HYDERABAD: Every year, we celebrate April 11 as World Parkinson’s Day. Parkinson’s disease (PD) is one of the most common neurological disorders, affecting approximately 1% of individuals older than 60 years and causing progressive disability that can be slowed, but not halted, by treatment. The incidence of Parkinson’s disease has been estimated to be 4.5-21 cases per 100,000 population per year, and estimates of prevalence range from 18 to 328 cases per 100,000 population. The incidence and prevalence of PD increase with age, and the average age of onset is approximately 60 years and it is about 1.5 times more common among men than among women.
Etiology
Most cases of Parkinson’s disease are hypothesised to be due to a combination of genetic and environmental factors. However, no environmental cause has yet been proven. A known genetic cause can be identified in approximately 10% of cases, and these are more common in younger-onset patients.
Environmental causes
Environmental risk factors commonly associated include use of pesticides, living in a rural environment, consumption of well water, self injection with MPTP, exposure to herbicides, and proximity to industrial plants or quarries.
Genetic factors
Genetic factors appear to be very important when the disease begins at or before 50 years. A total of 18 loci in various genes have now been proposed. Mutations within six of these loci (SNCA, LRRK2, PRKN, DJ1, PINK1, and ATP 13A2) are well-validated causes of familial parkinsonism.
Diabetes
In a large cohort study, researchers found that individuals with type 2 diabetes had a 32% increased risk of developing PD later than those without diabetes. The relative increase was greater in patients with diabetic complications and in younger individuals with Type 2 diabetes aged between 25 and 44 years.
Treatment
Symptomatic anti-Parkinson medications usually provide good control of motor signs for 4-6 years. After this, disability often progresses despite best medical management, and many patients develop long-term motor complications, including fluctuations and dyskinesias.
Deep brain stimulation(DBS)
DBS has become the surgical procedure of choice for Parkinson disease for the following reasons:
It does not involve destruction of brain tissue
It is reversible
It can be adjusted as the disease progresses or adverse events occur
Bilateral procedures can be performed without a significant increase in adverse event
The writer is a consultant neurologist at KIMS Hospitals. (The views expressed in this column are the writer’s own).