Vagal Nerve Stimulation To Enhance Cognition and Learning

Stroke survivors frequently experience persistent cognitive, memory, and language-related difficulties that can affect independence and quality of life. VNS paired with rehabilitation has been shown to enhance motor recovery after stroke, and paired stimulation may support experience-dependent neural plasticity. This study extends that approach to cognitive and language learning by pairing VNS with structured foreign-language vocabulary training.

Eligible participants will be adults with prior stroke who are scheduled to receive, or have received, clinically indicated Vivistim VNS implantation for rehabilitation and who are able to participate in the language-learning intervention. Participants will be randomized to active VNS or sham stimulation during daily language-learning sessions over approximately six weeks. The active stimulation group will receive programmed VNS paired with language-learning stimuli; the sham group will undergo the same language-learning procedures with stimulation amplitude set to zero or otherwise configured according to the sham protocol. Participants will be blinded to group assignment when feasible.

The neuroimaging sub-study will include MRI/fMRI at up to three time points: pre-surgery baseline, when feasible before clinically indicated implantation; post-surgery/pre-language-training baseline; and post-training. The post-surgery/pre-training scan is the key baseline for the language-learning intervention, particularly for participants who already have the device implanted. MRI sessions will include structural MRI, resting-state fMRI, and a task-based foreign-word semantic matching paradigm. The primary task-based fMRI contrast will examine changes in neural responses to future-trained versus trained foreign words compared with never-trained foreign words. Resting-state analyses will examine changes in functional connectivity across language, memory, salience/arousal, frontoparietal cognitive control, and stroke recovery networks. A brief optional 0-back/1-back working-memory fMRI task may be included if scan time and participant tolerance allow.

• Change in Global Cognition on the Montreal Cognitive Assessment (MoCA) [Срок оценки: 6 weeks]
• Change in Verbal Learning on the Rey Auditory Verbal Learning Test [Срок оценки: 6 weeks]
• Change in Delayed Verbal Memory on the Rey Auditory Verbal Learning Test [Срок оценки: 6 weeks]
• Change in Verbal Learning on the Hopkins Verbal Learning Test-Revised [Срок оценки: 6 weeks]
• Change in Delayed Verbal Memory on the Hopkins Verbal Learning Test-Revised [Срок оценки: 6 weeks]
• Change in Language Function on the Western Aphasia Battery [Срок оценки: 6 weeks]
• Change in Story Recall on the Automatic Story Recall Test [Срок оценки: 6 weeks]
• Change in Working Memory on the Digit Span Task [Срок оценки: 6 weeks]