Thank you @avaskham.bsky.social @thetransmitter.bsky.social for covering the ongoing discussion re lesion network mapping. It is commendable when a news publication covers both sides of an issue, and a great example of unbiased and responsible reporting.

‘Overdue’ debate unfurls over neuroimaging method After a January paper questioned the validity of an approach called lesion network mapping, its users are pressure testing their results.

A wave of new papers discuss the merits and limitations of lesion network mapping. #neuroskyence

By @avaskham.bsky.social

www.thetransmitter.org/brain-imagin...

When clinicians and researchers work together toward the goal of improving lives for those with #bipolardisorder, collaboration shifts how research progresses. Hear from Tracy Young-Pearse, PhD, on BD²'s integrated approach in the latest #InvestigatorInsights. 🧠

Congratulations @shansiddiqi.bsky.social and Joe Taylor
@braincircuits.bsky.social on their paper In Mol Psych demonstrating the translational power of LNM and brain circuit therapeutics. It has already changed clinical TMS practice
@massgeneralbrigham.bsky.social @harvardmed.bsky.social.

New paper in Molecular Psychiatry:

In patients with anxiety + depression, targeting a novel “anxiosomatic” circuit (dmPFC) outperforms standard dlPFC for anxiety—and is equally effective for depression.

Free link: rdcu.be/faL22
Full link: lnkd.in/e4WZTncu

But the bigger story is the pipeline
1/n

Should doctors be certified to deliver brain stimulation? @shansiddiqi.bsky.social @braincircuits.bsky.social says yes - kicking off the brain stimulation subspecialty summit (BraSS).

Many good points, one more: We empirically demonstrate that spatial bias does not contribute to real-world LNM findings when using appropriate specificity-testing: doi.org/10.64898/202...

Cool paper! Would love to see which imaging approach better predicts outcomes using an independent modality such as lesion deficits or brain stimulation effects.

🧠 Resting-state fMRI is often treated as the gold standard for studying the brain’s intrinsic organization.

But is it actually the best way to estimate functional architecture?

We tested this directly.

🧵1/8

What’s the difference between a neurological vs psychiatric disorder? @braincircuits.bsky.social , it’s only the circuit impacted. Honored to become one of the first full Professors of both Psychiatry and Neurology @harvardmed.bsky.social Excited to help bridge this divide.

We don't think it invalidates the approach.

We looked into this in our data and replicated the key result showing convergence to non-specific connectome structure. However, our results also suggest there is a practical fix that is already implemented in some LNM studies.

bsky.app/profile/pete...

This is a robust response. I particularly liked this figure - clarifying why the original critique showed what it did, and what was missing @foxmdphd.bsky.social

A recent @natneuro.nature.com paper analyzed lesion network mapping and raised concerns about the validity of the method.
See below 👇 for our response.

www.biorxiv.org/content/10.6...

For a discussion of why our conclusions may differ from those of van den Heuvel et al., please see our preprint:
www.biorxiv.org/content/10.6...

Taken together, these results suggest that LNM 1) shows symptom specificity across studies, 2) produces results that do not converge on a single map, and 3) controls for false positives with specificity testing.

Third, we tested the concern that LNM is prone to false positive results because of flawed specificity testing. We did not identify a single false positive in 1000 iterations when we compared 50 lesions randomly extracted from our database to the remaining 1040 lesions.

Second, we tested the concern that LNM results all converge to the same degree map. We found the spatial correlation between lesion networks from patients with the same symptom was higher than the spatial correlation w the degree map (median spatial r = 0.44 vs 0.16, p< 0.0001).

First, we tested the concern that LNM results are not symptom-specific. We found the spatial correlation between lesion networks from patients with the same symptom was significantly higher than between those with different symptoms (median spatial r= 0.44 vs 0.09; p < 0.0001).

A recent paper in @natureportfolio.nature.com raised concerns about the lesion network mapping method. Our team of 16 coauthors analyzed >1000 lesions and 34 symptoms and found that "The methodological foundations of lesion network mapping remain sound" www.biorxiv.org/content/10.6...

The deep brain stimulation response network in Parkinson’s disease operates in the high beta band Bahners et al. identify a brain network linked to optimal therapeutic outcomes in patients with Parkinson’s disease receiving deep brain stimulation. This

New @netstim.org publication alert: @bahnebahners.bsky.social in BRAIN out now:

academic.oup.com/brain/advanc...

A 🧵:

Lesions Causing Aphantasia are Connected to the Fusiform Imagery Node The absence of visual mental imagery, called aphantasia, occurs congenitally in up to 3% of the general population, but the brain regions responsible …

Can a brain injury make someone lose their imagination?

We describe rare cases of acquired aphantasia, people who lost the ability to visually imagine after a stroke or other brain injury. Now published in Cortex 🧠 @braincircuits.bsky.social

www.sciencedirect.com/science/arti...

Brain Medicine: Integrating the Clinical Neurosciences | Harvard Medical School Professional, Corporate, and Continuing Education Explore cutting-edge advances in brain medicine with this interdisciplinary course designed to equip clinicians with integrated tools for assessing and managing complex brain disorders, featuring expe...

One week away from launching our 2nd annual @harvardmed.bsky.social course Brain Medicine: Integrating the Clinical Neurosciences. On demand viewing for 30 days. Nearly 150 people registered. Join us! @jrbneuropsiq.bsky.social @foxmdphd.bsky.social

learn.hms.harvard.edu/programs/bra...

Spotlight on the Shingles Vaccine—Again! Two new studies add to a remarkable body of evidence for benefit

The Shingles vaccine and reduction of dementia: a new natural experiment from Canada replicated 3 others and adds to this week's link to slowing of biological aging.
erictopol.substack.com/p/spotlight-...

The Shingles vaccine has outperformed all expectations. Why?
erictopol.substack.com/p/spotlight-...

My understanding is that DIANA was a single paper, by a single group, that multiple groups then failed to replicate. In contrast, lesion network mapping is >200 papers by multiple groups, that a single group has reportedly failed to replicate.

Thanks Ravi. By “shades of Diana” does that mean you agree with the Van de Huevel critique that the lesion network mapping method is fundamentally flawed?

Methodological flaw may upend network mapping tool The lesion network mapping method, used to identify disease-specific brain networks for clinical stimulation, produces a nearly identical network map for any given condition, according to a new study.

Thanks to The Transmitter for reaching out to me for comments on this methodological challenge to lesion network mapping. Scientific debate is critical to methodological advancement - so let the debate begin!

www.thetransmitter.org/brain-imagin...

Investigating the methodological foundation of lesion network mapping - Nature Neuroscience The lesion network mapping method links diverse brain lesions to similar functional brain networks, reflecting general brain organization rather than disorder-specific circuits.

Are connectome-based network mapping methods and the >200 papers that have used it invalid?

New paper out in
@NatureNeuro
says YES. nature.com/articles/s41...

I have concerns about this new paper's methods and conclusions, but am biased. What do others think?

Mapping the Neuroanatomy of Dystonia Using Causal Brain Lesions Dystonia is one of the most prevalent movement disorders, but its neural substrates have remained enigmatic despite decades of research. Brain lesions leading to dystonia offer unique causal inference...

New pre-print out now from Dr Daniel Corp, @jjoutsa.bsky.social and @foxmdphd.bsky.social ‘Mapping the neuroanatomy of dystonia using causal brain lesions’ !! www.medrxiv.org/content/10.6...
We map networks for the different dystonias, showing significant differences, somatotopy...and much more!!

Very interesting findings! Gliomas selectively locate within in the Action-mode Network, using glioma network mapping derived from lesion network mapping @foxmdphd.bsky.social