What is the current usage of deep brain stimulation?

Parkinson's disese: In certain cases of pd when the medications previously helpful are no longer beneficial and are in fact causing major side effects (such as chorea like movements) putting a deep brain stimulator may help.

PD,ET,Dystonia,OCD: Dbs is fda approved in the United States for parkinson's disease, essential tremor, dystonia, and obsessive compulsive disorder. Dystonia and obsessive compulsive disorder treatment require a humanitarian device exemption (hde).