Neural Noise

Intracranial stimulation in epilepsy as a novel approach for mapping psychiatric circuits

2 min read

  • Intracranial stimulation during epilepsy monitoring is used as a novel approach to map psychiatric-relevant circuits.1
  • The method bridges iEEG and neuromodulation for circuit mapping and potential therapeutic targets.1
  • The work is on medRxiv and has a credible implementation path; preprints require validation.1 1

Gardner updates

  • Intracranial stimulation during epilepsy monitoring maps psychiatric-relevant circuits and bridges iEEG with neuromodulation for potential therapeutic targets (medRxiv). 1

Weekly enrichment (2026-07-20)

  • The medRxiv preprint tests whether stereo-electroencephalography (SEEG) depth electrodes, implanted to localize the epileptogenic zone in drug-resistant epilepsy, can double as a platform for identifying novel deep-brain-stimulation (DBS) targets for psychiatric disorders.2
  • The analysis drew on SEEG data from 86 drug-resistant epilepsy patients at the UK National Hospital for Neurology and Neurosurgery, spanning 6,372 electrode contacts.2
  • Normative structural and functional connectomes were combined with meta-analytic functional maps to estimate each contact’s probability of engaging psychiatric-symptom networks, and a linear validation model was built from published data on 80 OCD patients treated with DBS.2
  • Reward-processing networks emerged as the most feasible DBS target, with a predicted required sample of only 7 patients (range 4-33).2
  • Feasibility then ranked bipolar disorder (22 patients; range 10-44), depression (32; range 16-49), and anxiety (38; range 17-59); other disorders needed more than 40 patients, limiting single-center feasibility.2
  • Context: an independent OCD study implanted temporary SEEG across cortico-striato-thalamo-cortical circuits and ran roughly 10 days of stimulation mapping to find personalized therapeutic sites and electrophysiological biomarkers of target engagement.3
  • Context: earlier iEEG work in 25 epilepsy patients showed that unilateral lateral orbitofrontal cortex stimulation acutely and dose-dependently improved mood in those with moderate-to-severe depression, with no induced hypomania.4
  • Context: a 24-patient study found orbitofrontal iES improved mood in a state-specific way, suppressing delta-theta power and increasing gamma power within the emotional network only when the brain was already in a low-mood state.5
  • The method repurposes routine presurgical epilepsy monitoring for network-guided, personalized neuromodulation research, an emerging paradigm for studying psychiatric comorbidity via invasive electrophysiology in epilepsy.26
  • Caveat: the study is a preprint feasibility and connectome-based sample-size analysis rather than prospective clinical outcomes, so its target predictions require trial validation before informing DBS practice.2

Footnotes

  1. https://news.google.com/rss/articles/CBMie0FVX3lxTE43VGczenlydTVMeS1NYUhaVkE0UTE0V1ZiUjhRczVEMVlMUjRlNExIQ3JNM0k3LUR4dmRpcHlqSFVGWjFFbUxKaWczWjFSLWxZVjhFWTJoM3l6SFg0c1Eya19TOG5Ga0lJeU1lRXM0LWVZbkZRekVUM3o5MA?oc=5 ↩ ↩2 ↩3 ↩4 ↩5

  2. https://www.medrxiv.org/content/10.1101/2025.06.28.25330302v1.full ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7

  3. https://doi.org/10.1101/2025.03.14.25323348 ↩

  4. https://pubmed.ncbi.nlm.nih.gov/30503621/ ↩

  5. https://pubmed.ncbi.nlm.nih.gov/37467951/ ↩

  6. https://www.frontiersin.org/journals/human-neuroscience/articles/10.3389/fnhum.2021.702605/full ↩

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