Deep brain stimulation

Deep Brain Stimulation

In neurotechnology, deep brain stimulation (DBS) is a surgical treatment involving the implantation of a medical device called a brain pacemaker, which sends electrical impulses to specific parts of the brain. DBS in select brain regions has provided remarkable therapeutic benefits for otherwise treatment-resistant movement and affective disorders such as chronic pain, Parkinson’s disease, tremor and dystonia. Despite the long history of DBS, its underlying principles and mechanisms are still not clear. DBS directly changes brain activity in a controlled manner, its effects are reversible (unlike those of lesioning techniques) and is one of only a few neurosurgical methods that allows blinded studies

The Food and Drug Administration (FDA) approved DBS as a treatment for essential tremor in 1997, for Parkinson's disease in 2002, and dystonia in 2003. DBS is also routinely used to treat chronic pain and has been used to treat various affective disorders, including major depression. While DBS has proven helpful for some patients, there is potential for serious


Components and placement


The deep brain stimulation system consists of three components: the implanted pulse generator (IPG), the lead, and the extension. The IPG is a battery-powered neurostimulator encased in a titanium housing, which sends electrical pulses to the brain to interfere with neural activity at the target site. The lead is a coiled wire insulated in polyurethane with four platinum iridium electrodes and is placed in one of three areas of the brain. The lead is connected to the IPG by the extension, an insulated wire that runs from the head, down the side of the neck, behind the ear to the IPG, which is placed subcutaneously below the clavicle or in some cases, the abdomen. The IPG can be calibrated by a neurologist, nurse or trained technician to optimize symptom suppression and control side effects

DBS leads are placed in the brain according to the type of symptoms to be addressed. For non-Parkinsonian essential tremor the lead is placed in the ventrointermedial nucleus (VIM) of the thalamus. For dystonia and symptoms associated with Parkinson's disease (rigidity, bradykinesia/akinesia and tremor), the lead may be placed in either the globus pallidus or subthalamic nucleus

All three components are surgically implanted inside the body. Under local anesthesia, a hole about 14 mm in diameter is drilled in the skull and the electrode is inserted, with feedback from the patient for optimal placement. The installation of the IPG and lead occurs under general anesthesia. The right side of the brain is stimulated to address symptoms on the left side of the body and vice versa



References

Kringelbach ML, Jenkinson N, Owen SLF, Aziz TZ (2007). "Translational principles of deep brain stimulation". Nature Reviews Neuroscience. 8:623–635. PMID 17637800




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U.S. Department of Health and Human Services.FDA approves implanted brain stimulator to control tremors. Retrieved October 18, 2006


Brain pacemaker' treats dystonia. KNBC TV, April 22, 2003. Retrieved October 18, 2006


a b National Institute of Neurological Disorders and Stroke. Deep brain stimulation for Parkinson's Disease information page. Retrieved 23 November 2006


Volkmann J, Herzog J, Kopper F, Deuschl G. "Introduction to the programming of deep brain stimulators". Mov Disord. 2002 17, S181–187. PMID 11948775


Deep brain stimulation. Surgery Encyclopedia. Retrieved January 25, 2007


Deep Brain Stimulation, Department of Neurological Surgery, University of Pittsburgh. Retrieved 13 May 2008.