Progressively less invasive neurosurgical approaches for the treatment of 
movement disorders have evolved, beginning with open craniotomy for placement of 
lesions within pyramidal structures followed by refined stereotactic ablation of 
extrapyramidal targets that encouraged nondestructive electrode stimulation of 
deep brain structures. A noninvasive approach using transcranial high-energy 
focused ultrasound has emerged for the treatment of intractable tremor. The 
ability to target discreet intracranial sites millimeters in size through the 
intact skull using focused acoustic energy marks an important milestone in 
movement disorders surgery. This article describes the evolution of magnetic 
resonance-guided focused ultrasound for ventrolateral thalamotomy for tremor.