Congratulations to Drs. Wissam Deeb and Michael Okun on the publication of “Deep Brain Stimulation Management of Essential Tremor with Dystonic Features,” in the June issue of Tremor and Other Hyperkinetic Movements.
A 64-year-old female with essential tremor (ET) presents for evaluation of deep brain stimulation (DBS) candidacy. Examination revealed subtle dystonic features as well as a disabling postural-action tremor.
Can dystonia occur in the setting of the diagnosis of ET and can its presence alter DBS target selection?
Unilateral DBS implantation of the ventralis intermedius (Vim) led to improvement in both tremor and dystonic posturing.
Gap in Knowledge
Case reports of DBS in dystonic tremor suggest Vim, globus pallidus internus (GPi), and subthalamic targets may all be effective, to varying degrees, in improving both tremor and dystonia. More rigorous studies are needed to identify the optimal target(s).
This case underscores the limited evidence available to guide a clinician’s choice of DBS targets in patients with ET and dystonia. The severity of the dystonia and the presence of more generalized dystonia may alter the thinking about optimal targeting. Vim, GPi, and subthalamic targets appear potentially acceptable options, though Vim is usually the first target attempted when postural-action tremor is the chief complaint. Occasionally, a second rescue DBS lead may be necessary.