First introduced in the 1950s, thalamotomy is an invasive procedure, primarily effective for tremors such as those associated with Parkinson's Disease

Parkinson's disease

Parkinson's disease is a degenerative disorder of the central nervous system...

 (PD), where a selected portion of the thalamus

Thalamus

The thalamus is a midline paired symmetrical structure within the brains of vertebrates, including humans. It is situated between the cerebral cortex and midbrain, both in terms of location and neurological connections...

 is surgically destroyed (ablated). Neurosurgeons use specialized equipment to precisely locate an area of the thalamus, usually choosing to work on only one side (the side opposite that of the worst tremors). Bilateral procedures are poorly tolerated because of increased complication and risk, including vision and speech problems. The positive effects on tremor are immediate. Other less destructive procedures are preferred, such as subthalamic deep brain stimulation

Thalamic stimulator

A thalamic stimulator is a relatively new medical device that can suppress tremors, such as those caused by Parkinson's Disease or essential tremor. It was approved for use by the Food and Drug Administration on August 4, 1997. Installation is invasive, so it is typically only used when the...

(DBS), since this procedure can also improve tremor and other symptoms of PD.