Parkinson Hastalığında Bilişsel Bozukluğun Bakım Veren Yükü Üzerindeki Etkisi

Abstract

Parkinson hastalığı (PH) tremor, rijidite, bradikinezi/akinezi, postural instabilite gibi motor semptomların yanı sıra bilişsel bozukluğu da içeren motor olmayan semptomlara sahiptir. Birçok hasta dil, yürütücü işlevler, bellek, dikkat ve görsel-uzamsal yetenekler gibi çeşitli bilişsel alanlarda zorluk çekmektedir. Bu eksiklikler günlük yaşam aktivitelerini yerine getirmede ve zaman zaman öz bakımda zorluğa neden olacak düzeyde olabilir. Bu nedenle hasta bir bakım verene ihtiyaç duyabilir. Diğer tüm kronik hastalıklarda gösterildiği gibi, bakım verme hem zihinsel hem de fiziksel olarak zorlu bir süreçtir. Türk örnekleminde nonmotor semptomların yaygınlığına dayanan çalışmaların çoğu, bu semptomların sık olduğunu ve hem hastaların hem de bakım verenlerin yaşamlarını olumsuz etkilediğini göstermektedir. Ayrıca bilişsel eksiklik derinleştikçe bakım verenler üzerindeki yük de artmaktadır. Bu çalışmanın amacı, PH’nda bilişsel bozukluğu ve bunun bakım veren yükü üzerindeki etkisini literatür taraması yöntemiyle incelemektir. Ayrıca, literatürde PH ve bakım verenler üzerine birçok çalışma olmasına rağmen, bakım veren yükünü artıran bir faktör olarak bilişsel beceriler üzerine yapılan çalışmalar oldukça sınırlıdır. Bu çalışma, bilişsel işlevler başta olmak üzere bakım veren yüküne katkıda bulunan faktörlere odaklanarak bu boşluğu doldurmayı amaçlamaktadır. Çalışmaların gösterdiği gibi, bilişsel düşüş hastanın günlük yaşam aktivitelerine katılma ve öz bakım becerilerini bozmakta ve dolayısıyla hastayı bakım verene bağımlı hale getirmektedir. Bu da bakım verenin daha fazla görev üstlenmesine ve dolayısıyla yükünün artmasına neden olur. Hastalık deneyimi bireysel olduğu kadar sosyal olarak da şekillenir, bu nedenle bakım veren kişinin karşılaştığı yük gibi faktörler hastalığın sosyal etkilerini anlamada kritik bir rol oynar. Dolayısıyla, bakım verenleri olumsuz etkileyen faktörler daha fazla dikkate alınmalıdır.

Keywords

• Parkinson Hastalığı
• Bilişsel Bozukluk
• Bakım Veren Yükü

The Effect of Cognitive Impairments in Parkinson’s Disease on Caregiver Burden

Abstract

Parkinson’s disease (PD) has motor symptoms such as tremor, rigidity, bradykinesia/akinesis, postural instability and nonmotor symptoms including cognitive impairment. Many PD patients struggle in a variety of cognitive domains, including as language, executive functioning, memory, attention, and visuospatial abilities. These deficits may be at a level that causes difficulty in performing activities of daily living and occasionally self-care. For this reason, PD patients may need caregivers. As has been demonstrated in all other chronic diseases, caregiving is a demanding process, both mentally and physically. Most of the studies based on the prevalence of nonmotor symptoms in the Turkish sample show that these symptoms are frequent and negatively affect the lives of both patients and their caregivers. Additionally, as the cognitive deficit deepens, the burden on caregivers increases. The aim of this study was to examine cognitive impairment in PD and its effect on caregiver burden by using the literature review method. In addition, although there are many studies on PD and caregivers in the literature, studies on cognitive abilities as a factor that increases caregiver burden are very limited. This study aims to fill this gap by focusing on factors that contribute to caregiver burden, especially cognitive functions. As studies have shown, cognitive decline impairs the ability of the patient to participate in activities of daily living and self-care and thus makes them dependent on the caregiver. This leads to the caregiver taking on more duties and consequently increasing their burden. The experience of disease is shaped socially as well as individually, thus factors such as the burden faced by the caregiver play a critical role in understanding the social effects of the disease. Therefore, factors that negatively affect caregivers must be considered more.

Keywords

• Parkinson’s Disease
• Cognitive Impairment
• Caregiver Burden

References

1. Aarsland, D., Brønnick, K., Larsen, J. P., Tysnes, O. B., & Alves, G. (2009). Cognitive impairment in incident, untreated Parkinson disease: the Norwegian ParkWest study. Neurology, 72(13), 1121-1126.
2. Aarsland, D., Brønnick, K., & Fladby, T. (2011). Mild cognitive impairment in Parkinson’s disease. Current Neurology and Neuroscience Reports, 11, 371-378.
3. Aarsland, D., Creese, B., Politis, M., Chaudhuri, K. R., Ffytche, D. H., Weintraub, D., & Ballard, C. (2017). Cognitive decline in Parkinson disease. Nature Reviews Neurology, 13(4), 217-231.
4. Aarsland, D., Batzu, L., Halliday, G. M., Geurtsen, G. J., Ballard, C., Ray Chaudhuri, K., & Weintraub, D. (2021). Parkinson disease-associated cognitive impairment. Nature Reviews Disease Primers, 7(1), 47.
5. Altmann, L. J., & Troche, M. S. (2011). High‐level language production in parkinson′ s disease: a review. Parkinson’s Disease, 2011(1), 238956.
6. Baiano, C., Barone, P., Trojano, L., & Santangelo, G. (2020). Prevalence and clinical aspects of mild cognitive impairment in Parkinson's disease: A meta‐analysis. Movement Disorders, 35(1), 45-54.
7. Balestrino, R., & Martinez-Martin, P. (2017). Reprint of Neuropsychiatric symptoms, behavioural disorders, and quality of life in Parkinson's disease. Journal of the Neurological Sciences, 374, 3-8.
8. Balestrino, R., & Schapira, A. H. (2020). Parkinson disease. European Journal of Neurology, 27(1), 27-42.

9. Barone, P., Antonini, A., Colosimo, C., Marconi, R., Morgante, L., Avarello, T. P., ... & Dotto, P. D. (2009). The PRIAMO study: a multicenter assessment of nonmotor symptoms and their impact on quality of life in Parkinson's disease. Movement Disorders: Official Journal of the Movement Disorder Society, 24(11), 1641-1649.
10. Becker, S., Bäumer, A., Maetzler, W., Nussbaum, S., Timmers, M., Van Nueten, L., ... & Liepelt‐Scarfone, I. (2020). Assessment of cognitive‐driven activity of daily living impairment in non‐demented Parkinson's patients. Journal of Neuropsychology, 14(1), 69-84.
11. Becker, S., Bode, M., Brockmann, K., Gasser, T., Michaelis, K., Solbrig, S., ... & Liepelt-Scarfone, I. (2022). Cognitive-driven activities of daily living impairment as a predictor for dementia in Parkinson disease: a longitudinal cohort study. Neurology, 99(23), e2548-e2560.
12. Bek, J., Humphries, S., Poliakoff, E., & Brady, N. (2022). Mental rotation of hands and objects in ageing and Parkinson’s disease: Differentiating motor imagery and visuospatial ability. Experimental Brain Research, 240(7), 1991-2004.
13. Bode, M., Kalbe, E., & Liepelt-Scarfone, I. (2024). Cognition and Activity of Daily Living Function in people with Parkinson’s disease. Journal of Neural Transmission, 131(10), 1159-1186.
14. Cameron, I. G., Watanabe, M., Pari, G., & Munoz, D. P. (2010). Executive impairment in Parkinson's disease: response automaticity and task switching. Neuropsychologia, 48(7), 1948-1957.
15. Cao, F., Vogel, A. P., Gharahkhani, P., & Renteria, M. E. (2025). Speech and language biomarkers for Parkinson’s disease prediction, early diagnosis and progression. Npj Parkinson's Disease, 11(1), 57.
16. Carter, J. H., Stewart, B. J., Archbold, P. G., Inoue, I., Jaglin, J., Lannon, M., ... & Zoog, K. (1998). Living with a person who has Parkinson's disease: the spouse's perspective by stage of disease. Movement Disorders: Official Journal of the Movement Disorder Society, 13(1), 20-28.
17. Chade, A. R., Kasten, M., & Tanner, C. M. (2006). Nongenetic causes of Parkinson’s disease. Parkinson’s Disease and Related Disorders, 147-151.
18. Chandler, J. M., Nair, R., Biglan, K., Ferries, E. A., Munsie, L. M., Changamire, T., & Patel, N. (2021). Characteristics of Parkinson’s disease in patients with and without cognitive impairment. Journal of Parkinson’s Disease, 11(3), 1381-1392.
19. Choi, J. Y., Lee, S. H., & Yu, S. (2024). Exploring factors influencing caregiver burden: A systematic review of family caregivers of older adults with chronic illness in local communities. Healthcare, 12(10), 1002.
20. Compta, Y., Martí, M. J., Ibarretxe‐Bilbao, N., Junqué, C., Valldeoriola, F., Muñoz, E., ... & Tolosa, E. (2009). Cerebrospinal tau, phospho‐tau, and beta‐amyloid and neuropsychological functions in Parkinson's disease. Movement Disorders: Official Journal of the Movement Disorder Society, 24(15), 2203-2210.
21. Costa, A., Peppe, A., Brusa, L., Caltagirone, C., Gatto, I., & Carlesimo, G. A. (2008). Dopaminergic modulation of prospective memory in Parkinson’s disease. Behavioural Neurology, 19(1-2), 45-48.
22. Crucian, G. P., Barrett, A. M., Burks, D. W., Riestra, A. R., Roth, H. L., Schwartz, R. L., ... & Heilman, K. M. (2003). Mental object rotation in Parkinson's disease. Journal of the International Neuropsychological Society, 9(7), 1078-1087.
23. Davidsdottir, S., Cronin-Golomb, A., & Lee, A. (2005). Visual and spatial symptoms in Parkinson’s disease. Vision Research, 45(10), 1285-1296.
24. Dorsey, E. R., Elbaz, A., Nichols, E., Abbasi, N., Abd-Allah, F., Abdelalim, A., ... & Murray, C. J. (2018). Global, regional, and national burden of Parkinson's disease, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016. The Lancet Neurology, 17(11), 939-953.
25. Dujardin, K., Tard, C., Duhamel, A., Delval, A., Moreau, C., Devos, D., & Defebvre, L. (2013). The pattern of attentional deficits in Parkinson's disease. Parkinsonism & Related Disorders, 19(3), 300-305.
26. Einstein, G. O., & McDaniel, M. A. (2005). Prospective memory: Multiple retrieval processes. Current Directions in Psychological Science, 14(6), 286-290.
27. Emre, M., Aarsland, D., Brown, R., Burn, D. J., Duyckaerts, C., Mizuno, Y., ... & Dubois, B. (2007). Clinical diagnostic criteria for dementia associated with Parkinson's disease. Movement Disorders: Official Journal of the Movement Disorder Society, 22(12), 1689-1707.
28. Engel, G. L. (1977). The need for a new medical model: a challenge for biomedicine. Science, 196(4286), 129-136.
29. Eriksson, M., & Svedlund, M. (2006). ‘The intruder’: spouses’ narratives about life with a chronically ill partner. Journal of Clinical Nursing, 15(3), 324-333.
30. Erro, R., Santangelo, G., Barone, P., Picillo, M., Amboni, M., Longo, K., ... & Vitale, C. (2014). Do subjective memory complaints herald the onset of mild cognitive impairment in Parkinson disease?. Journal of Geriatric Psychiatry and Neurology, 27(4), 276-281.
31. Evans, I. E., Llewellyn, D. J., Matthews, F. E., Woods, R. T., Brayne, C., & Clare, L. (2019). Social isolation, cognitive reserve, and cognition in older people with depression and anxiety. Aging & Mental Health, 23(12), 1691-1700. Fama, R., Sullivan, E. V., Shear, P. K., Stein, M., Yesavage, J. A., Tinklenberg, J. R., & Pfefferbaum, A. (2000). Extent, pattern, and correlates of remote memory impairment in Alzheimer's disease and Parkinson's disease. Neuropsychology, 14(2), 265.
32. Feigin, V. L., Nichols, E., Alam, T., Bannick, M. S., Beghi, E., Blake, N., ... & Fischer, F. (2019). Global, regional, and national burden of neurological disorders, 1990–2016: a systematic analysis for the Global Burden of Disease Study 2016. The Lancet Neurology, 18(5), 459-480.
33. Feigin, V. L., Vos, T., Nichols, E., Owolabi, M. O., Carroll, W. M., Dichgans, M., ... & Murray, C. (2020). The global burden of neurological disorders: translating evidence into policy. The Lancet Neurology, 19(3), 255-265.
34. Fellows, R. P., & Schmitter-Edgecombe, M. (2019). Multimethod assessment of everyday functioning and memory abilities in Parkinson’s disease. Neuropsychology, 33(2), 169.
35. Fernández-Baizán, C., García, M. P. F., Díaz-Cáceres, E., Menéndez-González, M., Arias, J. L., & Méndez, M. (2022). Activities of daily living in Parkinson disease: are they related to short term and working memory and visuospatial abilities?. Topics in Geriatric Rehabilitation, 38(4), 285-295.
36. Foltynie, T., Brayne, C. E., Robbins, T. W., & Barker, R. A. (2004). The cognitive ability of an incident cohort of Parkinson’s patients in the UK. The CamPaIGN study. Brain, 127(3), 550-560.
37. Foster, E. R., & Doty, T. (2021). Cognitive correlates of instrumental activities of daily living performance in Parkinson disease without dementia. Archives of Rehabilitation Research and Clinical Translation, 3(3), 100138.
38. Galtier, I., Nieto, A., Lorenzo, J. N., & Barroso, J. (2016). Mild cognitive impairment in Parkinson’s disease: Diagnosis and progression to dementia. Journal of Clinical and Experimental Neuropsychology, 38(1), 40-50. García-Castro, F. J., Bendayan, R., Dobson, R. J., & Blanca, M. J. (2022). Cognition in informal caregivers: Evidence from an English population study. Aging & Mental Health, 26(3), 507-518.
39. Greenwell, K., Gray, W. K., Van Wersch, A., Van Schaik, P., & Walker, R. (2015). Predictors of the psychosocial impact of being a carer of people living with Parkinson's disease: a systematic review. Parkinsonism & Related Disorders, 21(1), 1-11.
40. He, Y., Tian, Y., Han, H., Cui, J., Ge, X., Qin, Y., ... & Yu, H. (2021). The path linking disease severity and cognitive function with quality of life in Parkinson’s disease: the mediating effect of activities of daily living and depression. Health and Quality of Life Outcomes, 19, 1-7.
41. Hiseman, J. P., & Fackrell, R. (2017). Caregiver burden and the nonmotor symptoms of Parkinson's disease. International Review of Neurobiology, 133, 479-497.
42. Hely, M. A., Reid, W. G., Adena, M. A., Halliday, G. M., & Morris, J. G. (2008). The Sydney multicenter study of Parkinson's disease: the inevitability of dementia at 20 years. Movement Disorders, 23(6), 837-844.
43. Holden, S. K., Medina, L. D., Hoyt, B., Sillau, S. H., Berman, B. D., Goldman, J. G., ... & Kluger, B. M. (2018). Validation of a performance‐based assessment of cognitive functional ability in Parkinson's disease. Movement Disorders, 33(11), 1760-1768.
44. Jellinger, K. A. (2023). Pathobiology of cognitive impairment in Parkinson disease: challenges and outlooks. International Journal of Molecular Sciences, 25(1), 498.
45. Keränen, T., Kaakkola, S., Sotaniemi, K., Laulumaa, V., Haapaniemi, T., Jolma, T., ... & Takala, A. (2003). Economic burden and quality of life impairment increase with severity of PD. Parkinsonism & Related Disorders, 9(3), 163-168.
46. Koerts, J., Borg, M. A., Meppelink, A. M., Leenders, K. L., van Beilen, M., & van Laar, T. (2010). Attentional and perceptual impairments in Parkinson's disease with visual hallucinations. Parkinsonism & Related Disorders, 16(4), 270-274.
47. Koros, C., Stefanis, L., & Scarmeas, N. (2022). Parkinsonism and dementia. Journal of the Neurological Sciences, 433, 120015.
48. Kummer, A., & Teixeira, A. L. (2009). Neuropsychiatry of Parkinson's disease. Arquivos de Neuro-psiquiatria, 67, 930-939.
49. Lau, K. M., & Au, A. (2011). Correlates of informal caregiver distress in Parkinson's disease: a meta-analysis. Clinical Gerontologist, 34(2), 117-131.
50. Lawson, R. A., Yarnall, A. J., Duncan, G. W., Khoo, T. K., Breen, D. P., Barker, R. A., ... & Burn, D. J. (2014). Severity of mild cognitive impairment in early Parkinson's disease contributes to poorer quality of life. Parkinsonism & Related Disorders, 20(10), 1071-1075.
51. Lawson, R. A., Yarnall, A. J., Johnston, F., Duncan, G. W., Khoo, T. K., Collerton, D., ... & ICICLE‐PD study group. (2017). Cognitive impairment in Parkinson's disease: impact on quality of life of carers. International Journal of Geriatric Psychiatry, 32(12), 1362-1370.
52. Lawton MP, Brody EM (1969). Assessment of older people: self-maintaining and instrumental activities of daily living. The Gerontologist, 9(3, Pt 1), 179–186. https://doi.org/10.1093/geront/9.3_Part_1.179
53. Leroi, I., McDonald, K., Pantula, H., & Harbishettar, V. (2012). Cognitive impairment in Parkinson disease: impact on quality of life, disability, and caregiver burden. Journal of Geriatric Psychiatry and Neurology, 25(4), 208-214.
54. Litvan, I., Goldman, J. G., Tröster, A. I., Schmand, B. A., Weintraub, D., Petersen, R. C., ... & Emre, M. (2012). Diagnostic criteria for mild cognitive impairment in Parkinson's disease: Movement Disorder Society Task Force guidelines. Movement Disorders, 27(3), 349-356.
55. Lord, S., Rochester, L., Hetherington, V., Allcock, L. M., & Burn, D. (2010). Executive dysfunction and attention contribute to gait interference in ‘off’state Parkinson's Disease. Gait & Posture, 31(2), 169-174.
56. Machado, L., Devine, A., & Wyatt, N. (2009). Distractibility with advancing age and Parkinson's disease. Neuropsychologia, 47(7), 1756-1764.
57. Malapani, C., Pillon, B., Dubois, B., & Agid, Y. (1994). Impaired simultaneous cognitive task performance in Parkinson's disease: a dopamine‐related dysfunction. Neurology, 44(2), 319-319.
58. Martinez-Horta, S., & Kulisevsky, J. (2019). Mild cognitive impairment in Parkinson’s disease. Journal of Neural Transmission, 126(7), 897-904.
59. Martinez‐Martin, P., Arroyo, S., Rojo‐Abuin, J. M., Rodriguez‐Blazquez, C., Frades, B., & de Pedro Cuesta, J. (2008). Burden, perceived health status, and mood among caregivers of Parkinson's disease patients. Movement Disorders: Official Journal of the Movement Disorder Society, 23(12), 1673-1680.
60. Martinez-Martin, P., Rodriguez-Blazquez, C., Forjaz, M. J., Frades-Payo, B., Agüera-Ortiz, L., Weintraub, D., ... & Chaudhuri, K. R. (2015). Neuropsychiatric symptoms and caregiver's burden in Parkinson's disease. Parkinsonism & Related Disorders, 21(6), 629-634.
61. McKeith, I. G., & Burn, D. (2000). Spectrum of Parkinson's disease, Parkinson's dementia, and Lewy body dementia. Neurologic Clinics, 18(4), 865-883.
62. Muslimovic, D., Post, B., Speelman, J. D., & Schmand, B. (2005). Cognitive profile of patients with newly diagnosed Parkinson disease. Neurology, 65(8), 1239-1245.
63. Naismith, S. L., Pereira, M., Shine, J. M., & Lewis, S. J. (2011). How well do caregivers detect mild cognitive change in Parkinson's disease? Movement Disorders, 26(1), 161-164.
64. Nieto-Escamez, F., Obrero-Gaitán, E., & Cortés-Pérez, I. (2023). Visual dysfunction in Parkinson’s disease. Brain Sciences, 13(8), 1173.
65. Obeso, I., Casabona, E., Bringas, M. L., Álvarez, L., & Jahanshahi, M. (2012). Semantic and phonemic verbal fluency in Parkinson’s disease: Influence of clinical and demographic variables. Behavioural Neurology, 25(2), 111-118.
66. Onder, H., & Comoglu, S. (2024). Prevalence and clinical correlates of nonmotor symptoms in Parkinson’s disease in a tertiary health-care center in Turkey. Neurological Research, 46(11), 1054-1062.
67. O'Reilly, F., Finnan, F., Allwright, S., Smith, G. D., & Ben-Shlomo, Y. (1996). The effects of caring for a spouse with Parkinson's disease on social, psychological and physical well-being. British Journal of General Practice, 46(410), 507-512.
68. O'Sullivan, S. S., Williams, D. R., Gallagher, D. A., Massey, L. A., Silveira‐Moriyama, L., & Lees, A. J. (2008). Nonmotor symptoms as presenting complaints in Parkinson's disease: a clinicopathological study. Movement Disorders, 23(1), 101-106.
69. Ou, Z., Pan, J., Tang, S., Duan, D., Yu, D., Nong, H., & Wang, Z. (2021). Global trends in the incidence, prevalence, and years lived with disability of Parkinson's disease in 204 countries/territories from 1990 to 2019. Frontiers in Public Health, 9, 776847.
70. Pinquart, M., & Sörensen, S. (2003). Differences between caregivers and noncaregivers in psychological health and physical health: a meta-analysis. Psychology and Aging, 18(2), 250.
71. Poewe, W., Seppi, K., Tanner, C. M., Halliday, G. M., Brundin, P., Volkmann, J., ... & Lang, A. E. (2017). Parkinson disease. Nature Reviews Disease Primers, 3(1), 1-21.
72. Prakash, K. M., Nadkarni, N. V., Lye, W. K., Yong, M. H., & Tan, E. K. (2016). The impact of non‐motor symptoms on the quality of life of Parkinson's disease patients: a longitudinal study. European Journal of Neurology, 23(5), 854-860.
73. Rissardo, J. P., & Caprara, A. L. F. (2023). Risk factors for Parkinson’s disease dementia. Annals of Movement Disorders, 6(3), 156-159.
74. Rocca, W. A. (2018). The burden of Parkinson's disease: a worldwide perspective. The Lancet Neurology, 17(11), 928-929.
75. Schulz, R., & Beach, S. R. (1999). Caregiving as a risk factor for mortality: the Caregiver Health Effects Study. Jama, 282(23), 2215-2219.
76. Stella, F., Banzato, C. E., Quagliato, E. M. B., Viana, M. A., & Christofoletti, G. (2009). Psychopathological features in patients with Parkinson's disease and related caregivers' burden. International Journal of Geriatric Psychiatry: A journal of the psychiatry of late life and allied sciences, 24(10), 1158-1165.
77. Thommessen, B., Aarsland, D., Braekhus, A., Oksengaard, A. R., Engedal, K., & Laake, K. (2002). The psychosocial burden on spouses of the elderly with stroke, dementia and Parkinson's disease. International Journal of Geriatric Psychiatry, 17(1), 78-84.
78. Uc, E. Y., Rizzo, M., Anderson, S. W., Sparks, J., Rodnitzky, R. L., & Dawson, J. D. (2006). Impaired visual search in drivers with Parkinson's disease. Annals of Neurology, 60(4), 407-413.
79. Xia, R., & Mao, Z. H. (2012). Progression of motor symptoms in Parkinson’s disease. Neuroscience Bulletin, 28, 39-48.
80. Wang, H. Y., Ren, L., Li, T., Pu, L., Huang, X., Wang, S., ... & Liang, Z. (2022). The impact of anxiety on the cognitive function of informal Parkinson’s disease caregiver: evidence from task-based and resting-state fNIRS. Frontiers in Psychiatry, 13, 960953.
81. Watson, G. S., & Leverenz, J. B. (2010). Profile of cognitive impairment in Parkinson's disease. Brain Pathology, 20(3), 640-645.
82. Williams-Gray, C. H., Evans, J. R., Goris, A., Foltynie, T., Ban, M., Robbins, T. W., ... & Barker, R. A. (2009). The distinct cognitive syndromes of Parkinson's disease: 5 year follow-up of the CamPaIGN cohort. Brain, 132(11), 2958-2969.
83. Woollacott, M., & Shumway-Cook, A. (2002). Attention and the control of posture and gait: a review of an emerging area of research. Gait & Posture, 16(1), 1-14.
84. Yang, Y., Tang, B. S., & Guo, J. F. (2016). Parkinson’s disease and cognitive impairment. Parkinson’s Disease, 2016(1), 6734678.
85. Yilmaz, F. T., Celik, S., Anataca, G., & Sakar, E. M. (2023). Associations of nonmotor symptom burden, activities of daily living, and fear of falling in Parkinson disease. Journal of Neuroscience Nursing, 55(4), 137-142.
86. Zaman, V., Shields, D. C., Shams, R., Drasites, K. P., Matzelle, D., Haque, A., & Banik, N. L. (2021). Cellular and molecular pathophysiology in the progression of Parkinson’s disease. Metabolic Brain Disease, 36, 815-827.