Deep Brain Stimulation of the Ventral Intermediate Nucleus of the Thalamus for Control of Tremors in Parkinson’s Disease and Essential Tremor

Abstract

The beneficial effects of ventral intermediate nucleus (VIM) stimulation were evaluated in 20 patients with tremor refractory to medical therapy. Thalamic stimulation is a non-ablative procedure which has the advantage of a reversible, non-destructive lesion. Eleven patients [7 with Parkinson’s disease (PD) and 4 with essential tremor (ET)] received unilateral VIM implantation, while 9 patients had staged bilateral VIM implantation (4 with PD, 5 with ET). PD patients showed a significant improvement in contralateral arm and leg rest tremor and ipsilateral leg rest tremor (p < 0.02) at a mean follow-up period of 16.2 ± 7.0 months. Patients with PD did not demonstrate any significant decrease in medication use at follow-up. ET patients demonstrated significant improvement in postural and action tremor in the contralateral arm (p < 0.001), but no significant improvement in the contralateral leg tremor at follow-up. Significant improvements were also seen in ET patients in the Clinical Rating Scale for Tremor (p < 0.001) with respect to several activities of daily living at a mean follow-up of 14.9 ± 8.1 months. Deep brain stimulation is a safe and effective treatment for severe tremor refractory to medications. It is a highly effective, reversible, adaptable, and predictable procedure which avoids the complication of cognitive deficit seen in patients with bilateral thalamotomies.

Effects on cognition and quality of life with unilateral magnetic resonance–guided focused ultrasound thalamotomy for essential tremor

“…1,9,26,30,35,41 Despite their delivered improvement in tremor, these therapeutic modalities are often accompanied by adverse effects on speech or language. Recently, a meta-analysis demonstrated that speech difficulty occurred in 19.8% of patients after RF thalamotomy and 19.4% after DBS.…”

Deep Brain Stimulation and Tremor

“…There have been multiple reports of the benefits of DBS of the Vim of the thalamus for the treatment of ET. 7,[11][12][13][14][15][16][17][18][19][20][21][22][23][24] Table 1 summarizes selected long-term studies of Vim DBS for ET. The first North American multicenter study 11 of unilateral DBS of the thalamus in 29 ET patients demonstrated a significant improvement in contralateral hand tremor of approximately 60% and an improvement of between 43% and 68% in activities of daily living such as writing, drawing and pouring, 3 and 12 months after surgery.…”

Intracranial Applications of Magnetic Resonance-guided Focused Ultrasound

“…DBS is a nonablative alternative to thalamotomy, and involves the insertion of stimulating electrodes into the Vim, which are then connected to an implanted pulse generator. Both RF thalamotomy and DBS are highly effective in treating ET, with tremor control rates approaching 80-90 % [37,38,44,45]. DBS can be performed bilaterally, whereas thalamotomy is typically restricted to one side.…”