0.  

1. Wirdefeldt K, Adami HO, Cole P, Trichopoulos D, Mandel J. Epidemiology and etiology of Parkinson's disease: a review of the evidence. Eur J Epidemiol. 2011;26 Suppl 1:S1-58. [DOI:10.1007/s10654-011-9581-6] [PMID]

2. Tysnes OB, Storstein A. Epidemiology of Parkinson's disease. J Neural Transm (Vienna). 2017 Aug;124(8):901-905. eng. Epub 20170201. [DOI:10.1007/s00702-017-1686-y] [PMID]

3. Hussain G, Rasul A, Anwar H, Sohail MU, Kamran SKS, Baig SM, Shabbir A. Epidemiological data of neurological disorders in Pakistan and neighboring countries: a review. Pakistan Journal of Neurological Sciences (PJNS). 2017;12(4):52-70.

4. Nussbaum RL, Ellis CE. Alzheimer's disease and Parkinson's disease. N Engl J Med. 2003 Apr 3;348(14):1356-1364. [DOI:10.1056/NEJM2003ra020003] [PMID]

5. de Lau LM, Breteler MM. Epidemiology of Parkinson's disease. Lancet Neurol. 2006;5(6):525-535. [DOI:10.1016/S1474-4422(06)70471-9] [PMID]

6. Angelopoulou E, Papadopoulos AN, Spantideas N, Bougea A. Migraine, Tension-Type Headache and Parkinson's Disease: A Systematic Review and Meta-Analysis. Medicina (Kaunas). 2022;58(11):1-10. [DOI:10.3390/medicina58111684] [PMID] []

7. Sampaio Rocha-Filho PA, Leite Souza-Lima CF. Parkinson's Disease and Headaches: A Cross-Sectional Study. Headache. 2020;60(5):967-973. [DOI:10.1111/head.13815] [PMID]

8. Fil A, Cano-de-la-Cuerda R, Muñoz-Hellín E, Vela L, Ramiro-González M, Fernández-de-Las-Peñas C. Pain in Parkinson disease: a review of the literature. Parkinsonism Relat Disord. 2013 Mar;19(3):285-294. [DOI:10.1016/j.parkreldis.2012.11.009] [PMID]

9. Lorentz IT. A survey of headache in Parkinson's disease. Cephalalgia. 1989;9(2):83-86. https://doi.org/10.1046/j.1468-2982.1989.902083.x [DOI:10.1046/j.1468-2982.1989.0902083.x] [PMID]

10. Nunes JC, Costa Bergamaschi EN, Freitas FC, Diaz AP, Queiroz LP, Debona R, et al. Prevalence of headache in patients with Parkinson's disease and its association with the side of motor symptom onset. Neurol Sci. 2014;35(4):595-600. [DOI:10.1007/s10072-013-1571-x] [PMID]

11. Shulman LM, Bhat V. Gender disparities in Parkinson's disease. Expert Rev Neurother. 2006;6(3):407-416. [DOI:10.1586/14737175.6.3.407] [PMID]

12. Peters GL. Migraine overview and summary of current and emerging treatment options. Am J Manag Care. 2019 25(2 Suppl):23-34.

13. Mohammadi P, Khodamorovati M, Vafaee K, Hemmati M, Darvishi N, Ghasemi H. Prevalence of migraine in Iran: a systematic review and meta-analysis. BMC Neurology. 2023 2023;23(1):172-182. [DOI:10.1186/s12883-023-03215-5] [PMID] []

14. Prashanth R, Dutta Roy S. Novel and improved stage estimation in Parkinson's disease using clinical scales and machine learning. Neurocomputing. 2018;305:78-103. [DOI:10.1016/j.neucom.2018.04.049]

15. Rabey J, Korczyn A. The Hoehn and Yahr rating scale for Parkinson's disease. Instrumental methods and scoring in extrapyramidal disorders. Springer; 1995. p. 7-17. [DOI:10.1007/978-3-642-78914-4_2]

16. Roos DS, Klein M, Deeg DJH, Doty RL, Berendse HW. Prevalence of Prodromal Symptoms of Parkinson's Disease in the Late Middle-Aged Population. Journal of Parkinson's Disease. 2022;12:967-974. [DOI:10.3233/JPD-213007] [PMID] []

17. Sampaio Rocha-Filho PA, Leite Souza-Lima CF. Parkinson's Disease and Headaches: A Cross-Sectional Study. Headache: The Journal of Head and Face Pain. 2020;60(5):967-973. [DOI:10.1111/head.13815] [PMID]

18. Angelopoulou E, Papadopoulos AN, Spantideas N, Bougea A. Migraine, Tension-Type Headache and Parkinson's Disease: A Systematic Review and Meta-Analysis. Medicina. 2022;58(11):1684. [DOI:10.3390/medicina58111684] [PMID] []