Despite a paucity of controlled data, stereotactic pallidotomy is incr
easingly used for the treatment of advanced Parkinson's disease (PD).
To study the efficacy of the procedure on the cardinal PD features of
rigidity, tremor, bradykinesia, and postural instability, we blindly r
ated randomized videos of 34 patients recorded in the ''off'' state im
mediately before and 3 months after unilateral stereotactic lesioning
of the globus pallidus internus. Total ''off' time Unified Parkinson's
Disease Rating Scale motor scores improved 13.6% from 28.9 +/- 7.5 to
25.0 +/- 7.0 (p < 0.001). Particularly robust improvement was seen in
contralateral tremor, gait, and arising from a chair (p < 0.001). Sig
nificant improvement was also seen in ipsilateral tremor, contralatera
l and some ipsilateral dexterity measures, and body bradykinesia. Most
other features tended toward improvement but did not reach statistica
l significance. We conclude that pallidotomy is a safe and effective t
reatment of parkinsonian symptoms, many of which improve bilaterally.