Parkinson's disease is a neurodegenerative disorder characterized by motor and nonmotor deficits majorly caused by the loss of dopaminergic cells in the Substantia Nigra pars compacta (SNc) as well as the destruction of nigrostriatal pathway. Despite the numerous advances in cutting-edge approaches for the treatment or prevention of PD, there still exists some obstacles that have incapacitated the definitive treatment of this disease.
New therapeutic strategies have emerged over recent years to treat PD, including gene- and stem cell- based therapies, targeted delivery of neurotrophic factors, and brain stimulation techniques such as Transcranial Magnetic Stimulation (TMS), transcranial Direct Current Stimulation (tDCS), and Deep Brain Stimulation (DBS).
The review covers various gene therapy strategies including Adeno-Associated Virus-Glutamic Acid Decarboxylase (AAV-GAD), AAV-Aromatic L-Amino Acid Decarboxylase (AAV-AADC), Lenti-AADC/Tyrosine Hydroxylase/Guanosine Triphosphate- Cyclohydrolase I (Lenti-AADC/TH/GTP-CH1), AAV-Neurturin (AAV-NRTN), α-Synuclein silencing, and PRKN gene delivery. The review also covers the advantages and disadvantages of these treatments along with the results of relevant trials. With many advances in treatments for PD, there still exist some hurdles that have resulted in treatment failure; the reasons for failure of treatment were described, with hope separated from hype.