Parkinson’s – A disease burden for the elderly

Parkinson’s disease (PD) is the second most common progressive chronic neurodegenerative disease following Alzheimer’s disease (AD) (Gallegos et al., 2015). It affects approximated 2% of the world’s population over the age of 60 (Ouyang and Shen, 2006; Ikeda et al., 2008) and appears in two major forms, familial and sporadic, with the latter affecting nearly 90-95% of all diagnosed patients (Banerjee et al., 2014). In the United Kingdom (UK) in 2012, it was estimated that 127,000 people were affect (on average one person in every 500 is affected by PD) and is expected to increase to 162,000 by 2020 (Parkinson’s UK, 2012). The annual costs amount to £13,804, with £11,088 accounted for by in-formal care. Based on a prevalence of 168 of 100,000, the number of people in the UK with PD is around 100,000, and resulting in the total service costs £275 million, excluding informal care, and £1.4 billion, including informal care (McCrone et al., 2007). In comparison to the Western world, there is a paucity of research on PD in Asia. However, as PD is a disease of the elderly, it makes it an important concern for the health sector of Sri Lanka as it has a high proportion of the elderly population.

PD is defined as a movement disorder associated with the degeneration of dopamine neuron due to the development of motor symptoms such as resting tremor, muscle rigidity, bradykinesia and postural instability (Gallegos et al., 2015). During the early onset of PD, pre-symptomatic phase, the patient develops non-motor defect including olfactory impairment, vagal dysfunction and sleep disorders (Gallegos et al., 2015). Motor symptoms occur on degradation of 50-60% of dopaminergic neurons followed by cognitive decline on advancement of the disorder, i.e. 70-80% degradation of dopaminergic neurons. Braak et al., 2003, classified the degree of PD pathology into 6 stages.

In order to preclude the progression of PD there are various treatment available for early stages followed by enhanced disease stage therapies. A potential cure of PD is yet elusive and the most widely administered and cheaper form of treatment for PD is levodopa or a combination of dopamine agonist and monoamine oxidase inhibitors (MAOIs) such as (MAO)-B.

Deep-brain stimulation (DBS) does not eradicate the disease but according to research it indicated a distinct decrease in motor instability and loss of drug-induced dyskinesia which resulted in patients with prolonged quality of life and a decreased progression in the disorder (Pienaar et al., 2015). DBS is a functional neurosurgery which involves in delivering a constant electrical stimulation to a neural brain structure through implanted electrodes connected to an internalized neuro-pacemaker or stimulator (Benabid, 2003). It is a safe and effective surgery but with slight complications such as haemorrhage and infection with lesser being leakage of cerebrospinal fluid, erosion, lead fractures, hardware breakage, and battery failure in the generator (Godden, 2014).

Phase 3 clinical trial relative to DBS for PD sponsored by University of Minnesota, has been completed since 2009. It is mainly involved analysing the Unified Parkinson’s Disease Rating Scale (UPDRA) to analyse the effect in quality of life relative to day to day activity, behaviour and moods and complications of therapy of the patient.