Deep brain stimulation (ECP) is a reversible therapy that involves the placement of a thin electrode in the brain (the place depends on the pathology that we want to treat), which is connected by means of an extension to a small device called neurostimulator (quite similar to a pacemaker), which is usually implanted under the skin of the chest or in the abdominal region.
It is a fully implantable system, so patients will not see the electrodes or the neurostimulator outside their body. When the neurostimulator is activated, it produces electrical impulses that reach the brain to stop or reduce the electrical signals that cause the symptoms of various diseases.. If the patient stops benefiting from the therapy, the system can be turned off or withdrawn. Currently the ECP is approved in Europe for Parkinson's disease, essential tremor, dystonia, Obsessive Compulsive Disorder and Epilepsy.
The candidate for this treatment
One of the most important aspects in the success of this therapy is the adequate selection of the patient. In the case of Parkinson's disease, neurologists consider ECP therapy in the case of patients who, despite optimal medical treatment, begin to experience significant disability because symptoms such as motor fluctuations (i.e. called "off" periods) and dyskinesias interfere with their normal daily activities (such as holding a cup or walking), as well as in those patients in whom the medication is associated with intolerable side effects. Not all patients with PD are candidates for ECP.
Only a team consisting of a neurologist in collaboration with a neurosurgeon, a neuropsychologist and a nurse can determine if a patient is a candidate for this type of surgery.
Characteristics of the intervention
The duration of the operation depends on the experience of the team. The operation usually lasts between 4 and 6 hours. The first part of the procedure, during which the electrodes are placed in the brain, can be performed under general anesthesia or with a local anesthetic applied to the area of the scalp at the insertion sites of the electrodes.. This part of the intervention is performed with very advanced technology to place the electrodes exactly in the part of the brain where they are needed.
During the second part of the operation, the neurostimulator is implanted in the chest or abdominal region and connected to the electrodes with a thin extension cable located under the skin, so that the therapy is invisible. During this phase, patients are under general anesthesia.
After the operation they should stay a short time in the hospital (1-4 days) to recover from the operation. Depending on the hospital, the neurostimulator will be scheduled immediately or after a couple of weeks. In any case, this programming will always be adjusted to the patient's medical needs.
Control of the intensity of the impulses
There is a doctor programmer that allows to make variations in the configuration of the stimulation parameters to optimize the effects of the therapy. Patients also have a patient programmer that allows them to see the state of the stimulator battery. If the doctor deems it appropriate, he will be able to program pulse intensity ranges so that the patient can raise or lower the intensity always within the range established by the doctor.
Follow-up schedule visits are required to adjust stimulation and medication, if necessary. The number of follow-up visits often decreases after the first year after the operation, but no criteria have been agreed regarding the frequency. Patients are advised to contact the ECP center whenever necessary.
Benefits of deep brain stimulation
Depending on the pathology we are treating, we will have different benefits. In the case of Parkinson's disease, where the use of CPE is more widespread, there is an average improvement in motor symptoms that is between 50-70% with an additional 5.1 hours per day in the "on" period compared to pharmacological treatment alone, providing longer periods during the day in which patients do not suffer the motor symptoms of Parkinson's disease. This improvement helps many patients to normalize normal daily activities and significantly improves their quality of life.