Deep Brain Stimulation
Deep brain stimulation (DBS) is a surgical procedure that involves implanting a small device, known as a neurostimulator, into the brain. This device delivers electrical impulses to specific areas of the brain that control movement, mood, and other functions. DBS is primarily used as a treatment for movement disorders such as Parkinson’s disease, essential tremor, and dystonia, but it is also being investigated as a treatment for other conditions such as depression and obsessive-compulsive disorder.
The DBS system consists of three main components: the neurostimulator, the lead (or leads), and the extension. The neurostimulator is a battery-powered device that is implanted under the skin, typically in the chest or abdomen. The lead is a thin, insulated wire implanted into the brain and connected to the neurostimulator via the extension, which is a thin wire that runs under the skin from the neurostimulator to the lead.
DBS works by interrupting abnormal electrical signals in the brain that cause movement disorders. The neurostimulator sends electrical impulses to the targeted area of the brain, which effectively “jams” the abnormal signals and restores normal brain function. The amount of stimulation is controlled by a handheld device that the patient can use to adjust the settings based on their symptoms.
DBS is typically reserved for patients who have not responded to other treatments such as medications or physical therapy. It is also not a cure for movement disorders, but rather a way to manage symptoms and improve quality of life. DBS does not damage healthy brain tissue, and the effects of the stimulation are reversible, meaning that the device can be turned off or removed if necessary. The DBS procedure involves several steps. First, the patient undergoes a series of tests, including a neurological exam, brain imaging, and psychological evaluation. This helps to determine whether the patient is a good candidate for DBS and which area of the brain to target.
Next, the patient undergoes surgery to implant the lead(s) into the brain. The surgery is typically done while the patient is awake so that the surgeon can test the effects of the stimulation in real-time. Once the lead(s) are in place, the patient undergoes a second surgery to implant the neurostimulator and extension. The patient is usually discharged from the hospital a few days after the second surgery.
DBS is generally considered safe, but like any surgery, there are risks involved. These include bleeding in the brain, infection, and problems with the device such as displacement or malfunction. There is also a small risk of personality changes or cognitive impairment, although these side effects are usually temporary and can be managed by adjusting the stimulation settings. DBS has been shown to be effective in treating movement disorders such as Parkinson’s disease, essential tremor, and dystonia.
In Parkinson’s disease, DBS can improve motor symptoms such as tremors, rigidity, and bradykinesia (slowness of movement). It can also reduce medication side effects such as dyskinesia (involuntary movements). In essential tremor, DBS can reduce or eliminate tremors that interfere with daily activities such as eating and writing. In dystonia, DBS can improve abnormal postures and movements that cause pain and disability.
DBS is also being investigated as a treatment for other conditions such as depression and obsessive-compulsive disorder (OCD). In depression, DBS targets the subcallosal cingulate gyrus, a region of the brain that is believed to play a role in regulating mood. Preliminary studies have shown promising results in patients who have not responded to other treatments such as medication and psychotherapy. In OCD, DBS targets the nucleus accumbens, a region of the brain that is involved in reward processing and motivation.