Purpose: To assess clinical efficacy of deep brain stimulation (DBS) of the pallidum in Myoclonus-Dystonia (M-D) patients, and to compare pre- and post-operative striatal dopamine D2 receptor availability.
Methods: Clinical parameters were scored using validated rating scales for myoclonus and dystonia. Dopamine D2 receptor binding of three patients was studied before surgery and approximately 2 years post-operatively using 123-I-iodobenzamide Single Photon Emission Computed Tomography. Two patients who did not undergo surgery served as controls.
Results: Clinically, the three M-D patients improved 83, 17, and 100%, respectively on the myoclonus rating scale and 78, 23, and 65% on the dystonia rating scale after DBS. Dopamine D2 receptor binding did not change after surgery. In the two control subjects, binding has lowered further.
Conclusion: These findings confirm that DBS of the pallidum has beneficial effects on motor symptoms in M-D and suggest this procedure might stabilize dopamine D2 receptor binding.
Keywords: DBS; IBZM-SPECT; dystonia; myoclonus.