Surgical treatment for Parkinson’s disease
Why does medication gradually become ineffective? Why does “ochronosis” occur?
Generally speaking, the effects of medication become progressively less effective over time because the body’s concentration of the medication needed to treat the disease increases. In the past, it was thought that postponing the period of medication or reducing the amount of medication taken could delay this process. However, scientific studies have shown that this does not actually delay the gradual increase in the therapeutic threshold of the drug and the gradual decrease in its side effects.
Due to the narrowing of the effective therapeutic threshold, the patient’s concentration of the drug at the time of taking the drug is high, which not only exceeds the therapeutic threshold but also exceeds the threshold for the occurrence of side effects, so that some special clinical conditions, such as “ochronosis”, occur; and a few hours after taking the drug, the concentration of the drug in the body does not reach the effective therapeutic concentration The patient’s symptoms reappear as a result of the lack of efficacy of the medication.
Why do I need surgery?
Surgery is a way to fundamentally change the clinical pathology of Parkinson’s disease and free the patient from the worries of taking medication.
After surgery, patients can not only take less medication or even stop taking it, but more importantly, avoid some of the problems associated with long-term medication, such as the shortening of the overall effect of medication and the duration of daily effectiveness, and the development of “allodynia” in patients.
There are three main types of surgery for Parkinson’s disease: destructive, neuromodulation, and rejuvenation. At the current state of science, destructive surgery has faded from the clinic, while rejuvenation surgery is not yet mature, so here we will mainly introduce neuromodulation surgery.
Neuromodulation surgery can also significantly reduce the “on-off” phenomenon and maintain effective control of tremor, rigidity, and other symptoms.
Am I a candidate for surgery?
Primary Parkinson’s disease is most effective when the symptoms are mainly tremor and rigidity. Improvement of symptoms such as postural imbalance and dysphonia and dysphagia is not very good. The efficacy is better in early cases than in advanced cases. In general, unconditioned tremor and some cases of torsional spasm are not suitable for surgery in patients with clinical stage 5. In contrast, surgery should be more aggressive for patients in stage 3.
How is the surgery performed?
1.What is stereotactic surgery
The surgery is done by stereotactic technique method. Specifically, since the brain is a substantial organ, the position of its internal tissue structures such as the nucleus pulposus is relatively fixed. Therefore, one can accurately reach the desired target through some spatial reference points – “stereotactically” determining the direction and “target point”.
Modern stereotactic technology is the use of computerized tomography (CT) or magnetic resonance imaging (MRI) technology, on a computer workstation to more intuitively “see” the target point, more accurately calculate its coordinates in three-dimensional space, and can simulate the surgical process, in order to complete the surgery in a safer and more accurate means.
2.Surgical procedure.
Placement of stereotactic head frame: This is the first step of stereotactic surgery, and is the most basic and important step. The special device placed on the head accurately reflects the spatial position of the nucleus in the brain into a three-dimensional mathematical model, which calculates the three-dimensional coordinates of the nucleus “target point”.
The placement of the cephalic frame is performed under local anesthesia, and the special metal cephalic frame is stably fixed to the skull by means of several special fixation pins according to the surgical requirements.
Magnetic resonance scan: The patient wears this head frame and its special markers on the head frame and undergoes a thin magnetic resonance scan. In this way, the spatial coordinates of the nuclei within the brain are digitally linked to the markers outside the skull.
Calculation of the coordinates of the target point: With special calculation software, the surgeon can not only calculate the spatial coordinates of the target point, but also simulate the surgical path: all the details of the “walk” from the entrance of the skull to the target nucleus can be simulated on the computer workstation. The surgeon carefully checks and verifies the surgical path to be “traversed” and confirms that there are no critical nerves or blood vessels before finalizing the surgical plan.
Placement of the test electrode: Under local anesthesia, an incision of only about 3 cm is made in the skin and a small hole is drilled in the skull according to the surgical plan, and the electrode is implanted in the exact path shown by the computer. The patient feels no pain at all during this procedure.
Intraoperative testing: While the electrodes are implanted near the target, the neurologist closely observes the patient’s status while testing with a temporary intraoperative pulse generator. At this point, the patient can often feel a dramatic change: the tremor immediately diminishes or even disappears, and the limb is no longer stiff but moves freely.
Determination of the permanent electrode: After continuous testing to confirm the best target site, the permanent implantable electrode is fixed in this position. The electrodes are connected to the neuromodulated pulse generator (“pacemaker”) through a “tunnel” under the skin.
Implantation of the neuromodulation pulse generator: Since the subcutaneous “tunnel” and placement of the pulse generator are not suitable for local anesthesia, at this stage the procedure is performed under general anesthesia instead. After the surgery is completed, the patient gradually wakes up as the anesthetic is metabolized and excreted.
At this point, the surgery was completed perfectly.
What do I have to pay attention to before and after the surgery?
Routine examination and neurological assessment are performed before the surgery, and therapeutic drugs targeting neurological symptoms are discontinued one day before the surgery to facilitate objective assessment of the efficacy of neuromodulation during the surgery.
Due to the discontinuation of medication prior to surgery, the patient may feel some discomfort due to increased symptoms before surgery, but this is necessary to overcome in order to reach a good outcome. Some short-acting or other alternative symptomatic medications may be used if necessary.
Some steps of the procedure, from placement of the head frame to intraoperative testing, are performed under local anesthesia, so patients are asked to be aware of the procedure, remain quiet, and cooperate with the examination and procedure as requested by the physician.
After the surgery, you can usually start drinking water after 6 hours of anesthesia wakefulness (for those who receive general anesthesia): you can try a small sip at first, and if swallowing is normal and there is no choking and coughing, you can eat fluids normally, and you can start to resume taking the medications temporarily stopped before the surgery.
In general, normal preoperative diet can be resumed on the first day after surgery, and patients should be encouraged to do more deep breathing and exercise as much as they can.
There is usually no special reaction after surgery, and the wound pain is usually not significant because there is no muscle pulling in the vicinity of the surgical wound.
After surgery, the patient may experience some improvement in symptoms due to the “micro-damage effect”. However, this effect does not usually last long, but usually subsides in a few days to a few weeks. In order to avoid the effect of this effect on the programmed process, the official “start-up” is usually done about 4 weeks after the surgery: the power of the pulse generator is turned on for the initial adjustment.
The medication adjustment is usually done after a period of time, and the dosage is gradually reduced according to the situation.
What further treatment is needed after the surgery and discharge?
The successful completion of surgery marks a new phase of treatment. A process of programmed optimization and gradual adjustment of medications is also required after surgery. In general, even if there are very good results after the first start, the results may still change after a period of time.
Therefore, several more adjustments of the pulse generator parameters, as well as simultaneous adjustments of the drug dosage, are needed to maintain a stable efficacy. With the adaptive change of the disease itself and neurological function over time, the patient’s self-perception may also change somewhat: the original preoperative primary symptoms get better, while the original secondary symptoms turn into a patient concern, and some other patients develop some new conditions.
In fact, it is important to know that although neuromodulation can reduce the symptoms and slow down the disease progression, it does not completely stop the degeneration of neurons, so patients still need to adjust the method, variety and dosage of medication and adjust the parameter settings of the optimized pulse generator.
What should I pay attention to in my life after surgery?
Post-operative programming: where, how and when: Patients are advised to return to the hospital outpatient clinic for their first on-time programming so that the surgeon can be kept informed. Generally 2-3 months after surgery, the program control will be needed several times, and will be basically stable from 6 months to 8 months. At that time, the program control engineer will contact the patient to arrange the specific program control. If you have any questions, please contact the doctor responsible for the program control engineer or the program control engineer
1. Avoid huge external forces acting directly on the pacemaker implantation site.
2.If the surgical incision is red, swollen, oozing or broken, prompt medical consultation is required.
3. Please keep the patient identification card and control magnet properly.
4. If you need to do a whole-body or local MRI examination, please contact the surgeon or programmer concerned in advance and put the pulse generator in the “off” state before performing the MRI examination.
In addition, MRI parameters require special adjustments, so it is best to undergo the examination at a hospital accredited for DBS surgery or with the instructions of the programmer.
After surgery, the pulse generator implantation site and its vicinity cannot receive ultrasound examinations, local physiotherapy (high temperature), radiation exposure, high-output ultrasound lithotripsy, or other examinations or treatments that may disrupt or interfere with the work of the pulse generator. If special examinations or treatments are required, the surgeon or programmer concerned must be contacted.
Passing through the anti-theft device may cause the brain pacemaker to turn on or off. However, the magnetic environment of everyday life does not normally cause abnormalities in the work of the pacemaker.