The Development of Treatment for Parkinson’s Disease

Abstract

Parkinson’s disease (PD) is a slowly progressive, age-related, second most common neurodegenerative disorder after Alzheimer’s disease of unknown etiology. Dopamine replacement therapies were introduced five decades ago and still remain the mainstay of treatment for Parkinson’s disease. However, with long-term treatment with L-dopa, more than 50% of patients were found to develop motor response complications approximately after 4 - 5 years of initiation of continuous treatment, in 80% of patients treated for 10 years, and in nearly 100% patients with young-onset disease. The complications of long-term treatment with levodopa include-motor fluctuations, dyskinesias, and nonmotor fluctuations are such as mood disturbance, cognitive dysfunction, dysautonomia and pain. Till date, there are various therapeutic approaches having been developed for the treatment of advanced PD comprising Pharmacotherapy, neurotrophic factors, surgical procedures such as DBS, cell-based therapies and gene therapies. The pharmacological and surgical therapies are only aiming to improve the symptoms of PD, but none are proven to have a significant effect on the underlying disease process with respect to either slowing disease progression or restoring the affected dopaminergic neurons. Although there is no cure for PD, Gene based therapy has significant prospective advantages over the conventional treatment modalities for PD, as it could theoretically be used to preserve or restore dopaminergic neurons affected by PD through the action of neurotrophic factors or alternatively increase the availability of enzymes required for dopamine synthesis. All commonly employed PD therapies focus on the amelioration of symptoms and do not cure disease. In this review only we summarize the newer therapeutic strategies for the treatment of PD such as anti-inflammatories, neurotrophic factors, neurosurgical procedures (DBS), cell based therapies and gene therapies.