Deep brain stimulation (DBS) is a new method developed in recent years for the treatment of movement disorders, and it has been applied to primary Parkinson’s patients (PD) with bilateral electrode implantation with good therapeutic results; for the first time, bilateral STN-DBS was used to treat secondary dystonia (secondary dystonia). The recent results were satisfactory and are reported below. Data and methods 1. Clinical data: PD patients, 23 males and 17 females. Age 38-77 years old, average 56 years old. The duration of the disease ranged from 2 to 22 years, with an average of 5 years. The selection criteria were clinical diagnosis of proto-Parkinson’s disease. All patients had varying degrees of limb tremor, rigidity and motor retardation, and Hoehn-Yahr stages: 2 cases in stage II, 28 cases in stage III, 9 cases in stage IV, and 1 case in stage V. All patients had taken levodopa drugs systematically, and had experienced a decline in drug efficacy and drug-induced side effects, such as the “on-off” phenomenon. “Three patients with secondary dystonia, one male, 27 years old, with hypoxia of prematurity and a history of 26 years, had generalized secondary dystonia; two females, one 19 years old, focal, with a history of 9 years and MRI showing bilateral lesions in the basal ganglia; the other 28 years old, from Albania, due to antidepressant drugs, with a history of 4 years, and one 28 years old, from Albania. The other case was 28 years old, from Albania, due to antidepressant drugs, with a history of 4 years, and was a delayed generalized dystonia, with poor results of drug treatment. The patient was taken off medication in the morning of surgery and was routinely fasted from food and water; the LEKSELL positioning frame was installed under local anesthesia, and the frame baseline was made parallel to the AC-PC line as much as possible, and a GE 3.0 MRI image was scanned using the FLAIR technique with a layer thickness of 2 mm, and the optical cable transmitted the image information to the surgiplan system for Three-dimensional reconstruction was performed to determine the coordinates of the nucleus accumbens target. In all cases, a bilateral STN-DBS was used, with the reference coordinates of the STN being 2-3 mm behind the AC-PC midpoint line, 12-13 mm paracentral opening, and 4 mm below the AC-PC plane. ~2kHz, the micropropeller is advanced at 1/1000ms speed, and the measured signal is processed by the amplification and rectification system and amplified 20,000 times and displayed on the monitor, and converted into sound signal at the same time for functional localization. 3. Stimulation electrode implantation and efficacy assessment: The implanted electrode was made of MEDTRONIC type 3389 electrode, connected with a temporary stimulator, and given electrical stimulation from the two most distal contacts with minimum stimulation voltage by bipolar conduction, and observed the improvement of the stimulation on the symptoms, including side effects, and fixed the electrode after satisfaction, and then implanted the stimulator under the subclavian skin. The stimulation parameters were 0-4 V, 2-185 Hz, and 60-450 μsec pulse width, and the UPDRS score was performed in PD patients before and 3 months after surgery and in the “on” and “off” states; one patient with dystonia was compared with one patient with “on” and “off” states, respectively. The UDRS and BFMS scores were performed preoperatively and 3 months postoperatively; the UDRS and BFMS scores were performed preoperatively and 1 month postoperatively in the other two patients. Results 1. Postoperative efficacy: PD patients showed good improvement in postoperative symptoms such as limb stiffness, tremor, bradykinesia and postural balance disorders, and bilateral STN electrode implantation improved midline symptoms more significantly. The preoperative and postoperative UPDRS scores were 75.2 and 39.8 for the “off” state, 68.5 and 33.9 for the motor ability score, 36.3 and 9.2 for the ADL score, and 920.8 mg and 580.4 mg for the levodopa dose. There was a significant difference (p < 0.01) in the pre-post comparison. "Among the three patients with dystonia, one case was a drug-induced delayed dystonia, and the stimulator was turned on one month after surgery, and the patient's symptoms showed a trend of gradual relief. The postural abnormalities of trunk and extremities were basically relieved, the speech was clearer than before, and the patient was able to take care of himself completely. At present, there is only mild right shoulder elevation, slightly delayed movement and slight tremor in both hands. The BFMS and UDRS scores 3 months after surgery showed that the symptom relief was above 90%; in one patient with secondary generalized dystonia, the symptom relief was 50% nearly 1 month after postoperative stimulation; in another patient, MRI showed bilateral lesions in the basal ganglia area, which was secondary to focal dystonia, and the symptom improvement was 20% nearly 1 month after postoperative stimulation. 2, intraoperative microelectrode recording results: the electrical signal of STN nuclei recorded intraoperatively mostly showed clusters of high frequency, high amplitude and background noise, accompanied by irregular intermittent bursts of single cell discharge, individual patients can also be recorded intraoperatively "tremor cells", that is, the patient's tremor rhythm is consistent with the rhythm of the electrical signal, although this Although this signal is not specific to STN, the typical electrical signal can help in functional localization. The length of the typical STN electrical signal was generally recorded as 3-5 mm, with the longest being 6 mm. Complications and side effects: No serious complications such as intracranial hemorrhage and hemiparesis occurred intraoperatively or postoperatively, and no electrode breakage occurred, while in one case the electrode position was too deep and the electrode was moved up in a second operation; other side effects occurred after the stimulator was turned on. The symptoms disappeared when the voltage was lowered or other parameters were changed; two patients had eyelid ptosis, which improved after parameter adjustment; one patient had increased libido after the operation, and the others were all transient, such as limb numbness and dizziness. Discussion 1. STN-DBS for PD: DBS for PD is considered to be the most important progress achieved since the giant of levodopa department [1], and the bilateral DBS procedure has a very comprehensive improvement of PD symptoms, including motor inability, tremor, rigidity, gait and balance disorders in the off phase, and also eliminates drug-induced motor complications, such as "on-off It can also eliminate drug-induced motor complications, such as "on-off" phenomenon and on-stage dyskinesia, especially in the "off" state, where UPDRS motor scores and daily living ability scores are significantly reduced [2]; after bilateral STN electrical stimulation, patients' levodopa dosage is also reduced to varying degrees. Most patients took small doses of levodopa, and the dose of levodopa could be reduced 1 to 3 months after continuous STN stimulation [3]; in our data, there were also 2 patients who did not take anti-Parkinsonian drugs after surgery, and there was a significant difference between the mean drug dosage before and after surgery. In contrast, the literature reports no reduction in the dosage of Gpi electrostimulation, and the long-term effects of STN electrostimulation are superior to Gpi electrostimulation if the dose of levodopa is kept to a minimum; not only that, a non-randomized, multicenter study including 96 cases of STN-DBS and 38 cases of Gpi-DBS found that all outcomes favored the STN group, except for a significant reduction in motor deficits caused by levodopa in both groups STN group [1]. Bilateral STN stimulation also improves preoperative midline symptoms in response to levodopa, which is one reason why bilateral DBS surgery replaces bilateral pallidum destruction (PVP) and, more importantly, causes up to 25% temporary or permanent functional impairment postoperatively, regardless of simultaneous bilateral or staged bilateral PVP surgery [4]. In addition to the complications inherent to stereotactic surgery, the "additional" side effects of DBS are mainly hardware problems with the stimulation system and side effects after the stimulator is turned on, the former being less commonly reported in China and the latter, although common, causing lasting neurological deficits that can disappear or be reduced by parameter adjustments, mostly transient. Foreign reports are seen in about 3% of patients [5], which include some indeterminate symptoms such as depression, obesity and increased libido, and we also found a case of a 67-year-old patient with increased libido after bilateral STN-DBS. Accurate targeting and careful surgical manipulation not only provide good surgical results but also help to reduce complications. Strict indications and proper patient selection and evaluation are the key to successful treatment and an important basis for prognostic judgment. Even drug-experienced physicians have a certain rate of misdiagnosis of primary Parkinson's disease, and an objective predictor is the individual sensitivity to levodopa. DBS only works on those symptoms that can be improved when levodopa is most effective, and preoperative levodopa drug trials can be used to help confirm the diagnosis. The timing of surgery is also a concern. It is generally believed that surgical intervention can be considered when PD has reached a certain stage of development and the efficacy of the medication has declined or drug-induced side effects have occurred after systematic medication. The severity of the "off phase" motor symptoms and athetoid syndrome, as an entry criterion for surgical intervention, is being attempted in some studies abroad: these include a UPDRS motor score of at least 30; or the presence of severe athetoid syndrome or tremor in at least one limb. The author believes that individualization should also be considered under the general principle. Individual patients who are in stage II of Hoehn-Yahr staging but whose tremor cannot be controlled by medication can also be treated surgically, and there are two such patients in our data who have satisfactory postoperative control of tremor. Animal experiments have shown that STN-DBS can reduce the release of glutamate in the substantia nigra densa (SNc), so that the persistent excitotoxicity to SNc caused by STN activity decreases, thus providing a protective effect on nerve cells [6, 7], and if this theory is valid, it can slow down the disease progression and early DBS surgery is feasible. 2, STN-DBS for dystonia: dystonia is defined as an involuntary movement disorder characterized by repetitive, intrinsic or sustained muscle contractions resulting in abnormal twisting movements or postures, so it is also known as torsional spasm in China, however, the clinical types are broader and include some other movement abnormalities such as myoclonus, tremor, bradykinesia and increased and decreased muscle tone. Due to the variability and uncertainty in treatment outcomes, clinical staging of dystonia is crucial, and can be classified as primary or secondary based on etiology; and focal, segmental, generalized, and eccentric based on symptoms. Stereotactic surgery for severe dystonia has been performed for decades, including thalamotomy and pallidotomy, which has been thoroughly discussed by many scholars such as Task, Andrew, and Cooper, with certain results, with pallidotomy being more effective, and even good results have been reported in some individual cases with bilateral pallidotomy, but the inherent bilateral surgery However, the irreversible damage caused by the higher complications inherent in bilateral surgery has limited its development. In recent years, the advent of DBS has ushered in a new era in the treatment of dystonia, with DBS replacing the trend of pallidum destruction with its minimally invasive, bilateral surgery with few side effects. dystonia scores decreased by a mean of 81.3% in 15 PGD patients after surgery, including a mean improvement of 90.3% in BFMS motor scores in 7 DYT1-positive PGD patients [8]. Other investigators have also achieved significant improvements with Gpi-DBS treatment, including seven patients with PGD, only two of whom had DYT1 mutations [9]. In patients with secondary dystonia, the situation is more complex, with variable symptom improvement after DBS treatment, with two patients with eccentric dystonia reported to have improvement after unilateral pallidus DBS treatment, in contrast to four patients with post-hypoxic dystonia with incomplete or no improvement at all, and other patients with post-traumatic dystonia reported to have symptom improvement after DBS, explaining this discrepancy This difference may be explained by the fact that trauma patients have a single, well-defined lesion site, whereas hypoxic patients have a widely diffuse lesion [10]. Whereas all three patients in our data were secondary to dystonia, one of the patients with secondary generalized dystonia, who also had a history of premature hypoxia, showed a 50% improvement in symptoms 1 month after STN-DBS, the 27-year history of the disease caused the patient to develop limb contractures, making full recovery more difficult; therefore, it is recommended that patients with severe dysfunction should undergo DBS as early as possible.Volkman concluded that Systemic dystonia progressing to the stage of severe dysfunction or life-threatening, with heterolateral or segmental dystonia causing severe motor impairment and pain, is the main indication for stereotactic surgery today. For patients with focal dystonia with lesions in the fundic region, no DBS treatment has been reported. In one patient in our group, MRI showed bilateral lesions in the fundic region, and 1 month after STN-DBS, limb stiffness and language improved, and the long-term efficacy needs further observation. Another case in this group was secondary to generalized dystonia caused by antidepressants, also called delayed dystonia (TDt), and showed an encouraging result with over 90% improvement in symptoms 3 months after STN-DBS, and the patient was able to take care of himself completely.Trottenberg et al [11] used bilateral GPi as a target for DBS surgery to treat a case of TDt in which the patient's symptoms were also rapidly relieved; what is more surprising is that all three patients in this group were treated with bilateral STN electrical stimulation, and STN-DBS has also been used to treat PGD in China with good results, which has not been reported abroad, creating a precedent for STN-DBS in the treatment of dystonia diseases. It is generally believed that it takes time to improve the symptoms after DBS, and several parameter adjustments and program control are essential in the early stage, and the comprehensive evaluation after 3 months is more meaningful, but the improvement of some symptoms, such as abnormal movement, rigidity and tremor, can also be observed intraoperatively, and the subjective feeling of patients also helps to judge the efficacy. In addition, the functional positioning of microelectrodes also plays a big role.