Data from: Longitudinal follow-up with VIM Thalamic Deep Brain Stimulation for Dystonic or Essential Tremor

Objective: To assess longitudinal tremor outcomes with ventral
intermediate nucleus deep brain stimulation (VIM DBS) in patients with
dystonic tremor (DT) and to draw comparisons with DBS outcomes in
essential tremor (ET). Methods: We retrospectively investigated VIM DBS
outcomes for 163 patients followed at our center diagnosed with either DT
or ET. The Fahn-Tolosa-Marin tremor rating scale (TRS) was used to assess
change in tremor and activities of daily living (ADL) at 6 months, 1 year,
2–3 years, 4–5 years, and ≥ 6 years after surgery. Results: Twenty-six DT
and 97 ET patients were analyzed. Compared to preoperative baseline, there
were significant improvements in TRS motor up to 4–5 years (52.2%; p =
0.032) and a tendency to improve at ≥ 6 years (46.0%, p = 0.063) in DT
which was comparable to the outcomes in ET. While the improvements in the
upper extremity tremor, head tremor, and axial tremor were also comparable
between DT and ET throughout the follow-up, the ADL improvements in DT
were lost at 2-3 years follow-up. Conclusion: Overall, tremor control with
VIM DBS in DT and ET was comparable and remained sustained at long-term
likely related to intervention at the final common node in the
pathological tremor network. However, the long-term ADL improvements in DT
did not remain sustained possibly due to inadequate control of concomitant
dystonia symptoms. These findings from a large cohort of DT indicate that
VIM targeting is reasonable if the tremor is considerably more disabling
than the dystonic features.