<unk>  (; ) is a surgical procedure in which an opening is made into the thalamus to improve the overall brain function in patients. First introduced in the 1950s, it is primarily effective for tremors such as those associated with Parkinson's disease, where a selected portion of the thalamus 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 complications and risk, including vision and speech problems. The positive effects on tremors are immediate. Other less destructive procedures are sometimes preferred, such as subthalamic deep brain stimulation, since this procedure can also improve tremors and other symptoms of PD.
Thalamotomy
Corpus callosotomy
Ventriculotomy 
Ventriculostomy
Amygdalotomy
Endoscopic third ventriculostomy
Bilateral cingulotomy
Cerebrospinal fluid diversion