Study on Deep brain Stimulation and Parkinson Disease: A review

Parkinson’s disease (PD) has evolved from an era of limited understanding and desperate measures in the 1930s and 1940s to the present, where it affects over 10 million individuals globally as a progressive neurodegenerative movement disorder. In the early stages, little was known about the causes or treatments for PD, leading to extreme measures such as ablating different regions of the neuraxis in hopes of improving patients' lives. While this approach resulted in common morbidity and mortality, some patients experienced improved motor signs with lesions affecting the basal ganglia or thalamus. The discovery of L-dopa marked the onset of medical therapy, overshadowing surgical interventions. However, issues like drug-induced dyskinesia and motor fluctuations associated with medical treatment prompted a resurgence of interest in surgical therapies. Concurrently, studies in monkeys, coupled with the development of a monkey model of PD using the neurotoxin MPTP, contributed significantly to understanding the functional organization of the basal ganglia. This knowledge paved the way for characterizing physiological changes in the basal ganglia in PD and proposing models of basal ganglia function and dysfunction. These foundational studies provided the scientific basis for reviving procedures like pallidotomy and the subsequent emergence of deep brain stimulation (DBS). This paper outlines the evolution of monkey studies, their role in unraveling the pathophysiology of PD, their contribution to the rationale for surgical procedures, and their instrumental role in advancing surgical therapies for treating PD.