Comment by cpncrunch | Hacker News Reader

Comment by cpncrunch | Hacker News Reader

Bear in mind that the placebo effect from DBS for Parkinson's is 39% of the active treatment, so you can't really tell much from a single unblinded patient report.

https://www.sciencedirect.com/science/article/abs/pii/S13538...

Here is a meta-analysis of DBS for Parkinson's: https://bmjmedicine.bmj.com/content/3/1/e000705

Principal findings:

"All results had a high risk of bias and the certainty of the evidence was very low for all primary outcomes. The information size was insufficient when assessing all cause mortality. Meta-analysis showed that deep brain stimulation increased the risk of serious adverse events, mainly because of an increased risk of perioperative complications, such as cerebral haemorrhages and postoperative confusion, and events related to hardware, such as infection at the stimulator site, dislocation of the device, or reoperations. Meta-analyses indicated that deep brain stimulation might reduce symptoms specific to Parkinson's disease, but the assessments of disease specific symptoms had several methodological limitations."

So, it's an interesting treatment, but more evidence is needed before we can conclude that it is actually helpful.

That placebo effect study is 20 years old. Most of the included trials in the meta analysis are 10-20 years old as well.

The BBC article is about a new device. The evidence base may be slim but the technology looks to be improving. I look forward to seeing new clinical trial results on modern DBS systems.

>That placebo effect study is 20 years old.

Has it been contradicted anywhere? I don't see any other studies that have looked into it.

>Most of the included trials in the meta analysis are 10-20 years old as well.

The meta-analysis is from less than 6 months ago, and looked at all the studies available, which cover a range from recent to 10-20 years ago. That is normal for a meta-analysis, so I'm not sure why you're making it sound like it's out of date.

>The BBC article is about a new device.

Yes, there seems to be one study underway, which is still recruiting:

https://clinicaltrials.gov/study/NCT04681534

that study is about "selfhypnotic placebo effects by gadgets showing promises against stress"?

Not sure what you’re referring to here. You may have clicked on the wrong link somewhere.

^ I assume the meta-analysis covered the available data well.

My point is that the available data may not tell us much about the safety and efficacy of this new device.

>>That placebo effect study is 20 years old. >Has it been contradicted anywhere? I don't see any other studies that have looked into it.

Somewhat tangentially, and not specific to Parkinson's or DBS, but placebo has been getting stronger for at least some classes of treatment. E.g.:

Tuttle AH, Tohyama S, Ramsay T, Kimmelman J, Schweinhardt P, Bennett GJ, Mogil JS. Increasing placebo responses over time in U.S. clinical trials of neuropathic pain. Pain. 2015 Dec;156(12):2616-2626. doi: 10.1097/j.pain.0000000000000333. PMID: 26307858.

Walsh BT, Seidman SN, Sysko R, Gould M. Placebo Response in Studies of Major Depression: Variable, Substantial, and Growing. JAMA. 2002;287(14):1840–1847. doi:10.1001/jama.287.14.1840

So I would not be surprised if placebo got stronger in this area as well.

If DBS itself is not a viable treatment for Parkinsons, as the study suggests, then no amount of technological improvement of DBS-based devices will change that.

It would take a lot more than an old, low-confidence set of trials (which is how the meta-analysis describes its inputs) to convince me of your premise.

The default position is that a treatment will do nothing to help for a condition. You need to see evidence for DBS helping with Parkinsons to believe it will, lack of strong evidence in favor of effectiveness just reverts to the default position.

So if that meta study finds that generally all evidence related to DBS effects on Parkinsons is low-confidence and old, then why believe that it is even the right direction?

I’m sure there is plenty of evidence for DBS being plausibly safe and effective when they get the technology right. It will be in the form of:

- Studies on the purported mechanism(s) of action

- Preclinical results in vivo

- Anecdotal results like the one in the BBC article

- Mixed effects from older versions of the tech

That’s plenty to motivate further research and trials into this treatment.

Again, we have a meta-study that has looked at all of the available evidence up to ~6 months ago, and has found no strong evidence that DBS is a promising treatment option. Better devices to achieve the un-promising treatment won't change that fact, not significantly.

Since Parkinsons is for now an incurable and barely treatable disease, it makes sense to try even things that are not very promising. But that doesn't mean we should hold out much hope for them, when all evidence suggests that they are not going to pan out.

Your points are all things that the authors of the meta-study should have looked for, or irrelevancies (anecdotes of people feeling better at some points after they underwent major neuro-surgery are entirely irrelevant to the complexity of a very slow acting degenerative disease).

I'm (genuinely) quite surprised by that. A family member had the procedure a year ago and the difference is so immediate and dramatic. Thanks for the links

Parkinsons involves dopamine, which is very amenable to placebo. Surgery and devices like dbs are very effective placebos.

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