Idiopathic Parkinson Disease: Etiology, Epidemiology

00:01 In this talk, let's review idiopathic Parkinson's disease.

00:07 Let's start with some epidemiology.

00:09 idiopathic Parkinson's disease or idiopathic PD is one of the most common neurodegenerative disorders.

00:15 It has an annual incidence of 4 to 21 cases per 100,000, and that's pretty common.

00:21 You may know an individual who has been affected or have idiopathic PD, it's one of those things that we frequently see in the clinic and shows up on test questions.

00:31 The mean age of onset is 60 years, there are some early onset cases or early onset Parkinson's disease, as well as later onset disease.

00:41 And the lifetime risk is about 2% for men, and slightly younger for women 1.3%.

00:48 What are the etiologies, or their causes of idiopathic Parkinson's disease that we should be aware of? Well, this is a little bit unclear, there are some risk factors that are environmental, but those likely interact polygenetically with underlying genetic risk factors and here's a few things I'd like for you to remember.

01:06 There are some risk factors for the development of idiopathic Parkinson's disease.

01:11 Studies support that exposure to pesticides, nitrogen dioxide and history of traumatic brain injury do increase the likelihood or the potential of subsequently developing idiopathic PD.

01:23 Exposure to certain solvents can also increase the risk as well as living in various areas, although those data are more controversial.

01:33 In addition, living in close proximity to industrial plants has been reported in the literature.

01:38 Well, water drinking MPTP is probably the most important occupational exposure or risk factor for the development of Parkinson's disease.

01:48 And in the lab when we're studying Parkinson's disease, we look at MPTP models.

01:54 Excessive body weight has unclear association as well as type II diabetes.

02:01 Other genetic risk factors does indeed increase the risk of developing idiopathic PD and account for the minority of cases.

02:08 In general, idiopathic PD is a polygenetic condition.

02:12 There's not one specific gene, but a few rare cases can be seen.

02:17 These genes include the alpha-synuclein gene and abnormalities of that gene, LRRK2 PARK2 and PINK1.

02:25 And again, these are present in the minority of patients that develop idiopathic PD.

02:29 The vast majority of patients have some underlying polygenetic condition that cannot be determined with genetic testing and in combination with a lifetime adverse environmental exposures.