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Parkinson’s Disease

Parkinson’s disease is the second most common neurodegenerative disease in the world (1). Approximately 23,500 people aged 40 and older were affected by this disease in Quebec in 2019 (2). Across Canada, about 100,000 people had the disease in 2021, and this number could reach 163,000 by 2031 (3-4). The average age of diagnosis is between 60 and 65 years.
This disease is characterized by the progressive loss of dopaminergic neurons in areas of the brain associated with movement. This loss is due to a toxic accumulation of a protein, alpha-synuclein, within these neurons. The symptoms of the disease are diverse and can be divided into two main groups:

Motor Symptoms: The disease is typically diagnosed upon the onset of these symptoms. It is estimated that 50% of dopaminergic neurons are lost at the time of the first diagnosis. These symptoms often begin with resting tremors in the extremities (such as fingers and hands) and progress to body stiffness and slowness of movement (6-7).

Non-motor Symptoms: These symptoms often appear in the early stages of the disease and may include loss of smell (5), constipation, fatigue, and sleep disturbances.

Parkinson’s disease is multifactorial, meaning it can have genetic and/or environmental origins. Certain genes have been identified as being linked to the disease (8). Additionally, exposure to pesticides may promote the accumulation of alpha-synuclein protein involved in the disease.To date, there is no curative treatment for Parkinson’s disease. Current treatments aim to maintain dopamine levels in the brain to reduce motor symptoms. The most commonly used medication is levodopa, developed in the 1960s. However, long-term use may lead to side effects such as dyskinesias (abnormal involuntary movements).
Alternative treatments, such as deep brain stimulation (DBS) (9), may be offered to certain patients. This method can reduce or even eliminate motor symptoms.
Research on Parkinson’s disease is active, with efforts to develop new approaches such as protecting dopaminergic neurons and reducing alpha-synuclein accumulation (10). Other studies focus on replacing lost dopaminergic neurons through grafts (11).


The city of Quebec is well-represented in Parkinson’s disease research, with research centers and renowned researchers such as Professors Martin Parent, Martin Lévesque at the CERVO Research Center, and Francesca Cicchetti at the CHUL Research Center. An initiative, the Parkinson Quebec Network, connects patients and researchers for research projects.

Credits: Charles Gora, doctoral student, CERVO brain research centre

Useful Links:
• Réseau Parkinson Québec
• Parkinson Québec
• Parkinson Canada
• World Parkinson Coalition

  1. AW Willis, E Roberts, J C Beck, B Fiske,WRoss, R Savica, S K Van Den Eeden, CMTanner, C Marras, Roy Alcalay, Michael Schwarzschild, Brad Racette, Honglei Chen, Tim Church, Bill Wilson, James M Doria, and on behalf of the Parkinson’s Foundation P4 Group. Incidence of Parkinson disease in North America. npj Parkinson’s Disease, 8(1) :170, 2022.
  2. Site web parkinson Québec et parkinson Canada rapport de 2022
  3. Agence de la santé publique du Canada. Canadian Chronic Disease Surveillance System (CCDSS), Data Tool 2000–2016, 2018 Edition. Ottawa (ON) : Agence de la santé publique du Canada ; 2019.)
  4. POHEM – affections neurologiques (Statistique Canada et Agence de la santé publique du Canada). Tableau 3-5 : Prévalence projetée, selon l’affection neurologique sélectionnée, Canada, 2011, 2016, 2021, 2026 et 2031, Projet – Microsimulation, idem, p. 72.
  5. Antje Haehner, Thomas Hummel, and Heinz Reichmann. Olfactory Loss in Parkinson’s Disease. Parkinson’s Disease, 2011 :450939, 2011.
  6. A J Hughes, S E Daniel, L Kilford, and A J Lees. Accuracy of clinical diagnosis of idiopathic Parkinson’s disease: a clinico-pathological study of 100 cases. Journal of neurology, neurosurgery, and psychiatry, 55(3) :181–184, mar 1992
  7. J. Jankovic. Parkinson’s disease: Clinical features and diagnosis. Journal of Neurology, Neurosurgery and Psychiatry, 79(4) :368–376, 2008
  8. Suzanne Lesage and Alexis Brice. Parkinson’s disease: from monogenic forms to genetic susceptibility factors. Human molecular genetics, 18(1) :48–59, apr 2009
  9. Balachandar A, Phokaewvarangkul O, Fasano A. Closed-loop systems for deep brain stimulation to treat neuropsychiatric disorders. Expert Rev Med Devices. 2024 Dec;21(12):1141-1152. doi: 10.1080/17434440.2024.2438309. Epub 2024 Dec 10. PMID: 39644189
  10. Castonguay AM, Gravel C, Lévesque M. Treating Parkinson’s Disease with Antibodies: Previous Studies and Future Directions. J Parkinsons Dis. 2021;11(1):71-92. doi: 10.3233/JPD-202221. PMID: 33104039; PMCID: PMC7990466
  11. Cha Y, Park TY, Leblanc P, Kim KS. Current Status and Future Perspectives on Stem Cell-Based Therapies for Parkinson’s Disease. J Mov Disord. 2023 Jan;16(1):22-41. doi: 10.14802/jmd.22141. Epub 2023 Jan 12. PMID: 36628428; PMCID: PMC9978267.
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