Deep brain stimulation (DBS) therapy has become an effective method for the treatment of Parkinson’s disease (PD) in the middle and late stages. In order to better standardize the living evidence and process of DBS therapy in China, and to further strengthen the close cooperation and cooperation between neurology and surgery, this expert consensus is made.
I. DBS team
Most of the PD patients who receive DBS therapy in China are seen directly by a hospital with DBS surgery capability rather than by a neurologist, so it is necessary to establish a DBS team to evaluate the patient, consisting of at least a neurologist, a surgeon and, if necessary, an internist, a psychologist and a psychiatrist. The role of the DBS team is to determine, on an individual basis, whether surgery is appropriate, the risks and long-term outcomes of surgery, and the best surgical target (if surgery is performed).
DBS therapy is indicated for
1.Primary Parkinson’s disease.
2.Taking compound levodopa has had good results.
3, the efficacy has been significantly reduced or there are severe motor fluctuations or isokinetic disorder, affecting the quality of life.
4.Except dementia and serious psychiatric diseases.
Third, patient washout
DBS teams recite often use what they think is the best method to evaluate patients, and most centers use responsiveness to compound levodopa treatment and MRI examination as necessary criteria for clinical evaluation. Given the current situation in our country, the diagnosis should first be determined in patients with intent to undergo DBS therapy, and those who meet the indications need to undergo a series of evaluations. The disease duration is also one of the indicators for deciding whether to operate. Since patients in the early stages of Parkinson’s disease respond well to drug therapy, it is not recommended that patients receive DBS therapy early. In addition, Parkinson’s superimposed syndrome such as multisystem atrophy (40%) and progressive supranuclear palsy (20%), which have symptoms similar to Parkinson’s disease and can respond well to compound levodopa preparations in the early stages of the disease, are also not recommended to receive DBS therapy prematurely.
1, Diagnosis.
(1) Meet the diagnostic criteria of primary PD of the United KinffdomParkinson’s Disease Society’ brain hank or primary PD in China.
(2) Fulminant PD or various genotypes of PD can also be operated as long as they respond well to compound levodopa.
2.Duration of disease.
(1)Less than five years;
(2) Patients with diagnosed primary PD, mainly tremor, with unsatisfactory improvement of tremor by standard drug therapy, and tremor seriously affecting patients’ quality of life, if patients strongly request early surgery to improve symptoms, the duration of disease can be relaxed to less than 3 years after discussion and evaluation.
3. Age:
(1) The patient’s age should not exceed 75 years;
(2) Elderly patients may be relaxed to about 80 years of age after individualized assessment of benefit and risk;
(3) The age limit may be relaxed for elderly patients with predominantly severe tremor.
4. Drug use.
(1) There has been good efficacy for compounded levodopa;
(2) Optimal drug therapy (adequate dose, at least compounded levodopa and dopamine agonist) has been administered;
(3) currently cannot satisfactorily control symptoms, the efficacy is significantly reduced or there are difficult motor fluctuations or isokinetic disorders that affect the quality of life or are drug-refractory tremor, or are intolerant to drugs.
5.Severity of disease:Off stage Hoehn-Yahr 2.5 a 4 stage.
6, reasonable postoperative expectations: physicians should fully communicate with patients and their families on surgical expectations before surgery, suggestions include:
(1) Surgery cannot solve all symptoms, and some symptoms cannot be relieved by surgery.
(2) The symptoms that can be relieved by surgery are the main cause of the patient’s functional impairment.
(3) Parkinson’s disease cannot be cured, and the disease will progress.
(4) Not all patients will be able to reduce or stop their medication after surgery.
(5) Patients need to be aware of the benefits and risks of surgery.
7. Coexisting diseases: Those with the following conditions are not suitable for surgery
(1) Significant cognitive impairment that affects the patient’s ability to perform daily activities (e.g., social interaction, work, medication use, etc.)
(2) Obviously severe (refractory) depression, anxiety, schizophrenia and other psychiatric disorders (3) Obvious medical coexisting disorders affecting surgery or survival.
8, suitable for referral of patients waiting for baptism:
(1) meet all the above criteria
(2) Patients and family members have the will to operate and good compliance
(3) Can be regularly followed up for program control
(4) Can be considered for referral to DBS treatment center for further screening and evaluation.
Assessment tests
1. MRI: Check for other abnormalities that may constitute a contraindication to surgery or increase the difficulty of surgery, such as cerebral atrophy: assess the target of washout surgery. If MRI is not applicable, CT examination is also feasible instead.
2. Motor assessment:The responsiveness of patients with motor fluctuations and allodynia to compound levodopa is extremely important, and a good responsiveness predicts a good outcome of DBS therapy. Assessment of dyskinesia and compounded levodopa responsiveness mostly uses UPDRS-III as an evaluation tool. The duration of the open period is not important, but rather the degree of improvement in motor symptoms levoclonachallenge teat is an important predictor of the efficacy of DBS therapy by:Subjects discontinued dopamine agonists 72h before the test and compounded levodopa preparations and other anti-PD drugs 12h before the test This test was performed by 2 neurologists who did not The trial was evaluated by 2 neurologists who did not participate in the case screening.
The trial drug should be a standard compounded levodopa tablet, and the dose should be 1.5 times the levoclona eauivalentclose (LED) converted from the previous anti-PD drug taken for the first time each morning. The UPDRS-III score was performed as a baseline under fasting status, followed by oral administration of domperidone 10 mg, followed by administration of standard levodopa tablets 30 min later, followed by UPDRS-III score every 30 min until 4 h after administration, and the maximum improvement rate of UPDRS was calculated as (pre-dose baseline score – post-dose minimum score)/pre-dose baseline score x 100%.
During the trial, patients’ heart rate and blood pressure were monitored and adverse effects were recorded. The average of the 2 raters was used as the maximum improvement rate of the subjects taking compound levodopa. Improvement greater than or equal to 30% suggests that DBS therapy may have good efficacy. If symptoms other than tremor persisted, it suggested that DBS therapy was less effective. It should be noted that this test has little predictive value for the efficacy of refractory tremor.
3. Cognitive testing: Severe cognitive impairment (dementia) is a contraindication to DBS, and about 40% of patients with advanced PD will develop dementia. It is recommended that patients with preoperative diagnosis of dementia should not be treated surgically, but should be evaluated with reference to the brief assessment methods recommended in the guidelines for diagnosis and treatment of dementia in Parkinson’s disease developed by the Chinese Academy of Neurology and the Neuropsychology and Behavioral Neurology Group, and the SE, MoCA, ADAS-Cog, and Wechsler Adult Intelligence Scale.
4. Psychiatric testing: Severe and refractory mental disorders are contraindications to DBS therapy, and the Hamilton Depression Inventory and Hamilton Anxiety Inventory are recommended for assessing mood disorders, and the Neuropsychiatric Inventory and Brief Psychiatric Inventory for assessing mental disorders. However, there is a lack of multiple uniform safety assessment criteria in the preoperative evaluation of DBS therapy, therefore, as a rule of thumb, patients should be able to clearly describe their medical history and read and sign an informed consent form.
V. Preoperative medication guidance
As the immediate efficacy of DBS should be observed during dry surgery, preoperative discontinuation or reduction of anti-Parkinsonian drugs is necessary. Usually, dopamine agonists should be stopped 3 d before surgery, and levodopa drugs should be stopped 12 h before surgery, so that the patient can be in a relatively “off” state during surgery (to ensure that the patient can cooperate during surgery).
Sixth, stereotactic surgery
First, the patient is given local anesthesia and a stereotactic head frame is installed. Afterwards, imaging (MRI or CT) is performed to locate the target site (direct localization, indirect localization). The patient is again anesthetized locally or generally, sterilized, toweled, drilled for stereotactic target microelectrode recording, and microstimulation or coarse stimulation is started. And then stimulation electrodes are implanted and tested. The location of the stimulation electrode is verified with the aid of recitation imaging, the stimulation electrode is fixed and the incision is sutured. The patient is given general or local anesthesia, the area is disinfected, toweled, and the subcutaneous capsular bag and tunnel are prepared. The stimulator is implanted and connected to the extension lead, and the incision is sutured.
VII. Postoperative management
1. The timing of starting anti-PD drugs after DBS therapy in PD patients: when they are awake and can feed themselves after surgery.
2. The medication regimen after DBS therapy: initially the same as before surgery, adjust the medication according to the patient’s response, and control the patient’s motor symptoms with the minimum effective dose. The number and type of medications can be reduced within 1 month after surgery, and most patients start medication adjustment from 3 months to 6 months after surgery, and the LED is reduced by 30% to 70%. dopamine agonists and compound dopa preparations are the most commonly used anti-PD drugs after DBS therapy.
3, DBS therapy after the start (that is, the first program control) timing: cerebral edema subsided, the patient’s general condition can be turned on, 2-4 weeks after surgery is more appropriate.
4, the setting of the start-up parameters: the vast majority of frequency 130 Hz, pulse width 60us. voltage adjustment according to the patient’s response, generally not more than 3V, but the foot bridge nucleus DBS frequency is lower.
5, long-term DBS parameter changes: the first few years after surgery parameters need more adjustment, the thalamic nucleus-DBS voltage changes more, less over the discussion 3.5 V; frequency changes followed, less over the discussion 170 Hz, pulse width relatively less change. The vast majority were unipolar settings, less bipolar; the proportion of bipolar settings increased slightly with the vertebral shift in time.
6.After receiving DBS therapy, if the condition requires cranial imaging, cranial CT can be performed without parameter adjustment; cranial MRI can only be performed in a 1.5 Tesla horizontal hole MRI, and the patient’s pulse generator voltage should be returned to zero and turned off before the examination.
7. After receiving DBS therapy, PD patients and their families should read the neurostimulation system patient manual in detail.