Deep brain stimulation

Deep brain stimulation (DBS) is a surgical therapy used for the treatment of Parkinson’s disease (PD). During DBS surgery, a special wire, called a lead, is inserted into a specific area of the brain. The lead, which has four electrodes, delivers electrical currents to precise brain locations responsible for movement, regulating the abnormal brain cell activity that causes symptoms such as tremor and gait problems.

In DBS surgery, leads (wires with tiny electrodes) are implanted within a small and specific target area in the brain. Depending on the case, the target will be the STN, GPi, or Vim. STN or GPi are the preferred targets for improving most PD symptoms. Leads may be placed on one side of the brain (unilaterally) or both sides (bilaterally). Once the lead is placed, it is attached to a wire that runs under the scalp and just beneath the skin of the neck.

It is then connected to a pulse generator or neurostimulator. The neurostimulator is located just below the collarbone and under the skin of the chest. Similar to a pacemaker, the pulse generator delivers electricity to the lead that is implanted in the brain. The pulse generator can be either single-chamber (connects only one lead) or dual-chamber (connects two leads). The pulse generator is turned on and off by a remote control similar to the ones used for televisions.

A: No, DBS is not a cure for PD. It is a treatment that helps relieve the motor symptoms of PD, as well as some of the non-motor symptoms. It is called asymptomatic therapy; it does not change disease progression.

A: DBS can help improve the motor symptoms of PD. Typically, these are:

• Tremor, or shaking (in 80% of sufferers). Complete or partial tremor suppression
• Rigidity, or stiffness
• Bradykinesia, or slowness of movement

DBS is a powerful therapy for addressing the motor complications of PD, which are often related to medication (e.g., Sinemet and agonists):

• Dyskinesia – involuntary, irregular, writhing movement – can range from mild to violent and can sometimes be unpredictable. Dyskinesia can be particularly severe when medications are at peak levels.

• Dystonia – sustained, involuntary contraction of muscles – can lead to painful cramping of the feet or hands, curling toes, or turning and twisting of the neck. Dystonia can also in select cases be a side-effect of medications.

• “On/off” fluctuations are when a person cycles between “on” time, when the medication is working to control symptoms, and “off” time when medication has worn off and PD symptoms return. DBS helps address symptoms that respond to dopaminergic medication (e.g., Sinemet, Madopar, agonists). DBS will usually temper the degree of fluctuations experienced during “on” and “off” periods. DBS will not address dopaminergic unresponsive symptoms, such as walking, talking, and thinking issues. DBS will, however, address medication-unresponsive tremor

 DBS can also improve some non-motor symptoms, including the following: 

• Mood
• Energy level
• general sense of well-being

As a general rule, symptoms that are helped by medication will be improved by DBS.