Therapies for Parkinson's diseases: alternatives to current pharmacological interventions

Parkinson's disease (PD) is the second most common neurodegenerative disorder caused by the selective and progressive loss of dopaminergic neurons in the substantia nigra pars compacta. Although PD has been heavily researched, the precise etiology and pathogenesis for PD are still inconclusive. Consequently, current pharmacological treatments for PD are largely symptomatic rather than preventive and there is still no cure for this disease nowadays. Moreover, nonmotor symptoms caused by intrinsic PD pathology or side effects induced by currently used pharmacological interventions are gaining increasing attention and urgently need to be treated due to their influence on quality of life. As ancient traditional healing systems, Tai Chi, Yoga, acupuncture and natural products have long been considered as complementary or alternative therapeutic options for PD. Recently, several newly developed non-pharmacological therapeutic strategies, including deep brain stimulation, repetitive transcranial magnetic stimulation, near-infrared light, gene therapy and cell replacement therapy, have also been suggested to give benefits to relieve parkinsonian symptoms. This review will summarize and update the therapeutic potential and the most recent research progresses of these traditional and modern therapeutic options and highlight their clinical meaning for the therapy of not only PD but also other neurodegenerative diseases.