DBS can substantially improve arm tremor (e.g. by over 80%) and, to a lesser extent, midline tremor such as voice and head tremor (e.g. by 50%). DBS can thereby improve function such as eating, drinking and writing. DBS can reduce or eliminate the need to take anti-tremor medication.
DBS is not a cure for tremor and tremor returns when stimulation is switched off. However the benefits of DBS usually persist, as long as stimulation continues (although we recommend turning off stimulation at night to avoid the small chance that stimulation may ‘wear off’ with time).
The major target for tremor is a zone encompassing the motor thalamus (VOP/VIM) and beneath (posterior subthalamic area). We target both regions in a single trajectory and choose the most effective location for the individual.
Side effects include slurred speech, imbalance when walking and a tingling sensation. These side effects (if they occur) often reduce over time – and usually disappear when stimulation is turned down or switched off. Occasionally, a compromise may be necessary between the level of stimulation and any side effect.
Overall, DBS for arm and leg tremor is usually very effective and can substantially improve function. DBS for head and voice tremor is usually incomplete. Side effects, if they occur, are typically temporary or can be reversed by reducing stimulation.