AbstractsMedical & Health Science

Background. Parkinson’s disease (PD) is the second most common neurodegenerative disorder with complex presentations consisting of different motor and non-motor symptoms. The multisystem and progressive nature of PD has made it a complicated entity with broad variation in manifestations and reciprocal effects on several aspects of daily life. Aims. This doctoral thesis investigated different neuroepidemiologic aspects of PD and parkinsonism including its screening and prevalence in the urban area of Tehran, Iran, nutritional status and risk factors for malnutrition, clinical and psychiatric features, healthrelated quality of life (HRQoL) and its determinants in Iranian PD patients. For this purpose, we also aimed to validate several questionnaires and make a new screening instrument. Study I. Psychometric properties of the Persian-translated version of the short-form Parkinson’s disease questionnaire (PDQ-8) were assessed in 114 Iranian patients with PD consecutively recruited from an outpatient Movement Disorder Clinic. The Cronbach’s alpha coefficient of the entire PDQ-8 was 0.740 (95% CI: 0.661-0.806). Replacement of PDQ-8 items with other questions with the highest internal consistency within each dimension of the long-form PDQ (PDQ-39) did not further improve reliability. The Persian version of the PDQ-8 was shown to be a valid and reliable instrument to assess HRQoL in Iranian PD population especially in mental and behavioral aspects. PDQ-8 is a practical and informative instrument in daily clinical practice where clinicians are in shortage of time and need a validated self-reported brief questionnaire. Study II. To develop a new instrument for screening of parkinsonism in community-based surveys, a comprehensive questionnaire consisting of 25 items on different PD symptoms was filled in 157 patients with parkinsonism and 110 controls. Using the concept of clinical utility index (CUI), six items on “stiffness & rigidity”, “tremor & shaking”, “troublesome buttoning”, “troublesome arm swing”, “feet stuck to floor” and “slower daily activity” demonstrated good validity (CUI≥0.64) to be included in the new screening tool . We introduced a new set of six items to screen parkinsonism, which showed higher diagnostic values [area under curve (AUC)=0.977] compared to the previously developed questionnaires. This new instrument could be used in population-based surveys to screen parkinsonism in poor-resource settings. Study III. Following a random multistage sampling of the households within the network of “Health Centers” with 374 subunits in all 22 urban districts of Tehran, 20,621 individuals answered the baseline checklist and the screening questionnaire developed in study II. Data from 19,500 persons aged ≥30 years were entered in the final analysis. A total number of 157 cases were positively screened for parkinsonism that resulted in age- and sex-adjustment prevalence rates of 222.9/100,000 (95% CI: 160-300) and 285/100,000 (95% CI: 240-329) based on the real Tehran population and “WHO World Standard…