Comprehensive Information About Deep Brain Stimulation (DBS) Technology

Deep brain stimulation (DBS), also known as a 'brain pacemaker' among the public, is a surgical method used in the treatment of certain neurological and psychiatric disorders. This technology aims to regulate brain activity by sending electrical stimuli through electrodes implanted in specific brain regions.

What is Deep Brain Stimulation?

Deep brain stimulation (DBS), also known as a 'brain pacemaker', is a surgical method used in the treatment of certain neurological and psychiatric disorders such as Parkinson's, tremor, dystonia, and epilepsy. This technology aims to regulate brain activity through electrodes placed in specific brain regions that send electrical stimuli. The DBS system works with electrodes placed in the disease-related brain region and a battery system connected to these electrodes. The battery is implanted under the skin in the chest area.

Which Conditions is DBS Used For?

• Movement Disorders: Parkinson's disease, essential tremor, dystonia, Huntington's disease
• Psychiatric Disorders: Obsessive compulsive disorder (OCD), Tourette syndrome, treatment-resistant depression
• Epilepsy
• Chronic Pain

How Does DBS Work?

1. Surgical Procedure: DBS surgery is generally performed in two stages. In the first stage, electrodes are placed in the targeted brain regions. In the second stage, a battery-like device (neurostimulator) implanted in the chest area sends electrical stimuli through cables connected to the electrodes.
2. Electrical Stimulation: Electrical stimuli sent by the neurostimulator help relieve symptoms by regulating abnormal neural activity in the targeted brain region.
3. Programming & Follow-up: DBS treatment is personalized. Stimulation parameters (frequency, intensity, duration) are adjusted according to the patient's needs and monitored through regular doctor check-ups.

In Which Conditions is DBS Used?

DBS can be used in the treatment of the following conditions, particularly Parkinson's disease:

• Movement Disorders: Parkinson's disease, essential tremor, dystonia
• Psychiatric Disorders: Obsessive compulsive disorder (OCD), Tourette syndrome, treatment-resistant depression
• Epilepsy
• Chronic Pain

Advantages of DBS

• Can be effective in patients who do not respond to medication or are adversely affected by its side effects.
• Can significantly reduce symptoms and improve quality of life.
• It is a reversible method, meaning stimulation can be stopped or electrodes removed if desired.
• Can reduce medication use.

When is DBS Needed in Parkinson's Patients?

When the diagnosis is made, medication treatment is initiated. In the first few years, patients may return to their pre-illness lives as if they were never sick. This period is called the 'honeymoon period.' However, as years pass, when symptoms such as tremor, freezing, rigidity, and slowness of movement can no longer be controlled despite medication, when the duration of off periods during the day increases, and when dance-like involuntary movements appear with increasing medication doses, it can be said that the time to consider DBS surgery has arrived. DBS surgery is not recommended within the first 5 years from diagnosis. The most important reason for this is that Parkinson's disease can be confused with other diseases. In such diseases, called Parkinson-plus, DBS surgeries unfortunately do not yield results as successful as they do in Parkinson's disease.

Which Parkinson's Patients May Not Be Suitable for DBS?

For DBS surgery, it is necessary that the onset of the disease dates back at least 5 years. The reason for this is that Parkinson's disease can be clinically confused with some other neurological diseases. DBS surgery is not recommended in patients who fall frequently and whose medications provide almost no benefit even for a short period of time. Moreover, in patients where falls and balance problems are particularly advanced, a slight increase in complaints may even be observed after surgery. Likewise, DBS surgery should not be performed in patients with severe psychiatric depression or serious mental disorders we call psychosis. Since grief and anxiety can occur in patients whose quality of life has declined and who lead a restricted life due to Parkinson's disease, such mild clinical psychiatric conditions do not constitute a barrier to surgery. But for the more severe psychiatric problems mentioned earlier, medication treatment should be initiated first and the surgery should be performed after the patients' psychiatric treatment is completed. Patients who had such complaints in the past and improved with psychiatric medication treatment should be closely monitored after DBS surgery. Before surgery, this information must be shared in detail with the patient and their family.

Another surgical barrier is patients whose cognitive status is behind their age. DBS surgery should not be performed in patients with signs of dementia. Additionally, DBS surgery is not appropriate in patients with other severe and uncontrolled chronic diseases. However, diseases such as hypertension, heart disease, or diabetes that are under control do not prevent the surgery.

Is There an Age Limit for DBS Surgery?

Although there is no legal age limit for DBS surgery, it is not recommended for patients over the age of 80. Until 5-10 years ago, this limit was set at 70 years of age, and more recently at 75. As long as there are no cognitive, psychiatric, or severe chronic diseases that would pose a barrier to surgery, DBS surgery can be performed on increasingly older patients day by day. However, we still recommend a more meticulous pre-surgical examination for patients in the advanced age group.

How is the Decision for DBS Surgery Made?

DBS surgeries are not procedures where a single physician makes the decision. To understand whether Parkinson's patients are suitable for surgery, we admit our patients to our DBS center for a few days. During this period, our experienced movement disorder neurologists first check whether they are receiving the most appropriate medication treatment. If necessary, we add new medications. Afterwards, detailed tests measuring the degree of Parkinson's disease are administered to our patients during their medicated and unmedicated periods — that is, during on and off periods — again by our neurologists. Based on the results of these tests, we decide whether they are neurologically suitable for surgery. If we find our patients suitable for surgery, they are then subjected to a detailed examination by our psychiatrist. To assess the dementia or cognitive status of our patients, our neuropsychologist applies detailed neuropsychological tests. Brain MRI imaging is performed on all our patients to determine whether there is a problem in the brain MRI that would prevent surgery. To rule out any condition that would constitute a barrier to surgery, a meticulous preliminary examination is also conducted by our anesthesiologist. At the end of this process, which takes approximately 3 days, we determine whether or not our patients are suitable for DBS surgery by the joint decision of the neurology, neurosurgery, and psychiatry physicians and our neuropsychologist. We inform our suitable patients of our evaluation results, explain in detail the possible beneficial effects and risks of the surgery. If they accept the DBS treatment, we discharge them with an appointment for surgery and the necessary recommendations. For patients we find unsuitable, we also explain the reasons for our decision, adjust their medication treatments, and send them home with a follow-up appointment.

How is DBS Surgery Performed?

1. Surgical Procedure: DBS surgery is generally performed in two stages. In the first stage, electrodes are placed in the targeted brain regions. In the second stage, a battery-like device (neurostimulator) implanted in the chest area sends electrical stimuli through cables connected to the electrodes.
2. Electrical Stimulation: Electrical stimuli sent by the neurostimulator help relieve symptoms by regulating abnormal neural activity in the targeted brain region.
3. Programming & Follow-up: DBS treatment is personalized. Stimulation parameters (frequency, intensity, duration) are adjusted according to the patient's needs and monitored through regular doctor check-ups.

DBS surgeries are generally performed with patients awake. There are one or two important reasons for this. Even though we surgeons perform precise calculations before surgery by looking at patients' brain MRIs, we still prefer patients to be awake in order to send the electrodes to the most accurate location in the brain. Because the areas we target are points located in deep regions of the brain and are only a few millimeters in size. If we were to place the electrodes a millimeter or two in a different location, it is not very likely that we would get the good results we expect. For this reason, in DBS surgeries we use the microelectrode recording method where we electrophysiologically record a single cell in the brain. Thanks to this technique, we can listen to and record the sound of each individual cell in the brain, and precisely locate the brain region with abnormal activity without any margin of error. We also give patients low-voltage electrical stimulation during surgery, while our neurologist examines the patient and observes the beneficial effects and possible side effects. Our patients also feel the extent to which their complaints have improved during surgery — we actually perform the surgery together with our patients, in a sense. However, some patients may feel anxious about having surgery while awake. In this case, we can also perform DBS surgeries by putting our patients to sleep but still using microelectrode recording during surgery.

What is the Process After DBS Surgery?

• After surgery, we may activate our patients' device at low voltage the next day, or we may leave it for later days depending on the patient's condition. In some patients, we may also make minor medication dose adjustments in the first days.
• We discharge our patients 5 to 10 days after surgery. Our Parkinson's nurse provides discharge education to all our patients, and we give them a brochure with written information about the precautions to be taken.
• We call our patients for check-ups at the 1st and 3rd month after surgery, adjusting medications and device settings. Generally, by the end of the 3rd month, we have been able to relatively reduce medication doses and optimize device settings for the majority of our patients.

What Should the Expectations be from DBS Treatment?

DBS treatment is truly an effective method for patients who are found suitable for this surgery as a result of the tests performed. Results are particularly encouraging for patients with complaints such as tremor, freezing, rigidity, slowness of movement, and involuntary movements. First and foremost, patients are freed from their restricted daily life. The off periods, during which patients spend most of the day immobile, shorten considerably. This provides patients with a significant freedom in their lives. We can also reduce the medication doses after surgery, freeing patients from the known side effects of Parkinson's medications. However, there are a few important points to know. DBS treatment is not a treatment that completely stops Parkinson's disease. Unfortunately, the disease continues to progress over the years. But even so, the DBS method is currently the best treatment for suitable patients. This view has been scientifically proven many times. Especially in comparative scientific studies with patients undergoing drug treatment, the superiority of DBS has been demonstrated. In other words, deep brain stimulation has actually become a patient right for those found suitable for this treatment.

What Should Patients Pay Attention to After DBS?

After DBS surgery, patients are prone to weight gain especially in the first months due to both reduced joint stiffness and increased appetite. Our dietitian provides nutritional education before surgery and during follow-up visits to prevent this. Another problem may be wound infection. To prevent this, our Parkinson's nurse provides patients with careful and detailed information during discharge. After surgery, some patients may experience temporary psychiatric complaints — in this case, we recommend that they contact our center. We strongly advise against contact sports such as football, judo, wrestling, and boxing. However, we recommend all non-contact sports. We also advise patients not to pass through X-ray devices at airports and similar places, and we provide them with a document stating that they carry a brain pacemaker.

Is Battery Replacement Needed? How Long Does the Battery Last?

We can say the average battery life is approximately 5 years. This period may be longer in some patients and shorter in others depending on the electrical stimulation delivered. When the battery life decreases, an increase in patients' complaints is observed. Sometimes our patients do not take these increases in complaints seriously and come to us with complaints that have worsened even further after the battery suddenly runs out. We recommend coming for regular check-ups and having the battery life measurements taken, so that this situation does not occur.

With advancing technology in recent years, we can also use rechargeable batteries. Their average lifespan is 20-25 years. These batteries will need to be charged on certain days of the week.

Battery replacement surgery is a relatively simple and short procedure that can be performed under local anesthesia in approximately 15-20 minutes.

What Does the Success of DBS Treatment Depend On?

We can say that the success of DBS treatment depends on the correct identification of suitable patients by neurologists, the meticulous and flawless performance of the surgery by neurosurgeons, and the placement of electrodes in the most accurate location. The careful and meticulous approaches of related fields such as psychiatry, neuropsychology, and anesthesiology are also important factors affecting success. From the quality of the MRI taken, to post-surgery physiotherapy, speech therapy, and nutritional education, all of these make very valuable contributions to increasing success. Also, the Parkinson's nurse — who has completed their field training, ensures the coordinated work of all these fields, assists physicians in pre- and post-operative patient follow-up, and ensures the regular functioning of the center — constitutes one of the most important parts of this team. As can be seen, success depends on a complete team effort. For this reason, centers that specialize in this field, that can work as a team, and that can bring all the related fields under one roof in a harmonious manner, will be the ones that take the success rate of DBS treatment to higher levels.

What are the Risks and Side Effects of DBS?

Since DBS surgery is a surgical intervention, it carries certain risks. The risks of DBS surgery can be listed as follows: