Neural Noise

tACS and transcranial stimulation for post-stroke vision recovery

2 min read

  • Brain stimulation can restore or improve vision after stroke by rewiring visual pathways.1
  • Non-invasive neuromodulation for post-stroke visual rehabilitation is an active clinical research direction.2 12

Weekly enrichment (2026-07-20)

  • A double-blind, randomized, cross-over trial (Raffin, Bevilacqua et al., Neuro-X Institute, EPFL) enrolled 16 chronic stroke patients with occipital lesions to test pathway-specific cross-frequency tACS (cf-tACS) for visual field recovery.34
  • The protocol paired daily direction-discrimination training with either “forward” cf-tACS (alpha-tACS over primary visual cortex V1 plus gamma-tACS over motion area MT/V5) or “backward” cf-tACS as the control condition; patients completed two blocks of 10 daily sessions over 15 days, at least one month apart.34
  • Forward cf-tACS (feedforward-promoting) significantly enhanced motion-discrimination learning and enlarged kinetic visual field borders compared with backward cf-tACS.34
  • Static (Humphrey) perimetry showed a mean visual field increase of +62.9°² after forward and +65.5°² after backward cf-tACS, gains comparable to months of home-based training but achieved in far less time.3
  • 11 of 15 patients in the forward condition showed meaningful improvement in direction-range thresholds after only six sessions, an improvement rate the authors estimate is several times faster than prior training-only studies.3
  • The size of the behavioral benefit was proportional to residual V1–MT structural fibers and to TMS-evoked perilesional V1 activity, providing markers of target engagement.3
  • Cohort characteristics: mean age 59.93 years (range 34–74), median 11 months post-stroke, 12 patients with homonymous hemianopia and 4 with quadrantanopia.3
  • The study is registered as ClinicalTrials.gov NCT05220449; a separate trial (NCT04043689) is evaluating tACS of fronto-parietal and occipito-parietal networks in chronic post-stroke hemianopia.56
  • Visual field loss affects roughly one-third of stroke patients in the chronic stage, and there is currently no accepted restorative therapy, making non-invasive cf-tACS a notable proof-of-concept for clinical rehabilitation.3

Footnotes

  1. https://news.google.com/rss/articles/CBMilgFBVV95cUxPa1dCd0tHeEdqcFYydzg0aEQtRjVxWVVDUFE4MDZKWldHaUlZcUdEMHNudmFUWWtxTzJ6RUw0aEU0UUd0Ny1BRGptc1YwcVNIWmZNbUN4R1cteFJRb1R5SGlNYnhiNWs1QnFRV0dxZjYzSk5QazFIdmlZeVBpSE10ZUNSV19INnM1UWh2R25LTnRIOERoY0E?oc=5 ↩ ↩2

  2. https://news.google.com/rss/articles/CBMivAFBVV95cUxOYlVQd3EtdEFfUXFRRGpyN09RT0pnWGNpUHV2X2dld2l5SzVoak1xaFBTM09HeV9ySXNHU19JTUZCVFZyMG9jQ2hkMDFLRlA0aHpGOHQ2YTlIbkZheTRPVUo2MDdaWTA3b1ZWWXBhX1h1Rm5FZFlqWnRwOG43UUtjQ1VNa1hLOHBxUXNfbmJ5WHJpZDFTYU5jMldLTEFmeEIyOEFlN0VrZEM2NThFQ2dJOUlWUVY5ZlZqY2w2RQ?oc=5 ↩ ↩2

  3. https://pmc.ncbi.nlm.nih.gov/articles/PMC12677025/ ↩ ↩2 ↩3 ↩4 ↩5 ↩6 ↩7 ↩8

  4. https://conexiant.com/neurology/articles/brain-stimulation-boosts-vision-recovery/ ↩ ↩2 ↩3

  5. https://clinicaltrials.gov/study/NCT05220449 ↩

  6. https://clinicaltrials.gov/study/NCT04043689 ↩

Graph View