Preface to the experience report on deep brain stimulation

from Jurgen Zender

Should I or should not I? 

Like many others, I'm torn and, at least so far, I've hardly felt able to make a decision that went beyond a "let's see". My diagnosis is only three years old, but the first symptoms that can clearly be attributed to Parkinson's date back to 2014. I've had olfactory disorders and REM sleep disorders for at least 15 years.

Apart from some fluctuations in the effects, I'm actually feeling quite well and I hardly notice any side effects from the dopamine agonists. I have no or at least only a slight tremor, my cardinal symptoms are rigidity and bradykinesia. And I should be ready for one deep brain stimulation be?

There is a lot to be said for it. I'm slowly feeling the first fluctuations in my balance, I've already had my first falls and if I don't get enough sleep, which happens often, I'm stiff as a board the next day, I feel miserable, I find myself falling asleep spontaneously, and with increasing frequency When you are tired, you suddenly start to over-move. I manage it quite well with power napping, Madopar LT and, if things get really tough, with two Imbrija inhalations. But now at 7 milligrams dopamine per kilogram of body weight per day, I'm slowly reaching the end of the line and further dopamine increases will, for better or worse, end my time with few side effects.

My neurologist's advice on this is something like this: "If you are unsure, just wait until the suffering is great enough".

Do I really want this? 

After reading the following article by Dr. Johannes Heimann, whose advice I value very much, the decision is clear for me. I will make an appointment today with Professor Haslinger in the neurosurgery of the Klinikum Rechts der Isar in Munich and will have the procedure performed on me in the first quarter of 2023.

One year after my deep brain stimulation - a testimonial from Dr. Johannes Heimann

It will soon be October 26th, the day of my surgery.

A year with a significantly better quality of life lies between the operation and today. I haven't regretted the operation for a second.

I need half of the medication I used to take, if at all. The side effects of the medication are correspondingly lower. I often feel so good that I forget to take my pills.

Everyone who knows me says I'm in a much better mood now, I seem more stable, more energetic, I'm walking faster again and I'm gesticulating. My diagnosis of Idiopathic Parkinson's Syndrome is still not visible on the street. 

And depending on how I feel on the day, not always, but quite often, I type – for example this report – using touch typing just as quickly as I used to.

All of my expectations that I had of the operation have been fully met (though you also need to know what to expect and what not).

In retrospect, this operation was a piece of cake, a trifle. I can reassure anyone who fears that this operation would change a person's personality. I'm still the same

In the next few days, I will also attend a Parkinson's seminar, which my surgeon will also attend – he will interview me in front of the other patients and I have almost nothing but good things to say to him. Only one expectation was not fulfilled – I could not revive playing the violin –

but that may also be due to my cervical spine. And one side effect of the operation is new – I will report on that later.

A year ago

 ... my Parkinson's was known for 6 years. I needed 700 mg of Levo-Dopa in 24 hours, at 4-hourly intervals throughout the day. In addition, 1 mg rasagiline, 50 mg Ongentys and a dopamine agonist in higher doses. So the classic combination that can hardly be optimized.

That's just how it went. I sometimes had very vivid dreams - almost daydreaming, which can be taken as a precursor to drug-induced psychosis.

It was clear: one would not have gained much, if at all, with another change of medication. At some point, drug therapy is exhausted. Then just waiting and seeing how things would only get worse and worse over the years - that wasn't my thing.

But I was still in good physical shape. I didn't want to prematurely lose the skills I still had. I haven't been able to jog for a long time, but it was important to me to keep cycling. Maybe dancing too (I couldn't try it with my wife because of Corona). I thought that what you have lost can only be regained with difficulty.

Favorable conditions

 Of course, the conditions for the operation were favorable for me: as a doctor who had also been operating for many years, I was able to assess DBS for what it is: a long-lasting but actually small operation. Not like any other neurosurgical operation: You don't have to remove anything from the brain, just push in two wires. It seemed very unlikely to me that this would lead to serious complications (bleeding, infection). In addition, I am a curious person. I was just interested in what would change. So I experienced the day of the operation without any fear.

In addition, I was able to read the original scientific papers. Nothing will be played down there. The so-called “early stim” study had a special influence: it is better to have the operation early than too late: then you will benefit from it for longer!

I can reassure anyone who expects serious side effects from deep brain stimulation. You just can't turn on the neurostimulator, then everything would be the same as before. So you don't have to remove the wires. But I don't know anyone who would have seriously wanted to do that.

What to expect from deep brain stimulation and what not?

 I assume that you are familiar with the stages of development of idiopathic Parkinson's syndrome.

In stage I, the cranial nerve nuclei of the gastrointestinal nerve and the olfactory nerve are affected and perish. The corresponding symptoms: chronic constipation and loss of smell are not affected by the operation.

In stage II, cranial nerve nuclei in the brainstem break down. These regulate sleep and mood. The corresponding symptoms: disturbed day-night rhythm, other sleep disorders and chronic depression are not affected by the operation.

In stage III, it's the substantia nigra's turn: the dopamine-producing cells slowly but surely break down. The dopamine deficiency has an effect on the classic Parkinson's symptoms: akinesia (movement disorders) - rigidity - tremor. And this is where deep brain stimulation works great. When, a few days before the operation, I had been set to zero medication for 36 hours and sat accordingly stiff and sedentary in the chair, I was given 200 mg Levo-Dopa = 2 tablets as a test.

Madopar 100/25 at a time. After two hours I was fine and underwent the same tests as before the pills: everything had improved significantly. "And you can hope for this effect from the operation!" This has come true. So, deep brain stimulation only addresses the symptoms that respond to Levo-Dopa.

In stage IV, higher parts of the brain are damaged. This results in increasing mental and mental sluggishness, in the appearance of freezing (feet sticking) and in the sense of balance disorders. In stages V and VI, this all increases and surpasses in importance the dopamine deficiency symptoms we all know.

Balance disorders and a tendency to fall are the main problems. These symptoms are not affected by deep brain stimulation. This also shows that there is also a “Too late!” for this operation.

Before the operation

… you generally spend 1 week in a neurological department. All possible tests are carried out there, also in order not to have to identify "red flags" = indications of an atypical Parkinson's syndrome. The preliminary examinations also include high-resolution magnetic resonance imaging and computer tomography. The target region, the subthalamic nucleus, can be clearly seen in magnetic resonance imaging. This nucleus is 10-12 mm long and 3 mm thick and lies at a depth of about 8 cm measured from the top of the skull. It's a little different for everyone. How exactly are you going to meet him? Everything depends on that. This is because the subthalamic nucleus is not visible in the computer tomogram – and this is the only thing available during the operation. A trick is used: the magnetic resonance tomogram and the computer tomogram are assigned to one another and the data is transferred to the computer tomogram. Now only the stereotaxic ring, which was attached to the head during the operation, has to be shown in another computed tomography at the beginning of the operation, and now one can calculate. For example: drill hole on the right front 4 cm from the center line, so and so the exact coordinates, and now demonstrate wire: for example 8,2 cm wide, at an angle of 15,3 degrees backwards and 3,4 degrees inwards. Met!

The operation day

 I was taken to the operating room at 8am. The anesthetist gave me an injection of an opiate, which put me in a pleasantly good mood, and I was just sleepy enough not to disturb and awake enough to respond to speech. The stereotaxic ring was attached to the head under local anesthesia. That didn't hurt at all. The subsequent computed tomography was also no problem. Then it was back from the X-ray department to the operating room. The repeated opiate injections made me doze off and I didn't let the 10 people around me disturb my peace. Apart from that, the routine and the good cooperation between the neurosurgeon, the neurologist and the anesthetist was very reassuring - the three apparently understood each other without many words. I knew what was coming: it was about to get loud: a clatter while a circular hole was being sawed into the top of the skull.

After that it was quiet. Introducing the wire according to the previously calculated coordinates didn't hurt. Then I had to be more awake. The wire was corrected by a tenth of a mm, while I moved my hand and answered all sorts of questions: The main thing was the suppleness of the hand and finger movements and the ability to articulate. The tremor on one side went away during the operation (and didn't come back that year). Then it was the other side's turn: loud again = drilling hole, silent = pushing the wire forward, neurological testing and speech. Then I was allowed to sleep, which meant general anesthesia, because my cooperation was no longer needed to lay the wires under the scalp and behind the left ear and down to under the collarbone and insert the neurostimulator. I woke up at some point in the night and sat (!) eating breakfast the next morning. My medicine box was only half full. All in all, not bad at all! At no point did I Pain, fear or even panic. After five days I was allowed to go home. Until then, the neurostimulator was set to a low starting dosage and changed several times depending on my symptoms.

aftercare

The 3-week rehab after the operation was perhaps not as important as the check-ups every 8-12 weeks with the neurologist who looked after me before and during the operation. Very knowledgeable, he tinkers with my setting, adjusts the amperage, changes the pulse frequency and pulse width and is happy with me that only very low amperages are currently required and there is still a lot of room for improvement.

It doesn't work without sensible self-evaluation. And that's not so easy: when the soles of the feet get a life of their own: is it overstimulation, i.e. too much electricity, or is there a lack of electricity or dopamine, as I initially thought? It helped me a lot that my neurologist unlocked certain areas for me so that I could increase or decrease within limits.

Trying is better than studying! It turned out to be overstimulation and reducing the current made me symptom free.

Insist on the possibility of self-employment!

 Even my neurologist was often wrong with his attitude. DBS-induced hypermobility can be quite uncomfortable. But I had the opportunity to take some juice out. I feel sorry for those who have not been unlocked for certain areas! You can only hope to get a correction appointment soon.

side effects of the operation

 If you read some people on forums, they write: "Never! That's out of the question for me!” Do these people know what they are talking about?

I can only say: THS does not make any personality changes. Or maybe I do: I need significantly less medication, so I feel better.

DBS doesn't hurt. You don't notice anything of the whole apparatus. And my hairdresser has got used to the fact that my scalp is a bit bumpy: where the cables run under the scalp.

It's a bit difficult that many doctors can't handle it. Especially x-ray doctors who don't want to do the magnetic resonance imaging that is needed elsewhere. Here it should be reassuringly said: up to a magnetic field of 1,5 Tesla, magnetic resonance imaging, for example of the knee or abdomen, is harmless.

But I don't want to hide one side effect: my speech has become a little less clear. When I'm tired, my wife has trouble understanding me. This is a typical DBS side effect.

When is DBS indicated?

It is urgently indicated when the drugs are not tolerated. This applies above all to the so-called dopamine agonists: in some people, these can lead to pathological shopping addiction with impoverishment of the whole family or to other addictive behavior. This must be avoided. It is better to stop the dopamine agonists and let the DBS create it.

The same goes for high Levo-Dopa dosages. Anyone who exceeds a daily average of 5 - 6 mg / kg body weight (in women) or 6 - 7 mg / kg body weight (in men) is doing themselves no good: tardive dyskinesia can occur as a late consequence. These are quite unpleasant, hardly treatable over-movements.

Or also: if you have psychosis or psychosis-like disorders under the medication, you should urgently reduce it. But this is only possible if Parkinson's is tackled in a different way: with deep brain stimulation. 

In general, I advise considering the operation if the drug treatment (in a reasonable combination of rasagiline + levodopa + dopamine agonist + Ongentys) no longer achieves a good result. Instead of suffering unnecessarily: Visit a neurosurgeon and get advice!

If you are afraid: oh what am I doing to my brain with the operation, you should open a counter calculation: What affects me more: a drug treatment at or above the highest dosage range that hits my whole brain in an untargeted manner, or instead a circumscribed electrical stimulation that is targeted at the point where it matters?

It is too late when significant symptoms of stage IV are already present: balance disorders, a tendency to fall or the development of dementia. All this is not improved with the THS. The treatment effect of the DBS is then too small.

How deep brain stimulation works

 We all know that the cause of the classic Parkinson's symptoms of akinesia - rigidity - tremor is the progressive destruction of the dopamine-producing cells in the substantia nigra. The lack of dopamine causes the following:

1.
The so-called striatum is not stimulated enough, and this then no longer sufficiently stimulates the thalamus, our relay circuit, our central processor.

2.
The so-called subthalamic nucleus is not slowed down enough, so it becomes hyperactive and uninhibited, and this then increasingly slows down the thalamus.

Deep brain stimulation uses the second regulatory mechanism: the overactivity in the subthalamic nucleus is slowed down by the probes.

What's next? Long-term perspectives

Of course, DBS does not prevent the brain cells from slowly but surely dying off. Parkinson's does not progress in phases, but continuously and unfortunately inexorably. But the process is slow.

In the past, before there were medicines, it took about 7-10 years for a Parkinson's patient to become wheelchair-bound and constantly and permanently dependent on outside help. The medication roughly doubles this time. With deep brain stimulation you can add another 3 – 5 – 7 years. And this with a better quality of life over many years.

The time during which I will benefit the most from DBS is yet to come: just when drug treatment can achieve less and less, one will be happy to have a completely different active principle at one's disposal.

If someone promises you today that Parkinson's could be cured with "his method", please don't believe him. All corresponding therapies are still experimental and come too late for all of us.

Here some more pictures

Left and center: This completely normal mobile phone can contact the neurostimulator under the collarbone via Bluetooth and, for example, query the battery status or the electrical voltage for the left or right half of the body. The electrical tension is here
very low at 1,1 or 1,0 volts: only a tiny area of ​​a few mm in size is covered by the electric current. I can change this voltage myself in the areas that have been activated for me. I can charge the neurostimulator under the skin with an external device using a circulating magnetic field. This is required about once every three weeks and takes about an hour. The device doesn't do any more work for me. – Right: This X-ray image of a skull could be mine: You can see electrodes inserted on both sides.

Two deep brain stimulation electrodes with a target area of ​​the subthalamic nucleus Therapy of Parkinson's disease. An electric field with monopolar stimulation of 3V on the second lowest contact is shown. White arrows represent the E-field vector. Calculation with finite element method using Lead-DBS software.
Picture credits: (CC BY-SA 4.0)