Objective: To identify whether there is evidence for cognitive dysfunction in participants identified as being at higher risk of Parkinson’s disease (PD) using the PREDICT-PD algorithm.

Background: The prodromal phase of PD includes non-motor as well as motor symptoms; cognitive dysfunction is found at higher rates 2 years before diagnosis in PD cases compared to controls[1]. The PREDICT-PD study uses online assessment of multiple risk factors to estimate participants’ risk of future PD and stratify into higher (highest 15%), intermediate and lower (lowest 15%) risk groups. The higher risk group show an increased rate of motor disturbance[2], increased frequency of markers associated with PD (smell loss, sleep disturbance and slowed finger tapping), and increased incidence of PD diagnosis during follow-up. Cognition in the cohort has been tested online and in-person.

Methods: Screening questions covering memory and executive function were included in the year 2 PREDICT-PD online survey; both domains were scored out of 10 giving a total score out of 20. Selected participants were additionally assessed in-person using the Montreal Cognitive Assessment (MOCA). 175 participants were included in the analysis (64 higher-risk and 111 lower or intermediate-risk).

Online cognitive screening scores were validated against MOCA scores. Higher and lower-risk groups were compared using both scores. Finally, the relationship between cognitive scores and risk score was analysed with linear regression used to adjust for confounders.

Results: Median cognitive screening score was 16 (interquartile range 15-18). Screening score significantly positively correlated with MOCA score (r = 0.25; p=0.001). The higher-risk group had slightly but significantly lower MOCA and screening scores than the lower-risk group (27 vs 28, p=0.01; 15 vs 17, p<0.0001). MOCA and screening score increased as PD risk decreased (r = 0.19, p=0.01; r = 0.23, p=0.003). After adjustment for vascular risk factors ischaemic heart disease, hypertension, hypercholesterolaemia and diabetes, risk score still significantly contributed to variation in MOCA score (p=0.004).

Conclusions: These results are suggestive of early, subtle cognitive dysfunction in the PREDICT-PD higher-risk group and show poorer cognitive function may be associated with increased risk of PD. Further work to characterise the profile of cognitive dysfunction and define sensitive measures for cognition in this group may prove useful in risk profiling for PD.

References: [1] Schrag A et al. Prediagnostic presentations of Parkinson’s disease in primary care: a case-control study. Lancet Neurol 2015; 14(1): 57-64

[2] Noyce AJ et al. Subtle motor disturbances in PREDICT-PD participants. JNNP 2016; pii: jnnp-2016-314524. doi: 10.1136/jnnp-2016-314524. Dec 16 [Epup ahead of print]

« Back to 2017 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/cognition-in-the-predict-pd-cohort/