What factors have driven the rapid adoption of focused ultrasound and what role should it have in the neurosurgical management of tremor?

Relief of medically refractory tremor is one of the most gratifying functional neurosurgery procedures. Stereotactic radiofrequency (RF) ablation of the motor thalamus was introduced in the 1950s, benefiting tens-of-thousands of patients in the following decades (figure 1).1 Gamma knife (GK) lacks an immediate tremor effect to guide targeting; therefore, the advent of high-quality MRI in the 1990s was necessary before it could be used successfully for tremor.2 By then, thalamic deep brain stimulation (DBS) was available with its early reversibility and stimulation adjustment to maximise efficacy versus adverse effects.3 4 Consequently, thalamotomy was largely relegated to those who could not undergo, or could not afford, DBS.