Vagus Nerve Stimulation Amplifies Task-Induced Cerebral Blood Flow Increase

Area of Science:

• Neuroscience
• Neurosurgery

Background:

• Vagus nerve stimulation (VNS) is a palliative treatment for refractory epilepsy.
• Combining VNS with rehabilitation is gaining attention for enhancing neural plasticity.
• Objective evidence linking VNS, cortical recruitment, and blood flow is limited.

Purpose of the Study:

• To test if pairing VNS with a cognitive task amplifies task-induced cerebral blood flow (CBF).

Main Methods:

• 21 epilepsy patients with VNS implants participated.
• Near-infrared spectroscopy (NIRS) measured frontal cortical CBF changes.
• CBF was assessed during rest and a verbal fluency task with VNS.

Main Results:

• VNS alone at rest did not alter CBF.
• Pairing VNS with a verbal fluency task significantly increased CBF.
• This effect was stimulation intensity-dependent in responders, but not in non-responders.

Conclusions:

• Results provide biological evidence for VNS interaction with cortical recruitment.
• Supports the combination of VNS with rehabilitation strategies for epilepsy.
• Highlights the potential of VNS to modulate cognitive task-related brain activity.