Neural Noise

Cerebellar tDCS for post-stroke upper extremity motor function (RCT protocol)

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  • A randomized controlled clinical trial protocol evaluates effects of cerebellar transcranial direct current stimulation on improving post-stroke upper extremity motor function (Frontiers).1
  • The protocol is decision-useful for non-invasive neuromodulation and trial design; tier-1.1 1

Weekly enrichment (2026-07-20)

  • Double-blind, randomized, sham-controlled RCT protocol enrolling 48 unilateral-stroke patients with moderate-to-severe upper-extremity impairment (post-stroke chronicity 1 week–2 years), randomized to active versus sham anodal cerebellar tDCS with both arms receiving conventional upper limb rehabilitation (CULR); registered as ChiCTR2500101094 and published in Frontiers in Neurology 2025 (Huang et al., 16:1670721).2
  • Stimulation delivers anodal c-tDCS to the ipsilesional cerebellar hemisphere at 2 mA for 20 min/day over 10 consecutive days, with the anode (5 × 7 cm) placed 3 cm lateral to the inion and the cathode (5 × 7 cm) over the ipsilateral upper trapezius; the sham arm uses current ramp-up/down to mimic scalp sensation and preserve blinding.2
  • Conventional rehabilitation runs 45 min immediately after each session: roughly 15 min of neuromuscular electrical stimulation plus range-of-motion work, 20 min of task-oriented reach/grasp training, and 10 min of strengthening.2
  • Primary outcome is the Fugl-Meyer Assessment for the upper extremity (FMA-UE), analyzed by intention-to-treat with multiple imputation and a Group × Time mixed-model ANOVA across T0, T1, and a one-month follow-up (T2).2
  • Mechanistic readouts include fNIRS (NirSmart system, 730/850 nm, 12 sources and 10 detectors giving 24 channels at ~3.0 cm separation, 11 Hz) tracking HbO/HbR and a laterality index over prefrontal and parietal cortex, plus TMS-derived motor evoked potentials from bilateral M1 (70 mm figure-of-eight coil, 10 MEPs at 120% resting motor threshold) with an interhemispheric amplitude ratio.2
  • The rationale invokes the cerebellum’s role in motor coordination, timing, and learning and crossed cerebellar diaschisis, noting that up to 75% of the roughly 14 million annual stroke survivors experience chronic disability.2
  • A prior single-center RCT (n = 77; 39 cerebellar-tDCS, 38 control) using anodal cerebellar tDCS at 2 mA, 20 min for 4 weeks reported FMA-UE gains of 10.7 points at 4 weeks and 18.9 points at 60 days—comparable to conventional M1 tDCS (~9–10 points)—with reasonable safety.3
  • Broader evidence is mixed: a 2025 meta-analysis of 24 RCTs found tDCS significantly improved lower-limb FMA (mean difference 1.63, 95% CI 1.15–2.11) but not upper-limb function (mean difference 1.13, 95% CI −0.03 to 2.30, P = 0.056), with the largest benefit for M1 anodal stimulation, current density ≥0.05 mA/cm², treatment beyond 2 weeks, and acute/subacute phases.4

Footnotes

  1. https://news.google.com/rss/articles/CBMikAFBVV95cUxQN3h1blZUcUVjekhObFNzQi1oMkdJdDJ0aDNZMTZVaFE3bnFfelBkV2N3S3RFU2JiVi1fb2pyQ1ozejluc2kwNkppQ1diTmU3RWhVbF9Va3VDZnRiUlNZNWJWeUxhazNZdmpFcDJRY0dsdVA4MkprRTM5MlNEbUJkOVZHRFdQNGNqWG1HZ3VDZlk?oc=5 ↩ ↩2 ↩3

  2. https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2025.1670721/full ↩ ↩2 ↩3 ↩4 ↩5 ↩6

  3. https://www.frontiersin.org/journals/neurology/articles/10.3389/fneur.2023.1044333/full ↩

  4. https://journals.lww.com/bnam/fulltext/2025/01000/transcranial_direct_current_stimulation_for_upper.1.aspx ↩

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