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by unsrsly 1908 days ago
Awake cortical mapping has much better resolution than fMRI, and it avoids image registration issues, but it requires a great deal of planning and patient motivation. If it turns out that the language center is on the opposite side from the area of the surgery, then awake mapping might not even be necessary. This is why fMRI is often used as a planning step before awake cortical mapping during the actual surgery.
2 comments

> why fMRI is often used as a planning step

It really isn't - see my other comment.

The other thing to consider here is unintentional media bias - when a lay publication wants information they tend to go to tier 1 research & academic institutions; exactly the sort of place that has all the latest new toys. This is often very far from typical practice. So people outside of healthcare hear about all sort of things that are a decade or more from general usage, even if they get there eventually.

From the outside, it's probably difficult to understand how conservative medicine is generally. Even effective new practices often take decades to become really mainstream.

> It really isn't - see my other comment.

> [...] exactly the sort of place that has all the latest new toys. This is often very far from typical practice. So people outside of healthcare hear about all sort of things that are a decade or more from general usage, even if they get there eventually.

To give a bit more context to my anecdata.

The surgery I was talking about was performed 10 years ago. In Poland. In city with around 700k people. In probably the best hospital for such surgeries in this city with only one other hospital also doing neurosurgery in this city but specializing more in the spinal surgery. The neurosurgical ward back then was in dire need of renovations so not exactly shiny new place that has funds for the best toys.

As I said it looked pretty routine back then.

She did not have fMRI for her following surgeries because tumors were not close to the speech center (opposite hemisphere, then frontal lobes).

> 10 years ago. In Poland.

Interesting; I've much more exposure to US. Overall, I'd say there are sites that do it pretty routinely, but far more sites that basically never do it. And others that don't even have the equipment/licenses if they wanted to. For what it's worth, overall neurosurgeons do much more spine surgery than brain. In the particular case you mention, I've seen a lot of mapping and/or testing for surgeries near eloquent function, but little fMRI. Outside of that, basically unheard of.

I'm not on the outside of medicine. Significant practice variation exists, but complex neurosurgical conditions are usually managed at academic centers and fMRI is used for planning in neurooncology [1] and epilepsy surgery [2].

[1] https://thejns.org/focus/view/journals/neurosurg-focus/48/2/...

[2] https://n.neurology.org/content/88/4/395.long

> I'm not on the outside of medicine.

Fair enough, I didn't mean to suggest you were I was speaking more generally but worded that poorly.

My comments come from systems supporting thousands of clinical neurooncological procedures (i.e. tumor resections) in planning and execution with very little interest or utilization of fMRI beyond a handful proponents and their sites. Quite literally barely on the radar of most of the neurosurgeons apart from occasional papers, and some of them are quite negative about it also.

I could have an inaccurate picture of the breadth of clinical practice, and it's certainly a couple years out of date, but I would be very surprised to find a huge upsurge of usage outside research had happened.

It is certainly the case that the articles claim of "transformation" hasn't happened in that space.

If the article had instead claimed that some of the trickiest cases tend to have fMRI done (true, surgeons will take all they help they can get trying cases that otherwise might be inoperable) or that they are a feature of high profile academic sites (also mostly true) I wouldn't have objected.

I respect your experience, and I'll concede that fMRI for pre-surgical planning in neurooncology is used at only some centers. If you worked mainly in neurooncology you may have missed some of the uses of fMRI for epilepsy surgery. Thanks for the discussion.
Hey that's a good point - I have much less data on epilepsy (although we were interested in it)

For me fMRI falls into the cool-but-has-some-issues (mainly around consistency and processing) side of tech.

And yes, thanks for the discussion.

> Awake cortical mapping

She had that too.

> This is why fMRI is often used as a planning step before awake cortical mapping during the actual surgery.

That must have been the case.

I guess surgeons were trying to do whatever was in their power to not damage her speech center. Right after operation she had a few brief seizures when she lost ability to speak for a minute or two, but as the damage healed they quickly stopped.

That must have been scary, but I'm glad she had a good outcome.