After taking the medication for a period of time, Parkinson’s patients always feel that the medication is not as effective as during the honeymoon period, can they have surgery? How to determine if a patient is suitable for a pacemaker? In fact, it is not possible to have a pacemaker just because you want it. The doctor has to confirm that the patient is in stage 2.5 to 4 of primary Parkinson’s disease and that the cardiopulmonary function can tolerate the surgery before deciding whether the patient is suitable for surgery or not. Since the installation of a pacemaker is very complex and involves many surgical steps, instruments and personnel, it is important to have a surgical plan (also called a standardized surgical procedure) and to arrange the work of everyone involved before the surgery to ensure a smooth operation. So, how do you define a standardized procedure for each patient? This requires a series of pre-operative examinations and assessments. Generally, during the outpatient visit, the doctor will be able to initially determine if the patient has primary Parkinson’s, but this assessment is more subjective and is best done by an experienced physician. In addition, the doctor will examine the patient’s current symptoms and use a scale score to determine how the patient’s disease is progressing and to rule out other diseases. After the initial evaluation, the patient can be considered for a brain pacemaker and then an appointment is made for admission for further tests. To ensure the safety of the procedure, routine preoperative tests include: electrocardiogram, blood count, liver and kidney function, blood clotting tests, and respiratory function tests. In addition, there is a very important test – levodopa shock test, which is mainly to assess what kind of effect the patient can achieve after the installation of a brain pacemaker. Theoretically, the specific operation is as follows: the patient is admitted to the hospital, and after stopping the drug for three days, the Parkinson’s symptoms will be very obvious, which is called the “off period”; then take 1.5 times more levodopa drugs than usual, and the drug effect will be fully developed, which is called the “on period “Then the doctor recorded the scores of these two periods in the dosage table. If the difference between the scores before and after is greater than 30%, it indicates that the patient is responding better to dopamine, and likewise, the pacemaker will work better. This is the standard experimental procedure. In practice, it is not possible to stop the patient’s medication for three days, which would cause a lot of inconvenience and a heavy psychological burden for the patient. Therefore, the modified experimental procedure is as follows: after admission, the patient is stopped once, and before the next dose, the patient is given a score; after that, the patient can take the medication normally without any increase in dosage, and after the state is stable, another score is given. The scores of these two times are certainly not the same as those in the standard experimental state, but if the difference between the scores of these two times is still greater than 30%, the same can be predicted that the patient can obtain a good result after surgery. In addition to the drug experiment, preoperative MRI is also performed to collect brain tissue imaging data from the patient. On the day of surgery, the patient is also fitted with a stereotactic stent for the head under local anesthesia and then goes to the CT room for a scan. After obtaining the CT scan data, the CT data is fused with the first day’s MRI data through computer software to precisely locate the target site for the implantation of the stimulation electrodes before the surgery can officially begin. It should be added that the so-called standardized surgical procedure is not an assembly line work. The standardization is only to ensure that the whole procedure is carried out smoothly and that the procedure is safe and effective. For patients with different lesions and different disease development, the surgical protocol is set up individually. For example, some patients have obvious symptoms on both sides, so the data of bilateral lesions should be collected and the surgical procedure should be set based on the plan of implanting bilateral electrodes. Other patients have mild anxiety or cognitive impairment, but their willingness to operate is very strong in order to improve the quality of life. Then the doctor will fully communicate with the patient before the operation, adjust the patient’s mental symptoms, or train the patient to learn to have good response or communication with the doctor during the operation to avoid wrong feedback during the operation, so that the operation is also possible.