Clinical and experimental study on the over-excitatory of facial nerve in intratemporal facial paralysis

Objective: To study the manifestation,significance and mechanisms of facial nerve over-excitatory in facial paralysis.Methods: The normal threshold of the excitatory of facial nerve was tested in 100 normal persons by nerve-excitatory testing machine.The excitatory of 190 patients suffering from facial paralysis was also tested.The experimental model of facial paralysis was made in guinea pigs.Electromyograph was tested and the changes of myelin sheath of nerve fibers were observed by transmission electron microscope.The cure duration of the over and none over-excitatory group was compared by t-test.Results: The normal threshold of excitatory of facial nerve was 1.72～-1.57 mA in normal person.Of the 190 patients suffering from facial paralysis,29 showed over-excitatory.It took(23.4±6.0)days for the over-excitatory group to be clinically cured, while it took(42.6±11.2)days for the none over-excitatory group(P0.01).The threshold of 8 guinea pigs decreased after compression in 23 guinea pigs showing over-excitatory.Slight separation of myelin sheath layer of nerve fibers was observed by electron microscopy.Conclusion: The prognosis of facial paralysis with over-excitatory is good.Over-excitatory and separation of myelin sheath make the amount of ions that increase the excitatory of nerve.