CMS is considering a national coverage determination for bilateral deep brain stimulation of the subthalamic nucleus or the globus pallidus interna for treatment of essential tremors in advanced Parkinson's disease patients. Now the Medicare Coverage Issues manual states only that Medicare coverage of deep brain stimulation by an implanted stimulator device "is not prohibited," and allows individual carriers to cover the procedure at their discretion. The move closely follows a Jan. 14, 2002, statement by the FDA approving the Medtronic Activa Parkinson's control therapy system for bilateral stimulation of the internal globus pallidus or the subthalamic nucleus for adjunctive therapy to reduce symptoms of advanced, levodopa-responsive Parkinson's disease unresponsive to medication. A CMS panel met on June 12 to discuss the issue, although a decision has yet to be announced. A favorable decision would ensure Medicare reimbursement for surgeons implanting bilateral brain stimulation devices for Parkinson's patients.