M.D. Prior to the availability of L-dopa in the late 1960's, thalamotomy was widely employed to treat Parkinson's disease. With the introduction of L-dopa 35 years ago, which was the first drug to be effective for Parkinson's disease, few thalamotomies or pallidotomies were performed. The mainstay treatment for Parkinson's disease became medical management. For example, the effectiveness of L- dopa diminishes over time. Usually, after five years, the drug-induced dyskinesias often outweigh the benefits of continued administration.
Dyskinesias are often severe enough to be disabling.
For these reasons, and because of advances in imaging techniques and a more complete understanding of the neuro-physiological mechanism structures involved in movement disorders, the surgical management of Parkinson's disease with stereotactic intervention is now much more frequently recommended than just two to three years ago. For a short time, adrenal gland transplantation into the caudate nucleus was thought to be an effective treatment for Parkinson's disease. Today, thalamotomy is considered to provide the best relief for tremor, when tremor is the most troublesome aspect of the disease. Thalamotomy is less effective for bradykinesia and dyskinesias. When thalamotomy is employed, approximately 85 percent to 90 percent of patients have relief of tremor, while only about 50 percent have improvement of rigidity and bradykinesia.