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 The surgical treatment of Parkinson's disease and other movement disorders can be dated back to the early 1940s when Meyers performed destructive lesions in the basal ganglia, deep structures in the brain. The results of these ablative procedures evolved over the next 20-30 years with the advent of stereotaxis. However, once L-dopa become available, the number of surgeries declined significantly for several years. As the long-term adverse effects of L-dopa therapy such as dyskinesias and motor fluctuations surfaced, interest in surgical treatments returned. Laitinen reexplored Leksell's posteroventral pallidotomy leading to a resurgence in the early 1990s. Also during this time, attention was shifted from lesioning toward placing stimulators (DBS) in the thalamus (Vim) and pallidum (GPi). High frequency stimulation (>100Hz) during physiologic localization of specific thalamic nuclei demonstrated marked tremor suppression. However, the first therapeutic usage of electrical stimulation in deep brain structures dates back to the 1950s when Heath implanted electrodes to treat chronic pain. In 1987 Benabid demonstrated that DBS placed in the Vim was highly effective in alleviating various forms of medically refractory tremor including parkinsonian tremor, essential tremor, and intention tremor. In 1995 Vim-DBS gained approval in Europe, Canada, and Australia to treat tremor in PD and ET. The FDA gave its approval in 1997. click on image to enlarge 
Two decades ago, neurologist Mahlon DeLong recognized that a deficiency
of dopamine makes certain areas of the brain fire off excessive electrical
energey and cause motor disorders. That observation laid the groundwork
for new surgical treatments for Parkinson's disease. As further understanding
of the pathophysiology of the basal ganglia evolved after the development
of the primate model for PD with the discovery of the neurotoxin, MPTP,
lesioning and stimulation of deep structures such as GPi and STN predominated.
In 1998 in Europe, Canada, and Australia approved GPi-DBS and STN-DBS
as a therapy for not only tremor of PD, but also all cardinal symptoms
of PD such as rigidity, bradykinesia, and dyskinesias. Recently, in January
2002, the FDA extended the use of DBS to treat medically refractory PD.
With the advancements in surgical technique and improved physiologic and
radiographic targeting, DBS has evolved to be a safe and efficacious therapy
for patients with refractory forms of PD and tremor. Benefits of DBS over
lesioning procedures include reversibility, adjustability, and a lower
rate of permanent side effects with bilateral procedures. In the future surgical procedures for movement disorders may be carried out earlier in the course of the disease. Click here to review a discussion of this issue. |
