For many people, a line connecting the two endpoints of birth and death is switched on and off only once by God’s key, whereas for people with Parkinson’s disease, life can take several turns each day. Not being a Parkinson’s patient, it is difficult to understand the unique on/off phenomenon of Parkinson’s disease. At the time he was diagnosed with Parkinson’s disease by his doctor, Li Liangxiu was 36 years old. He was young compared to the predominantly middle-aged and elderly population with the disease. Li Liangxiu began to actively take medication, and thus deeply experienced the fear of “on and off”. In his book “Walking through the valley of Parkinson’s”, he describes that when he is “on”, his whole body is free, as if he has entered the light from darkness, all the physical symptoms have disappeared, and he can move freely. When the patient enters the “off” stage, he is completely opposite, walking as if his feet are shackled with lead weights, making it difficult for him to take a step. Why do patients experience this terrible switch phenomenon? Drugs are often a double-edged sword, switch phenomenon is Parkinson’s disease patients with long-term application of levodopa drugs after the fluctuation of drug effect phenomenon. Levodopa drugs, as the basic drugs in the field of Parkinson’s disease treatment, have been used clinically with good results in the early days. Since it was utilized in 1968, it has had a significant effect on eliminating the motor symptoms of Parkinson’s disease – tremor, rigidity, reduced and slowed movements. However, after taking levodopa drugs for 3 to 5 years, the limitations of the drug will appear, and long-term use will cause pathological changes in brain tissue, which in turn will cause various motor complications, and the switch phenomenon is only one of the side effects. The switch phenomenon appears in the late stage of drug taking. Throughout the day, the patient’s symptoms fluctuate between sudden relief (on phase) and exacerbation (off phase), which can be repeated and rapidly alternated several times. This change is very rapid and unpredictable, like a power switch. Clinically, this physiological phenomenon is figuratively referred to as the on-off phenomenon. The “switch” changes the patient’s lifestyle The unique side effects of taking medication can have a profound impact on the lifestyle of Parkinson’s patients and seriously affect their quality of life. A Parkinson’s patient who has been ill for several years said that many middle-aged and elderly patients, in order to once and for all solve the problems brought about by the switch phenomenon, lock themselves up at home all day long, without leaving the house, staring at the clock every day to take their medication, and once they are “turned off”, they will be quietly waiting for the “on” of the “on”. Once they are “off”, they quietly wait for the “on” to come. In addition to the switch phenomenon, there are many other side effects of taking medication, such as the commonly occurring end-of-dose phenomenon. This refers to the shorter and shorter duration of the medication, and the worsening of Parkinson’s disease symptoms at the end of each dose. In addition, after taking the medication, although it improves symptoms such as tremor, most patients will also experience the phenomenon of anisotropy, in which choreographic or simple repetitive involuntary movements can occur in the facial muscles, the neck, the back and the limbs. The amplitude of such involuntary movements can be large and can last throughout the onset of levodopa-based medications. “Many side effects are caused by failing to use the drugs reasonably for a long period of time, such as large doses and pulsatile drug delivery methods, which delay patients’ lives but seriously affect their quality of life and cause them to endure great pain.” Zhang Zhenxin told reporters that in some remote areas, patients tend to keep increasing the dose of medication on their own because they don’t get proper clinical guidance. This is very dangerous, overdose will make patients hallucinate, and even bring life hazards. With the deepening of research on Parkinson’s disease, new medications and technologies continue to emerge, bringing light to alleviate patients’ suffering. Currently, deep brain electrical stimulation is being used internationally to treat Parkinson’s patients after taking medication. This procedure was adopted by a French neurosurgeon in 1987 and was successful. China’s Beijing Tiantan Hospital was the first to apply this technology to treat Parkinson’s disease in China, and a number of hospitals in China have carried it out one after another. At present, this surgery is still in the exploratory stage. Deep Brain Electrical Stimulation is a stereotactic surgery that uses stimulation electrodes implanted into the diseased parts of the brain of Parkinson’s disease patients, and a stimulation generator implanted under the skin of the patient’s anterior chest to stimulate specific parts of the brain through electrical impulses, thus improving the symptoms of primary tremor, tonus, motor retardation and other diseases. There are strict indications for Deep Brain Electrical Stimulation for Parkinson’s Disease, which can be used in patients who have experienced diminishing effects and serious complications after several years of medication, and who must be free of serious systemic disease. Deep brain electrical stimulation is completely different from deep brain nucleus pulposus destruction (also known as cytoknife), which was once popular internationally and domestically. Deep brain nucleus pulposus disfigurement had good results in the early stage, but because Parkinson’s disease is a bilateral brain lesion, if bilateral deep brain nucleus pulposus disfigurement is done, the patient’s speech, intelligence and other aspects will have serious complications. Nowadays, deep brain nuclei destruction surgery has been abandoned by the international medical community. In recent years, a new generation of drugs has emerged frequently, giving patients a ray of hope to improve their side effects. New drugs, such as inhibitors of catechol oxygen methyltransferase, are now available to replace pulsed stimulation with continuous stimulation. The advent of non-ergot dopaminergic receptor agonists has not only greatly prolonged the duration of drug action but also theoretically has a neuroprotective effect. The goal of the pharmacological community is to develop drugs that not only significantly improve symptoms such as tremor and muscle rigidity, as levodopa preparations do, but also effectively prevent and ameliorate motor complications associated with levodopa analogs, such as the switch phenomenon, end-of-dose phenomenon, and anisotropic phenomena, and to improve the depressive symptoms that are prevalent in Parkinson’s patients. Parkinson’s disease is a common neurological disorder with symptoms such as involuntary tremor of limbs and head at rest, muscle rigidity, slow movement and postural balance disorders, which can lead to patients’ inability to take care of themselves. Depression is very common in patients with Parkinson’s disease, with data showing that 30% to 40% of patients have different forms of depressive symptoms.