title: Ninth cranial nerve stimulation for epilepsy control. Part 1: efficacy in an animal model.
abstract: OBJECTIVE
  To characterize the effects of stimulation of the nerve of Hering (HN; cranial nerve nine) in controlling seizure activity using a canine model.
  
  
  METHODS
  Using penicillin applied topically to a region of the cerebral cortex, 16 seizure-type continuous epileptiform discharges were generated. Ten specimens of HN (five left-sided and five right-sided) were dissected from the cervical region in five dogs and stimulated at varying parameters to determine the effects in controlling epileptiform activity. Electroencephalography (using a multielectrode array), electrocardiography and other vital signs were continuously monitored for side effects.
  
  
  RESULTS
  Resolution of continuous epileptiform activity following stimulation was found in 12 of 16 trials (75%); no spontaneous resolution was noted in the absence of stimulation, and stimulation significantly shortened seizure duration (p < 0.05). Mean epileptiform activity duration was 139 s prior to stimulation (range 1-432 s), with a mean poststimulation delay of 17 s until resolution and a mean interictal time of 399 s. Two specimens became free of seizure activity for the duration of our study (p < 0.001). No significant side effects (such as the potentially life-threatening cardiac problems seen with right-sided cervical vagal nerve stimulation) were found with stimulation of either left- or right-sided HN. Stimulation of other regional nerves (e.g. twelfth cranial nerve, nerves of the cervical plexus) failed to yield similar control of epileptiform activity.
  
  
  CONCLUSIONS
  The results of this pilot study suggest that stimulation of the HN can successfully control focal seizure activity in the majority of cases. Pending further study, stimulation of the HN may have a role in the management of patients suffering from medically and otherwise surgically refractory epilepsy.
authors.affiliation: School of Medicine, University of Alabama at Birmingham, USA. rpatwardhan@sport.rr.com
authors.forename: Ravish V
authors.initials: RV
authors.lastname: Patwardhan
authors.forename: R Shane
authors.initials: RS
authors.lastname: Tubbs
authors.forename: Cheryl R
authors.initials: CR
authors.lastname: Killingsworth
authors.forename: Dennis L
authors.initials: DL
authors.lastname: Rollins
authors.forename: William M
authors.initials: WM
authors.lastname: Smith
authors.forename: Raymond E
authors.initials: RE
authors.lastname: Ideker
mesh_terms: D000818:Animals; D004285:Dogs; D004599:Electric Stimulation Therapy / Q000009:adverse effects / Q000379:methods; D004569:Electroencephalography; D004827:Epilepsy / Q000175:diagnosis / Q000517:prevention & control*; D005930:Glossopharyngeal Nerve / Q000502:physiology*; D023421:Models, Animal; D019635:Neurosurgical Procedures / Q000379:methods