A Pilot Study On The Effect And Basic Mechanism Of Ninth Cranial Nerve Stimulation For Epilepsy Control

Objective: To search a new way in the management of patients suffering from medically and otherwise surgically refractory epilepsy, using penicillin applied topically to a region of the cerebral cortex and epileptiform discharges were generated. The hering nerves, a branch of ninth cranial verve, were stimulated at certain parameters to determine the effect in controlling epileptiform activity and the variation of EEG. Additionally, the expression of Glumate and GABA in cortex and nucleus tract solitary neuron was determined by immunohistochemistry to study the primary mechanism of HNS for epilepsy control. Materials and methods: Forty health New Zealand white rabbits weighting from 2 to 2.5 kg were divided randomly into 4 groups: ① hering nerve stimulation group(HNSgroup)10 rabbits ② penicillin to the cortex group(PTC group)10 rabbits③ penicillin to cortex and HNS group (PTC+HNS group)10 rabbits ④ nature contrast group(NC)10 rabbits, neither stimulation of the nerve nor penicillin to cortex but anatomy . Anesthetized by 3% pentobarbitone (50mg/kg) via injection to hip muscles. All rabbits were placed in prone position. Approximate 2×2cm2 double frontoparietal cortex craniotomy were performed using a twist drill and bone rongeurs: the dura was carefully exposed and then incised in a cruciate fashion to expose the underlying cortex. The scalp was conglutinated by adhesive tape to using. Following that, the rabbits were turned to supine position and fixed. The HN was exposed via an initial skin incision about 5cm long along the medial border of the sternocleidomastoid, with deep dissection along this border to the carotid sheath and incising the sheath, the HN was easily localized just superior to the carotid bifurcation, loosely adherent to the internal carotid artery via areolar tissue and dissected it for about 1~2cm long to using. The rabbits in the PTC group were immediately applied penicillin to cortex after completing cranial open. A stimulating electrode was placed around the HN loosely and connected stimulator in HNS group and PTC+HNS group. Stimulation was conducted at the following parameters: voltage 4V, frequency 40Hz, pulse width 0.5mS, constant square wave generating, every 30~50S stimulation for 1~2 minutes interval and all time is about 30minutes. Following stimulation topical penicillin was applied to the cerebral cortex in the PTC+HNS group. Before stimulation a custom-designed needle electroencephalogram array was placed in direct contact with a certain position of the brain to register the variation of EEG and a physiology monitor was connected for the blood pressure. Comparing the difference of latent period and ponderance of seizure activity and the EEG between the PTC+HNS group and HNS group. Comparing the variation of blood pressure and EEG between HNS group and NC group to study the adverse effect. The measure data was conducted by t test and the count data by x2 test. Observed for 2 hours all rabbits were killed by deep anaesthesia and lavaged in PB contained 4% formaldehydum polymerisatum via placing catheter from left ventricle to the major aorta. The brain and cervical tissue was moved quickly and wholly. the cortex and the medulla were fixed in 4% formaldehydum polymerisatum for about 24 hours and embedded in the paraffin. The slice thick is about 5um. Immmunohistochemistary were completed. The staining of tissue section was analyzed by hi-sharpness color pathological photo processing system. The amounts of positive cell of Glu and GABA were detected and the differences among the groups were compared to study the relativity between the expression of Glu and GABA in neuron and HNS. Result:Behavior: in the HNS group 10 rabbits were always quiet ,no change of respiration and no seizure activity can be observed. About 60 minutes later all rabbits were conscious. In the PTC group seizure activity can be observed about 20 minutes later after applying penicillin to the cortex. Initially 10 rabbits were partial seizure as whiskers moving, mouse twitching and no...