Comment on Szewczyk-Krolikowski et al.: the influence of age and gender on motor and non-motor features of early Parkinson's disease: initial findings from the Oxford Parkinson Disease Center (OPDC) discovery cohort.

Abstract

We read with great interest the paper “The influence of age and gender on motor and non-motor features of early Parkinson's disease: Initial findings from the Oxford Parkinson Disease Center (OPDC) discovery cohort” recently published by Szewczyk-Krolikowski and colleagues [ [1] Szewczyk-Krolikowski K. Tomlinson P. Nithi K. Wade-Martins R. Talbot K. Ben-Shlomo Y. et al. The influence of age and gender on motor and non-motor features of early Parkinson's disease: initial findings from the Oxford Parkinson Disease Center (OPDC) discovery cohort. Parkinsonism Relat Disord. 2014; 20: 99-105 Abstract Full Text Full Text PDF PubMed Scopus (174) Google Scholar ]. The influence of age and gender on motor and non-motor features of early Parkinson's disease: Initial findings from the Oxford Parkinson Disease Center (OPDC) discovery cohortParkinsonism & Related DisordersVol. 20Issue 1PreviewIdentifying factors influencing phenotypic heterogeneity in Parkinson's Disease is crucial for understanding variability in disease severity and progression. Age and gender are two most basic epidemiological characteristics, yet their effect on expression of PD symptoms is not fully defined. We aimed to delineate effects of age and gender on the phenotype in an incident cohort of PD patients and healthy controls from the Oxford Parkinson Disease Centre (OPDC). Full-Text PDF Letter in response to Picillo et al., in relation to Szewczyk-Krolikowski et al.: The influence of age and gender on motor and non-motor features of early Parkinson's disease: Initial findings from the Oxford Parkinson disease Center (OPDC) discovery cohortParkinsonism & Related DisordersVol. 20Issue 11PreviewWe thank Picillo et al. for their interest in our recent publication [1]. Their previous study [2] has several differences from the OPDC study and in particular was smaller (200 PD patients and 93 controls versus 490 PD patients and 176 controls). Whilst their data suggested that there were gender differences in the frequency of non-motor symptoms (NMS) between PD patients and controls, they did not include any formal statistical test for interaction, making this hard to interpret as some differences may be due to chance. Full-Text PDF