KI: 39%, PwPD: 34%) [Figure 1]. KIs also observed changes in PwPD occurring more than 10 years before diagnosis at higher rates than PwPD-reported changes, e.g., excessive sweating (KI: 26%, PwPD: 20%). Inter-generational reporting differences were observed [Table 2], with KIs from a different generation than their PwPD reporting changes like worsening balance (36%) and shuffling feet or small steps (30%) more frequently than same-generation KIs (20% each). Overall, KIs demonstrated heightened recognition of certain observable changes compared to PwPD, particularly gait changes such as shuffling feet or small steps, which ranked 7th among KIs (23%) but 28th among PwPD (16%) [Figure 2]. Qualitative analysis further characterized KI observations of gait changes [Figure 3], with some changes first noticed up to 21 years preceding clinical diagnosis.

Conclusion: These findings elucidate the potential of KIs in recognizing early changes in PwPD, providing a complementary perspective to PwPD self-reports. KI reporting may facilitate early detection and intervention.

Table 1

Figure 1

Table 2

Figure 2

Figure 3

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MDS Abstracts - https://www.mdsabstracts.org/abstract/the-role-of-knowledgeable-informants-in-the-early-detection-of-parkinsons-disease/