When exactly Parkinson’s patients should consider surgical treatment is not clearly defined, and patients consider different surgical options such as disruptive surgery or deep brain electrical stimulation (DBS) differently. Because there is evidence that DBS of the thalamic nucleus (STN) has a neuroprotective effect by decreasing the excitability of the STN, thereby reducing the excitotoxicity of glutamate release to the substantia nigra (SNc) and slowing the progression of Parkinson’s disease, it is generally believed that Parkinson’s patients should be treated with DBS earlier than with disruption surgery. However, despite this, those patients with early PD such as those who have good symptom control with a single drug and do not experience any drug-induced side effects should not be considered for surgical treatment. Although surgery is effective for drug-induced side effects such as motor fluctuations and allodynia, surgery should not be used as a method to delay or prevent these side effects, as surgery is equally effective for these drug-induced side effects even in the late stages of the disease. On the other hand, a large number of clinical studies have shown that surgical treatment of Parkinson’s should not wait until the patient with PD loses his job, his ability to care for himself in daily life, or his ability to socialize due to the severity of his symptoms before considering surgery, because then the best time for surgery is lost and he cannot benefit from it to the maximum extent.
In conclusion, surgical treatment of Parkinson’s disease is only indicated for those patients who have been treated by an experienced neurologist/movement disorder specialist and whose motor dysfunction continues to interfere with daily life or work despite adequate and effective medication. Specifically, surgery should be considered for patients who have one or more of the following conditions despite a drug “off” period of more than 2 hours per day or anomalies of more than 2 hours per day, levodopa taken more than 5 times per day, or a combination of levodopa, receptor agonists, COMT inhibitors, etc.
I. Implementation of surgical treatment
Surgery for Parkinson’s disease should be performed in a hospital with certain conditions, including the availability of MRI, precise stereotactic system and radiofrequency therapy system, intraoperative electrophysiological monitoring system, intraoperative X-ray (C-arm machine), etc. The surgical team includes experienced neurologists/specialists in movement disorders, clinical psychologists and specially trained neurosurgeons and stereotactic neurosurgeons.
The preoperative evaluation is particularly important in the surgical management of Parkinson’s disease and can sometimes determine the success of the surgery. The preoperative evaluation should be performed by a neurologist and psychologist with specialized training in movement disorders. Whether the patient is treated with disruptive surgery or deep brain stimulation, the patient should receive a thorough and complete preoperative evaluation to determine the patient’s suitability for surgery and to predict the outcome of the procedure and to document the data for long-term follow-up. Patients are evaluated 3-7 days prior to surgery for motor and other functional status during the “on” and “off” phases of the drug. Commonly used assessment scales include the UPDRS, Hoehn-Yahr Scale, Schwab-England Daily Living Scale, and the Brief Psychiatric Symptom Inventory and Hamilton Depression Inventory. For patients with suspected cognitive impairment, the patient’s intelligence, memory, comprehension, judgment, and operative functions should be assessed preoperatively.
Discontinue all anticoagulant agents two weeks before surgery to reduce intraoperative bleeding and to control the patient’s hypertension and diabetes mellitus. All anti-PD agents should be discontinued one day prior to surgery to allow for a complete “off” state during surgery.
Postoperative patient management: Postoperative management of PD patients undergoing surgical treatment, especially after the end of DBS implantation, is particularly important and can sometimes determine the outcome of the procedure. For post-destruction patients, the main focus is on the adjustment of PD medications, while for post-DBS patients, the postoperative management includes DBS program control, medication adjustment and side effect management.
II. Nucleus accumbens destruction treatment
Pallidotomy is the most commonly used nucleus disruption procedure for Parkinson’s disease. Although it has the defects of diminished long-term efficacy and cannot be performed bilaterally, it is one of the surgical treatment options because it is inexpensive and has good efficacy for certain Parkinson’s disease symptoms. Pallidum destruction can significantly improve tremor, drug-induced allodynia, demotion, and movement retardation, but it is less effective for midline symptoms such as speech, cognitive function, autonomic function, and gait impairment in patients with Parkinson’s disease.
Third, the indications for pallidum destruction are.
1, primary Parkinson’s disease.
2, a previous good response to levodopa.
3. patients not older than 80 years old, with better surgical results in younger patients
4, involuntary movements (anisocoria), end-of-dose phenomena, motor fluctuations, etc. resulting from long-term use of levodopa preparations.
5, patients with limb tremor, stiffness and slow movement as the main symptoms affecting the quality of life, and unilateral in nature.
6.Patients and their families have more realistic expectations of the surgical results and can cooperate with postoperative management such as medication adjustment, etc.
IV. Contraindications for pallidus destruction are.
1, Parkinson’s syndrome.
2.Hoehn-Yahr score stage 4 in the “open” phase.
3, severe cognitive deficits.
4. Uncontrollable hypertension, heart disease and coagulation disorders or poor general condition that cannot tolerate stereotactic surgery.
Thalamic Vim nucleus destruction has been rarely used for the treatment of primary Parkinson’s disease in recent years, because it has little effect on improving the slow movement and drug-induced isokinetic and end-dose phenomena in PD, but for PD with severe tremor as the main cause, it can well control the tremor and thus significantly improve the quality of life of patients.
V. Deep brain electrical stimulation (DBS)
DBS has fully replaced destructive surgery for the treatment of Parkinson’s disease in recent years. It can be said that except for the defect of high treatment cost, DBS is superior to destructive surgery in all other aspects, specifically in.
1, non-destructive effects on brain tissue.
2, modifiability.
3, reversible side effects.
4, repeatable on – off for precise assessment of treatment effects.
5, safety of bilateral surgery.
VI. The ideal deep brain electrical stimulation may achieve the following effects.
1. In the state of electrical stimulation, the motor function of the patient in the off period is similar to the best state in the preoperative “on” period.
2. reduction of the “off” phase.
3. reduction of allodynia and motor fluctuations.
4. improvement of major Parkinson’s disease motor symptoms.
5. Improvement of speech disorders that can be improved in the “on” phase after DBS.
6. Mild postural instability can be improved, but severe balance disorders are difficult to improve.
Since the ideal DBS surgery is better than antiparkinsonian drugs in terms of fibrillation control, it is only equivalent to the best state of the “on” phase of drugs in terms of other parkinsonian symptoms control, so the preoperative evaluation of DBS, especially the levodopa shock test, is particularly important because it can give patients a more realistic expectation of DBS treatment. This is why the preoperative evaluation of DBS, especially the levodopa shock test, is so important, as it allows the patient to have a more realistic expectation of DBS treatment. Ideally, the levodopa shock test in patients with surgical indications for DBS should result in an increase in UPDRS scores when the drug is “on” compared to when it is off? Although the side effects of DBS can be adjusted as much as possible by DBS program control, sometimes the stimulation produces therapeutic effects as well as unavoidable side effects, including anisometropia (only seen at the beginning of STN stimulation), hypotonia, difficulty in eyelid opening, cognitive impairment, mood disorders, etc. Some of these side effects can be improved by adjusting the stimulation parameters, some gradually disappear after a period of adaptation. Some of these side effects may improve with stimulation parameters, some may disappear after a period of adaptation, and some may persist for a long time along with the therapeutic effects of stimulation.
Postoperative management of DBS is an important part of treatment and sometimes determines whether the best outcome is achieved. It specifically includes.
(1) Postoperative program control
Because the micro-destructive effect of electrode implantation allows patients to show significant improvement in motor symptoms even without stimulation 3-5 days after surgery, the first program is usually started after 1 week. This includes the selection of the best electrode contact for stimulation, evaluation of the stimulation effect, evaluation of side effects, definition of the treatment window and setting of the stimulation parameters (during the “off” and “on” phases of the drug, respectively). (during the “off” and “on” phases of the drug);
(2) Drug adjustment
This is usually done when the stimulation is “on” and is not identical for different patients and different stimulation sites (GPi or STN). In patients with STN DBS, levodopa dosage can often be reduced, and in a few young patients it can even be stopped completely, with an average reduction of 50%, whereas in patients with GPi DBS it can rarely be reduced. Levodopa drugs should be reduced gradually, and abrupt discontinuation should be avoided in patients on long-term, high-dose levodopa therapy because of the possibility of motor inability crisis. In addition, attention must be paid to non-motor symptoms such as apathy (lack of pleasure, lack of willpower) and even depression that occur during the drug reduction process.
(3) Postoperative patient education for DBS
Post-operative patient management needs to be repeated several times over the course of several months to a year in order to optimize stimulation and to perfect synergy with medication. Unlike destructive surgery, patients need to avoid being near magnetic fields in their daily lives due to the DBS implantation device in the patient’s body, and learn to apply a magnet switch or patient programmable control so that it can be turned on quickly in case the stimulation period is turned off due to proximity to high magnetic fields. In addition, the DBS device may cause infection, rejection or skin necrosis in some patients, so call back to the surgeon as soon as the wound becomes red, swollen or broken.