Parkinson's disease is a chronic progressive disorder caused by the reduction of dopamine in the brain, typically occurring in older ages. The disease almost always begins with symptoms on one side of the body and progresses slowly. Slowness of movement, hand tremors typically seen at rest resembling coin-counting, joint stiffness and rigidity, walking with small steps, and gait disturbances are the most important symptoms that impair patients' quality of life. Speech disorders, mask-like face, constipation, decreased sense of smell, joint and muscle pain, sleep problems, depression, and some psychological issues are also among the significant symptoms of the disease.

Deep brain stimulation (DBS) is a surgical method used to correct symptoms in Parkinson's patients and other movement disorder diseases. Thanks to low-voltage, high-frequency electrical current delivered to certain deep regions of the brain, symptoms such as tremor, slowness of movement, joint stiffness, inability to walk, and freezing can be corrected. The DBS system has 3 components: electrodes placed in deep brain regions, a battery placed in the chest cavity, and cables connecting them. After surgery, voltage, frequency, and electrical amplitude can be adjusted using an external device placed over the battery.

Drug therapy begins once the diagnosis is made. Patients may return to their pre-illness lives for the first few years. However, as the disease progresses, when tremor, freezing, stiffness, and slowness of movement become difficult to control despite medication, the period of 'off' states increases, and involuntary dance-like movements appear with higher drug doses, it may be time to consider DBS surgery. DBS is not recommended during the first 5 years from diagnosis, primarily because Parkinson's disease can be confused with other neurological conditions.

The disease must have started at least 5 years before DBS surgery. Patients with frequent falls or whose medications provide little benefit are not recommended for DBS. Patients with severe psychiatric depression or serious mental disorders should not undergo DBS surgery. Patients with dementia are also not candidates. Additionally, patients with severe uncontrolled chronic diseases are not suitable for DBS. However, controlled hypertension, heart disease, or diabetes are not obstacles to surgery.

Although there is no legal age limit for DBS surgery, it is generally not recommended for patients over 80 years old. This limit was 70 years ago years ago, then 75 years. As long as there are no disqualifying cognitive, psychiatric, or severe chronic conditions, DBS can be performed on increasingly older patients. However, we recommend more careful pre-surgical evaluation for elderly patients.

DBS decisions are not made by a single physician. We hospitalize patients at our DBS center for a few days to evaluate suitability. During this time, our experienced movement disorder neurologists check whether they are receiving optimal drug therapy. Detailed tests are performed in both medicated and unmedicated states. A psychiatrist and neuropsychologist also conduct detailed evaluations. DBS eligibility is determined by the joint decision of all relevant specialists.

DBS is a truly effective method for patients deemed suitable. Especially for patients with tremor, freezing, stiffness, slowness, and involuntary movements, results are encouraging. Patients are freed from their restricted daily lives and medication doses can be reduced after surgery. However, DBS does not completely stop Parkinson's disease — the disease unfortunately continues to progress over the years. Nevertheless, for suitable patients, DBS is currently the best available treatment.

DBS surgeries are generally performed while patients are awake. We prefer awake surgery to place the electrodes as precisely as possible in the target areas. We use microelectrode recording to listen to and record individual brain cells, finding the exact brain region with abnormal activity in Parkinson's without error. Some patients are uncomfortable with awake surgery, in which case we can perform the procedure under general anesthesia while still using microelectrode recording.

After surgery, the battery may be activated the next day at low voltage, or activation may be delayed depending on the patient's condition. Patients are discharged within 5 to 10 days after surgery. Our Parkinson's nurse provides discharge training to all patients. We schedule follow-up visits at 1 and 3 months after surgery to adjust medications and stimulation settings.

After DBS surgery, patients tend to gain weight in the early months due to reduced joint stiffness and increased appetite. We try to prevent this through nutritional counseling. We strongly advise against contact sports such as football, judo, wrestling, and boxing. However, we encourage all non-contact sports. We also advise patients not to pass through X-ray devices at airports and similar places, and provide them with documentation stating they have a DBS implant.

The average battery life is approximately 5 years, though this may be longer or shorter depending on the stimulation settings. Battery replacement is a relatively simple procedure performed under local anesthesia and takes approximately 15–20 minutes. With recent advances in technology, rechargeable batteries are also available. These have an average lifespan of 20–25 years and need to be recharged on certain days of the week.

The success of DBS depends on correct patient selection by neurologists, precise and careful surgery by neurosurgeons, and optimal electrode placement. Careful involvement of psychiatry, neuropsychology, and anesthesia also plays a major role. Post-surgical physiotherapy, speech therapy, and nutritional counseling further contribute to success. Ultimately, success depends on true teamwork — specialized centers capable of coordinating all these disciplines will achieve the highest DBS success rates.