fNIRS-Guided neuronavigated rTMS augments naming recovery in subacute post-stroke aphasia: a double-blind randomized controlled trial.

Background: Selecting an optimal stimulation target is a persistent barrier to maximizing the efficacy of repetitive transcranial magnetic stimulation (rTMS) for subacute post-stroke aphasia. This trial evaluated an individualized, fNIRS-based targeting strategy derived from task-evoked activation during picture naming.

Methods: We conducted a double-blind, randomized, sham-controlled clinical trial. Patients with first-ever left-hemispheric stroke and subacute aphasia (1-6 months post-onset; 35-80 years) were recruited at Huashan Hospital (2021-2023) and randomized 1:1 to receive fNIRS-guided active rTMS or fNIRS-guided sham stimulation, in addition to 3 weeks of intensive speech-language therapy. Individual targets were defined as the fNIRS channel showing the strongest picture-naming task activation and were delivered under neuronavigation. Active stimulation used 10 Hz, 80% resting motor threshold, 2,000 pulses per session, for 15 sessions (3 weeks); sham used an identical schedule with a sham configuration. Primary/secondary outcomes included the Chinese Boston Naming Test (BNT), WAB-R indices, picture-naming behavioral performance, and task/resting-state fNIRS measures.

Results: Twenty-eight participants were enrolled and 27 completed the protocol (active rTMS: n = 14; sham: n = 13). Language performance improved over time in both groups; however, active rTMS produced significantly larger gains in confrontation naming on the BNT (Time × Group: F = 16.04, p < 0.01) and higher picture-naming accuracy (Time × Group: F = 20.10, p < 0.01), with an additional advantage on the WAB-R naming subscore (Time × Group: F = 4.44, p < 0.05). Neurophysiologically, task-based fNIRS indicated increased activation in the left dorsolateral prefrontal cortex and left Broca's area after active treatment, accompanied by strengthened resting-state connectivity between these regions; connectivity change was positively correlated with BNT improvement (r = 0.6405, p < 0.05).

Conclusion: fNIRS-guided rTMS protocol based on individualized, task-evoked activation mapping is a safe and effective approach for improving picture-naming performance in patients with subacute post-stroke aphasia. The intervention yields promising short-term therapeutic benefits and is associated with enhanced activation in the left dorsolateral prefrontal cortex and Broca's area, as well as strengthened functional connectivity between these language-related regions.

Clinical trial registration: https://www.chictr.org.cn/showproj.html?proj=61768, Unique identifier: ChiCTR2000038515.