Subthalamic Nucleus Deep Brain Stimulation for Dystonia: Evidence, Pros and Cons

Abstract

The primary target for deep brain stimulation (DBS) for medication refractory dystonia has traditionally been the globus pallidus internus (GPi), however alternate targets have also been explored with the hope they might offer similar or superior outcomes with less side effects and reduced battery demands. Recent studies have shown comparable outcomes with both pallidal and subthalamic (STN) DBS, although the level of evidence is still superior for the GPi. There may not be an “optimal target” for all dystonia patients, with both targets offering the potential for excellent control of dystonia but more comparison studies are needed. In this review, we will discuss the history, efficacy, as well as target specific benefits and possible side effects of STN DBS for dystonia.

Engaging dystonia networks with subthalamic stimulation

“…The potential of subthalamic stimulation for treatment of dystonia has been previously demonstrated 15 , 16 , 63 , and our study now provides neuroimaging evidence underlying improvement and consistency of optimal stimulation sites. We discover a differential mapping of neural substrates mediating stimulation effects on dystonic symptoms that occur in limbs and eyes vs. cervical / axial presentation.…”

“…and adjacent white matter), while generalized and periocular manifestations would respond better to activating distal contacts (within the STN). During STN-DBS programming, one should consider possible provocations of affective symptoms 77 and dyskinesias 63 , 78 . The latter might be resolved by a slower increase in the stimulation amplitude and selection of dorsal contacts 78 , 79 .…”

“…Namely, secondary limb dystonia has been linked to incidental basal ganglia lesions 25,30 . For secondary blepharospasm, a preferential lesion localization was not observed 25,61 , however, both subthalamic and pallidal stimulations were shown to be effective in the symptom reduction 62,63 . These findings are now corroborated by the present results showing that alleviation of dystonias occurring in effectors (such as limbs and periocular region) is associated with the subthalamic circuitry accessed via the STN proper, as well as hyperdirect and indirect pathways , ( Figs.…”