Cognitive Function During Vagus Nerve Stimulation for Treatment-Refractory Epilepsy: A Pilot Study Using the Critical Flicker Fusion Test

  • Kanu Achinivu
  • Ekkehart Staufenberg
  • Christine Cull
  • Andrea E. Cavanna
  • Howard Ring


This pilot study assessed neuro-cognitive functioning in 7 adults treated with Vagus Nerve Stimulation (VNS) for refractory epilepsy over a 12-month period. All patients were assessed using the Critical Flicker Fusion (CFF) test, a sensitive measure of the ability of the central nervous system to discriminate items of sensory information, along with a standardized battery of neuropsychological and behavioral measures. Reduction in seizure frequency and psychiatric ratings was accompanied by a selective but significant (p<.05) improvement in CFF performance. These findings suggest that the CFF test could be a useful indicator of improvement in neurocognitive functioning during VNS.