Dear Sir,We read with great interest the article published by Ampar et al.,[1] “Electrophysiological evaluation of audiovestibular pathway dysfunction in Parkinson’s disease and its correlates: A case-control study.” The authors have done a commendable job in highlighting audiovestibular pathway dysfunction in Parkinson’s patients. However, there are few concerns regarding this study.The study title reads “Electrophysiological evaluation of audiovestibular pathway dysfunction in Parkinson’s disease and its correlates: A case-control study” which implies that this study was comparative in nature with two groups. Case-control studies examine the possible relation of an exposure to a certain disease where a group of individuals with disease and other group comprising people without that disease are compared.[2] The authors have rightly taken matched controls for comparison. However, in the materials and methods section, the authors have mentioned, “the study was a prospective, cross-sectional, analytical study.” This has led to confusion which does not corroborate with the title and methodology adopted in the current study.Prospective study is a term used for cohort study or longitudinal study where the subjects are followed for a period of time and events are measured/recorded. On the other hand, cross-sectional study is a one-time examination of population which is also known commonly as prevalence study. Analytical studies are epidemiological studies which are conducted to test hypothesis. It includes case-control and cohort studies.[3] The methodology adopted in the study points toward a study design of case-control study. Also, in a case-control study, the strength of association between risk factor and outcome is measured by odds ratio.[3] The calculation of odds ratio would have further strengthened the results of the present study.The authors have rightly highlighted role of cervical vestibular evoked myogenic potential as predictive marker for occurrence of rapid eye movement sleep behavior disorder and postural instability in Parkinson’s disease.