The long-term results of stereotaxic surgery and L-dopa therapy in patients with Parkinson's disease. A 10-year follow-up study.

Sixty patients with Parkinson's disease underwent sterotaxic surgery in Edinburgh between 1965 and 1967, and were examined every 2 years for a total follow-up period of 10 years. Although stereotaxic surgery had been extremely effective in treating tremor and rigidity, the other manifestations of Parkinson's disease were noted to progressively affect more patients at each follow-up examination. L-dopa therapy was instituted in 36 patients after 1968. The effect of L-dopa on bradykinesia was remarkable, but the long-term benefit on the other manifestations of Parkinson's disease was negligible. Furthermore in most cases L-dopa became progressively ineffective for bradykinesia after 3 to 5 years. L-dopa-induced tremor and involuntary movements were less frequently noted in limbs contralateral to the side of a previous stereotaxic procedure. It was concluded that in patients presenting with tremor and rigidity as the major problem in their parkinsonian syndrome, the most effective form of palliative therapy is stereotaxic surgery, and that L-dopa should be reserved for the management of bradykinesia.