Surgery for Dystonia and Tremor

Abstract

Surgical procedures for dystonia and tremor have evolved over the past few decades, and our understanding of risk, benefit, and predictive factors has increased substantially in that time. Deep brain stimulation (DBS) is the most utilized surgical treatment for dystonia and tremor, though lesioning remains an effective option in appropriate patients. Dystonic syndromes that have shown a substantial reduction in severity secondary to DBS are isolated dystonia, including generalized, cervical, and segmental, as well as acquired dystonia such as tardive dystonia. Essential tremor is quite amenable to DBS, though the response of other forms of postural and kinetic tremor is not nearly as robust or consistent based on available evidence. Regarding targeting, DBS lead placement in the globus pallidus internus has shown marked efficacy in dystonia reduction. The subthalamic nucleus is an emerging target, and increasing evidence suggests that this may be a viable target in dystonia as well. The ventralis intermedius nucleus of the thalamus is the preferred target for essential tremor, though targeting the subthalamic zone/caudal zona incerta has shown promise and may emerge as another option in essential tremor and possibly other tremor disorders. In the carefully selected patient, DBS and lesioning procedures are relatively safe and effective for the management of dystonia and tremor.

Cost‐effectiveness of focused ultrasound, radiosurgery, and DBS for essential tremor

“…Nearly 60% of ET patients are refractory to pharmacologic therapy and thus suffer significant diminution of quality of life . It is these patients who require procedural intervention . Deep brain stimulation (DBS) targeting the ventrointermediate nucleus of the thalamus is currently the intervention of choice for stereotactic neurosurgeons because of its proven efficacy, reversibility, adjustability, and durability .…”

Rescue Procedures after Suboptimal Deep Brain Stimulation Outcomes in Common Movement Disorders

“…DBS is a proven surgical treatment for dystonia refractory to medication and botulinum toxin injections, particularly primary generalized dystonia (i.e., genetic or idiopathic) [5]. This treatment received Humanitarian Device Exemption from the FDA in 2003.…”

“…The primary target has been the GPi in the majority of cases due to prior experience with lesioning therapies and the use of the target in the PD population [57]. More recent DBS cases have used the STN target as well, most commonly with focal cervical dystonia [5,58]. Some studies report up to a 60%–70% improvement on dystonia rating scales in generalized dystonia post GPi DBS [5,58,59,60,61].…”

“…The most common dystonia, cervical dystonia, does tend to have good response post DBS [62,63,64]. The responses to DBS in other types of focal or segmental dystonia are less well defined and reported less in the literature [5]. Post-surgical programming in this population can also often be challenging compared to PD and ET.…”

“…When done correctly, the efficacy of DBS is well established [5,6,7,8]. However, in some instances, even under optimal circumstances with a multidisciplinary team approach, DBS can lead to suboptimal results either immediately after the initial surgery or, later, as symptom benefit declines [9,10,11].…”